1
|
Pardo AC, Rinaldi GJ, Mosca SM. Mitochondrial calcium handling in normotensive and spontaneously hypertensive rats: correlation with systolic blood pressure levels. Mitochondrion 2014; 20:75-81. [PMID: 25530492 DOI: 10.1016/j.mito.2014.12.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 12/04/2014] [Accepted: 12/11/2014] [Indexed: 01/10/2023]
Abstract
The aim was to study the mitochondrial Ca(2+) handling of mitochondria isolated from normotensive Wistar Kyoto (WKY) and spontaneously hypertensive rats (SHR) hearts and to establish a possible correlation with systolic blood pressure (SBP). Mitochondrial swelling after Ca(2+) addition, Ca(2+)-retention capacity (CRC) by calcium green method, and membrane potential (ΔΨm) were assessed. SBP was 124±1 (WKY) and 235±6mmHg (SHR). CRC, Ca(2+) response and ΔΨm were lower in SHR than WKY mitochondria. The conclusion is: the more depolarized state of SHR than WKY mitochondria results in an abnormal Ca(2+) handling and this event is closely associated with the SBP.
Collapse
Affiliation(s)
- Alejandro Ciocci Pardo
- Centro de Investigaciones Cardiovasculares, CCT-CONICET, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Buenos Aires, Argentina
| | - Gustavo J Rinaldi
- Centro de Investigaciones Cardiovasculares, CCT-CONICET, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Buenos Aires, Argentina
| | - Susana M Mosca
- Centro de Investigaciones Cardiovasculares, CCT-CONICET, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Buenos Aires, Argentina.
| |
Collapse
|
2
|
Ding-hua X, Zi-an X, Shu Y. Acetylcholine–induced calcium oscillation in isolated outer hair cells in guinea pig. J Otol 2006. [DOI: 10.1016/s1672-2930(06)50021-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
|
3
|
Guinamard R, Demion M, Magaud C, Potreau D, Bois P. Functional expression of the TRPM4 cationic current in ventricular cardiomyocytes from spontaneously hypertensive rats. Hypertension 2006; 48:587-94. [PMID: 16966582 DOI: 10.1161/01.hyp.0000237864.65019.a5] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cardiac hypertrophy is associated with electrophysiological modifications, including modification of action potential shape that can give rise to arrhythmias. We report here a higher detection of a calcium-activated nonselective cation current in cardiomyocytes of spontaneously hypertensive rats (SHRs), a model of hypertension and heart hypertrophy when compared with Wistar-Kyoto (WKY) rat, its normotensive equivalent. Freshly isolated cells from the left ventricles of 3- to 6-month-old WKY rats or SHRs were used for patch-clamp recordings. In inside-out patches, the channel presented a linear conductance of 25+/-0.5 pS, did not discriminate Na(+) over K(+), and was not permeable to Ca(2+). Open probability was increased by depolarization and a rise in [Ca(2+)](i) (dissociation constant=10+/-5.4 micromol/L) but reduced by 0.5 mmol/L [ATP](i), 10 micromol/L glibenclamide, or flufenamic acid (IC(50)=5.5+/-1.7 micromol/L). Thus, it owns the fingerprint of the TRPM4 current. Although rarely detected in WKY cardiomyocytes, the current was present in >50% of patches from SHR cardiomyocytes. Moreover, by performing RT-PCR from ventricular samples, we observed that TRPM4 mRNA detection was higher in SHRs than in WKY rats. We propose that a TRPM4 current is expressed in ventricular cardiomyocytes from SHRs. According to its properties, this channel may contribute to the transient inward current implicated in delayed-after-depolarizations observed during [Ca(2+)] overload of cardiomyocytes.
Collapse
Affiliation(s)
- Romain Guinamard
- Institut de Physiologie et Biologie Cellulaires, Centre National de la Recherche Scientifique Unité Mixte de Recherche, Université de Poitiers, Poitiers, France.
| | | | | | | | | |
Collapse
|
4
|
Izu LT, Means SA, Shadid JN, Chen-Izu Y, Balke CW. Interplay of ryanodine receptor distribution and calcium dynamics. Biophys J 2006; 91:95-112. [PMID: 16603499 PMCID: PMC1479049 DOI: 10.1529/biophysj.105.077214] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Spontaneously generated calcium (Ca2+) waves can trigger arrhythmias in ventricular and atrial myocytes. Yet, Ca2+ waves also serve the physiological function of mediating global Ca2+ increase and muscle contraction in atrial myocytes. We examine the factors that influence Ca2+ wave initiation by mathematical modeling and large-scale computational (supercomputer) simulations. An important finding is the existence of a strong coupling between the ryanodine receptor distribution and Ca2+ dynamics. Even modest changes in the ryanodine receptor spacing profoundly affect the probability of Ca2+ wave initiation. As a consequence of this finding, we suggest that there is information flow from the contractile system to the Ca2+ control system and this dynamical interplay could contribute to the increased incidence of arrhythmias during heart failure.
Collapse
Affiliation(s)
- Leighton T Izu
- Department of Internal Medicine, University of Kentucky, School of Medicine, Lexington, Kentucky 40536-0509, USA.
| | | | | | | | | |
Collapse
|
5
|
Tanaka H, Takamatsu T. Spatiotemporal Visualization of Intracellular Ca2+ in Living Heart Muscle Cells Viewed by Confocal Laser Scanning Microscopy. Acta Histochem Cytochem 2003. [DOI: 10.1267/ahc.36.193] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- Hideo Tanaka
- Department of Pathology and Cell Regulation, Kyoto Prefectural University of Medicine
| | - Tetsuro Takamatsu
- Department of Pathology and Cell Regulation, Kyoto Prefectural University of Medicine
| |
Collapse
|
6
|
Mazzetti L, Ruocco C, Giovannelli L, Ciuffi M, Franchi-Micheli S, Marra F, Zilletti L, Failli P. Guanosine 3': 5'-cyclic monophosphate-dependent pathway alterations in ventricular cardiomyocytes of spontaneously hypertensive rats. Br J Pharmacol 2001; 134:596-602. [PMID: 11588114 PMCID: PMC1572975 DOI: 10.1038/sj.bjp.0704275] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
1. We investigated the effect of the NO-donor S-nitroso-N-acetyl-DL-penicillamine (SNAP) on cardiomyocytes isolated from control normotensive Wistar Kyoto (WKY) and spontaneously hypertensive (SHR) rats. 2. Ventricular cardiomyocytes were isolated from SHR and WKY hearts and imaging analysis of fura-2-loaded cells was performed in order to evaluate calcium transient in electrical field paced (0.5 Hz) cells. 3. In WKY cardiomyocytes, 1 - 200 microM SNAP dose-dependently increased cyclic GMP content. In basal conditions, cyclic GMP content of SHR cardiomyocytes was significantly higher than in WKY, but SNAP failed to further increase cyclic GMP over the basal level. 4. In control conditions, the Delta F/F and decay time of the calcium transient were similar in both strains. In WKY cardiomyocytes, SNAP (1 - 100 microM) reduced the decay time. In SHR cardiomyocytes, SNAP was ineffective. Dibutyryl cyclic GMP (10(-6) - 10(-8) M), a membrane permeable cyclic GMP analogue, behaved similarly to SNAP. 5. In WKY and SHR cardiomyocytes, 10(-8) M isoprenaline similarly increased Delta F/F and decreased the decay time. SNAP and dibutyryl cyclic GMP prevented the effect of isoprenaline in WKY, whereas both molecules were ineffective in SHR cardiomyocytes. In WKY, SNAP effects were blocked by pretreating cells with the cGK inhibitor KT-5823. 6. Western blotting analysis of cGK type I showed that the enzyme was expressed in WKY isolated cardiomyocytes, but absent in four out of five SHR preparations. 7. We concluded that the low expression of cGKI may determine the lack of NO/cyclic GMP-dependent regulation on calcium transient in SHR cardiomyocytes. This alteration may contribute to the development of heart hypertrophy in hypertensive status.
Collapse
Affiliation(s)
- Luca Mazzetti
- Department of Pharmacology, Viale Pieraccini, 6, University of Florence, 50139 Florence, Italy
| | - Carlo Ruocco
- Department of Pharmacology, Viale Pieraccini, 6, University of Florence, 50139 Florence, Italy
| | - Lisa Giovannelli
- Department of Pharmacology, Viale Pieraccini, 6, University of Florence, 50139 Florence, Italy
| | - Mario Ciuffi
- Department of Pharmacology, Viale Pieraccini, 6, University of Florence, 50139 Florence, Italy
| | - Sergio Franchi-Micheli
- Department of Pharmacology, Viale Pieraccini, 6, University of Florence, 50139 Florence, Italy
| | - Fabio Marra
- Department of Internal Medicine, Viale Morgagni, 85, University of Florence, 50139 Florence, Italy
| | - Lucilla Zilletti
- Department of Pharmacology, Viale Pieraccini, 6, University of Florence, 50139 Florence, Italy
| | - Paola Failli
- Department of Pharmacology, Viale Pieraccini, 6, University of Florence, 50139 Florence, Italy
- Author for correspondence:
| |
Collapse
|
7
|
Subramanian S, Viatchenko-Karpinski S, Lukyanenko V, Györke S, Wiesner TF. Underlying mechanisms of symmetric calcium wave propagation in rat ventricular myocytes. Biophys J 2001; 80:1-11. [PMID: 11159379 PMCID: PMC1301210 DOI: 10.1016/s0006-3495(01)75991-7] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Calcium waves in heart cells are mediated by diffusion-coupled calcium-induced calcium release. The waves propagate in circular fashion. This is counterintuitive in view of the accepted ultrastructure of the cardiac myocyte. The density of calcium release sites in the transverse direction is four times higher than in the longitudinal direction. Simulations with release sites localized along Z-lines and isotropic diffusion yielded highly elliptical, nonphysiological waves. We hypothesized that subcellular organelles counteracted the higher release site density along the Z-lines by acting as transverse diffusion barriers and sites of active calcium uptake. We quantified the reduction of transverse diffusion by microinjecting cells with the nonreactive dye fluorescein. The ratio of the radial diffusion coefficient to the longitudinal coefficient was 0.39. Inhibition of mitochondrial uptake by rotenone accelerated the wave in the transverse direction. Simulations with release sites clustered at the Z-lines and a transverse diffusion coefficient 50% of the longitudinal coefficient generated waves of ellipticity 2/1 (major axis along the Z-line). Introducing additional release sites between the Z-lines at a density 20% of that on the Z-lines produced circular waves. The experiments and simulations support the presence of transverse diffusion barriers, additional uptake sites, and possibly intermediate release sites as well.
Collapse
Affiliation(s)
- S Subramanian
- Department of Chemical Engineering, Texas Tech University, Lubbock, Texas 79409, USA
| | | | | | | | | |
Collapse
|
8
|
Failli P, Fazzini A, Ruocco C, Mazzetti L, Cecchi E, Giovannelli L, Marra F, Milani S, Giotti A. Lack of nitric oxide- and guanosine 3':5'-cyclic monophosphate-dependent regulation of alpha-thrombin-induced calcium transient in endothelial cells of spontaneously hypertensive rat hearts. Br J Pharmacol 2000; 130:1468-76. [PMID: 10928946 PMCID: PMC1572213 DOI: 10.1038/sj.bjp.0703453] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
While the expression and/or activity of endothelial nitric oxide synthase (eNOS) has been characterized in spontaneously hypertensive (SHR) and normotensive Wistar Kyoto rat (WKY) hearts, in coronary endothelial cells (ECs) from both strains, the effect of NO on intracellular calcium concentration ([Ca(2+)](i)) is still unknown. Coronary microvascular ECs were isolated from SHR and WKY and characterized. Immunocytochemistry and Western blot analysis showed that eNOS was similarly expressed in ECs from both strains. Measuring [Ca(2+)](i) by imaging analysis of fura-2-loaded cells, we demonstrated that alpha-thrombin (3-180 U l(-1)) induced a superimposable dose-dependent calcium transient in ECs from both strains. In WKY ECs, S-nitroso-N-acetyl-DL-penicillamine (SNAP) dose-dependently (10 - 100 microM) and 0.1 microM atrial natriuretic factor (ANF) reduced the maximum and the decay time of alpha-thrombin-induced calcium transient. The inhibitory effects of SNAP and ANF were prevented by blocking cyclic GMP-dependent protein kinase. Non selective eNOS inhibitors prolonged the decay time of alpha-thrombin-induced calcium transient, while the selective inducible NOS inhibitor 1400 W was ineffective. SNAP (100 microM) and 0.1 microM ANF increased cyclic GMP content up to 22.9 and 42.3 fold respectively. In SHR ECs, alpha-thrombin-induced calcium transient was not modified by SNAP, ANF or eNOS inhibition. SNAP (100 microM) and 0.1 microM ANF increased cyclic GMP content up to 9. 3 and 51 fold respectively. In WKY ECs, SNAP dose-dependently (10 - 100 microM) reduced also bradykinin-induced calcium transient, while in SHR ECs was ineffective. We concluded that in SHR ECs, the cyclic GMP-dependent regulation of calcium transient is lost.
Collapse
Affiliation(s)
- P Failli
- Department of Pharmacology, Viale Pieraccini, 6 50139 Florence, Italy.
| | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Chi Y, Gupta RK. Alterations in heart and kidney membrane phospholipids in hypertension as observed by 31P nuclear magnetic resonance. Lipids 1998; 33:1023-30. [PMID: 9832083 DOI: 10.1007/s11745-998-0301-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Abnormalities of phospholipids in hypertension have previously been described in human erythrocyte, platelet, and plasma lipoproteins. Since the heart and kidney are adversely affected by hypertension, we investigated possible alterations in their membrane phospholipids, which could play a role in the derangement of intracellular ion balance widely observed in hypertension. The phospholipid compositions of heart and kidney from spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats were determined by using 31P nuclear magnetic resonance (NMR) spectroscopy. Absolute contents of all phospholipids in hypertensive hearts and kidneys were significantly higher than in normotensive hearts and kidneys. Expressed as a fraction of total phospholipid, cardiolipin (CL) and phosphatidylethanolamine plasmalogen (PEp) were significantly increased in SHR hearts compared to WKY hearts (CL and PEp were 7.95+/-0.22% and 13.16+/-0.35% in SHR vs. 7.01+/-0.20% and 11.19+/-0.42% in WKY rats, P< or =0.05), but phosphatidylethanolamine (PE) and phosphatidylcholine (PC) were significantly decreased in SHR (PE and PC were 22.46+/-0.37% and 44.81+/-0.43% in SHR vs. 24.02+/-0.44% and 46.01+/-0.50% in WKY rats, P< or =0.05). In the phospholipids extracted from rat kidneys, the percentage of PE was significantly higher for SHR than for WKY rats (20.37+/-0.60% vs. 18.43+/-0.37%, P< or =0.05), while PEp and phosphatidylserine (PS) were significantly lower for SHR (PEp and PS were 10.22+/-0.36% and 8.42+/-0.28% in SHRs vs. 11.29+/-0.36% and 9.71+/-0.40% in WKY rats, P< or =0.05). The above alterations in phospholipid composition might contribute to the higher oxygen consumption in the hypertensive heart and abnormal intracellular ion concentrations and ion transport in the heart and the kidney in hypertension.
Collapse
Affiliation(s)
- Y Chi
- Department of Physiology and Biophysics, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York 10461, USA
| | | |
Collapse
|