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El-Lakany MA, Haghbin N, Arora N, Hashad AM, Mironova GY, Sancho M, Gros R, Welsh DG. Ca V3.1 channels facilitate calcium wave generation and myogenic tone development in mouse mesenteric arteries. Sci Rep 2023; 13:20407. [PMID: 37989780 PMCID: PMC10663617 DOI: 10.1038/s41598-023-47715-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 11/17/2023] [Indexed: 11/23/2023] Open
Abstract
The arterial myogenic response to intraluminal pressure elicits constriction to maintain tissue perfusion. Smooth muscle [Ca2+] is a key determinant of constriction, tied to L-type (CaV1.2) Ca2+ channels. While important, other Ca2+ channels, particularly T-type could contribute to pressure regulation within defined voltage ranges. This study examined the role of one T-type Ca2+ channel (CaV3.1) using C57BL/6 wild type and CaV3.1-/- mice. Patch-clamp electrophysiology, pressure myography, blood pressure and Ca2+ imaging defined the CaV3.1-/- phenotype relative to C57BL/6. CaV3.1-/- mice had absent CaV3.1 expression and whole-cell current, coinciding with lower blood pressure and reduced mesenteric artery myogenic tone, particularly at lower pressures (20-60 mmHg) where membrane potential is hyperpolarized. This reduction coincided with diminished Ca2+ wave generation, asynchronous events of Ca2+ release from the sarcoplasmic reticulum, insensitive to L-type Ca2+ channel blockade (Nifedipine, 0.3 µM). Proximity ligation assay (PLA) confirmed IP3R1/CaV3.1 close physical association. IP3R blockade (2-APB, 50 µM or xestospongin C, 3 µM) in nifedipine-treated C57BL/6 arteries rendered a CaV3.1-/- contractile phenotype. Findings indicate that Ca2+ influx through CaV3.1 contributes to myogenic tone at hyperpolarized voltages through Ca2+-induced Ca2+ release tied to the sarcoplasmic reticulum. This study helps establish CaV3.1 as a potential therapeutic target to control blood pressure.
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Affiliation(s)
- Mohammed A El-Lakany
- Department of Physiology & Pharmacology, Schulich School of Medicine, Robarts Research Institute, University of Western Ontario, 1151 Richmond Road N, London, ON, N6A 5B7, Canada.
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt.
| | - Nadia Haghbin
- Department of Physiology & Pharmacology, Schulich School of Medicine, Robarts Research Institute, University of Western Ontario, 1151 Richmond Road N, London, ON, N6A 5B7, Canada
| | - Naman Arora
- Department of Physiology & Pharmacology, Schulich School of Medicine, Robarts Research Institute, University of Western Ontario, 1151 Richmond Road N, London, ON, N6A 5B7, Canada
| | - Ahmed M Hashad
- Department of Physiology & Pharmacology, Schulich School of Medicine, Robarts Research Institute, University of Western Ontario, 1151 Richmond Road N, London, ON, N6A 5B7, Canada
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt
| | - Galina Yu Mironova
- Department of Physiology & Pharmacology, Schulich School of Medicine, Robarts Research Institute, University of Western Ontario, 1151 Richmond Road N, London, ON, N6A 5B7, Canada
| | - Maria Sancho
- Department of Physiology, Faculty of Medicine, Complutense University of Madrid, Madrid, Spain
| | - Robert Gros
- Department of Physiology & Pharmacology, Schulich School of Medicine, Robarts Research Institute, University of Western Ontario, 1151 Richmond Road N, London, ON, N6A 5B7, Canada
| | - Donald G Welsh
- Department of Physiology & Pharmacology, Schulich School of Medicine, Robarts Research Institute, University of Western Ontario, 1151 Richmond Road N, London, ON, N6A 5B7, Canada.
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Liu J, Li X, Xu N, Han H, Li X. Role of ion channels in the mechanism of proteinuria (Review). Exp Ther Med 2022; 25:27. [PMID: 36561615 PMCID: PMC9748662 DOI: 10.3892/etm.2022.11726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 10/10/2022] [Indexed: 11/25/2022] Open
Abstract
Proteinuria is a common clinical manifestation of kidney diseases, such as glomerulonephritis, nephrotic syndrome, immunoglobulin A nephropathy and diabetic nephropathy. Therefore, proteinuria is considered to be a risk factor for renal dysfunction. Furthermore, proteinuria is also significantly associated with the progression of kidney diseases and increased mortality. Its occurrence is closely associated with damage to the structure of the glomerular filtration membrane. An impaired glomerular filtration membrane can affect the selective filtration function of the kidneys; therefore, several macromolecular substances, such as proteins, may pass through the filtration membrane and promote the manifestation of proteinuria. It has been reported that ion channels play a significant role in the mechanisms underlying proteinuria. Ion channel mutations or other dysfunctions have been implicated in several diseases, therefore ion channels could be used as major therapeutic targets. The mechanisms underlying the action of ion channels and ion transporters in proteinuria have been overlooked in the literature, despite their importance in identifying novel targets for treating proteinuria and delaying the progression of kidney diseases. The current review article focused on the four key ion channel groups, namely Na+, Ca2+, Cl- and K+ ion channels and the associated ion transporters.
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Affiliation(s)
- Jie Liu
- Department of Nephrology, Affiliated Hospital of Weifang Medical University, Weifang, Shandong 261000, P.R. China
| | - Xuewei Li
- Department of Rheumatology, Affiliated Hospital of Weifang Medical University, Weifang, Shandong 261000, P.R. China
| | - Ning Xu
- Department of Nephrology, Affiliated Hospital of Weifang Medical University, Weifang, Shandong 261000, P.R. China
| | - Huirong Han
- Department of Anesthesiology, Weifang Medical University, Weifang, Shandong 261000, P.R. China
| | - Xiangling Li
- Department of Nephrology, Affiliated Hospital of Weifang Medical University, Weifang, Shandong 261000, P.R. China,Correspondence to: Professor Xiangling Li, Department of Nephrology, Affiliated Hospital of Weifang Medical University, 2428 Yu He Road, Weifang, Shandong 261000, P.R. China
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3
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Zhou HF, Li WY, Peng LY, Li XN, Zuo ZL, Zhao QS. Rhynchines A-E: Ca v3.1 Calcium Channel Blockers from Uncaria rhynchophylla. Org Lett 2021; 23:9463-9467. [PMID: 34818888 DOI: 10.1021/acs.orglett.1c03641] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Rhynchines A-E (1-5), five new indole alkaloids with an unprecedented skeleton, were isolated from Uncaria rhynchophylla. The new skeleton was characterized by an indole moiety and a 2-oxa-8-azatricyclo[6,5,01,5,01,8]tridecane core, forming a unique 6/5/7/5/5 ring system. Their structures were determined by nuclear magnetic resonance, high-resolution electrospray ionization mass spectrometry, infrared spectroscopy, and calculated electronic circular dichroism (ECD) and were confirmed by X-ray crystallography. Interestingly, 1 and 2 showed strong inhibitory activities against the Cav3.1 calcium channel with IC50 values of 6.86 and 10.41 μM.
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Affiliation(s)
- Hao-Feng Zhou
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, People's Republic of China.,University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Wen-Yan Li
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, People's Republic of China
| | - Li-Yan Peng
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, People's Republic of China
| | - Xiao-Nian Li
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, People's Republic of China
| | - Zhi-Li Zuo
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, People's Republic of China.,University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Qin-Shi Zhao
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, People's Republic of China.,University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
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4
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Calcium channel blocker in patients with chronic kidney disease. Clin Exp Nephrol 2021; 26:207-215. [PMID: 34748113 PMCID: PMC8847284 DOI: 10.1007/s10157-021-02153-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Accepted: 10/24/2021] [Indexed: 10/26/2022]
Abstract
BACKGROUND Chronic kidney disease (CKD) is involved in a progressive deterioration in renal function over the years and is now a global public health problem. Currently, reducing the number of patients progressing to end-stage renal failure is urgently necessary. Hypertension and CKD interact with each other, and good control of blood pressure (BP) can improve CKD patients' prognosis. With the current global trend for more strict BP control, the importance of BP management and the need for medication to achieve this strict goal are increasing. Calcium channel blockers (CCBs), which target voltage-dependent calcium channels, are frequently used in combination with renin-angiotensin-aldosterone system inhibitors for CKD patients because of their strong BP-lowering properties and relatively few adverse side effects. Calcium channels have several subtypes, including L, N, T, P/Q, and R, and three types of CCBs, L-type CCBs, L-/T-type CCBs, and L-/N-type CCBs, that are available. Nowadays, the new functions and effects of the CCBs are being elucidated. CONCLUSION We should use different types of CCBs properly depending on their pharmacological effects, such as the strength of antihypertensive effects and the organ protection effects, taking into account the pathophysiology of the patients. In this article, the role and the use of CCBs in CKD patients are reviewed.
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K 2P2.1 (TREK-1) potassium channel activation protects against hyperoxia-induced lung injury. Sci Rep 2020; 10:22011. [PMID: 33319831 PMCID: PMC7738539 DOI: 10.1038/s41598-020-78886-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 12/01/2020] [Indexed: 12/20/2022] Open
Abstract
No targeted therapies exist to counteract Hyperoxia (HO)-induced Acute Lung Injury (HALI). We previously found that HO downregulates alveolar K2P2.1 (TREK-1) K+ channels, which results in worsening lung injury. This decrease in TREK-1 levels leaves a subset of channels amendable to pharmacological intervention. Therefore, we hypothesized that TREK-1 activation protects against HALI. We treated HO-exposed mice and primary alveolar epithelial cells (AECs) with the novel TREK-1 activators ML335 and BL1249, and quantified physiological, histological, and biochemical lung injury markers. We determined the effects of these drugs on epithelial TREK-1 currents, plasma membrane potential (Em), and intracellular Ca2+ (iCa) concentrations using fluorometric assays, and blocked voltage-gated Ca2+ channels (CaV) as a downstream mechanism of cytokine secretion. Once-daily, intra-tracheal injections of HO-exposed mice with ML335 or BL1249 improved lung compliance, histological lung injury scores, broncho-alveolar lavage protein levels and cell counts, and IL-6 and IP-10 concentrations. TREK-1 activation also decreased IL-6, IP-10, and CCL-2 secretion from primary AECs. Mechanistically, ML335 and BL1249 induced TREK-1 currents in AECs, counteracted HO-induced cell depolarization, and lowered iCa2+ concentrations. In addition, CCL-2 secretion was decreased after L-type CaV inhibition. Therefore, Em stabilization with TREK-1 activators may represent a novel approach to counteract HALI.
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DEMİRTAŞ ŞAHİN T, UTKAN T, KARSON A, YAZIR Y, KARAOZ E. Genetik absans epilepsili WAG/Rij sıçanlarda kardiyovasküler değişiklikler: Kronik etosüksimid tedavisinin etkileri. CUKUROVA MEDICAL JOURNAL 2020. [DOI: 10.17826/cumj.724491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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7
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Jensen EP, Møller S, Hviid AV, Veedfald S, Holst JJ, Pedersen J, Ørskov C, Sorensen CM. GLP-1-induced renal vasodilation in rodents depends exclusively on the known GLP-1 receptor and is lost in prehypertensive rats. Am J Physiol Renal Physiol 2020; 318:F1409-F1417. [PMID: 32390511 DOI: 10.1152/ajprenal.00579.2019] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Glucagon-like peptide-1 (GLP-1) is an incretin hormone known to stimulate postprandial insulin release. However, GLP-1 also exerts extrapancreatic effects, including renal effects. Some of these renal effects are attenuated in hypertensive rats, where renal expression of GLP-1 receptors is reduced. Here, we assessed the expression and vascular function of GLP-1 receptors in kidneys from young prehypertensive rats. We also examined GLP-1-induced vasodilation in the renal vasculature in wild-type (WT) and GLP-1 receptor knockout mice using wire and pressure myography and the isolated perfused juxtamedullary nephron preparation. We investigated whether GLP-1 and the metabolite GLP-1(9-36)amide had renal vascular effects independent of the known GLP-1 receptor. We hypothesized that hypertension decreased expression of renal GLP-1 receptors. We also hypothesized that GLP-1-induced renal vasodilatation depended on expression of the known GLP-1 receptor. In contrast to normotensive rats, no immunohistochemical staining or vasodilatory function of GLP-1 receptors was found in kidneys from prehypertensive rats. In WT mice, GLP-1 induced renal vasodilation and reduced the renal autoregulatory response. The GLP-1 receptor antagonist exendin 9-39 inhibited relaxation, and GLP-1(9-36)amide had no vasodilatory effect. In GLP-1 receptor knockout mice, no relaxation induced by GLP-1 or GLP-1(9-36)amide was found, the autoregulatory response in afferent arterioles was normal, and no GLP-1-induced reduction of autoregulation was found. We conclude that in prehypertensive kidneys, expression and function of GLP-1 receptors is lost. The renal vasodilatory effect of GLP-1 is mediated exclusively by the known GLP-1 receptor. GLP-1(9-36)amide has no renal vasodilatory effect. GLP-1 attenuates renal autoregulation by reducing the myogenic response.
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Affiliation(s)
- Elisa P Jensen
- NNF Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sophie Møller
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Aleksander Vauvert Hviid
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Simon Veedfald
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens J Holst
- NNF Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens Pedersen
- NNF Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Cathrine Ørskov
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Charlotte M Sorensen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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8
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Huang L, Chu Y, Huang X, Ma S, Lin K, Huang K, Sun H, Yang Z. Association between gene polymorphisms of voltage-dependent Ca 2+ channels and hypertension in the Dai people of China: a case-control study. BMC MEDICAL GENETICS 2020; 21:44. [PMID: 32111194 PMCID: PMC7049211 DOI: 10.1186/s12881-020-0982-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 02/20/2020] [Indexed: 12/24/2022]
Abstract
BACKGROUND Abnormal calcium homeostasis related to the development of hypertension. As the key regulator of intracellular calcium concentration, voltage-dependent calcium channels (VDCCs), the variations in these genes may have important effects on the development of hypertension. Here we evaluate VDCCs variability with respect to hypertension in the Dai ethnic group of China. METHODS A total of 1034 samples from Dai individuals were collected, of which 495 were used as cases, and 539 were used as controls. Blood pressure was measured using a standard mercury measurement method, three times with a rest for 5 min, and the average was used for analyses. Seventeen single nucleotide polymorphisms (SNPs) in the four protein-coding genes (CACNA1A, CACNA1C, CACNA1S, CACNB2) of VDCCs were identified by multiplex PCR-SNP typing technique. Chi-square tests and regression models were used to analyse the associations of SNPs with hypertension. RESULTS The results of chi-square tests showed that the allele frequencies of 5 SNPs were significantly different between the case and the control groups (P < 0.05), but the statistical significance was lost after Bonferroni's correction. However, after adjusting for BMI, age, sex and other factors by logistic regression analyses, the results showed that 5 SNPs consistent with chi-square tests (rs2365293, rs17539088, rs16917217, rs61839222 and rs10425859) were still statistically positive. CONCLUSIONS This finding suggested that the significant association of these SNPs with hypertension may be noteworthy in future studies.
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Affiliation(s)
- Lifan Huang
- Institute of Medical Biology Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming, China
| | - Yan Chu
- Department of General Surgery of the 2nd People Hospital of Yunnan Province, Kunming, China
| | - Xiaoqin Huang
- Institute of Medical Biology Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming, China
| | - Shaohui Ma
- Institute of Medical Biology Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming, China
| | - Keqin Lin
- Institute of Medical Biology Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming, China
| | - Kai Huang
- Institute of Medical Biology Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming, China
| | - Hao Sun
- Institute of Medical Biology Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming, China.
| | - Zhaoqing Yang
- Institute of Medical Biology Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming, China.
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9
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Thuesen AD, Finsen SH, Rasmussen LL, Andersen DC, Jensen BL, Hansen PBL. Deficiency of T-type Ca 2+ channels Ca v3.1 and Ca v3.2 has no effect on angiotensin II-induced hypertension but differential effect on plasma aldosterone in mice. Am J Physiol Renal Physiol 2019; 317:F254-F263. [PMID: 31042060 DOI: 10.1152/ajprenal.00121.2018] [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] [Indexed: 01/18/2023] Open
Abstract
T-type Ca2+ channel Cav3.1 promotes microvessel contraction ex vivo. It was hypothesized that in vivo, functional deletion of Cav3.1, but not Cav3.2, protects mice against angiotensin II (ANG II)-induced hypertension. Mean arterial blood pressure (MAP) and heart rate were measured continuously with chronically indwelling catheters during infusion of ANG II (30 ng·kg-1·min-1, 7 days) in wild-type (WT), Cav3.1-/-, and Cav3.2-/- mice. Plasma aldosterone and renin concentrations were measured by radioimmunoassays. In a separate series, WT mice were infused with ANG II (100 ng·kg-1·min-1) with and without the mineralocorticoid receptor blocker canrenoate. Cav3.1-/- and Cav3.2-/- mice exhibited no baseline difference in MAP compared with WT mice, but day-night variation was blunted in both Cav3.1 and Cav3.2-/- mice. ANG II increased significantly MAP in WT, Cav3.1-/-, and Cav3.2-/- mice with no differences between genotypes. Heart rate was significantly lower in Cav3.1-/- and Cav3.2-/- mice compared with control mice. After ANG II infusion, plasma aldosterone concentration was significantly lower in Cav3.1-/- compared with Cav3.2-/- mice. In response to ANG II, fibrosis was observed in heart sections from both WT and Cav3.1-/- mice and while cardiac atrial natriuretic peptide mRNA was similar, the brain natriuretic peptide mRNA increase was mitigated in Cav3.1-/- mice ANG II at 100 ng/kg yielded elevated pressure and an increased heart weight-to-body weight ratio in WT mice. Cardiac hypertrophy, but not hypertension, was prevented by the mineralocorticoid receptor blocker canrenoate. In conclusion, T-type channels Cav3.1and Cav3.2 do not contribute to baseline blood pressure levels and ANG II-induced hypertension. Cav3.1, but not Cav3.2, contributes to aldosterone secretion. Aldosterone promotes cardiac hypertrophy during hypertension.
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Affiliation(s)
- Anne D Thuesen
- Department of Cardiovascular and Renal Research, University of Southern Denmark , Odense , Denmark
| | - Stine H Finsen
- Department of Cardiovascular and Renal Research, University of Southern Denmark , Odense , Denmark
| | - Louise L Rasmussen
- Department of Cardiovascular and Renal Research, University of Southern Denmark , Odense , Denmark
| | - Ditte C Andersen
- Department of Cardiovascular and Renal Research, University of Southern Denmark , Odense , Denmark.,Laboratory of Molecular and Cellular Cardiology, Department of Clinical Biochemistry and Pharmacology, Odense University Hospital , Odense , Denmark.,Clinical Institute, University of Southern Denmark , Odense , Denmark
| | - Boye L Jensen
- Department of Cardiovascular and Renal Research, University of Southern Denmark , Odense , Denmark
| | - Pernille B L Hansen
- Department of Cardiovascular and Renal Research, University of Southern Denmark , Odense , Denmark.,Cardiovascular and Metabolic Disease, Innovative Medicines and Early Development Biotech Unit, AstraZeneca, Gothenburg , Sweden
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10
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Thuesen AD, Andersen K, Lyngsø KS, Burton M, Brasch-Andersen C, Vanhoutte PM, Hansen PBL. Deletion of T-type calcium channels Cav3.1 or Cav3.2 attenuates endothelial dysfunction in aging mice. Pflugers Arch 2017; 470:355-365. [DOI: 10.1007/s00424-017-2068-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 09/10/2017] [Accepted: 09/13/2017] [Indexed: 12/26/2022]
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11
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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: 212] [Impact Index Per Article: 30.3] [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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12
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Thuesen AD, Lyngsø KS, Rasmussen L, Stubbe J, Skøtt O, Poulsen FR, Pedersen CB, Rasmussen LM, Hansen PBL. P/Q-type and T-type voltage-gated calcium channels are involved in the contraction of mammary and brain blood vessels from hypertensive patients. Acta Physiol (Oxf) 2017; 219:640-651. [PMID: 27273014 DOI: 10.1111/apha.12732] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 03/21/2016] [Accepted: 06/01/2016] [Indexed: 12/12/2022]
Abstract
AIM Calcium channel blockers are widely used in cardiovascular diseases. Besides L-type channels, T- and P/Q-type calcium channels are involved in the contraction of human renal blood vessels. It was hypothesized that T- and P/Q-type channels are involved in the contraction of human brain and mammary blood vessels. METHODS Internal mammary arteries from bypass surgery patients and cerebral arterioles from patients with brain tumours with and without hypertension were tested in a myograph and perfusion set-up. PCR and immunohistochemistry were performed on isolated blood vessels. RESULTS The P/Q-type antagonist ω-agatoxin IVA (10-8 mol L-1 ) and the T-type calcium blocker mibefradil (10-7 mol L-1 ) inhibited KCl depolarization-induced contraction in mammary arteries from hypertensive patients with no effect on blood vessels from normotensive patients. ω-Agatoxin IVA decreased contraction in cerebral arterioles from hypertensive patients. L-type blocker nifedipine abolished the contraction in mammary arteries. PCR analysis showed expression of P/Q-type (Cav 2.1), T-type (Cav 3.1 and Cav 3.2) and L-type (Cav 1.2) calcium channels in mammary and cerebral arteries. Immunohistochemical labelling of mammary and cerebral arteries revealed the presence of Cav 2.1 in endothelial and smooth muscle cells. Cav 3.1 was also detected in mammary arteries. CONCLUSION P/Q- and T-type Cav are present in human internal mammary arteries and in cerebral penetrating arterioles. P/Q- and T-type calcium channels are involved in the contraction of mammary arteries from hypertensive patients but not from normotensive patients. Furthermore, in cerebral arterioles P/Q-type channels importance was restricted to hypertensive patients might lead to that T- and P/Q-type channels could be a new target in hypertensive patients.
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Affiliation(s)
- A. D. Thuesen
- Department of Cardiovascular and Renal Research; Institute of Molecular Medicine; University of Southern Denmark; Odense Denmark
| | - K. S. Lyngsø
- Department of Cardiovascular and Renal Research; Institute of Molecular Medicine; University of Southern Denmark; Odense Denmark
| | - L. Rasmussen
- Department of Cardiovascular and Renal Research; Institute of Molecular Medicine; University of Southern Denmark; Odense Denmark
| | - J. Stubbe
- Department of Cardiovascular and Renal Research; Institute of Molecular Medicine; University of Southern Denmark; Odense Denmark
| | - O. Skøtt
- Department of Cardiovascular and Renal Research; Institute of Molecular Medicine; University of Southern Denmark; Odense Denmark
| | - F. R. Poulsen
- Department of Neurosurgery; Odense University Hospital; Odense Denmark
- Clinical Institute; University of Southern Denmark; Odense Denmark
| | - C. B. Pedersen
- Department of Neurosurgery; Odense University Hospital; Odense Denmark
| | - L. M. Rasmussen
- Clinical Institute; University of Southern Denmark; Odense Denmark
- Department of Clinical Biochemistry and Pharmacology; Centre for Individualized Medicine in Arterial Diseases; Odense University Hospital; Odense Denmark
| | - P. B. L. Hansen
- Department of Cardiovascular and Renal Research; Institute of Molecular Medicine; University of Southern Denmark; Odense Denmark
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13
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Tamargo J, Ruilope LM. Investigational calcium channel blockers for the treatment of hypertension. Expert Opin Investig Drugs 2016; 25:1295-1309. [DOI: 10.1080/13543784.2016.1241764] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- J Tamargo
- Department of Pharmacology, School of Medicine, Instituto de Investigación Sanitaria Gregorio Marañón, Universidad Complutense, Madrid, Spain. CIBER of Cardiovascular Diseases
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14
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Zhou Y, Greka A. Calcium-permeable ion channels in the kidney. Am J Physiol Renal Physiol 2016; 310:F1157-67. [PMID: 27029425 DOI: 10.1152/ajprenal.00117.2016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 03/29/2016] [Indexed: 02/07/2023] Open
Abstract
Calcium ions (Ca(2+)) are crucial for a variety of cellular functions. The extracellular and intracellular Ca(2+) concentrations are thus tightly regulated to maintain Ca(2+) homeostasis. The kidney, one of the major organs of the excretory system, regulates Ca(2+) homeostasis by filtration and reabsorption. Approximately 60% of the Ca(2+) in plasma is filtered, and 99% of that is reabsorbed by the kidney tubules. Ca(2+) is also a critical signaling molecule in kidney development, in all kidney cellular functions, and in the emergence of kidney diseases. Recently, studies using genetic and molecular biological approaches have identified several Ca(2+)-permeable ion channel families as important regulators of Ca(2+) homeostasis in kidney. These ion channel families include transient receptor potential channels (TRP), voltage-gated calcium channels, and others. In this review, we provide a brief and systematic summary of the expression, function, and pathological contribution for each of these Ca(2+)-permeable ion channels. Moreover, we discuss their potential as future therapeutic targets.
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Affiliation(s)
- Yiming Zhou
- Department of Medicine and Glom-NExT Center for Glomerular Kidney Disease and Novel Experimental Therapeutics, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts; and
| | - Anna Greka
- Department of Medicine and Glom-NExT Center for Glomerular Kidney Disease and Novel Experimental Therapeutics, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts; and The Broad Institute of MIT and Harvard, Cambridge, Massachusetts
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15
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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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16
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17
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Abstract
Intrarenal autoregulatory mechanisms maintain renal blood flow (RBF) and glomerular filtration rate (GFR) independent of renal perfusion pressure (RPP) over a defined range (80-180 mmHg). Such autoregulation is mediated largely by the myogenic and the macula densa-tubuloglomerular feedback (MD-TGF) responses that regulate preglomerular vasomotor tone primarily of the afferent arteriole. Differences in response times allow separation of these mechanisms in the time and frequency domains. Mechanotransduction initiating the myogenic response requires a sensing mechanism activated by stretch of vascular smooth muscle cells (VSMCs) and coupled to intracellular signaling pathways eliciting plasma membrane depolarization and a rise in cytosolic free calcium concentration ([Ca(2+)]i). Proposed mechanosensors include epithelial sodium channels (ENaC), integrins, and/or transient receptor potential (TRP) channels. Increased [Ca(2+)]i occurs predominantly by Ca(2+) influx through L-type voltage-operated Ca(2+) channels (VOCC). Increased [Ca(2+)]i activates inositol trisphosphate receptors (IP3R) and ryanodine receptors (RyR) to mobilize Ca(2+) from sarcoplasmic reticular stores. Myogenic vasoconstriction is sustained by increased Ca(2+) sensitivity, mediated by protein kinase C and Rho/Rho-kinase that favors a positive balance between myosin light-chain kinase and phosphatase. Increased RPP activates MD-TGF by transducing a signal of epithelial MD salt reabsorption to adjust afferent arteriolar vasoconstriction. A combination of vascular and tubular mechanisms, novel to the kidney, provides for high autoregulatory efficiency that maintains RBF and GFR, stabilizes sodium excretion, and buffers transmission of RPP to sensitive glomerular capillaries, thereby protecting against hypertensive barotrauma. A unique aspect of the myogenic response in the renal vasculature is modulation of its strength and speed by the MD-TGF and by a connecting tubule glomerular feedback (CT-GF) mechanism. Reactive oxygen species and nitric oxide are modulators of myogenic and MD-TGF mechanisms. Attenuated renal autoregulation contributes to renal damage in many, but not all, models of renal, diabetic, and hypertensive diseases. This review provides a summary of our current knowledge regarding underlying mechanisms enabling renal autoregulation in health and disease and methods used for its study.
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Affiliation(s)
- Mattias Carlström
- Department of Medicine, Division of Nephrology and Hypertension and Hypertension, Kidney and Vascular Research Center, Georgetown University, Washington, District of Columbia; Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden; and Department of Cell Biology and Physiology, UNC Kidney Center, and McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Christopher S Wilcox
- Department of Medicine, Division of Nephrology and Hypertension and Hypertension, Kidney and Vascular Research Center, Georgetown University, Washington, District of Columbia; Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden; and Department of Cell Biology and Physiology, UNC Kidney Center, and McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - William J Arendshorst
- Department of Medicine, Division of Nephrology and Hypertension and Hypertension, Kidney and Vascular Research Center, Georgetown University, Washington, District of Columbia; Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden; and Department of Cell Biology and Physiology, UNC Kidney Center, and McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
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18
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Hansen PBL. Functional importance of T-type voltage-gated calcium channels in the cardiovascular and renal system: news from the world of knockout mice. Am J Physiol Regul Integr Comp Physiol 2015; 308:R227-37. [DOI: 10.1152/ajpregu.00276.2014] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Over the years, it has been discussed whether T-type calcium channels Cav3 play a role in the cardiovascular and renal system. T-type channels have been reported to play an important role in renal hemodynamics, contractility of resistance vessels, and pacemaker activity in the heart. However, the lack of highly specific blockers cast doubt on the conclusions. As new T-type channel antagonists are being designed, the roles of T-type channels in cardiovascular and renal pathology need to be elucidated before T-type blockers can be clinically useful. Two types of T-type channels, Cav3.1 and Cav3.2, are expressed in blood vessels, the kidney, and the heart. Studies with gene-deficient mice have provided a way to investigate the Cav3.1 and Cav3.2 channels and their role in the cardiovascular system. This review discusses the results from these knockout mice. Evaluation of the literature leads to the conclusion that Cav3.1 and Cav3.2 channels have important, but different, functions in mice. T-type Cav3.1 channels affect heart rate, whereas Cav3.2 channels are involved in cardiac hypertrophy. In the vascular system, Cav3.2 activation leads to dilation of blood vessels, whereas Cav3.1 channels are mainly suggested to affect constriction. The Cav3.1 channel is also involved in neointima formation following vascular damage. In the kidney, Cav3.1 regulates plasma flow and Cav3.2 plays a role setting glomerular filtration rate. In conclusion, Cav3.1 and Cav3.2 are new therapeutic targets in several cardiovascular pathologies, but the use of T-type blockers should be specifically directed to the disease and to the channel subtype.
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Affiliation(s)
- Pernille B. L. Hansen
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense C, Denmark
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19
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Eskildsen MP, Hansen PB, Stubbe J, Toft A, Walter S, Marcussen N, Rasmussen LM, Vanhoutte PM, Jensen BL. Prostaglandin I
2
and Prostaglandin E
2
Modulate Human Intrarenal Artery Contractility Through Prostaglandin E2-EP4, Prostacyclin-IP, and Thromboxane A2-TP Receptors. Hypertension 2014; 64:551-6. [DOI: 10.1161/hypertensionaha.113.03051] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cyclooxygenase inhibitors decrease renal blood flow in settings with decreased effective circulating volume. The present study examined the hypothesis that prostaglandins, prostaglandin E
2
(PGE
2
) and prostacyclin (PGI
2
), induce relaxation of human intrarenal arteries through PGE
2
-EP and PGI
2
-IP receptors. Intrarenal arteries were microdissected from human nephrectomy samples (n=53, median diameter ≈362 μm, 88% viable, 76% relaxed in response to acetylcholine). Rings were suspended in myographs to record force development. In vessels with K
+
-induced tension (EC
70
: –log [mol/L]=1.36±0.03), PGE
2
and PGI
2
induced concentration-dependent relaxation (–log EC
50
: PGE
2
=7.1±0.3 and PGI
2
=7.7). The response to PGE
2
displayed endothelium dependence and desensitization. Relaxation by PGE
2
was mimicked by an EP4 receptor agonist (CAY10598, EC
50
=6.7±0.2). The relaxation after PGI
2
was abolished by an IP receptor antagonist (BR5064, 10
–8
mol/L). Pretreatment of quiescent arteries with PGE
2
for 5 minutes (10
–6
mol/L) led to a significant right shift of the concentration–response to norepinephrine (EC
50
from 6.6±0.1–5.9±0.1). In intrarenal arteries with K
+
-induced tone, PGE
2
and PGI
2
at 10
–5
mol/L elicited increased tension. This was abolished by thromboxane receptor (TP) antagonist (S18886, 10
–6
mol/L). A TP agonist (U46619, n=6) evoked tension (EC
50
=8.1±0.2) that was inhibited by S18886. Polymerase chain reaction and immunoblotting showed EP4, IP, and TP receptors in intrarenal arteries. In conclusion, PGE
2
and PGI
2
may protect renal perfusion by activating cognate IP and EP4 receptors associated with smooth muscle cells and endothelium in human intrarenal arteries and contribute to increased renal vascular resistance at high pathological concentrations mediated by noncognate TP receptor.
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Affiliation(s)
- Morten P. Eskildsen
- From the Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense C, Denmark (M.P.E., P.B.L.H., J.S., B.L.J.); State Key Laboratory for Pharmaceutical Biotechnologies and Department of Pharmacology and Pharmacy, University of Hong Kong, Pokfulam, Hong Kong (P.M.V.); and Departments of Urology, Biochemistry and Clinical Pathology, Odense University Hospital, Odense, Denmark (M.P.E., P.B.L.H., J.S., A.T., S.W., N.M., L.M.R.)
| | - Pernille B.L. Hansen
- From the Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense C, Denmark (M.P.E., P.B.L.H., J.S., B.L.J.); State Key Laboratory for Pharmaceutical Biotechnologies and Department of Pharmacology and Pharmacy, University of Hong Kong, Pokfulam, Hong Kong (P.M.V.); and Departments of Urology, Biochemistry and Clinical Pathology, Odense University Hospital, Odense, Denmark (M.P.E., P.B.L.H., J.S., A.T., S.W., N.M., L.M.R.)
| | - Jane Stubbe
- From the Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense C, Denmark (M.P.E., P.B.L.H., J.S., B.L.J.); State Key Laboratory for Pharmaceutical Biotechnologies and Department of Pharmacology and Pharmacy, University of Hong Kong, Pokfulam, Hong Kong (P.M.V.); and Departments of Urology, Biochemistry and Clinical Pathology, Odense University Hospital, Odense, Denmark (M.P.E., P.B.L.H., J.S., A.T., S.W., N.M., L.M.R.)
| | - Anja Toft
- From the Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense C, Denmark (M.P.E., P.B.L.H., J.S., B.L.J.); State Key Laboratory for Pharmaceutical Biotechnologies and Department of Pharmacology and Pharmacy, University of Hong Kong, Pokfulam, Hong Kong (P.M.V.); and Departments of Urology, Biochemistry and Clinical Pathology, Odense University Hospital, Odense, Denmark (M.P.E., P.B.L.H., J.S., A.T., S.W., N.M., L.M.R.)
| | - Steen Walter
- From the Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense C, Denmark (M.P.E., P.B.L.H., J.S., B.L.J.); State Key Laboratory for Pharmaceutical Biotechnologies and Department of Pharmacology and Pharmacy, University of Hong Kong, Pokfulam, Hong Kong (P.M.V.); and Departments of Urology, Biochemistry and Clinical Pathology, Odense University Hospital, Odense, Denmark (M.P.E., P.B.L.H., J.S., A.T., S.W., N.M., L.M.R.)
| | - Niels Marcussen
- From the Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense C, Denmark (M.P.E., P.B.L.H., J.S., B.L.J.); State Key Laboratory for Pharmaceutical Biotechnologies and Department of Pharmacology and Pharmacy, University of Hong Kong, Pokfulam, Hong Kong (P.M.V.); and Departments of Urology, Biochemistry and Clinical Pathology, Odense University Hospital, Odense, Denmark (M.P.E., P.B.L.H., J.S., A.T., S.W., N.M., L.M.R.)
| | - Lars M. Rasmussen
- From the Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense C, Denmark (M.P.E., P.B.L.H., J.S., B.L.J.); State Key Laboratory for Pharmaceutical Biotechnologies and Department of Pharmacology and Pharmacy, University of Hong Kong, Pokfulam, Hong Kong (P.M.V.); and Departments of Urology, Biochemistry and Clinical Pathology, Odense University Hospital, Odense, Denmark (M.P.E., P.B.L.H., J.S., A.T., S.W., N.M., L.M.R.)
| | - Paul M. Vanhoutte
- From the Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense C, Denmark (M.P.E., P.B.L.H., J.S., B.L.J.); State Key Laboratory for Pharmaceutical Biotechnologies and Department of Pharmacology and Pharmacy, University of Hong Kong, Pokfulam, Hong Kong (P.M.V.); and Departments of Urology, Biochemistry and Clinical Pathology, Odense University Hospital, Odense, Denmark (M.P.E., P.B.L.H., J.S., A.T., S.W., N.M., L.M.R.)
| | - Boye L. Jensen
- From the Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense C, Denmark (M.P.E., P.B.L.H., J.S., B.L.J.); State Key Laboratory for Pharmaceutical Biotechnologies and Department of Pharmacology and Pharmacy, University of Hong Kong, Pokfulam, Hong Kong (P.M.V.); and Departments of Urology, Biochemistry and Clinical Pathology, Odense University Hospital, Odense, Denmark (M.P.E., P.B.L.H., J.S., A.T., S.W., N.M., L.M.R.)
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20
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Abstract
PURPOSE OF REVIEW The purpose of this review is to provide an update on the current knowledge regarding the role of the intrarenal rennin-angiotensin system (RAS) in the regulation of glomerular function including glomerular dynamics and filtration rate, glomerular permeability and structural alterations during chronic increases in intrarenal angiotensin (Ang) II. RECENT FINDINGS Recent studies have continued to delineate the complex interactions among the various RAS components that participate in regulating glomerular function. Although Ang II acting on AT1 receptors remains as the predominant influence on glomerular dynamics, some of these effects are indirectly mediated by Ang II modulating the sensitivity of the macula densa tubuloglomerular feedback mechanism as well as the more recently described feedback mechanism from the connecting tubule. Interestingly, the actions of Ang II on these systems cause opposite effects on glomerular function demonstrating the complexities associated with the influences of Ang II on glomerular function. When chronically elevated, Ang II also stimulates and/or interacts with other factors, including reactive oxygen species, cytokines and growth factors and other hormones or paracrine agents, to elicit structural alterations. SUMMARY Recent studies have provided further evidence for the presence of many components of the RAS in glomerular structures, which supports the importance of locally produced angiotensin peptides to regulate glomerular haemodynamics, filtration rate and macromolecular permeability and contribute to fibrosis and glomerular injury when inappropriately augmented.
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21
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Thuesen AD, Andersen H, Cardel M, Toft A, Walter S, Marcussen N, Jensen BL, Bie P, Hansen PBL. Differential effect of T-type voltage-gated Ca2+ channel disruption on renal plasma flow and glomerular filtration rate in vivo. Am J Physiol Renal Physiol 2014; 307:F445-52. [PMID: 24966091 DOI: 10.1152/ajprenal.00016.2014] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Voltage-gated Ca(2+) (Cav) channels play an essential role in the regulation of renal blood flow and glomerular filtration rate (GFR). Because T-type Cav channels are differentially expressed in pre- and postglomerular vessels, it was hypothesized that they impact renal blood flow and GFR differentially. The question was addressed with the use of two T-type Cav knockout (Cav3.1(-/-) and Cav3.2(-/-)) mouse strains. Continuous recordings of blood pressure and heart rate, para-aminohippurate clearance (renal plasma flow), and inulin clearance (GFR) were performed in conscious, chronically catheterized, wild-type (WT) and Cav3.1(-/-) and Cav3.2(-/-) mice. The contractility of afferent and efferent arterioles was determined in isolated perfused blood vessels. Efferent arterioles from Cav3.2(-/-) mice constricted significantly more in response to a depolarization compared with WT mice. GFR was increased in Cav3.2(-/-) mice with no significant changes in renal plasma flow, heart rate, and blood pressure. Cav3.1(-/-) mice had a higher renal plasma flow compared with WT mice, whereas GFR was indistinguishable from WT mice. No difference in the concentration response to K(+) was observed in isolated afferent and efferent arterioles from Cav3.1(-/-) mice compared with WT mice. Heart rate was significantly lower in Cav3.1(-/-) mice compared with WT mice with no difference in blood pressure. T-type antagonists significantly inhibited the constriction of human intrarenal arteries in response to a small depolarization. In conclusion, Cav3.2 channels support dilatation of efferent arterioles and affect GFR, whereas Cav3.1 channels in vivo contribute to renal vascular resistance. It is suggested that endothelial and nerve localization of Cav3.2 and Cav3.1, respectively, may account for the observed effects.
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Affiliation(s)
- Anne D Thuesen
- Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
| | - Henrik Andersen
- Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
| | - Majken Cardel
- Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
| | - Anja Toft
- Department of Urology, Odense University Hospital, Odense, Denmark; and
| | - Steen Walter
- Department of Urology, Odense University Hospital, Odense, Denmark; and
| | - Niels Marcussen
- Clinical Pathology, Odense University Hospital, Odense, Denmark
| | - Boye L Jensen
- Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
| | - Peter Bie
- Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark
| | - Pernille B L Hansen
- Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark;
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22
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T-type Ca2+ channels facilitate NO-formation, vasodilatation and NO-mediated modulation of blood pressure. Pflugers Arch 2014; 466:2205-14. [DOI: 10.1007/s00424-014-1492-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 02/25/2014] [Accepted: 02/26/2014] [Indexed: 11/28/2022]
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23
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Beierwaltes WH, Harrison-Bernard LM, Sullivan JC, Mattson DL. Assessment of renal function; clearance, the renal microcirculation, renal blood flow, and metabolic balance. Compr Physiol 2013; 3:165-200. [PMID: 23720284 DOI: 10.1002/cphy.c120008] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Historically, tools to assess renal function have been developed to investigate the physiology of the kidney in an experimental setting, and certain of these techniques have utility in evaluating renal function in the clinical setting. The following work will survey a spectrum of these tools, their applications and limitations in four general sections. The first is clearance, including evaluation of exogenous and endogenous markers for determining glomerular filtration rate, the adaptation of estimated glomerular filtration rate in the clinical arena, and additional clearance techniques to assess various other parameters of renal function. The second section deals with in vivo and in vitro approaches to the study of the renal microvasculature. This section surveys a number of experimental techniques including corticotomy, the hydronephrotic kidney, vascular casting, intravital charge coupled device videomicroscopy, multiphoton fluorescent microscopy, synchrotron-based angiography, laser speckle contrast imaging, isolated renal microvessels, and the perfused juxtamedullary nephron microvasculature. The third section addresses in vivo and in vitro approaches to the study of renal blood flow. These include ultrasonic flowmetry, laser-Doppler flowmetry, magnetic resonance imaging (MRI), phase contrast MRI, cine phase contrast MRI, dynamic contrast-enhanced MRI, blood oxygen level dependent MRI, arterial spin labeling MRI, x-ray computed tomography, and positron emission tomography. The final section addresses the methodologies of metabolic balance studies. These are described for humans, large experimental animals as well as for rodents. Overall, the various in vitro and in vivo topics and applications to evaluate renal function should provide a guide for the investigator or physician to understand and to implement the techniques in the laboratory or clinic setting.
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Affiliation(s)
- William H Beierwaltes
- Hypertension and Vascular Research Division, Department of Internal Medicine, Henry Ford Hospital, and Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan, USA.
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24
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Senadheera S, Bertrand PP, Grayson TH, Leader L, Tare M, Murphy TV, Sandow SL. Enhanced contractility in pregnancy is associated with augmented TRPC3, L-type, and T-type voltage-dependent calcium channel function in rat uterine radial artery. Am J Physiol Regul Integr Comp Physiol 2013; 305:R917-26. [DOI: 10.1152/ajpregu.00225.2013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
In pregnancy, α-adrenoceptor-mediated vasoconstriction is augmented in uterine radial arteries and is accompanied by underlying changes in smooth muscle (SM) Ca2+ activity. This study aims to determine the Ca2+ entry channels associated with altered vasoconstriction in pregnancy, with the hypothesis that augmented vasoconstriction involves transient receptor potential canonical type-3 (TRPC3) and L- and T-type voltage-dependent Ca2+ channels. Immunohistochemistry showed TRPC3, L-type Cav1.2 (as the α1C subunit), T-type Cav3.1 (α1G), and Cav3.2 (α1H) localization to the uterine radial artery SM. Fluorescence intensity of TRPC3, Cav1.2, and Cav3.2 was increased, and Cav3.1 decreased in radial artery SM from pregnant rats. Western blot analysis confirmed increased TRPC3 protein expression in the radial artery from pregnant rats. Pressure myography incorporating pharmacological intervention to examine the role of these channels in uterine radial arteries showed an attenuation of phenylephrine (PE)-induced constriction with Pyr3 {1-[4-[(2,3,3-trichloro-1-oxo-2-propen-1-yl)amino]phenyl]-5-(trifluoromethyl)-1 H-pyrazole-4-carboxylic acid}-mediated TRPC3 inhibition or with nifedipine-mediated L-type channel block alone in vessels from pregnant rats; both effects of which were diminished in radial arteries from nonpregnant rats. Combined TRPC3 and L-type inhibition attenuated PE-induced constriction in radial arteries, and the residual vasoconstriction was reduced and abolished with T-type channel block with NNC 55-0396 in arteries from nonpregnant and pregnant rats, respectively. With SM Ca2+ stores depleted and in the presence of PE, nifedipine, and NNC 55-0396, blockade of TRPC3 reversed PE-induced constriction. These data suggest that TRPC3 channels act synergistically with L- and T-type channels to modulate radial artery vasoconstriction, with the mechanism being augmented in pregnancy.
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Affiliation(s)
- Sevvandi Senadheera
- Department of Physiology, School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Paul P. Bertrand
- Department of Physiology, School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - T. Hilton Grayson
- Department of Physiology, School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Leo Leader
- Leo Leader, School of Women's and Children's Health, Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Marianne Tare
- Department of Physiology, Monash University, Melbourne, Australia; and
| | - Timothy V. Murphy
- Department of Physiology, School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Shaun L. Sandow
- Department of Physiology, School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, Australia
- Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Maroochydoore, Australia
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25
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Gurkoff G, Shahlaie K, Lyeth B, Berman R. Voltage-gated calcium channel antagonists and traumatic brain injury. Pharmaceuticals (Basel) 2013; 6:788-812. [PMID: 24276315 PMCID: PMC3816709 DOI: 10.3390/ph6070788] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Revised: 06/06/2013] [Accepted: 06/06/2013] [Indexed: 01/17/2023] Open
Abstract
Traumatic brain injury (TBI) is a leading cause of death and disability in the United States. Despite more than 30 years of research, no pharmacological agents have been identified that improve neurological function following TBI. However, several lines of research described in this review provide support for further development of voltage gated calcium channel (VGCC) antagonists as potential therapeutic agents. Following TBI, neurons and astrocytes experience a rapid and sometimes enduring increase in intracellular calcium ([Ca2+]i). These fluxes in [Ca2+]i drive not only apoptotic and necrotic cell death, but also can lead to long-term cell dysfunction in surviving cells. In a limited number of in vitro experiments, both L-type and N-type VGCC antagonists successfully reduced calcium loads as well as neuronal and astrocytic cell death following mechanical injury. In rodent models of TBI, administration of VGCC antagonists reduced cell death and improved cognitive function. It is clear that there is a critical need to find effective therapeutics and rational drug delivery strategies for the management and treatment of TBI, and we believe that further investigation of VGCC antagonists should be pursued before ruling out the possibility of successful translation to the clinic.
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Affiliation(s)
- Gene Gurkoff
- Department of Neurological Surgery, One Shields Avenue, University of California, Davis, CA 95616, USA; E-Mails: (K.S.); (B.L.); (R.B.)
- NSF Center for Biophotonics Science and Technology, Suite 2700 Stockton Blvd, Suite 1400, Sacramento, CA, 95817, USA
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-530-754-7501; Fax: +1-530-754-5125
| | - Kiarash Shahlaie
- Department of Neurological Surgery, One Shields Avenue, University of California, Davis, CA 95616, USA; E-Mails: (K.S.); (B.L.); (R.B.)
| | - Bruce Lyeth
- Department of Neurological Surgery, One Shields Avenue, University of California, Davis, CA 95616, USA; E-Mails: (K.S.); (B.L.); (R.B.)
| | - Robert Berman
- Department of Neurological Surgery, One Shields Avenue, University of California, Davis, CA 95616, USA; E-Mails: (K.S.); (B.L.); (R.B.)
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26
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Wan J, Yamamura A, Zimnicka AM, Voiriot G, Smith KA, Tang H, Ayon RJ, Choudhury MSR, Ko EA, Wang J, Wang C, Makino A, Yuan JXJ. Chronic hypoxia selectively enhances L- and T-type voltage-dependent Ca2+ channel activity in pulmonary artery by upregulating Cav1.2 and Cav3.2. Am J Physiol Lung Cell Mol Physiol 2013; 305:L154-64. [PMID: 23686856 DOI: 10.1152/ajplung.00313.2012] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Hypoxia-induced pulmonary hypertension (HPH) is characterized by sustained pulmonary vasoconstriction and vascular remodeling, both of which are mediated by pulmonary artery smooth muscle cell (PASMC) contraction and proliferation, respectively. An increase in cytosolic Ca²⁺ concentration ([Ca²⁺]cyt) is a major trigger for pulmonary vasoconstriction and an important stimulus for cell proliferation in PASMCs. Ca²⁺ influx through voltage-dependent Ca²⁺ channels (VDCC) is an important pathway for the regulation of [Ca²⁺]cyt. The potential role for L- and T-type VDCC in the development of HPH is still unclear. Using a hypoxic-induced pulmonary hypertension mouse model, we undertook this study to identify if VDCC in pulmonary artery (PA) are functionally upregulated and determine which type of VDCC are altered in HPH. Mice subjected to chronic hypoxia developed pulmonary hypertension within 4 wk, and high-K⁺- and U-46619-induced contraction of PA was greater in chronic hypoxic mice than that in normoxic control mice. Additionally, we demonstrate that high-K⁺- and U-46619-induced Ca²⁺ influx in PASMC is significantly increased in the hypoxic group. The VDCC activator, Bay K8864, induced greater contraction of the PA of hypoxic mice than in that of normoxic mice in isometric force measurements. L-type and T-type VDCC blockers significantly attenuated absolute contraction of the PA in hypoxic mice. Chronic hypoxia did not increase high-K⁺- and U-46619-induced contraction of mesenteric artery (MA). Compared with MA, PA displayed higher expression of calcium channel voltage-dependent L-type α1C-subunit (Cav1.2) and T-type α1H-subunit (Cav3.2) upon exposure to chronic hypoxia. In conclusion, both L-type and T-type VDCC were functionally upregulated in PA, but not MA, in HPH mice, which could result from selectively increased expression of Cav1.2 and Cav3.2.
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Affiliation(s)
- Jun Wan
- Department of Medicine, Institute for Personalized Respiratory Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
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27
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Harraz OF, Welsh DG. T-Type Ca2+Channels in Cerebral Arteries: Approaches, Hypotheses, and Speculation. Microcirculation 2013; 20:299-306. [DOI: 10.1111/micc.12038] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Accepted: 01/07/2013] [Indexed: 01/08/2023]
Affiliation(s)
- Osama F. Harraz
- Department of Physiology & Pharmacology; Hotchkiss Brain and Libin Cardiovascular Research Institutes; University of Calgary; Calgary AB Canada
| | - Donald G. Welsh
- Department of Physiology & Pharmacology; Hotchkiss Brain and Libin Cardiovascular Research Institutes; University of Calgary; Calgary AB Canada
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28
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Howitt L, Chaston DJ, Sandow SL, Matthaei KI, Edwards FR, Hill CE. Spreading vasodilatation in the murine microcirculation: attenuation by oxidative stress-induced change in electromechanical coupling. J Physiol 2013; 591:2157-73. [PMID: 23440962 PMCID: PMC3634526 DOI: 10.1113/jphysiol.2013.250928] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Accepted: 02/19/2013] [Indexed: 12/17/2022] Open
Abstract
Regulation of blood flow in microcirculatory networks depends on spread of local vasodilatation to encompass upstream arteries; a process mediated by endothelial conduction of hyperpolarization. Given that endothelial coupling is reduced in hypertension, we used hypertensive Cx40ko mice, in which endothelial coupling is attenuated, to investigate the contribution of the renin-angiotensin system and reduced endothelial cell coupling to conducted vasodilatation of cremaster arterioles in vivo. When the endothelium was disrupted by light dye treatment, conducted vasodilatation, following ionophoresis of acetylcholine, was abolished beyond the site of endothelial damage. In the absence of Cx40, sparse immunohistochemical staining was found for Cx37 in the endothelium, and endothelial, myoendothelial and smooth muscle gap junctions were identified by electron microscopy. Hyperpolarization decayed more rapidly in arterioles from Cx40ko than wild-type mice. This was accompanied by a shift in the threshold potential defining the linear relationship between voltage and diameter, increased T-type calcium channel expression and increased contribution of T-type (3 μmol l(-1) NNC 55-0396), relative to L-type (1 μmol l(-1) nifedipine), channels to vascular tone. The change in electromechanical coupling was reversed by inhibition of the renin-angiotensin system (candesartan, 1.0 mg kg(-1) day(-1) for 2 weeks) or by acute treatment with the superoxide scavenger tempol (1 mmol l(-1)). Candesartan and tempol treatments also significantly improved conducted vasodilatation. We conclude that conducted vasodilatation in Cx40ko mice requires the endothelium, and attenuation results from both a reduction in endothelial coupling and an angiotensin II-induced increase in oxidative stress. We suggest that during cardiovascular disease, the ability of microvascular networks to maintain tissue integrity may be compromised due to oxidative stress-induced changes in electromechanical coupling.
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Affiliation(s)
- Lauren Howitt
- John Curtin School of Medical Research, Australian National University, Canberra ACT 0200, Australia
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29
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Hansen PBL. Functional and pharmacological consequences of the distribution of voltage-gated calcium channels in the renal blood vessels. Acta Physiol (Oxf) 2013; 207:690-9. [PMID: 23351056 DOI: 10.1111/apha.12070] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 11/26/2012] [Accepted: 01/22/2013] [Indexed: 12/15/2022]
Abstract
Calcium channel blockers are widely used to treat hypertension because they inhibit voltage-gated calcium channels that mediate transmembrane calcium influx in, for example, vascular smooth muscle and cardiomyocytes. The calcium channel family consists of several subfamilies, of which the L-type is usually associated with vascular contractility. However, the L-, T- and P-/Q-types of calcium channels are present in the renal vasculature and are differentially involved in controlling vascular contractility, thereby contributing to regulation of kidney function and blood pressure. In the preglomerular vascular bed, all the three channel families are present. However, the T-type channel is the only channel in cortical efferent arterioles which is in contrast to the juxtamedullary efferent arteriole, and that leads to diverse functional effects of L- and T-type channel inhibition. Furthermore, by different mechanisms, T-type channels may contribute to both constriction and dilation of the arterioles. Finally, P-/Q-type channels are involved in the regulation of human intrarenal arterial contractility. The calcium blockers used in the clinic affect not only L-type but also P-/Q- and T-type channels. Therefore, the distinct effect obtained by inhibiting a given subtype or set of channels under experimental settings should be considered when choosing a calcium blocker for treatment. T-type channels seem to be crucial for regulating the GFR and the filtration fraction. Use of blockers is expected to lead to preferential efferent vasodilation, reduction of glomerular pressure and proteinuria. Therefore, renovascular T-type channels might provide novel therapeutic targets, and may have superior renoprotective effects compared to conventional calcium blockers.
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Affiliation(s)
- P. B. L. Hansen
- Department of Cardiovascular and Renal Research; Institute of Molecular Medicine; University of Southern Denmark; Odense; Denmark
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30
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Nistala R, Sowers JR. Hypertension: Synergy of antihypertensives in elderly patients with CKD. Nat Rev Nephrol 2012. [PMID: 23183840 DOI: 10.1038/nrneph.2012.264] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Ravi Nistala
- Diabetes and Cardiovascular Center, University of Missouri School of Medicine, One Hospital Drive, Columbia, MO 65212, USA
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31
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Abd El-Rahman RR, Harraz OF, Brett SE, Anfinogenova Y, Mufti RE, Goldman D, Welsh DG. Identification of L- and T-type Ca2+ channels in rat cerebral arteries: role in myogenic tone development. Am J Physiol Heart Circ Physiol 2012; 304:H58-71. [PMID: 23103495 DOI: 10.1152/ajpheart.00476.2012] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
L-type Ca(2+) channels are broadly expressed in arterial smooth muscle cells, and their voltage-dependent properties are important in tone development. Recent studies have noted that these Ca(2+) channels are not singularly expressed in vascular tissue and that other subtypes are likely present. In this study, we ascertained which voltage-gated Ca(2+) channels are expressed in rat cerebral arterial smooth muscle and determined their contribution to the myogenic response. mRNA analysis revealed that the α(1)-subunit of L-type (Ca(v)1.2) and T-type (Ca(v)3.1 and Ca(v)3.2) Ca(2+) channels are present in isolated smooth muscle cells. Western blot analysis subsequently confirmed protein expression in whole arteries. With the use of patch clamp electrophysiology, nifedipine-sensitive and -insensitive Ba(2+) currents were isolated and each were shown to retain electrical characteristics consistent with L- and T-type Ca(2+) channels. The nifedipine-insensitive Ba(2+) current was blocked by mibefradil, kurtoxin, and efonidpine, T-type Ca(2+) channel inhibitors. Pressure myography revealed that L-type Ca(2+) channel inhibition reduced tone at 20 and 80 mmHg, with the greatest effect at high pressure when the vessel is depolarized. In comparison, the effect of T-type Ca(2+) channel blockade on myogenic tone was more limited, with their greatest effect at low pressure where vessels are hyperpolarized. Blood flow modeling revealed that the vasomotor responses induced by T-type Ca(2+) blockade could alter arterial flow by ∼20-50%. Overall, our findings indicate that L- and T-type Ca(2+) channels are expressed in cerebral arterial smooth muscle and can be electrically isolated from one another. Both conductances contribute to myogenic tone, although their overall contribution is unequal.
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Affiliation(s)
- Rasha R Abd El-Rahman
- Hotchkiss Brain and Libin Cardiovascular Research Institute and Department of Physiology and Pharmacology, University of Calgary, Alberta, Canada
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32
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Eikermann-Haerter K, Lee JH, Yuzawa I, Liu CH, Zhou Z, Shin HK, Zheng Y, Qin T, Kurth T, Waeber C, Ferrari MD, van den Maagdenberg AMJM, Moskowitz MA, Ayata C. Migraine mutations increase stroke vulnerability by facilitating ischemic depolarizations. Circulation 2011; 125:335-45. [PMID: 22144569 DOI: 10.1161/circulationaha.111.045096] [Citation(s) in RCA: 123] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Migraine is an independent risk factor for stroke. Mechanisms underlying this association are unclear. Familial hemiplegic migraine (FHM), a migraine subtype that also carries an increased stroke risk, is a useful model for common migraine phenotypes because of shared aura and headache features, trigger factors, and underlying glutamatergic mechanisms. METHODS AND RESULTS Here, we show that FHM type 1 (FHM1) mutations in Ca(V)2.1 voltage-gated Ca(2+) channels render the brain more vulnerable to ischemic stroke. Compared with wild-type mice, 2 FHM1 mutant mouse strains developed earlier onset of anoxic depolarization and more frequent peri-infarct depolarizations associated with rapid expansion of infarct core on diffusion-weighted magnetic resonance imaging and larger perfusion deficits on laser speckle flowmetry. Cerebral blood flow required for tissue survival was higher in the mutants, leading to infarction with milder ischemia. As a result, mutants developed larger infarcts and worse neurological outcomes after stroke, which were selectively attenuated by a glutamate receptor antagonist. CONCLUSIONS We propose that enhanced susceptibility to ischemic depolarizations akin to spreading depression predisposes migraineurs to infarction during mild ischemic events, thereby increasing the stroke risk.
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Affiliation(s)
- Katharina Eikermann-Haerter
- Stroke and Neurovascular Regulation Laboratory, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
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