Abstract
ICa was recorded in quinea pig ventricular myocytes using the whole-cell voltage-clamp technique. The shape of the I–V relation was unaffected by temperature (21–37°C) but there were large changes in ICa amplitude and time course. Steady-state responses indicated Q10 's of 2.96±0.14 (amplitude), 2.52±0.13 (time to peak), and 2.82±0.28 (T1/2 inactivation) (mean ± SD, n=6). Quick changes in temperature (T1/2<30 s) induced pronounced deviations from the steady-state Q10 relations (early depression, compensatory overshoot). Thus, cardiac ICa differs from other currents in having a high amplitude-Q10 and an oscillatory response to rapid temperature changes.
This is a preview of subscription content, log in via an institution to check access.
References
Hodgkin AL, Huxley AF, Katz B (1952) Measurements of current-voltage relations in the membrane of the giant axon ofLoligo. J Physiol (Lond) 116:424–448
Collins CA, Rojas E (1982) Temperature dependence of the sodium channel gating kinetics in the node of Ranvier. Quart J Exp Physiol 67:41–55
Colatsky TJ (1980) Voltage clamp measurements of sodium channel properties in rabbit cardiac purkinje fibres. J Physiol (Lond) 305:215–234
McDonald TF, Trautwein W (1978) Membrane currents in cat myocardium: separation of inward and outward components. J Physiol (Lond) 274:193–216
Sakmann B, Trube G (1984) Conductance properties of single inwardly rectifying potassium channels in ventricular cells from guinea-pig heart. J Physiol (Lond) 347: 641–657
Kostyuk PG, Krishtal OA, Pidoplichko VI (1981) Calcium inward current and related charge movements in the membrane of snail neurones. J Physiol (Lond) 310: 403–421
Byerly L, Chase PB, Stimers JR (1984) Calcium current activation kinetics in neurons of the snailLymnaea Stagnalis. J Physiol (Lond) 348: 187–207
Lux HD, Brown AM (1984) Patch and whole cell calcium currents recorded simultaneously in snail neurons. J Gen Physiol 83: 727–750
Mitchell MR, Powell T, Terrar DA, Twist VW (1983) Characteristics of the second inward current in cells isolated from rat ventricular muscle. Proc R Soc Lond B 219: 447–469.
Trautwein W, Pelzer D (1985) Gating of single calcium channels in the membrane of enzymatically isolated ventricular myocytes from adult mammalian hearts. In: Zipes DP, Jalife J (eds) Cardiac Electrophysiology and Arrhythmias. Grune & Stratton, Orlando and London, pp 31–42
Lee KS, Marban E, Tsien RW (1985) Inactivation of calcium channels in mammalian heart cells: Joint dependence of membrane potential and intracellular calcium. J Physiol (Lond) 364: 395–411
Bean BP (1985) Two kinds of calcium channels in canine atrial cells. Differences in kinetics, selectivity, and pharmacology. J Gen Physiol 86: 1–30
Moore LE, Holt (Jr) JP, Lindley BD (1971) Laser temperature-jump technique for relaxation studies of the ionic conductances in myelinated nerve fibers. Biophys J 12: 157–174
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Cavalié, A., McDonald, T.F., Pelzer, D. et al. Temperature-induced transitory and steady-state changes in the calcium current of guinea pig ventricular myocytes. Pflugers Arch. 405, 294–296 (1985). https://doi.org/10.1007/BF00582574
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00582574