Effects of heat-stress in rats, III. On pregnant rats, maternal organs and foetal tissues.

ABSTRACT

Exposure of intact and ovariectomized rats to high ambient temperature (34.4 degrees C, 60-65% relative humidity) resulted in reduction of their body weight, increased water consumption. The feed consumed which was lowered by 25% initially, did not alter later. Intact rats were also subjected to a still higher ambient temperature of 36.6 degrees C and 70 to 75% RH and the effects were observed. When compared with 'controls' no significant changes in the weights of ovaries or pituitary gland were seen due to heat stress in intact rats. But, the latter weighed heavier in ovariectomized rats. Adrenal glands were found enlarged and weighed more both in intact and ovariectomized rats. The average foetal weight due to high ambient temperature in intact rats was lower, but in ovariectomized rats it weighed more. Similarly, the average weight of the placenta was lower in intact rats but higher in ovariectomized rats due to thermal stress.