Does Time of Exposure to Estradiol and LHRH Effect LH Release From Bovine Pituitary Cells? 1

Summary

Time course of 17-β estradiol and luteinizing hormone-releasing hormone effect on LH release was studied using bovine pituitary cells on day 5 of culture. LHRH at concentrations of .1, 1, 10 and 100 ng/ml increased LH in medium linearly with increasing log concentration of LHRH when present for .75, 1.5, 3, 6 and 24 hr and the percent increase over controls was same at each time period. In addition, estradiol (present for 6, 12 or 24 hr) at .5, 5, and 50 ng/ml also increased LH release linearly both in the presence or absence of LHRH. We conclude that the stimulatory effect of LHRH on LH release from bovine pituitary is consistant over 24 hr and the stimulatory effect of E2 on both basal and LHRH induced LH release may be mediaed at least in part directly on the pituitary.

The authors acknowledge Dr. R. R. Neitzel and L. T. Chapin for valuable assistance with computer programming and P. Harkins and C. Wallace for technical help.