Leptin Role in Regulating Ovariectomized Induced Hypertension

Abstract

Hypertension is less prevalent in pre‐menopausal women compared to males of a similar age. Once women become menopausal, the incidence of hypertension increases significantly when compared to men. Though it has been established that estrogen plays a protective role against the development of hypertension in pre‐menopausal women, it is not clear what the underlying mechanisms might be. Most menopausal women experience a significant increase in body weight in the form of adipose tissue. Increases in adiposity is accompanied by increased levels of the “satiety hormone”, leptin, that also have cardiovascular regulatory properties. Thus, utilizing a menopausal rat model, we sought to test the hypothesis that leptin plays a role in increasing blood pressure and heart rate. Ovariectomized (OVX) adult female rats (i.e., 4‐week post‐surgery) were used in these experiments. OVX rats weighed more, had higher leptin and lower estrogen levels when compared to control females. Blood pressure and heart rate were significantly higher in OVX rats as well. When leptin was administered intracerebroventricularly into the control animals we observed a small decrease in blood pressure. However, administering the same dose in OVX rats resulted in an increase in blood pressure and heart rate. Taken together, these data suggest that estrogen dampens leptin's influence on blood pressure homeostasis and with the loss of estrogen, the influence of leptin on cardiovascular function is not inhibited.Support or Funding InformationIowa Osteopathic Educational Research Foundation