Influence of histamine on estrogen-induced inhibition of compensatory ovarian hypertrophy in hemiovariectomized rats.

The administration of histamine dihydrochloride (5 micrograms) into the lateral brain ventricle, H1-agonist IEM-813 (0.25 mg/kg) intraperitoneally, tavegil (0.05 mg/kg) intraperitoneally and dimedrol (50 mg/kg) subcutaneously did not change the rate of compensatory ovarian hypertrophy (COH) in hemiovariectomized rats. The treatment of rats with histamine or IEM-813 prevented the suppressive action of diethystilbestrol on COH, tavegil did not change and dimedrol enhanced the estrogen effect. Central histaminergic structures are suggested not be involved in the mechanism of PSH secretion. However, their stimulation inhibits the realisation of the negative feedback of estrogen.