Endogenous oxygen uptake of the hypothalamus in female rats

Abstract

The endogenous oxygen uptake has been determined in the hypothalamus, brain, hypophysis, and uterus of female rats. With the exception of the brain, similar changes have been detected in connection with estrous phases in all of these organs: lower respiratory rates were observed during diestrus and higher ones during estrus. Estradiol and progesterone were added in vitro to hypothalamus and brain slices of estrous and diestrous rats. Although both hormones consistently depressed the Qo₂ in brain, such effects were seen only in the hypothalamus of estrous animals.