Estradiol-dependent gene expression profile in the amygdala of ovariectomized SHRs

Pre-menopausal women exhibit a lower arterial pressure (AP), a lower sympathetic outflow and a greater baroreceptor reflex than age-matched men. However, AP and subsequent cardiovascular diseases dramatically increases in post-menopausal women. Estrogen level is believed to play a role in the regulation of the basal blood pressure, emotion and hormonal response in the different periods of life of a woman but the molecular mechanisms are still not well understood. Amygdala is a major nucleus of the limbic system involved in the control of cardiovascular, behavior and hormonal response to stress or fear. Since variations in estrogen level are associated with cardiovascular, behavior, and hormonal response changes, we hypothesized that it could also be associated with different neuronal functions in amygdala, characterized by a differential gene expression profile. Young Female SHRs were ovariectomized (OV) and half of them received an estradiol treatment (OV+E2) for one month. We investigated whether the amygdala of ovariectomized rats exhibit gene expression differences after estradiol treatment by using microarray technique. Two groups of female adult SHRs (4-weeks-old) were formed : ovariectomized rats (OV, n=4) and ovariectomized rats treated with estradiol (OV+E2, n=5) (Alzet minipump, 2 ug/day/rat) for one month. Rats were sacrificed by decapitation, brains were extracted, amygdala (right and left part) was dissected under microscope. Total RNAs were extracted from the amygadala and 200ng total RNAs of each rats were processed in the microarray experiment.