HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Cohen, N M Articles by Lederer, W J Search for Related Content PubMed PubMed Citation Articles by Cohen, N M Articles by Lederer, W J

Department of Physiology, University of Maryland, School of Medicine, Baltimore 21201.

1. Calcium current (ICa) was recorded in single rat heart cells at two periods during development: (1) at 2-7 days post-partum (neonatal), and (2) at 6-8 weeks (adult). 2. We measured both transient and steady-state components of ICa and could describe ICa in terms of the steady-state activation (d infinity) and inactivation (f infinity) parameters, the channel reversal potential (Echannel) and a relative conductance parameter, gr. 3. In adult single cells, the application of ryanodine (10 microM), an agent known to alter the function of the sarcoplasmic reticulum (SR), abolished contraction rapidly and increased ICa. Ryanodine also produced a 13 mV shift in f infinity towards more positive potentials and altered its slope, while producing a small increase in gr but no effect on d infinity. In neonatal single cells, ryanodine (10 microM) had no significant effect on contraction, ICa, d infinity, f infinity, or gr. Caffeine (10 mM), a less specific agent widely used to investigate sarcoplasmic reticulum function, had actions similar to those of ryanodine. 4. In adult myocytes, when EGTA (10 or 20 mM) or bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA, 10 mM) were included in the pipette solution, contractions were rapidly abolished, while a small (4 mV) shift of f infinity to more positive potentials was seen. A large additional shift of f infinity was observed when ryanodine (10 microM) was added to the superfusion solution in the continued presence of EGTA or BAPTA. The alterations of ICa in EGTA (or BAPTA) plus ryanodine were the same as those seen in ryanodine alone. In neonatal cells, in contrast, when EGTA or BAPTA were included in the pipette solution we observed only a small effect on f infinity and the application of ryanodine had no effect. 5. Electron micrographs of our preparations show that the dissociated adult cells have sharp sarcolemmal borders, fully developed sarcomeres with T-tubules and sarcoplasmic reticulum membranes. In contrast, the neonatal cells that we use have few of these intracellular structures. Our observations in these preparations are consistent with the work of others (e.g. Penefsky, 1974; Hirakow & Gotoh, 1975; Ishikawa & Yamada, 1975; Legato, 1975; Hoerter, Mazet & Vassort, 1981). 6. Our data suggest that fully developed sarcoplasmic reticulum in rat heart cells can affect ICa.(ABSTRACT TRUNCATED AT 400 WORDS)

This article has been cited by other articles:

				S. R. Houser and J. D. Molkentin Does Contractile Ca2+ Control Calcineurin-NFAT Signaling and Pathological Hypertrophy in Cardiac Myocytes? Sci. Signal., June 24, 2008; 1(25): pe31 - pe31. [Abstract] [Full Text] [PDF]

				L. J. Wang and E. A. Sobie Mathematical model of the neonatal mouse ventricular action potential Am J Physiol Heart Circ Physiol, June 1, 2008; 294(6): H2565 - H2575. [Abstract] [Full Text] [PDF]

				M. Reppel, B. K. Fleischmann, H. Reuter, P. Sasse, H. Schunkert, and J. Hescheler Regulation of the Na+/Ca2+ exchanger (NCX) in the murine embryonic heart Cardiovasc Res, July 1, 2007; 75(1): 99 - 108. [Abstract] [Full Text] [PDF]

				V. Raman, A. E. Pollard, and V. G. Fast Shock-induced changes of Cai2+ and Vm in myocyte cultures and computer model: Dependence on the timing of shock application Cardiovasc Res, January 1, 2007; 73(1): 101 - 110. [Abstract] [Full Text] [PDF]

				G.-W. He, Z.-D. Ge, A. P. C. Yim, Q. Yang, and R.-Z. Zhang Electrophysiologic and mechanical evidence of superiority of hyperpolarizing versus depolarizing cardioplegia in protection of endothelium-derived hyperpolarizing factor-mediated endothelial function: A study in coronary resistance arteries J. Thorac. Cardiovasc. Surg., June 1, 2004; 127(6): 1773 - 1780. [Abstract] [Full Text] [PDF]

				S. M. Tipparaju, R. Kumar, Y. Wang, R. W. Joyner, and M. B. Wagner Developmental differences in L-type calcium current of human atrial myocytes Am J Physiol Heart Circ Physiol, May 1, 2004; 286(5): H1963 - H1969. [Abstract] [Full Text] [PDF]

				U. Kirchhefer, L. R Jones, F. Begrow, P. Boknik, L. Hein, M. J Lohse, B. Riemann, W. Schmitz, J. Stypmann, and J. Neumann Transgenic triadin 1 overexpression alters SR Ca2+ handling and leads to a blunted contractile response to {beta}-adrenergic agonists Cardiovasc Res, April 1, 2004; 62(1): 122 - 134. [Abstract] [Full Text] [PDF]

				A. L. Escobar, R. Ribeiro-Costa, C. Villalba-Galea, M. E. Zoghbi, C. G. Perez, and R. Mejia-Alvarez Developmental changes of intracellular Ca2+ transients in beating rat hearts Am J Physiol Heart Circ Physiol, March 1, 2004; 286(3): H971 - H978. [Abstract] [Full Text] [PDF]

				S. A. McDowell, E. McCall, W. F. Matter, T. B. Estridge, and C. J. Vlahos Phosphoinositide 3-kinase regulates excitation-contraction coupling in neonatal cardiomyocytes Am J Physiol Heart Circ Physiol, February 1, 2004; 286(2): H796 - H805. [Abstract] [Full Text] [PDF]

				F. Brette and C. Orchard T-Tubule Function in Mammalian Cardiac Myocytes Circ. Res., June 13, 2003; 92(11): 1182 - 1192. [Abstract] [Full Text] [PDF]

				A. P Baader, L. Buchler, L. Bircher-Lehmann, and A. G Kleber Real time, confocal imaging of Ca2+ waves in arterially perfused rat hearts Cardiovasc Res, January 1, 2002; 53(1): 105 - 115. [Abstract] [Full Text] [PDF]

				L. Protas, D. DiFrancesco, and R. B. Robinson L-type but not T-type calcium current changes during postnatal development in rabbit sinoatrial node Am J Physiol Heart Circ Physiol, September 1, 2001; 281(3): H1252 - H1259. [Abstract] [Full Text] [PDF]

				C. Herr, N. Smyth, S. Ullrich, F. Yun, P. Sasse, J. Hescheler, B. Fleischmann, K. Lasek, K. Brixius, R. H. G. Schwinger, et al. Loss of Annexin A7 Leads to Alterations in Frequency-Induced Shortening of Isolated Murine Cardiomyocytes Mol. Cell. Biol., July 1, 2001; 21(13): 4119 - 4128. [Abstract] [Full Text] [PDF]

				C. Pignier and D. Potreau Characterization of nifedipine-resistant calcium current in neonatal rat ventricular cardiomyocytes Am J Physiol Heart Circ Physiol, November 1, 2000; 279(5): H2259 - H2268. [Abstract] [Full Text] [PDF]

				E. R. Cheek, R. E. Ideker, and V. G. Fast Nonlinear Changes of Transmembrane Potential During Defibrillation Shocks : Role of Ca2+ Current Circ. Res., September 15, 2000; 87(6): 453 - 459. [Abstract] [Full Text] [PDF]

				I. A. Hobai, J. C. Hancox, and A. J. Levi Inhibition by nickel of the L-type Ca channel in guinea pig ventricular myocytes and effect of internal cAMP Am J Physiol Heart Circ Physiol, August 1, 2000; 279(2): H692 - H701. [Abstract] [Full Text] [PDF]

				D. J. Chambers and D. J. Hearse Developments in cardioprotection: ""polarized"" arrest as an alternative to ""depolarized"" arrest Ann. Thorac. Surg., November 1, 1999; 68(5): 1960 - 1966. [Abstract] [Full Text] [PDF]

				L. Protas and R. B. Robinson Neuropeptide Y contributes to innervation-dependent increase in ICa,L via ventricular Y2 receptors Am J Physiol Heart Circ Physiol, September 1, 1999; 277(3): H940 - H946. [Abstract] [Full Text] [PDF]

				A. K. Snabaitis, M. J. Shattock, and D. J. Chambers LONG-TERM MYOCARDIAL PRESERVATION: EFFECTS OF HYPERKALEMIA, SODIUMCHANNEL, AND Na+/K+/2Cl- COTRANSPORTINHIBITION ON EXTRACELLULAR POTASSIUM ACCUMULATION DURING HYPOTHERMIC STORAGE J. Thorac. Cardiovasc. Surg., July 1, 1999; 118(1): 123 - 134. [Abstract] [Full Text] [PDF]

				M. P. Blaustein and W. J. Lederer Sodium/Calcium Exchange: Its Physiological Implications Physiol Rev, July 1, 1999; 79(3): 763 - 854. [Abstract] [Full Text] [PDF]

				H. Satoh, H. Katoh, P. Velez, M. Fill, and D. M. Bers Bay K 8644 Increases Resting Ca2+ Spark Frequency in Ferret Ventricular Myocytes Independent of Ca Influx : Contrast With Caffeine and Ryanodine Effects Circ. Res., December 14, 1998; 83(12): 1192 - 1204. [Abstract] [Full Text] [PDF]

				G.-W. He Potassium-channel opener in cardioplegia may restore coronary endothelial function Ann. Thorac. Surg., October 1, 1998; 66(4): 1318 - 1322. [Abstract] [Full Text] [PDF]

				M. K. Slodzinski and M. P. Blaustein Na+/Ca2+ exchange in neonatal rat heart cells: antisense inhibition and protein half-life Am J Physiol Cell Physiol, August 1, 1998; 275(2): C459 - C467. [Abstract] [Full Text] [PDF]

				J. P. Gaughan, C. A. Hefner, and S. R. Houser Electrophysiological properties of neonatal rat ventricular myocytes with alpha 1-adrenergic-induced hypertrophy Am J Physiol Heart Circ Physiol, August 1, 1998; 275(2): H577 - H590. [Abstract] [Full Text] [PDF]

				J. S Mitcheson, J. C Hancox, and A. J Levi Cultured adult cardiac myocytes: Future applications, culture methods, morphological and electrophysiological properties Cardiovasc Res, August 1, 1998; 39(2): 280 - 300. [Abstract] [Full Text] [PDF]

				M. B. Meyers, T. S. Puri, A. J. Chien, T. Gao, P.-H. Hsu, M. M. Hosey, and G. I. Fishman Sorcin Associates with the Pore-forming Subunit of Voltage-dependent L-type Ca2+ Channels J. Biol. Chem., July 24, 1998; 273(30): 18930 - 18935. [Abstract] [Full Text] [PDF]

				M. Wibo, O. Feron, L. Zheng, M. Maleki, F. Kolar, and T. Godfraind Thyroid status and postnatal changes in subsarcolemmal distribution and isoform expression of rat cardiac dihydropyridine receptors Cardiovasc Res, January 1, 1998; 37(1): 151 - 159. [Abstract] [Full Text] [PDF]

				A. K. Snabaitis, M. J. Shattock, and D. J. Chambers Comparison of Polarized and Depolarized Arrest in the Isolated Rat Heart for Long-term Preservation Circulation, November 4, 1997; 96(9): 3148 - 3156. [Abstract] [Full Text]

				J. Li, J. Qu, and R. D. Nathan Ionic basis of ryanodine's negative chronotropic effect on pacemaker cells isolated from the sinoatrial node Am J Physiol Heart Circ Physiol, November 1, 1997; 273(5): H2481 - H2489. [Abstract] [Full Text] [PDF]

				J Hescheler, B.K Fleischmann, S Lentini, V.A Maltsev, J Rohwedel, A.M Wobus, and K Addicks Embryonic stem cells: a model to study structural and functional properties in cardiomyogenesis Cardiovasc Res, November 1, 1997; 36(2): 149 - 162. [Full Text] [PDF]

				G.-W. He and C.-Q. Yang SUPERIORITY OF HYPERPOLARIZING TO DEPOLARIZING CARDIOPLEGIA IN PROTECTION OF CORONARY ENDOTHELIAL FUNCTION J. Thorac. Cardiovasc. Surg., October 1, 1997; 114(4): 643 - 650. [Abstract] [Full Text]

				S. L. Maskal, N. M. Cohen, P.-W. Hsia, A. S. Wechsler, and R. J. Damiano Jr. HYPERPOLARIZED CARDIAC ARREST WITH A POTASSIUM-CHANNEL OPENER, APRIKALIM J. Thorac. Cardiovasc. Surg., October 1, 1995; 110(4): 1083 - 1095. [Abstract] [Full Text]

				N. M. Cohen, R. J. Damiano Jr, and A. S. Wechsler Is There an Alternative to Potassium Arrest? Ann. Thorac. Surg., September 1, 1995; 60(3): 858 - 863. [Abstract] [Full Text]

				K. R. Sipido, G. Callewaert, and E. Carmeliet Inhibition and Rapid Recovery of Ca2+ Current During Ca2+ Release From Sarcoplasmic Reticulum in Guinea Pig Ventricular Myocytes Circ. Res., January 1, 1995; 76(1): 102 - 109. [Abstract] [Full Text]

				C. Berthier, A. Monteil, P. Lory, and C. Strube alpha1H mRNA in single skeletal muscle fibres accounts for T-type calcium current transient expression during fetal development in mice J. Physiol., March 15, 2002; 539(3): 681 - 691. [Abstract] [Full Text] [PDF]