[Relationship between the frequency and amplitude of myocardial contractions in rats adapted to heat].
Papillary muscles from the left ventricle of rats contracted under the effect of electrostimulation with the frequency of 0.2 c. p. s. in Krebs' solution at 28 degrees C. A study was made of the contraction amplitude with the increased stimulation frequency. Following preliminary heat adaptation (3 hours a day at 35 degrees C for one month) the contraction amplitude of the myocardium of the adapted animals with a high frequency was greater than the control level. This difference persisted at 36 degrees C and disappeared at 25 degrees C. Apparently adaptation leaves a definite structural trace in the cells of the cardiac muscle.
D000222:Adaptation, Physiological; D000818:Animals; D004558:Electric Stimulation; D006358:Hot Temperature; D008297:Male; D009200:Myocardial Contraction; D051381:Rats
Zavisimost' mezhdu chastotoĭ i amplitudoĭ sokrashcheniĭ serdechnoĭ myshtsy u adaptirovannykh k teplu krys.