[Effect of temperature on the myocardial chrono- and inotropism of warm-blooded animals].
The influence of temperature on interval-force characteristics of rabbit ventricular myocardium was studied in conditions of random Gaussian sequences stimulation intervals. The interval-force relationships were described with Volterra series and cross-correlation function. Decrease of temperature causes inverse influence of Tn and Tn-1 intervals of the contraction force: at 35 degrees C coefficient of cross-correlation rho (0) of Tn-Pn equals 0.1 and coefficient of cross-correlation Tn-1-Pn rho (+1) equals -0.75; at 20 degrees C rho (0) = 0.8; rho (+1) = -0.15. Index Q10 for the process responsible for extrasystolic potentiation is about 3.0 and Q10 for restitutions process equals 1.5. At high temperature calcium seems to enter the myoplasm from extracellular pool, to be absorbed by sarcoplasmic reticulum and released in next cycle contraction. At low temperature, a part of calcium entering from that pool directly activates contractions at the same cycle.
D000818:Animals; D002118:Calcium / Q000502:physiology; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004558:Electric Stimulation / Q000379:methods; D006339:Heart Rate; D066298:In Vitro Techniques; D008433:Mathematics; D009200:Myocardial Contraction; D010210:Papillary Muscles / Q000502:physiology; D011817:Rabbits; D011897:Random Allocation; D013696:Temperature
D002118:Calcium
Issledovanie vliianiia temperatury na khronoinotropiiu miokarda teplokrovnykh.