[Cold-induced paralysis and recovery of lung respiration and heart contractions in newborn rats (inversion of Arrhenius law for physiological functions)].
Arrest of respiration and heart activity in new-born rats aged 3-4 days and 10-11 days was shown to occur at a body temperature 6-7 degrees C and 2-3 degrees C lower than in adult rats, resp. At room temperature the body temperature of profoundly cooled rat's litter gradually increases and the functions are restored. In 3-4-day old rats, at the body temperature rising from profound cooling to 15-18 degrees C, the respiration and heart rates are 2-4-fold more than at the same temperature attained from the normal body temperature. These differences in the respiration and heart rates at the same body temperature suggest an inversion of the Arrhenius law (the Q10 coefficient) for physiological functions in early ontogenesis. This effect completely disappears in 10-11-day old rats.
Ivanov
K P
KP
I. P. Pavlov Institute of Physiology, Russian Acad. Sci., 199034, St. Petersburg, Nab. Makarova, 6, Russia.
Petrova
O P
OP
Nazarova
L A
LA
Morozov
G B
GB
D000818:Animals; D006323:Heart Arrest / Q000209:etiology / Q000503:physiopathology*; D006339:Heart Rate; D007036:Hypothermia, Induced / Q000009:adverse effects; D051381:Rats; D015656:Respiratory Mechanics; D017694:Rewarming