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Quintanilha JCF, Wang J, Sibley AB, Jiang C, Etheridge AS, Shen F, Jiang G, Mulkey F, Patel JN, Hertz DL, Dees EC, McLeod HL, Bertagnolli M, Rugo H, Kindler HL, Kelly WK, Ratain MJ, Kroetz DL, Owzar K, Schneider BP, Lin D, Innocenti F. Bevacizumab-induced hypertension and proteinuria: a genome-wide study of more than 1000 patients. Br J Cancer 2022; 126:265-274. [PMID: 34616010 PMCID: PMC8770703 DOI: 10.1038/s41416-021-01557-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 08/06/2021] [Accepted: 09/17/2021] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Hypertension and proteinuria are common bevacizumab-induced toxicities. No validated biomarkers are available for identifying patients at risk of these toxicities. METHODS A genome-wide association study (GWAS) meta-analysis was performed in 1039 bevacizumab-treated patients of European ancestry in four clinical trials (CALGB 40502, 40503, 80303, 90401). Grade ≥2 hypertension and proteinuria were recorded (CTCAE v.3.0). Single-nucleotide polymorphism (SNP)-toxicity associations were determined using a cause-specific Cox model adjusting for age and sex. RESULTS The most significant SNP associated with hypertension with concordant effect in three out of the four studies (p-value <0.05 for each study) was rs6770663 (A > G) in KCNAB1, with the G allele increasing the risk of hypertension (p-value = 4.16 × 10-6). The effect of the G allele was replicated in ECOG-ACRIN E5103 in 582 patients (p-value = 0.005). The meta-analysis of all five studies for rs6770663 led to p-value = 7.73 × 10-8, close to genome-wide significance. The most significant SNP associated with proteinuria was rs339947 (C > A, between DNAH5 and TRIO), with the A allele increasing the risk of proteinuria (p-value = 1.58 × 10-7). CONCLUSIONS The results from the largest study of bevacizumab toxicity provide new markers of drug safety for further evaluations. SNP in KCNAB1 validated in an independent dataset provides evidence toward its clinical applicability to predict bevacizumab-induced hypertension. ClinicalTrials.gov Identifier: NCT00785291 (CALGB 40502); NCT00601900 (CALGB 40503); NCT00088894 (CALGB 80303) and NCT00110214 (CALGB 90401).
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Affiliation(s)
- Julia C F Quintanilha
- Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Jin Wang
- Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | | | - Chen Jiang
- Duke Cancer Institute, Duke University Medical Center, Durham, NC, USA
| | - Amy S Etheridge
- Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Fei Shen
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Guanglong Jiang
- Department of BioHealth Informatics, Indiana University-Purdue University, Indianapolis, IN, USA
| | - Flora Mulkey
- Alliance Statistics and Data Center, Duke University, Durham, NC, USA
| | | | - Daniel L Hertz
- College of Pharmacy, University of Michigan, Ann Arbor, MI, USA
| | - Elizabeth Claire Dees
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Howard L McLeod
- Department of Cancer Epidemiology, Moffitt Cancer Center, Tampa, FL, USA
| | | | - Hope Rugo
- Department of Medicine, Hematology/Oncology, University of California at San Francisco, San Francisco, CA, USA
| | - Hedy L Kindler
- University of Chicago Comprehensive Cancer Center, Chicago, IL, USA
| | | | - Mark J Ratain
- University of Chicago Comprehensive Cancer Center, Chicago, IL, USA
| | - Deanna L Kroetz
- Department of Bioengineering and Therapeutic Sciences, University of California at San Francisco, San Francisco, CA, USA
| | - Kouros Owzar
- Duke Cancer Institute, Duke University Medical Center, Durham, NC, USA
- Department of Biostatistics and Bioinformatics, Duke University Medical Center, Durham, NC, USA
| | - Bryan P Schneider
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Danyu Lin
- Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Federico Innocenti
- Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
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An JR, Seo MS, Jung HS, Heo R, Kang M, Han ET, Park H, Jung WK, Choi IW, Park WS. Inhibition by Imipramine of the Voltage-Dependent K+ Channel in Rabbit Coronary Arterial Smooth Muscle Cells. Toxicol Sci 2020; 178:302-310. [PMID: 33010168 DOI: 10.1093/toxsci/kfaa149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Imipramine, a tricyclic antidepressant, is used in the treatment of depressive disorders. However, the effect of imipramine on vascular ion channels is unclear. Therefore, using a patch-clamp technique we examined the effect of imipramine on voltage-dependent K+ (Kv) channels in freshly isolated rabbit coronary arterial smooth muscle cells. Kv channels were inhibited by imipramine in a concentration-dependent manner, with an IC50 value of 5.55 ± 1.24 µM and a Hill coefficient of 0.73 ± 0.1. Application of imipramine shifted the steady-state activation curve in the positive direction, indicating that imipramine-induced inhibition of Kv channels was mediated by influencing the voltage sensors of the channels. The recovery time constants from Kv-channel inactivation were increased in the presence of imipramine. Furthermore, the application of train pulses (of 1 or 2 Hz) progressively augmented the imipramine-induced inhibition of Kv channels, suggesting that the inhibitory effect of imipramine is use (state) dependent. The magnitude of Kv current inhibition by imipramine was similar during the first, second, and third depolarizing pulses. These results indicate that imipramine-induced inhibition of Kv channels mainly occurs in the closed state. The imipramine-mediated inhibition of Kv channels was associated with the Kv1.5 channel, not the Kv2.1 or Kv7 channel. Inhibition of Kv channels by imipramine caused vasoconstriction. From these results, we conclude that imipramine inhibits vascular Kv channels in a concentration- and use (closed-state)-dependent manner by changing their gating properties regardless of its own function.
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Affiliation(s)
| | | | | | | | | | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine
| | - Hongzoo Park
- Department of Urology, Kangwon National University School of Medicine, Chuncheon 24341, South Korea
| | - Won-Kyo Jung
- Department of Biomedical Engineering, and Center for Marine-Integrated Biomedical Technology (BK21 Plus), Pukyong National University, Busan 48513, South Korea
| | - Il-Whan Choi
- Department of Microbiology, College of Medicine, Inje University, Busan 48516, South Korea
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3
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The inhibitory effect of ziprasidone on voltage-dependent K+ channels in coronary arterial smooth muscle cells. Biochem Biophys Res Commun 2020; 529:191-197. [DOI: 10.1016/j.bbrc.2020.06.038] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 06/08/2020] [Indexed: 11/17/2022]
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4
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An JR, Seo MS, Jung HS, Li H, Jung WK, Choi IW, Ha KS, Han ET, Hong SH, Park H, Bae YM, Park WS. Inhibition by the atypical antipsychotic risperidone of voltage-dependent K + channels in rabbit coronary arterial smooth muscle cells. Eur J Pharmacol 2020; 874:173027. [PMID: 32084421 DOI: 10.1016/j.ejphar.2020.173027] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 02/03/2020] [Accepted: 02/17/2020] [Indexed: 11/16/2022]
Abstract
We evaluated the inhibitory effects of the atypical antipsychotic drug risperidone on voltage-dependent K+ (Kv) channels in rabbit coronary arterial smooth muscle cells. Risperidone suppressed Kv currents in reversible and concentration-dependent manners with an apparent half-maximal effective concentration (IC50 value) of 5.54 ± 0.66 μM and a slope factor of 1.22 ± 0.07. The inactivation of Kv currents was significantly accelerated by risperidone. The rate constants of association and dissociation for risperidone were 0.25 ± 0.01 μM-1s-1 and 1.36 ± 0.14 s-1, respectively. Application of risperidone shifted the steady-state activation curve in the positive direction and the inactivation curve in the negative direction, suggesting that the risperidone-induced inhibition of Kv channels was mediated by effects on the voltage sensors of the channels. Application of train pulses at 1 and 2 Hz led to a progressive increase in the blockage of Kv currents by risperidone. In addition, the recovery time constants from inactivation were extended in the presence of risperidone, indicating that risperidone inhibited Kv channels in a use (state)-dependent manner. Pretreatment with the Kv1.5 subtype inhibitor reduced the inhibitory effects of risperidone on Kv channels. However, pretreatment with a Kv2.1 or Kv7.X subtype inhibitor did not affect the inhibitory effects of risperidone. Risperidone induced vasoconstriction and membrane depolarization. Based on these results, we conclude that risperidone inhibits Kv channels in a concentration-, time-, and state-dependent manners. Our results should be taken into consideration when using risperidone to study the kinetics of K+ channels in vascular smooth muscle.
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Affiliation(s)
- Jin Ryeol An
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, Chuncheon, 24341, South Korea
| | - Mi Seon Seo
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, Chuncheon, 24341, South Korea
| | - Hee Seok Jung
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, Chuncheon, 24341, South Korea
| | - Hongliang Li
- Institute of Translational Medicine, Medical College, Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment for Senile Diseases, Yangzhou University, Yangzhou, 225001, China
| | - Won-Kyo Jung
- Department of Biomedical Engineering, Center for Marine-Integrated Biomedical Technology (BK21 Plus), Pukyong National University, Busan, 48513, South Korea
| | - Il-Whan Choi
- Department of Microbiology, College of Medicine, Inje University, Busan, 48516, South Korea
| | - Kwon-Soo Ha
- Department of Molecular and Cellular Biochemistry, Kangwon National University School of Medicine, Scripps Korea Antibody Institute, Chuncheon, 24341, South Korea
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Chuncheon, 24341, South Korea
| | - Seok-Ho Hong
- Institute of Medical Sciences, Department of Internal Medicine, Kangwon National University School of Medicine, Chuncheon, 24341, South Korea
| | - Hongzoo Park
- Institute of Medical Sciences, Department of Urology, Kangwon National University School of Medicine, Chuncheon, 24341, South Korea
| | - Young Min Bae
- Department of Physiology, Konkuk University School of Medicine, Chungju, 27478, South Korea
| | - Won Sun Park
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, Chuncheon, 24341, South Korea.
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5
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An JR, Seo MS, Jung HS, Kang M, Heo R, Bae YM, Han ET, Yang SR, Park WS. Inhibition of voltage-dependent K + channels by iloperidone in coronary arterial smooth muscle cells. J Appl Toxicol 2020; 40:1297-1305. [PMID: 32285496 DOI: 10.1002/jat.3986] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 03/25/2020] [Accepted: 03/30/2020] [Indexed: 11/12/2022]
Abstract
Iloperidone, a second-generation atypical antipsychotic drug, is widely used in the treatment of schizophrenia. However, the side-effects of iloperidone on vascular K+ channels remain to be determined. Therefore, we explored the effect of iloperidone on voltage-dependent K+ (Kv) channels in rabbit coronary arterial smooth muscle cells using the whole-cell patch-clamp technique. Iloperidone inhibited vascular Kv channels in a concentration-dependent manner with a half-maximal inhibitory concentration (IC50 ) of 2.11 ± 0.5 μM and a Hill coefficient of 0.68 ± 0.03. Iloperidone had no effect on the steady-state inactivation kinetics. However, it shifted the steady-state activation curve to the right, indicating that iloperidone inhibited Kv channels by influencing the voltage sensors. Application of 20 repetitive depolarizing pulses (1 and 2 Hz) progressively increased the inhibition of the Kv current in the presence of iloperidone. Furthermore, iloperidone increased the recovery time constant from Kv channel inactivation, suggesting that iloperidone-induced inhibition of Kv channels is use (state)-dependent. Pretreatment with a Kv1.5 inhibitor (diphenyl phosphine oxide 1 [DPO-1]) inhibited the Kv current to a level similar to that with iloperidone alone. However, pretreatment with a Kv2.1 or Kv7.X inhibitor (guangxitoxin or linopirdine) did not affect the inhibitory effect of iloperidone on Kv channels. Therefore, iloperidone directly inhibits Kv channels in a concentration- and use (state)-dependent manner independently of its antagonism of serotonin and dopamine receptors. Furthermore, the primary target of iloperidone is the Kv1.5 subtype.
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Affiliation(s)
- Jin Ryeol An
- Department of Physiology, Kangwon National University School of Medicine, Chuncheon, South Korea
| | - Mi Seon Seo
- Department of Physiology, Kangwon National University School of Medicine, Chuncheon, South Korea
| | - Hee Seok Jung
- Department of Physiology, Kangwon National University School of Medicine, Chuncheon, South Korea
| | - Minji Kang
- Department of Physiology, Kangwon National University School of Medicine, Chuncheon, South Korea
| | - Ryeon Heo
- Department of Physiology, Kangwon National University School of Medicine, Chuncheon, South Korea
| | - Young Min Bae
- Department of Physiology, Konkuk University School of Medicine, Chungju, South Korea
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Chuncheon, South Korea
| | - Se-Ran Yang
- Department of Thoracic and Cardiovascular Surgery, Kangwon National University School of Medicine, Chuncheon, South Korea
| | - Won Sun Park
- Department of Physiology, Kangwon National University School of Medicine, Chuncheon, South Korea
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6
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An JR, Kang H, Li H, Seo MS, Jung HS, Jung WK, Choi IW, Ryu SW, Park H, Bae YM, Ryu SM, Park WS. Protriptyline, a tricyclic antidepressant, inhibits voltage-dependent K+ channels in rabbit coronary arterial smooth muscle cells. Acta Biochim Biophys Sin (Shanghai) 2020; 52:320-327. [PMID: 32060505 DOI: 10.1093/abbs/gmz159] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Revised: 11/19/2019] [Accepted: 11/07/2019] [Indexed: 11/13/2022] Open
Abstract
In this study, we explore the inhibitory effects of protriptyline, a tricyclic antidepressant drug, on voltage-dependent K+ (Kv) channels of rabbit coronary arterial smooth muscle cells using a whole-cell patch clamp technique. Protriptyline inhibited the vascular Kv current in a concentration-dependent manner, with an IC50 value of 5.05 ± 0.97 μM and a Hill coefficient of 0.73 ± 0.04. Protriptyline did not affect the steady-state activation kinetics. However, the drug shifted the steady-state inactivation curve to the left, suggesting that protriptyline inhibited the Kv channels by changing their voltage sensitivity. Application of 20 repetitive train pulses (1 or 2 Hz) progressively increased the protriptyline-induced inhibition of the Kv current, suggesting that protriptyline inhibited Kv channels in a use (state)-dependent manner. The extent of Kv current inhibition by protriptyline was similar during the first, second, and third step pulses. These results suggest that protriptyline-induced inhibition of the Kv current mainly occurs principally in the closed state. The increase in the inactivation recovery time constant in the presence of protriptyline also supported use (state)-dependent inhibition of Kv channels by the drug. In the presence of the Kv1.5 inhibitor, protriptyline did not induce further inhibition of the Kv channels. However, pretreatment with a Kv2.1 or Kv7 inhibitor induced further inhibition of Kv current to a similar extent to that observed with protriptyline alone. Thus, we conclude that protriptyline inhibits the vascular Kv channels in a concentration- and use-dependent manner by changing their gating properties. Furthermore, protriptyline-induced inhibition of Kv channels mainly involves the Kv1.5.
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Affiliation(s)
- Jin Ryeol An
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, Chuncheon 24341, South Korea
| | - Hojung Kang
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, Chuncheon 24341, South Korea
| | - Hongliang Li
- Institute of Translational Medicine, Medical College, Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment for Senile Diseases, Yangzhou University, Yangzhou 225001, China
| | - Mi Seon Seo
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, Chuncheon 24341, South Korea
| | - Hee Seok Jung
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, Chuncheon 24341, South Korea
| | - Won-Kyo Jung
- Department of Biomedical Engineering, and Center for Marine-Integrated Biomedical Technology (BK21 Plus), Pukyong National University, Busan 48513, South Korea
| | - Il-Whan Choi
- Department of Microbiology, College of Medicine, Inje University, Busan 48516, South Korea
| | - Sook Won Ryu
- Institute of Medical Sciences, Department of Laboratory Medicine, Kangwon National University School of Medicine, Chuncheon 24341, South Korea
| | - Hongzoo Park
- Department of Urology, Kangwon National University School of Medicine, Chuncheon 24341, South Korea
| | - Young Min Bae
- Department of Physiology, Konkuk University School of Medicine, Chungju 27478, South Korea
| | - Se Min Ryu
- Department of Thoracic and Cardiovascular Surgery, Kangwon National University Hospital, Kangwon National University School of Medicine, Chuncheon 24341, South Korea
| | - Won Sun Park
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, Chuncheon 24341, South Korea
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Sawicka D, Maciak S, Kozłowska H, Kasacka I, Kloza M, Sadowska A, Sokołowska E, Konarzewski M, Car H. Functional and structural changes in aorta of mice divergently selected for basal metabolic rate. J Comp Physiol B 2019; 190:101-112. [PMID: 31873784 DOI: 10.1007/s00360-019-01252-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 11/29/2019] [Accepted: 12/08/2019] [Indexed: 12/20/2022]
Abstract
Cardiovascular diseases (CVD) are one of the most common causes of mortality likely genetically linked to the variation in basal metabolic rate (BMR). A robust test of the significance of such association may be provided by artificial selection experiments on animals selected for diversification of BMR. Here we asked whether genetically determined differences in BMR correlate with anatomical shift in endothelium structure and if so, the relaxation and contraction responses of the aorta in mice from two lines of Swiss-Webster laboratory mice (Mus musculus) divergently selected for high or low BMR (HBMR and LBMR lines, respectively). Functional and structural study of aorta showed that a selection for divergent BMR resulted in the between-line difference in diastolic aortic capacity. The relaxation was stronger in aorta of the HBMR mice, which may stem from greater flexibility of aorta mediated by higher activity of Ca2+-activated K+ channels. Structural examination also indicated that HBMR mice had significantly thicker aorta's middle layer compared to LBMR animals. Such changes may promote arterial stiffness predisposing to cardiovascular diseases. BMR-related differences in the structure and relaxation ability of aortas in studied animals may be reminiscent of potential risk factors in the development of CVD in humans.
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Affiliation(s)
- Diana Sawicka
- Department of Experimental Pharmacology, Medical University of Bialystok, ul. Szpitalna 37, 15-295, Białystok, Poland.
| | - Sebastian Maciak
- Department of Evolutionary and Physiological Ecology, Faculty of Biology, University of Bialystok, ul. Ciołkowskiego 1J, 15-245, Białystok, Poland
| | - Hanna Kozłowska
- Department of Experimental Physiology and Pathophysiology, Medical University of Bialystok, ul. Mickiewicza 2A, 15-089, Białystok, Poland
| | - Irena Kasacka
- Department of Histology and Cytophysiology, Medical University of Bialystok, ul. Mickiewicza 2C, 15-222, Białystok, Poland
| | - Monika Kloza
- Department of Experimental Physiology and Pathophysiology, Medical University of Bialystok, ul. Mickiewicza 2A, 15-089, Białystok, Poland
| | - Anna Sadowska
- Department of Experimental Pharmacology, Medical University of Bialystok, ul. Szpitalna 37, 15-295, Białystok, Poland
| | - Emilia Sokołowska
- Department of Experimental Pharmacology, Medical University of Bialystok, ul. Szpitalna 37, 15-295, Białystok, Poland
| | - Marek Konarzewski
- Department of Evolutionary and Physiological Ecology, Faculty of Biology, University of Bialystok, ul. Ciołkowskiego 1J, 15-245, Białystok, Poland
| | - Halina Car
- Department of Experimental Pharmacology, Medical University of Bialystok, ul. Szpitalna 37, 15-295, Białystok, Poland
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Stannov SU, Brasen JC, Salomonsson M, Holstein‐Rathlou N, Sorensen CM. Interactions between renal vascular resistance and endothelium-derived hyperpolarization in hypertensive rats in vivo. Physiol Rep 2019; 7:e14168. [PMID: 31368238 PMCID: PMC6669277 DOI: 10.14814/phy2.14168] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 06/19/2019] [Accepted: 06/19/2019] [Indexed: 02/07/2023] Open
Abstract
Endothelium derived signaling mechanisms play an important role in regulating vascular tone and endothelial dysfunction is often found in hypertension. Endothelium-derived hyperpolarization (EDH) plays a significant role in smaller renal arteries and arterioles, but its significance in vivo in hypertension is unresolved. The aim of this study was to characterize the EDH-induced renal vasodilation in normotensive and hypertensive rats during acute intrarenal infusion of ACh. Our hypothesis was that the increased renal vascular resistance (RVR) found early in hypertension would significantly correlate with reduced EDH-induced vasodilation. In isoflurane-anesthetized 12-week-old normo- and hypertensive rats blood pressure and renal blood flow (RBF) was measured continuously. RBF responses to acute intrarenal ACh infusions were measured before and after inhibition of NO and prostacyclin. Additionally, RVR was decreased or increased using inhibition or activation of adrenergic receptors or by use of papaverine and angiotensin II. Intrarenal infusion of ACh elicited a larger increase in RBF in hypertensive rats compared to normotensive rats suggesting that endothelial dysfunction is not present in 12-week-old hypertensive rats. The EDH-induced renal vasodilation (after inhibition of NO and prostacyclin) was similar between normo- and hypertensive rats. Reducing RVR by inhibition of α1 -adrenergic receptors significantly increased the renal EDH response in hypertensive rats, but a similar increase was found after activating α-adrenergic receptors using norepinephrine. The results show that renal EDH is present and functional in 12-week-old normo- and hypertensive rats. Interestingly, both activation and inactivation of α1 -adrenergic receptors elicited an increase in the renal EDH-induced vasodilation.
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Affiliation(s)
- Søs U. Stannov
- Institute of Biomedical Sciences, Heart, Renal and CirculationUniversity of CopenhagenCopenhagenDenmark
| | - Jens Christian Brasen
- Institute of Biomedical Sciences, Heart, Renal and CirculationUniversity of CopenhagenCopenhagenDenmark
- Department of Electrical EngineeringTechnical University of DenmarkLyngbyDenmark
| | | | | | - Charlotte M. Sorensen
- Institute of Biomedical Sciences, Heart, Renal and CirculationUniversity of CopenhagenCopenhagenDenmark
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Apigenin relaxes rat intrarenal arteries, depresses Ca2+-activated Cl− currents and augments voltage-dependent K+ currents of the arterial smooth muscle cells. Biomed Pharmacother 2019; 115:108926. [DOI: 10.1016/j.biopha.2019.108926] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Revised: 04/25/2019] [Accepted: 04/25/2019] [Indexed: 01/08/2023] Open
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10
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Jackson WF. K V channels and the regulation of vascular smooth muscle tone. Microcirculation 2018; 25. [PMID: 28985443 DOI: 10.1111/micc.12421] [Citation(s) in RCA: 89] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 10/01/2017] [Indexed: 12/31/2022]
Abstract
VSMCs in resistance arteries and arterioles express a diverse array of KV channels with members of the KV 1, KV 2 and KV 7 families being particularly important. Members of the KV channel family: (i) are highly expressed in VSMCs; (ii) are active at the resting membrane potential of VSMCs in vivo (-45 to -30 mV); (iii) contribute to the negative feedback regulation of VSMC membrane potential and myogenic tone; (iv) are activated by cAMP-related vasodilators, hydrogen sulfide and hydrogen peroxide; (v) are inhibited by increases in intracellular Ca2+ and vasoconstrictors that signal through Gq -coupled receptors; (vi) are involved in the proliferative phenotype of VSMCs; and (vii) are modulated by diseases such as hypertension, obesity, the metabolic syndrome and diabetes. Thus, KV channels participate in every aspect of the regulation of VSMC function in both health and disease.
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Affiliation(s)
- William F Jackson
- Department of Pharmacology & Toxicology, Michigan State University, East Lansing, MI, USA
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11
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Yip KP, Balasubramanian L, Kan C, Wang L, Liu R, Ribeiro-Silva L, Sham JSK. Intraluminal pressure triggers myogenic response via activation of calcium spark and calcium-activated chloride channel in rat renal afferent arteriole. Am J Physiol Renal Physiol 2018; 315:F1592-F1600. [PMID: 30089032 DOI: 10.1152/ajprenal.00239.2018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Myogenic contraction of renal arterioles is an important regulatory mechanism for renal blood flow autoregulation. We have previously demonstrated that integrin-mediated mechanical force increases the occurrence of Ca2+ sparks in freshly isolated renal vascular smooth muscle cells (VSMCs). To further test whether the generation of Ca2+ sparks is a downstream signal of mechanotransduction in pressure-induced myogenic constriction, the relationship between Ca2+ sparks and transmural perfusion pressure was investigated in intact VSMCs of pressurized rat afferent arterioles. Spontaneous Ca2+ sparks were found in VSMCs when afferent arterioles were perfused at 80 mmHg. The spark frequency was significantly increased when perfusion pressure was increased to 120 mmHg. A similar increase of spark frequency was also observed in arterioles stimulated with β1-integrin-activating antibody. Moreover, spark frequency was significantly higher in arterioles of spontaneous hypertensive rats at 80 and 120 mmHg. Spontaneous membrane current recorded using whole cell perforated patch in renal VSMCs showed predominant activity of spontaneous transient inward currents instead of spontaneous transient outward currents when holding potential was set close to physiological resting membrane potential. Real-time PCR and immunohistochemistry confirmed the expression of Ca2+-activated Cl- channel (ClCa) TMEM16A in renal VSMCs. Inhibition of TMEM16A with T16Ainh-A01 impaired the pressure-induced myogenic contraction in perfused afferent arterioles. Our study, for the first time to our knowledge, detected Ca2+ sparks in VSMCs of intact afferent arterioles, and their frequencies were positively modulated by the perfusion pressure. Our results suggest that Ca2+ sparks may couple to ClCa channels and trigger pressure-induced myogenic constriction via membrane depolarization.
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Affiliation(s)
- Kay-Pong Yip
- Department of Molecular Pharmacology and Physiology, University of South Florida , Tampa, Florida
| | - Lavanya Balasubramanian
- Department of Molecular Pharmacology and Physiology, University of South Florida , Tampa, Florida
| | - Chen Kan
- Department of Industrial, Manufacturing, and System Engineering, University of Texas at Arlington , Arlington, Texas
| | - Lei Wang
- Department of Molecular Pharmacology and Physiology, University of South Florida , Tampa, Florida
| | - Ruisheng Liu
- Department of Molecular Pharmacology and Physiology, University of South Florida , Tampa, Florida
| | - Luisa Ribeiro-Silva
- Department of Molecular Pharmacology and Physiology, University of South Florida , Tampa, Florida
| | - James S K Sham
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine , Baltimore, Maryland
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12
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Liu B, Shi R, Li X, Liu Y, Feng X, Chen X, Fan X, Zhang Y, Zhang W, Tang J, Zhou X, Li N, Lu X, Xu Z. Downregulation of L-Type Voltage-Gated Ca 2+, Voltage-Gated K +, and Large-Conductance Ca 2+-Activated K + Channels in Vascular Myocytes From Salt-Loading Offspring Rats Exposed to Prenatal Hypoxia. J Am Heart Assoc 2018; 7:JAHA.117.008148. [PMID: 29545262 PMCID: PMC5907567 DOI: 10.1161/jaha.117.008148] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Background Prenatal hypoxia is suggested to be associated with increased risks of hypertension in offspring. This study tested whether prenatal hypoxia resulted in salt‐sensitive offspring and its related mechanisms of vascular ion channel remodeling. Methods and Results Pregnant rats were housed in a normoxic (21% O2) or hypoxic (10.5% O2) chamber from gestation days 5 to 21. A subset of male offspring received a high‐salt diet (8% NaCl) from 4 to 12 weeks after birth. Blood pressure was significantly increased only in the salt‐loading offspring exposed to prenatal hypoxia, not in the offspring that received regular diets and in control offspring provided with high‐salt diets. In mesenteric artery myocytes from the salt‐loading offspring with prenatal hypoxia, depolarized resting membrane potential was associated with decreased density of L‐type voltage‐gated Ca2+ (Cav1.2) and voltage‐gated K+ channel currents and decreased calcium sensitive to the large‐conductance Ca2+‐activated K+ channels. Protein expression of the L‐type voltage‐gated Ca2+ α1C subunit, large‐conductance calcium‐activated K+ channel (β1, not α subunits), and voltage‐gated K+ channel (KV2.1, not KV1.5 subunits) was also decreased in the arteries of salt‐loading offspring with prenatal hypoxia. Conclusions The results demonstrated that chronic prenatal hypoxia may program salt‐sensitive hypertension in male offspring, providing new information of ion channel remodeling in hypertensive myocytes. This information paves the way for early prevention and treatments of salt‐induced hypertension related to developmental problems in fetal origins.
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Affiliation(s)
- Bailin Liu
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Ruixiu Shi
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Xiang Li
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Yanping Liu
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Xueqin Feng
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Xueyi Chen
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Xiaorong Fan
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Yingying Zhang
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Wenna Zhang
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Jiaqi Tang
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Xiuwen Zhou
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Na Li
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Xiyuan Lu
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China
| | - Zhice Xu
- Institute for Fetology, First Hospital of Soochow University, Suzhou, China .,Center for Perinatal Biology, Loma Linda University, Loma Linda, CA
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Regional Heterogeneity in the Regulation of Vasoconstriction in Arteries and Its Role in Vascular Mechanics. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1097:105-128. [PMID: 30315542 DOI: 10.1007/978-3-319-96445-4_6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Vasoconstriction and vasodilation play important roles in the circulatory system and can be regulated through different pathways that depend on myriad biomolecules. These different pathways reflect the various functions of smooth muscle cell (SMC) contractility within the different regions of the arterial tree and how they contribute to both the mechanics and the mechanobiology. Here, we review the primary regulatory pathways involved in SMC contractility and highlight their regional differences in elastic, muscular, and resistance arteries. In this way, one can begin to assess how these properties affect important biomechanical and mechanobiological functions in the circulatory system in health and disease.
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14
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Nieves-Cintrón M, Syed AU, Nystoriak MA, Navedo MF. Regulation of voltage-gated potassium channels in vascular smooth muscle during hypertension and metabolic disorders. Microcirculation 2018; 25:10.1111/micc.12423. [PMID: 29044853 PMCID: PMC5760350 DOI: 10.1111/micc.12423] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 10/11/2017] [Indexed: 12/12/2022]
Abstract
Voltage-gated potassium (KV ) channels are key regulators of vascular smooth muscle contractility and vascular tone, and thus have major influence on the microcirculation. KV channels are important determinants of vascular smooth muscle membrane potential (Em ). A number of KV subunits are expressed in the plasma membrane of smooth muscle cells. Each subunit confers distinct kinetics and regulatory properties that allow for fine control of Em to orchestrate vascular tone. Modifications in KV subunit expression and/or channel activity can contribute to changes in vascular smooth muscle contractility in response to different stimuli and in diverse pathological conditions. Consistent with this, a number of studies suggest alterations in KV subunit expression and/or function as underlying contributing mechanisms for small resistance artery dysfunction in pathologies such as hypertension and metabolic disorders, including diabetes. Here, we review our current knowledge on the effects of these pathologies on KV channel expression and function in vascular smooth muscle cells, and the repercussions on (micro)vascular function.
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Affiliation(s)
| | - Arsalan U. Syed
- Department of Pharmacology, University of California, Davis, CA 95616
| | - Matthew A. Nystoriak
- Diabetes and Obesity Center, Department of Medicine, University of Louisville, Louisville, KY 40202
| | - Manuel F. Navedo
- Department of Pharmacology, University of California, Davis, CA 95616
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15
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Salomonsson M, Brasen JC, Sorensen CM. Role of renal vascular potassium channels in physiology and pathophysiology. Acta Physiol (Oxf) 2017; 221:14-31. [PMID: 28371470 DOI: 10.1111/apha.12882] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 05/10/2016] [Accepted: 03/22/2017] [Indexed: 12/31/2022]
Abstract
The control of renal vascular tone is important for the regulation of salt and water balance, blood pressure and the protection against damaging elevated glomerular pressure. The K+ conductance is a major factor in the regulation of the membrane potential (Vm ) in vascular smooth muscle (VSMC) and endothelial cells (EC). The vascular tone is controlled by Vm via its effect on the opening probability of voltage-operated Ca2+ channels (VOCC) in VSMC. When K+ conductance increases Vm becomes more negative and vasodilation follows, while deactivation of K+ channels leads to depolarization and vasoconstriction. K+ channels in EC indirectly participate in the control of vascular tone by endothelium-derived vasodilation. Therefore, by regulating the tone of renal resistance vessels, K+ channels have a potential role in the control of fluid homoeostasis and blood pressure as well as in the protection of the renal parenchyma. The main classes of K+ channels (calcium activated (KCa ), inward rectifier (Kir ), voltage activated (Kv ) and ATP sensitive (KATP )) have been found in the renal vessels. In this review, we summarize results available in the literature and our own studies in the field. We compare the ambiguous in vitro and in vivo results. We discuss the role of single types of K+ channels and the integrated function of several classes. We also deal with the possible role of renal vascular K+ channels in the pathophysiology of hypertension, diabetes mellitus and sepsis.
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Affiliation(s)
| | - J. C. Brasen
- Department of Electrical Engineering; Technical University of Denmark; Kgs. Lyngby Denmark
| | - C. M. Sorensen
- Department of Biomedical Sciences; Division of Renal and Vascular Physiology; University of Copenhagen; Copenhagen Denmark
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16
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Tykocki NR, Boerman EM, Jackson WF. Smooth Muscle Ion Channels and Regulation of Vascular Tone in Resistance Arteries and Arterioles. Compr Physiol 2017; 7:485-581. [PMID: 28333380 DOI: 10.1002/cphy.c160011] [Citation(s) in RCA: 222] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Vascular tone of resistance arteries and arterioles determines peripheral vascular resistance, contributing to the regulation of blood pressure and blood flow to, and within the body's tissues and organs. Ion channels in the plasma membrane and endoplasmic reticulum of vascular smooth muscle cells (SMCs) in these blood vessels importantly contribute to the regulation of intracellular Ca2+ concentration, the primary determinant of SMC contractile activity and vascular tone. Ion channels provide the main source of activator Ca2+ that determines vascular tone, and strongly contribute to setting and regulating membrane potential, which, in turn, regulates the open-state-probability of voltage gated Ca2+ channels (VGCCs), the primary source of Ca2+ in resistance artery and arteriolar SMCs. Ion channel function is also modulated by vasoconstrictors and vasodilators, contributing to all aspects of the regulation of vascular tone. This review will focus on the physiology of VGCCs, voltage-gated K+ (KV) channels, large-conductance Ca2+-activated K+ (BKCa) channels, strong-inward-rectifier K+ (KIR) channels, ATP-sensitive K+ (KATP) channels, ryanodine receptors (RyRs), inositol 1,4,5-trisphosphate receptors (IP3Rs), and a variety of transient receptor potential (TRP) channels that contribute to pressure-induced myogenic tone in resistance arteries and arterioles, the modulation of the function of these ion channels by vasoconstrictors and vasodilators, their role in the functional regulation of tissue blood flow and their dysfunction in diseases such as hypertension, obesity, and diabetes. © 2017 American Physiological Society. Compr Physiol 7:485-581, 2017.
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Affiliation(s)
- Nathan R Tykocki
- Department of Pharmacology, University of Vermont, Burlington, Vermont, USA
| | - Erika M Boerman
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri, USA
| | - William F Jackson
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan, USA
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17
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Bencze M, Behuliak M, Vavřínová A, Zicha J. Altered contractile responses of arteries from spontaneously hypertensive rat: The role of endogenous mediators and membrane depolarization. Life Sci 2016; 166:46-53. [DOI: 10.1016/j.lfs.2016.10.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 09/19/2016] [Accepted: 10/05/2016] [Indexed: 11/25/2022]
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18
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Ardanaz N, Pagano PJ. Hydrogen Peroxide as a Paracrine Vascular Mediator: Regulation and Signaling Leading to Dysfunction. Exp Biol Med (Maywood) 2016; 231:237-51. [PMID: 16514169 DOI: 10.1177/153537020623100302] [Citation(s) in RCA: 166] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Numerous studies have demonstrated the ability of a variety of vascular cells, including endothelial cells, smooth muscle cells, and fibroblasts, to produce reactive oxygen species (ROS). Until recently, major emphasis was placed on the production of superoxide anion (O2–) in the vasculature as a result of its ability to directly attenuate the biological activity of endothelium-derived nitric oxide (NO). The short half-life and radius of diffusion of O2– drastically limit the role of this ROS as an important paracrine hormone in vascular biology. On the contrary, in recent years, the O2– metabolite hydrogen peroxide (H2O2) has increasingly been viewed as an important cellular signaling agent in its own right, capable of modulating both contractile and growth-promoting pathways with more far-reaching effects. In this review, we will assess the vascular production of H2O2, its regulation by endogenous scavenger systems, and its ability to activate a variety of vascular signaling pathways, thereby leading to vascular contraction and growth. This discussion will include the ability of H2O2 to (i) Initiate calcium flux as well as (ii) stimulate pathways leading to sensitization of contractile elements to calcium. The latter involves a variety of protein kinases that have also been strongly implicated in vascular hypertrophy. Previous Intensive study has emphasized the ability of NADPH oxidase-derived O2– and H2O2 to activate these pathways in cultured smooth muscle cells. However, growing evidence indicates a considerably more complex array of unique oxidase systems in the endothelium, media, and adventitia that appear to participate in these deleterious effects in a sequential and temporal manner. Taken together, these findings seem consistent with a paracrine effect of H2O2 across the vascular wall.
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Affiliation(s)
- Noelia Ardanaz
- Hypertension and Vascular Research Division, RM 7044, E&R Building, Henry Ford Hospital, 2799 West Grand Boulevard, Detroit, MI 48202-2689, USA
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19
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Potassium Channels in Regulation of Vascular Smooth Muscle Contraction and Growth. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2016; 78:89-144. [PMID: 28212804 DOI: 10.1016/bs.apha.2016.07.001] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Potassium channels importantly contribute to the regulation of vascular smooth muscle (VSM) contraction and growth. They are the dominant ion conductance of the VSM cell membrane and importantly determine and regulate membrane potential. Membrane potential, in turn, regulates the open-state probability of voltage-gated Ca2+ channels (VGCC), Ca2+ influx through VGCC, intracellular Ca2+, and VSM contraction. Membrane potential also affects release of Ca2+ from internal stores and the Ca2+ sensitivity of the contractile machinery such that K+ channels participate in all aspects of regulation of VSM contraction. Potassium channels also regulate proliferation of VSM cells through membrane potential-dependent and membrane potential-independent mechanisms. VSM cells express multiple isoforms of at least five classes of K+ channels that contribute to the regulation of contraction and cell proliferation (growth). This review will examine the structure, expression, and function of large conductance, Ca2+-activated K+ (BKCa) channels, intermediate-conductance Ca2+-activated K+ (KCa3.1) channels, multiple isoforms of voltage-gated K+ (KV) channels, ATP-sensitive K+ (KATP) channels, and inward-rectifier K+ (KIR) channels in both contractile and proliferating VSM cells.
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20
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No apparent role for T-type Ca²⁺ channels in renal autoregulation. Pflugers Arch 2015; 468:541-50. [PMID: 26658945 DOI: 10.1007/s00424-015-1770-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 12/03/2015] [Indexed: 10/22/2022]
Abstract
Renal autoregulation protects glomerular capillaries against increases in renal perfusion pressure (RPP). In the mesentery, both L- and T-type calcium channels are involved in autoregulation. L-type calcium channels participate in renal autoregulation, but the role of T-type channels is not fully elucidated due to lack of selective pharmacological inhibitors. The role of T- and L-type calcium channels in the response to acute increases in RPP in T-type channel knockout mice (CaV3.1) and normo- and hypertensive rats was examined. Changes in afferent arteriolar diameter in the kidneys from wild-type and CaV3.1 knockout mice were assessed. Autoregulation of renal blood flow was examined during acute increases in RPP in normo- and hypertensive rats under pharmacological blockade of T- and L-type calcium channels using mibefradil (0.1 μM) and nifedipine (1 μM). In contrast to the results from previous pharmacological studies, genetic deletion of T-type channels CaV3.1 did not affect renal autoregulation. Pharmacological blockade of T-type channels using concentrations of mibefradil which specifically blocks T-type channels also had no effect in wild-type or knockout mice. Blockade of L-type channels significantly attenuated renal autoregulation in both strains. These findings are supported by in vivo studies where blockade of T-type channels had no effect on changes in the renal vascular resistance after acute increases in RPP in normo- and hypertensive rats. These findings show that genetic deletion of T-type channels CaV3.1 or treatment with low concentrations of mibefradil does not affect renal autoregulation. Thus, T-type calcium channels are not involved in renal autoregulation in response to acute increases in RPP.
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21
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Chronic hypoxia in pregnancy affected vascular tone of renal interlobar arteries in the offspring. Sci Rep 2015; 5:9723. [PMID: 25983078 PMCID: PMC4434890 DOI: 10.1038/srep09723] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 03/17/2015] [Indexed: 11/22/2022] Open
Abstract
Hypoxia during pregnancy could affect development of fetuses as well as cardiovascular systems in the offspring. This study was the first to demonstrate the influence and related mechanisms of prenatal hypoxia (PH) on renal interlobar arteries (RIA) in the 5-month-old male rat offspring. Following chronic hypoxia during pregnancy, phenylephrine induced significantly higher pressor responses and greater vasoconstrictions in the offspring. Nitric oxide mediated vessel relaxation was altered in the RIA. Phenylephrine-stimulated free intracellular calcium was significantly higher in the RIA of the PH group. The activity and expression of L-type calcium channel (Cav1.2), not T-type calcium channel (Cav3.2), was up-regulated. The whole-cell currents of calcium channels and the currents of Cav1.2 were increased compared with the control. In addition, the whole-cell K+ currents were decreased in the offspring exposed to prenatal hypoxia. Activity of large-conductance Ca2+-activated K+ channels and the expression of MaxiKα was decreased in the PH group. The results provide new information regarding the influence of prenatal hypoxia on the development of the renal vascular system, and possible underlying cellular and ion channel mechanisms involved.
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22
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Son YK, Hong DH, Li H, Kim DJ, Na SH, Park H, Jung WK, Choi IW, Park WS. Ca2+ channel inhibitor NNC 55-0396 inhibits voltage-dependent K+ channels in rabbit coronary arterial smooth muscle cells. J Pharmacol Sci 2014; 125:312-9. [PMID: 24989838 DOI: 10.1254/jphs.14054fp] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
We demonstrated the inhibitory effect of NNC 55-0396, a T-type Ca(2+) channel inhibitor, on voltage-dependent K(+) (K(V)) channels in freshly isolated rabbit coronary arterial smooth muscle cells. NNC 55-0396 decreased the amplitude of K(V) currents in a concentration-dependent manner, with an IC(50) of 0.080 μM and a Hill coefficient of 0.76.NNC 55-0396 did not affect steady-state activation and inactivation curves, indicating that the compound does not affect the voltage sensitivity of K(V) channel gating. Both the K(V) currents and the inhibitory effect of NNC 55-0396 on K(V) channels were not altered by depletion of extracellular Ca(2+) or intracellular ATP, suggesting that the inhibitory effect of NNC 55-0396 is independent of Ca(2+)-channel activity and phosphorylation-dependent signaling cascades. From these results, we concluded that NNC 55-0396 dosedependently inhibits K(V) currents, independently of Ca(2+)-channel activity and intracellular signaling cascades.
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Affiliation(s)
- Youn Kyoung Son
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, Korea
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23
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Tajada S, Cidad P, Colinas O, Santana LF, López-López JR, Pérez-García MT. Down-regulation of CaV1.2 channels during hypertension: how fewer CaV1.2 channels allow more Ca(2+) into hypertensive arterial smooth muscle. J Physiol 2013; 591:6175-91. [PMID: 24167226 DOI: 10.1113/jphysiol.2013.265751] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Hypertension is a clinical syndrome characterized by increased arterial tone. Although the mechanisms are varied, the generally accepted view is that increased CaV1.2 channel function is a common feature of this pathological condition. Here, we investigated the mechanisms underlying vascular dysfunction in a mouse model of genetic hypertension. Contrary to expectation, we found that whole-cell CaV1.2 currents (ICa) were lower in hypertensive (BPH line) than normotensive (BPN line) myocytes. However, local CaV1.2 sparklet activity was higher in BPH cells, suggesting that the relatively low ICa in these cells was produced by a few hyperactive CaV1.2 channels. Furthermore, our data suggest that while the lower expression of the pore-forming α1c subunit of CaV1.2 currents underlies the lower ICa in BPH myocytes, the increased sparklet activity was due to a different composition in the auxiliary subunits of the CaV1.2 complexes. ICa currents in BPN cells were produced by channels composed of α1c/α2δ/β3 subunits, while in BPH myocytes currents were probably generated by the opening of channels formed by α1c/α2δ/β2 subunits. In addition, Ca(2+) sparks evoked large conductance, Ca(2+)-activated K(+) (BK) currents of lower magnitude in BPH than in BPN myocytes, because BK channels were less sensitive to Ca(2+). Our data are consistent with a model in which a decrease in the global number of CaV1.2 currents coexist with the existence of a subpopulation of highly active channels that dominate the resting Ca(2+) influx. The decrease in BK channel activity makes the hyperpolarizing brake ineffective and leads BPH myocytes to a more contracted resting state.
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Affiliation(s)
- Sendoa Tajada
- Jose R. López-López: Departamento de Bioquímica y Biología Molecular y Fisiología, Universidad de Valladolid, Edificio IBGM, c/ Sanz y Forés s/n, 47003 Valladolid, Spain.
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Park MH, Son YK, Hong DH, Choi IW, Kim DJ, Lee H, Bang H, Na SH, Li H, Jo SH, Park WS. The Ca2+ channel inhibitor efonidipine decreases voltage-dependent K+ channel activity in rabbit coronary arterial smooth muscle cells. Vascul Pharmacol 2013; 59:90-5. [DOI: 10.1016/j.vph.2013.07.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 07/12/2013] [Accepted: 07/12/2013] [Indexed: 12/22/2022]
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25
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Saldanha PA, Cairrão E, Maia CJ, Verde I. Long- and short-term effects of androgens in human umbilical artery smooth muscle. Clin Exp Pharmacol Physiol 2013; 40:181-9. [PMID: 23278339 DOI: 10.1111/1440-1681.12047] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Revised: 11/25/2012] [Accepted: 12/12/2012] [Indexed: 12/19/2022]
Abstract
The aim of the present study was to determine the effects of androgens in the regulation of human umbilical artery (HUA) contractility. The short-term effects of testosterone on the tone of the HUA were investigated, as were the long-term effects of dihydrotestosterone (DHT) on the expression of some proteins involved in the contractile process. Endothelium-denuded HUA were treated for 24 h with DHT (2 μmol/L) or the vehicle control (ethanol) to analyse the genomic effects of androgens. Twenty-four hour treatment of HUA with DHT increased the mRNA expression of the β(1)-subunit of the large-conductance Ca(2+)-activated (BK(Ca)) channel and decreased expression of the α-subunit of L-type calcium channels. In organ bath studies, testosterone (1-100 μmol/L) produced similar relaxant responses in DHT- and vehicle-treated HUA rings precontracted with 5-HT, histamine and KCl. However, the relaxation response obtained by the combined application of testosterone (100 μmol/L) and nifedipine (10 μmol/L) was significantly greater in DHT- compared with vehicle-treated HUA. The results indicate that the rapid vasorelaxant effects of testosterone that are dependent on both BK(Ca) and voltage-sensitive potassium (K(V)) channel activity in control arteries become dependent solely on K(V) channel activity in DHT-treated HUA. Thus, the present study reveals the importance of the investigation of both the short- and long-term effects of androgens in human arteries.
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Affiliation(s)
- Paulo A Saldanha
- Health Sciences Research Centre, University of Beira Interior, Covilhã, Portugal
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26
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Role of BKCa channels in vascular smooth muscle during the development of environmental cold-induced hypertension. J Therm Biol 2013. [DOI: 10.1016/j.jtherbio.2013.01.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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27
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Joseph BK, Thakali KM, Moore CL, Rhee SW. Ion channel remodeling in vascular smooth muscle during hypertension: Implications for novel therapeutic approaches. Pharmacol Res 2013; 70:126-38. [PMID: 23376354 PMCID: PMC3607210 DOI: 10.1016/j.phrs.2013.01.008] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Revised: 01/10/2013] [Accepted: 01/17/2013] [Indexed: 02/07/2023]
Abstract
Ion channels are multimeric, transmembrane proteins that selectively mediate ion flux across the plasma membrane in a variety of cells including vascular smooth muscle cells (VSMCs). The dynamic interplay of Ca(2+) and K(+) channels on the plasma membrane of VSMCs plays a pivotal role in modulating the vascular tone of small arteries and arterioles. The abnormally-elevated arterial tone observed in hypertension thus points to an aberrant expression and function of Ca(2+) and K(+) channels in the VSMCs. In this short review, we focus on the three well-studied ion channels in VSMCs, namely the L-type Ca(2+) (CaV1.2) channels, the voltage-gated K(+) (KV) channels, and the large-conductance Ca(2+)-activated K(+) (BK) channels. First, we provide a brief overview on the physiological role of vascular CaV1.2, KV and BK channels in regulating arterial tone. Second, we discuss the current understanding of the expression changes and regulation of CaV1.2, KV and BK channels in the vasculature during hypertension. Third, based on available proof-of-concept studies, we describe the potential therapeutic approaches targeting these vascular ion channels in order to restore blood pressure to normotensive levels.
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Affiliation(s)
- Biny K Joseph
- Venenum Biodesign, 8 Black Forest Road, Hamilton, NJ 08691, USA
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28
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29
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Hong DH, Yang D, Choi IW, Son YK, Jung WK, Kim DJ, Han J, Na SH, Park WS. The T-type Ca2+ Channel Inhibitor Mibefradil Inhibits Voltage-Dependent K+ Channels in Rabbit Coronary Arterial Smooth Muscle Cells. J Pharmacol Sci 2012; 120:196-205. [DOI: 10.1254/jphs.12104fp] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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Magnusson L, Sorensen CM, Braunstein TH, Holstein-Rathlou NH, Salomonsson M. Mechanisms of K(+) induced renal vasodilation in normo- and hypertensive rats in vivo. Acta Physiol (Oxf) 2011; 202:703-12. [PMID: 21477070 DOI: 10.1111/j.1748-1716.2011.02304.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIM We investigated the mechanisms behind K(+) -induced renal vasodilation in vivo in normotensive Sprague-Dawley (SD) rats and spontaneously hypertensive rats (SHR). METHODS Renal blood flow (RBF) was measured utilizing an ultrasonic Doppler flow probe. Renal vascular resistance (RVR) was calculated as the ratio of mean arterial pressure (MAP) and RBF (RVR = MAP/RBF). Test drugs were introduced directly into the renal artery. Inward rectifier K(+) (K(ir) ) channels and Na(+) ,K(+) -ATPase were blocked by Ba(2+) and ouabain (estimated plasma concentrations ∼20 and ∼7 μm) respectively. RESULTS Confocal immunofluorescence microscopy demonstrated K(ir) 2.1 channels in pre-glomerular vessels of SD and SHR. Ba(2+) caused a transient (6-13%) increase in baseline RVR in both SD and SHR. Ouabain had a similar effect. Elevated renal plasma [K(+) ] (∼12 mm) caused a small and sustained decrease (5-13%) in RVR in both strains. This decrease was significantly larger in SHR than in SD. The K(+) -induced vasodilation was attenuated by Ba(2+) in control SD and SHR and by ouabain in SD. Nitric oxide (NO) blockade using l-NAME treatment increased MAP and decreased RBF in both rat strains, but did not affect the K(+) -induced renal vasodilation. CONCLUSION K(+) -induced renal vasodilation is larger in SHR, mediated by K(ir) channels in SD and SHR, and in addition, by Na(+) ,K(+) -ATPase in SD. In addition, NO is not essential for K(+) -induced renal vasodilation.
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Affiliation(s)
- L Magnusson
- Division of Renal and Vascular Physiology, Department of Biomedical Sciences, The Panum Institute, University of Copenhagen, Denmark
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Todorovic J, Nesovic-Ostojic J, Cemerikic D. Peritubular membrane potential in kidney proximal tubular cells of spontaneously hypertensive rats. ACTA PHYSIOLOGICA HUNGARICA 2011; 98:8-16. [PMID: 21388926 DOI: 10.1556/aphysiol.98.2011.1.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Peritubular membrane potential in kidney proximal tubular cells of spontaneously hypertensive rats (SHR-Okamoto strain adult rats) was measured with conventional 3 mol KCl microelectrodes, in vivo. Peritubular cell membrane potential was not different in SHR (-66.5 ± 0.7 mV) as compared with normotensive control Wistar rats (-67.5 ± 1.2 mV). To test the effects of possible altered sodium membrane transport in SHR on proximal tubule peritubular membrane potential, we allowed SHR and control rats to drink 1% NaCl for two weeks. Again, proximal tubule peritubular membrane potential was not different in SHR on 1% NaCl (-67.0 ± 1.0 mV) as compared with control rats on 1% NaCl (-64.7 ± 1.3 mV). From these results we concluded that peritubular membrane potential in kidney proximal tubular cells of SHR was not different from normotensive Wistar control rats, and if some alteration of sodium transport in kidney proximal tubular cells of SHR could exist, that was not possible to evaluate from the measurements of peritubular membrane potential in kidney proximal tubular cells.
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Affiliation(s)
- J Todorovic
- Medical Faculty, Department of Pathological Physiology, Belgrade, Serbia
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Poon CCW, Seto SW, Au ALS, Zhang Q, Li RWS, Lee WYW, Leung GPH, Kong SK, Yeung JHK, Ngai SM, Ho HP, Lee SMY, Chan SW, Kwan YW. Mitochondrial monoamine oxidase-A-mediated hydrogen peroxide generation enhances 5-hydroxytryptamine-induced contraction of rat basilar artery. Br J Pharmacol 2011; 161:1086-98. [PMID: 20977458 DOI: 10.1111/j.1476-5381.2010.00941.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE We evaluated the role(s) of monoamine oxidase (MAO)-mediated H₂O₂ generation on 5-hydroxytryptamine (5-HT)-induced tension development of isolated basilar artery of spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats. EXPERIMENTAL APPROACH Basilar artery (endothelium-denuded) was isolated for tension measurement and Western blots. Enzymically dissociated single myocytes from basilar arteries were used for patch-clamp electrophysiological and confocal microscopic studies. KEY RESULTS Under resting tension, 5-HT elicited a concentration-dependent tension development with a greater sensitivity (with unchanged maximum tension development) in SHR compared with WKY (EC(50) : 28.4 ± 4.1 nM vs. 98.2 ± 9.4 nM). The exaggerated component of 5-HT-induced tension development in SHR was eradicated by polyethylene glycol-catalase, clorgyline and citalopram whereas exogenously applied H₂O₂ enhanced the 5-HT-elicited tension development in WKY. A greater protein expression of MAO-A was detected in basilar arteries from SHR than in those from WKY. In single myocytes and the entire basilar artery, 5-HT generated (clorgyline-sensitive) a greater amount of H₂O₂ in SHR compared with WKY. Whole-cell iberiotoxin-sensitive Ca(2+) -activated K(+) (BK(Ca) ) amplitude measured in myocytes of SHR was approximately threefold greater than that in WKY (at +60 mV: 7.61 ± 0.89 pA·pF(-1) vs. 2.61 ± 0.66 pA·pF(-1) ). In SHR myocytes, 5-HT caused a greater inhibition (clorgyline-, polyethylene glycol-catalase- and reduced glutathione-sensitive) of BK(Ca) amplitude than in those from WKY. CONCLUSIONS AND IMPLICATIONS 5-HT caused an increased generation of mitochondrial H₂O₂ via MAO-A-mediated 5-HT metabolism, which caused a greater inhibition of BK(Ca) gating in basilar artery myocytes, leading to exaggerated basilar artery tension development in SHR.
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Affiliation(s)
- Christina Chui Wa Poon
- School of Biomedical Sciences (Programme in Vascular and Metabolic Biology), Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
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Firth AL, Remillard CV, Platoshyn O, Fantozzi I, Ko EA, Yuan JXJ. Functional ion channels in human pulmonary artery smooth muscle cells: Voltage-dependent cation channels. Pulm Circ 2011; 1:48-71. [PMID: 21927714 PMCID: PMC3173772 DOI: 10.4103/2045-8932.78103] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The activity of voltage-gated ion channels is critical for the maintenance of cellular membrane potential and generation of action potentials. In turn, membrane potential regulates cellular ion homeostasis, triggering the opening and closing of ion channels in the plasma membrane and, thus, enabling ion transport across the membrane. Such transmembrane ion fluxes are important for excitation–contraction coupling in pulmonary artery smooth muscle cells (PASMC). Families of voltage-dependent cation channels known to be present in PASMC include voltage-gated K+ (Kv) channels, voltage-dependent Ca2+-activated K+ (Kca) channels, L- and T- type voltage-dependent Ca2+ channels, voltage-gated Na+ channels and voltage-gated proton channels. When cells are dialyzed with Ca2+-free K+- solutions, depolarization elicits four components of 4-aminopyridine (4-AP)-sensitive Kvcurrents based on the kinetics of current activation and inactivation. In cell-attached membrane patches, depolarization elicits a wide range of single-channel K+ currents, with conductances ranging between 6 and 290 pS. Macroscopic 4-AP-sensitive Kv currents and iberiotoxin-sensitive Kca currents are also observed. Transcripts of (a) two Na+ channel α-subunit genes (SCN5A and SCN6A), (b) six Ca2+ channel α–subunit genes (α1A, α1B, α1X, α1D, α1Eand α1G) and many regulatory subunits (α2δ1, β1-4, and γ6), (c) 22 Kv channel α–subunit genes (Kv1.1 - Kv1.7, Kv1.10, Kv2.1, Kv3.1, Kv3.3, Kv3.4, Kv4.1, Kv4.2, Kv5.1, Kv 6.1-Kv6.3, Kv9.1, Kv9.3, Kv10.1 and Kv11.1) and three Kv channel β-subunit genes (Kvβ1-3) and (d) four Kca channel α–subunit genes (Sloα1 and SK2-SK4) and four Kca channel β-subunit genes (Kcaβ1-4) have been detected in PASMC. Tetrodotoxin-sensitive and rapidly inactivating Na+ currents have been recorded with properties similar to those in cardiac myocytes. In the presence of 20 mM external Ca2+, membrane depolarization from a holding potential of -100 mV elicits a rapidly inactivating T-type Ca2+ current, while depolarization from a holding potential of -70 mV elicits a slowly inactivating dihydropyridine-sensitive L-type Ca2+ current. This review will focus on describing the electrophysiological properties and molecular identities of these voltage-dependent cation channels in PASMC and their contribution to the regulation of pulmonary vascular function and its potential role in the pathogenesis of pulmonary vascular disease.
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Affiliation(s)
- Amy L Firth
- The Salk Institute for Biological Studies, La Jolla, California, USA
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Dalsgaard T, Kroigaard C, Simonsen U. Calcium-activated potassium channels - a therapeutic target for modulating nitric oxide in cardiovascular disease? Expert Opin Ther Targets 2010; 14:825-37. [PMID: 20560781 DOI: 10.1517/14728222.2010.500616] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
IMPORTANCE OF THE FIELD Cardiovascular risk factors are often associated with endothelial dysfunction, which is also prognostic for occurrence of cardiovascular events. Endothelial dysfunction is reflected by blunted vasodilatation and reduced nitric oxide (NO) bioavailability. Endothelium-dependent vasodilatation is mediated by NO, prostacyclin, and an endothelium-derived hyperpolarising factor (EDHF), and involves small (SK) and intermediate (IK) conductance Ca(2+)-activated K(+) channels. Therefore, SK and IK channels may be drug targets for the treatment of endothelial dysfunction in cardiovascular disease. AREAS COVERED IN THIS REVIEW SK and IK channels are involved in EDHF-type vasodilatation, but recent studies suggest that these channels are also involved in the regulation of NO bioavailability. Here we review how SK and IK channels may regulate NO bioavailability. WHAT THE READER WILL GAIN Opening of SK and IK channels is associated with EDHF-type vasodilatation, but, through increased endothelial cell Ca(2+) influx, L-arginine uptake, and decreased ROS production, it may also lead to increased NO bioavailability and endothelium-dependent vasodilatation. TAKE HOME MESSAGE Opening of SK and IK channels can increase both EDHF and NO-mediated vasodilatation. Therefore, openers of SK and IK channels may have the potential of improving endothelial cell function in cardiovascular disease.
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Affiliation(s)
- Thomas Dalsgaard
- Department of Pharmacology, Aarhus University, DK-8000 Aarhus C, Denmark.
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Ko EA, Park WS, Firth AL, Kim N, Yuan JXJ, Han J. Pathophysiology of voltage-gated K+ channels in vascular smooth muscle cells: Modulation by protein kinases. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2010; 103:95-101. [DOI: 10.1016/j.pbiomolbio.2009.10.001] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2009] [Accepted: 10/07/2009] [Indexed: 10/20/2022]
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Zhang HF, Chen XQ, Hu GY, Wang YP. Magnesium lithospermate B dilates mesenteric arteries by activating BKCa currents and contracts arteries by inhibiting K(V) currents. Acta Pharmacol Sin 2010; 31:665-70. [PMID: 20453873 DOI: 10.1038/aps.2010.40] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
AIM To examine the involvement of K(+) channels and endothelium in the vascular effects of magnesium lithospermate B (MLB), a hydrophilic active component of Salviae miltiorrhiza Radix. METHODS Isolated rat mesenteric artery rings were employed to investigate the effects of MLB on KCl- or norepinephrine-induced contractions. Conventional whole-cell patch-clamp technique was used to study the effects of MLB on K(+) currents in single isolated mesenteric artery myocytes. RESULTS MLB produced a concentration-dependent relaxation in mesenteric artery rings precontracted by norepinephrine (1 micromol/L) with an EC(50) of 111.3 micromol/L. MLB-induced relaxation was reduced in denuded artery rings with an EC(50) of 224.4 micromol/L. MLB caused contractions in KCl-precontracted artery rings in the presence of N-nitro-L-arginine methyl ester (L-NAME) with a maximal value of 130.3%. The vasodilatory effect of MLB was inhibited by tetraethylammonium (TEA) in both intact and denuded artery rings. In single smooth muscle cells, MLB activated BK(Ca) currents (EC(50) 156.3 micromol/L) but inhibited K(V) currents (IC(50) 26.1 micromol/L) in a voltage- and concentration-dependent manner. CONCLUSION MLB dilated arteries by activating BK(Ca) channels in smooth muscle cells and increasing NO release from endothelium, but it also contracted arteries precontracted with KCl in the presence of L-NAME.
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Expression and immunolocalization of ERG1 potassium channels in the rat kidney. Histochem Cell Biol 2009; 133:189-99. [DOI: 10.1007/s00418-009-0658-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/23/2009] [Indexed: 10/20/2022]
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Navar LG, Arendshorst WJ, Pallone TL, Inscho EW, Imig JD, Bell PD. The Renal Microcirculation. Compr Physiol 2008. [DOI: 10.1002/cphy.cp020413] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Testosterone deprivation by castration impairs expression of voltage-dependent potassium channels in rat aorta. Eur J Pharmacol 2008; 593:87-91. [DOI: 10.1016/j.ejphar.2008.07.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2008] [Revised: 06/26/2008] [Accepted: 07/09/2008] [Indexed: 11/21/2022]
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Abstract
Accumulating evidence supports the importance of redox signaling in the pathogenesis and progression of hypertension. Redox signaling is implicated in many different physiological and pathological processes in the vasculature. High blood pressure is in part determined by elevated total peripheral vascular resistance, which is ascribed to dysregulation of vasomotor function and structural remodeling of blood vessels. Aberrant redox signaling, usually induced by excessive production of reactive oxygen species (ROS) and/or by decreases in antioxidant activity, can induce alteration of vascular function. ROS increase vascular tone by influencing the regulatory role of endothelium and by direct effects on the contractility of vascular smooth muscle. ROS contribute to vascular remodeling by influencing phenotype modulation of vascular smooth muscle cells, aberrant growth and death of vascular cells, cell migration, and extracellular matrix (ECM) reorganization. Thus, there are diverse roles of the vascular redox system in hypertension, suggesting that the complexity of redox signaling in distinct spatial spectrums should be considered for a better understanding of hypertension.
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Affiliation(s)
- Moo Yeol Lee
- Department of Medicine, Division of Cardiology, Emory University, Atlanta, Georgia 30322, USA
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Navar LG, Arendshorst WJ, Pallone TL, Inscho EW, Imig JD, Bell PD. The Renal Microcirculation. Microcirculation 2008. [DOI: 10.1016/b978-0-12-374530-9.00015-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
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Ko EA, Han J, Jung ID, Park WS. Physiological roles of K + channels in vascular smooth muscle cells. J Smooth Muscle Res 2008; 44:65-81. [DOI: 10.1540/jsmr.44.65] [Citation(s) in RCA: 317] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Eun A Ko
- National Research Laboratory for Mitochondrial Signaling, FIRST Mitochondria Research Group, Department of Physiology and Biophysics, College of Medicine, Cardiovascular and Metabolic Disease Center, Inje University
| | - Jin Han
- National Research Laboratory for Mitochondrial Signaling, FIRST Mitochondria Research Group, Department of Physiology and Biophysics, College of Medicine, Cardiovascular and Metabolic Disease Center, Inje University
| | - In Duk Jung
- Department of Microbiology and Immunology and National Research Laboratory of Dentritic, Cell Differentiation and Regulation, Pusan National University, College of Medicine
| | - Won Sun Park
- National Research Laboratory for Mitochondrial Signaling, FIRST Mitochondria Research Group, Department of Physiology and Biophysics, College of Medicine, Cardiovascular and Metabolic Disease Center, Inje University
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Georgescu A, Pluteanu F, Flonta ML, Badila E, Dorobantu M, Popov D. Nebivolol induces a hyperpolarizing effect on smooth muscle cells in the mouse renal artery by activation of beta-2-adrenoceptors. Pharmacology 2007; 81:110-7. [PMID: 17952013 DOI: 10.1159/000110011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2007] [Accepted: 06/12/2007] [Indexed: 11/19/2022]
Abstract
Nebivolol is a highly selective beta(1)-adrenoceptor antagonist with vasodilator properties involving the vascular endothelium, but its effect on the smooth muscle cells (SMC) is still unclear. In this paper, we tested the effect of nebivolol on renal artery smooth muscle cells and investigated the cellular mechanism involved. To this purpose, the denuded renal arteries isolated from mice were studied in vitro using the myograph and the nitric oxide (NO) sensor techniques, while the SMC in culture were analyzed by the patch-clamp technique. The myograph technique was used to assay the vasodilator effect of nebivolol on the arterial muscular layer, and to establish the optimal dose of the drug to be tested on single SMC by the patch-clamp technique. Using both the myograph and the patch-clamp techniques, we examined the potential contribution of beta(2)-adrenoceptors and Ca(2+)-activated K(+) channels to the nebivolol-induced effects, by exposing the denuded arteries and SMC cultures to specific inhibitors such as butoxamine (100 micromol/l), tetraethylammonium (TEA, 1 mmol/l), and iberiotoxin (100 nmol/l). The direct measurement of NO using the NO sensor enabled us to evaluate if nebivolol induces/or not the release of NO in denuded renal arteries. The results of this study show that nebivolol exerts vasodilator effects on the SMC in the denuded renal arteries and the maximal response is achieved at a concentration of 50 micromol/l. Nebivolol effects involve binding to the beta(2)-adrenoceptors and the subsequent activation of Ca(2+)-activated K(+) channels in SMC, with no contribution of NO. Taken together, the study brings new insights into the mechanism underlying the nebivolol-induced arterial vasodilation.
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Affiliation(s)
- A Georgescu
- University of Bucharest, Faculty of Biology, Bucharest, Romania. adriana.georgescu@ icbp.ro
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Vascular large conductance calcium-activated potassium channels: functional role and therapeutic potential. Naunyn Schmiedebergs Arch Pharmacol 2007; 376:145-55. [PMID: 17932654 DOI: 10.1007/s00210-007-0193-3] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2007] [Accepted: 09/19/2007] [Indexed: 12/22/2022]
Abstract
Large-conductance Ca2+-activated K+ channels (BK Ca or maxiK channels) are expressed in different cell types. They play an essential role in the regulation of various cell functions. In particular, BK Ca channels have been extensively studied in vascular smooth muscle cells, where they contribute to the control of vascular tone. They facilitate the feedback regulation against the rise of intracellular Ca2+, membrane depolarization and vasoconstriction. BK Ca channels promote a K+ outward current and lead to membrane hyperpolarization. In endothelial cells expression and function of BK Ca channels play an important role in the regulation of the vascular smooth muscle activity. Endothelial BK Ca channels modulate the biosyntheses and release of various vasoactive modulators and regulate the membrane potential. Because of their regulatory role in vascular tone, endothelial BK Ca channels have been suggested as therapeutic targets for the treatment of cardiovascular diseases. Hypertension, atherosclerosis, and diabetes are associated with altered current amplitude, open probability, and Ca2+-sensing of BK Ca channels. The properties of BK Ca channels and their role in endothelial and vascular smooth muscle cells would address them as potential therapeutic targets. Further studies are necessary to identify the detailed molecular mechanisms of action and to investigate selective BK Ca channels openers as possible therapeutic agents for clinical use.
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Bae YM, Kim A, Lee YJ, Lim W, Noh YH, Kim EJ, Kim J, Kim TK, Park SW, Kim B, Cho SI, Kim DK, Ho WK. Enhancement of receptor-operated cation current and TRPC6 expression in arterial smooth muscle cells of deoxycorticosterone acetate-salt hypertensive rats. J Hypertens 2007; 25:809-17. [PMID: 17351373 DOI: 10.1097/hjh.0b013e3280148312] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES In deoxycorticosterone acetate (DOCA)-salt hypertensive rats, altered reactivity of blood vessels to vasoactive agonists is frequently associated with an elevation in blood pressure. Canonical transient receptor potential (TRPC) channels are believed to encode receptor-operated cation channels (ROC), the activation of which is involved in smooth muscle depolarization and vasoconstriction. The aims of the present study were to investigate whether the ROC current is increased in DOCA-hypertensive rats and determine whether aldosterone directly enhances the expression of TRPC. METHODS The nystatin-perforated patch-clamp technique was used for the recording of receptor-stimulated ion currents in mesenteric arterial smooth muscle cells, which were enzymatically dispersed from sham-operated and DOCA-salt hypertensive rats. Expressions of TRPCs were evaluated by reverse transcriptase-polymerase chain reaction (RT-PCR) and by Western blot analysis. RESULTS Receptor-stimulated currents activated by 5-hydroxytryptamine (serotonin) and norepinephrine were increased significantly in the mesenteric arterial smooth muscle cells of DOCA-salt hypertensive rats compared to sham-operated rats. Ion-substitution experiments revealed that the enhanced currents were cation currents (ROC currents). Enhanced expression of TRPC6 in mesenteric arteries from DOCA-salt hypertensive rats was demonstrated by real-time RT-PCR. Up-regulation of TRPC6 by aldosterone treatment in vitro was also observed in A7r5 cells by RT-PCR and in western blots. CONCLUSION These results suggest that aldosterone enhances TRPC6 expression and ROC currents in vascular smooth muscle cells, and that this may in turn contribute to altered vascular reactivity and to hypertension.
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MESH Headings
- Aldosterone/pharmacology
- Animals
- Aorta/cytology
- Arteries/cytology
- Blood Pressure/drug effects
- Blotting, Western
- Calcium Channels/biosynthesis
- Calcium Channels/drug effects
- Desoxycorticosterone
- Disease Models, Animal
- Hypertension/chemically induced
- Hypertension/metabolism
- Hypertension/physiopathology
- Mesenteric Artery, Superior/cytology
- Muscle, Smooth, Vascular/cytology
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Norepinephrine/pharmacology
- Potassium Channels, Calcium-Activated/drug effects
- Potassium Channels, Calcium-Activated/metabolism
- RNA, Messenger/drug effects
- RNA, Messenger/metabolism
- Rats
- Reverse Transcriptase Polymerase Chain Reaction
- Serotonin/pharmacology
- Serotonin Agents/pharmacology
- TRPC Cation Channels/biosynthesis
- TRPC Cation Channels/drug effects
- Up-Regulation/drug effects
- Vasoconstrictor Agents/pharmacology
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Affiliation(s)
- Young Min Bae
- Artificial Muscle Research Center, Departments of Physiology, College of Medicine, Konkuk University, Choongju, Korea
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Sonkusare S, Fraer M, Marsh JD, Rusch NJ. Disrupting calcium channel expression to lower blood pressure: new targeting of a well-known channel. Mol Interv 2007; 6:304-10. [PMID: 17200457 PMCID: PMC4917382 DOI: 10.1124/mi.6.6.3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Swapnil Sonkusare
- Department of Pharmacology & Toxicology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR 72205-7199, USA.
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Sonkusare S, Palade PT, Marsh JD, Telemaque S, Pesic A, Rusch NJ. Vascular calcium channels and high blood pressure: pathophysiology and therapeutic implications. Vascul Pharmacol 2006; 44:131-42. [PMID: 16427812 PMCID: PMC4917380 DOI: 10.1016/j.vph.2005.10.005] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2005] [Accepted: 10/05/2005] [Indexed: 10/25/2022]
Abstract
Long-lasting Ca(2+) (Ca(L)) channels of the Ca(v)1.2 gene family are heteromultimeric structures that are minimally composed of a pore-forming alpha(1C) subunit and regulatory beta and alpha(2)delta subunits in vascular smooth muscle cells. The Ca(L) channels are the primary pathways for voltage-gated Ca(2+) influx that trigger excitation-contraction coupling in small resistance vessels. Notably, vascular smooth muscle cells of hypertensive rats show an increased expression of Ca(L) channel alpha(1C) subunits, which is associated with elevated Ca(2+) influx and the development of abnormal arterial tone. Indeed, blood pressure per se appears to promote Ca(L) channel expression in small arteries, and even short-term rises in pressure may alter channel expression. Membrane depolarization has been shown to be one stimulus associated with elevated blood pressure that promotes Ca(L) channel expression at the plasma membrane. Future studies to define the molecular processes that regulate Ca(L) channel expression in vascular smooth muscle cells will provide a rational basis for designing antihypertensive therapies to normalize Ca(L) channel expression and the development of anomalous vascular tone in hypertensive pathologies.
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Affiliation(s)
- Swapnil Sonkusare
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences, 4301 West Markham Street, #611 Little Rock, AR 72205-7199, United States
| | - Philip T. Palade
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences, 4301 West Markham Street, #611 Little Rock, AR 72205-7199, United States
| | - James D. Marsh
- Department of Internal Medicine, College of Medicine, University of Arkansas for Medical Sciences, 4301 West Markham Street, Little Rock, AR 72205-7199, United States
| | - Sabine Telemaque
- Department of Internal Medicine, College of Medicine, University of Arkansas for Medical Sciences, 4301 West Markham Street, Little Rock, AR 72205-7199, United States
| | - Aleksandra Pesic
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences, 4301 West Markham Street, #611 Little Rock, AR 72205-7199, United States
| | - Nancy J. Rusch
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences, 4301 West Markham Street, #611 Little Rock, AR 72205-7199, United States
- Corresponding author. Tel.: +1 501 686 8038; fax: +1 501 686 5521. (N.J. Rusch)
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Bratz IN, Swafford AN, Kanagy NL, Dick GM. Reduced functional expression of K+channels in vascular smooth muscle cells from rats made hypertensive withNω-nitro-l-arginine. Am J Physiol Heart Circ Physiol 2005; 289:H1284-90. [PMID: 15879481 DOI: 10.1152/ajpheart.01053.2004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Smooth muscle membrane potential is determined, in part, by K+channels. In the companion paper to this article (Bratz IN, Dick GM, Partridge LD, and Kanagy NL. Am J Physiol Heart Circ Physiol 289: H1277–H1283, 2005), we demonstrated that superior mesenteric arteries from rats made hypertensive with Nω-nitro-l-arginine (l-NNA) are depolarized and express less K+channel protein compared with those from normotensive rats. In the present study, we used patch-clamp techniques to test the hypothesis that l-NNA-induced hypertension reduces the functional expression of K+channels in smooth muscle. In whole cell experiments using a Ca2+-free pipette solution, current at 0 mV, largely due to voltage-dependent K+(KV) channels, was reduced ∼60% by hypertension (2.7 ± 0.4 vs. 1.1 ± 0.2 pA/pF). Current at +100 mV with 300 nM free Ca2+, largely due to large-conductance Ca2+-activated K+(BKCa) channels, was reduced ∼40% by hypertension (181 ± 24 vs. 101 ± 28 pA/pF). Current blocked by 3 mM 4-aminopyridine, an inhibitor of many KVchannel types, was reduced ∼50% by hypertension (1.0 ± 0.4 vs. 0.5 ± 0.2 pA/pF). Current blocked by 1 mM tetraethylammonium, an inhibitor of BKCachannels, was reduced ∼40% by hypertension (86 ± 14 vs. 53 ± 19 pA/pF). Differences in BKCacurrent magnitude are not attributable to changes in single-channel conductance or Ca2+/voltage sensitivity. The data support the hypothesis that l-NNA-induced hypertension reduces K+current in vascular smooth muscle. Reduced molecular and functional expression of K+channels may partly explain the depolarization and augmented contractile sensitivity of smooth muscle from l-NNA-treated rats.
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Affiliation(s)
- Ian N Bratz
- Department of Physiology, LSU Health Sciences Center, 1901 Perdido St., New Orleans, LA 70112, USA
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Ghosh M, Hanna ST, Wang R, McNeill JR. Altered vascular reactivity and KATP channel currents in vascular smooth muscle cells from deoxycorticosterone acetate (DOCA)-salt hypertensive rats. J Cardiovasc Pharmacol 2005; 44:525-31. [PMID: 15505488 DOI: 10.1097/00005344-200411000-00003] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
This study was designed to evaluate the contribution of ATP-dependent potassium (KATP) channels to the changes in vascular reactivity and spontaneous tone observed in vessels isolated from deoxycorticosterone acetate (DOCA)-salt hypertensive rats. In phenylephrine preconstricted aortic rings, cromakalim induced concentration-dependent, glibenclamide-sensitive relaxation. The concentration response curve to cromakalim was shifted to the right in DOCA-salt hypertensive rats (EC50: 0.850 +/- 0.100 microM) compared with SHAM-normotensive rats (0.108 +/- 0.005 microM), and the maximum relaxation (Emax) evoked by cromakalim was significantly lower in aortic rings from the DOCA group (68 +/- 2%) compared with the SHAM group (108 +/- 5%). The results were similar in endothelium-denuded rings. Spontaneous tone was observed in aortic rings (5 g preload) from DOCA-salt but not SHAM rats. Cromakalim abolished spontaneous tone and the effect was blocked by glibencamide. In whole cell patch clamp studies, increasing extracellular K concentrations from 5.4 to 140 mM and the administration of cromakalim evoked dramatic increases in KATP channel currents in aortic cells isolated from SHAM rats. In contrast, in aortic cells from DOCA-salt hypertensive rats, KATP channel currents were either absent or weak in response to challenges by elevated extracellular K and by cromakalim. These findings suggest that the function of KATP channels is impaired in smooth muscle cells from aorta of DOCA-salt hypertensive rats, which may contribute to the impaired vasodilatation and spontaneous tone observed in these rats.
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MESH Headings
- Adenosine Triphosphate/pharmacology
- Adenosine Triphosphate/physiology
- Animals
- Aorta, Thoracic/drug effects
- Aorta, Thoracic/injuries
- Aorta, Thoracic/pathology
- Blood Pressure/drug effects
- Canada
- Cromakalim/antagonists & inhibitors
- Cromakalim/pharmacology
- Desoxycorticosterone
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Drug Implants/administration & dosage
- Electrophysiology/methods
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/injuries
- Endothelium, Vascular/pathology
- Glyburide/pharmacology
- Hypertension/chemically induced
- Hypertension/drug therapy
- Hypertension/pathology
- Male
- Membrane Potentials/drug effects
- Membrane Potentials/physiology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/pathology
- Muscle, Smooth, Vascular/physiopathology
- Nephrectomy/methods
- Phenylephrine/antagonists & inhibitors
- Phenylephrine/pharmacology
- Potassium Channels/classification
- Potassium Channels/drug effects
- Potassium Channels/physiology
- Potassium Chloride/metabolism
- Potassium Chloride/pharmacology
- Rats
- Rats, Sprague-Dawley
- Vasoconstriction/drug effects
- Vasoconstriction/physiology
- Vasodilation/drug effects
- Vasodilation/physiology
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Affiliation(s)
- Mahua Ghosh
- Department of Pharmacology, University of Saskatchewan, Saskatoon, Canada
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Bratz IN, Dick GM, Partridge LD, Kanagy NL. Reduced molecular expression of K(+) channel proteins in vascular smooth muscle from rats made hypertensive with N{omega}-nitro-L-arginine. Am J Physiol Heart Circ Physiol 2005; 289:H1277-83. [PMID: 15792990 DOI: 10.1152/ajpheart.01052.2004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Smooth muscle membrane potential (E(m)) depends on K(+) channels, and arteries from rats made hypertensive with N(omega)-nitro-l-arginine (LHR) are depolarized compared with control. We hypothesized that decreased K(+) channel function, due to decreased K(+) channel protein expression, underlies E(m) depolarization. Furthermore, K(+) channel blockers should move control E(m) (-46 +/- 1 mV) toward that in LHR (-37 +/- 2 mV) and normalize contraction. The E(m) vs. K(+) relationship was less steep in LHR (23 +/- 2 vs. 28 +/- 1 mV/log K(+) concentration), and contractile sensitivity to K(+) was increased (EC(50) = 37 +/- 1 vs. 23 +/- 1 mM). Iberiotoxin (10 nM), an inhibitor of large-conductance Ca(2+)-activated K(+) (BK(Ca)) channels, depolarized control and LHR E(m) to -35 +/- 1 and -30 +/- 2 mV, respectively; however, effects on K(+) sensitivity were more profound in LHR (EC(50) = 25 +/- 2 vs. 15 +/- 3 mM). The voltage-dependent K(+) (K(V)) channel blocker 4-aminopyridine (3 mM) depolarized control E(m) to the level of LHR (-28 +/- 1 vs. -28 +/- 1 mV); however, effects on K(+) sensitivity were greater in LHR (EC(50) = 17 +/- 4 vs. 4 +/- 4 mM). Western blots revealed reduced BK(Ca) and K(V)1.5 channel expression in LHR arteries. The findings suggest that diminished expression of K(+) channels contributes to depolarization and enhanced contractile sensitivity. These conclusions are supported by direct electrophysiological assessment of BK(Ca) and K(V) channel function in control and LHR smooth muscle cells.
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Affiliation(s)
- Ian N Bratz
- Department of Physiology, LSU Health Sciences Center, 1901 Perdido St., New Orleans, LA 70112, USA
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