Effects of interleukin-1β on secretion of Follicle-Stimulating Hormone (FSH) and luteinizing hormone (LH) by cultured rat anterior pituitary cells

Abstract

Interleukin-1β (IL-1β) at doses of 0.15 and 1.5 nM significantly inhibited FSH secretion and stimulated LH secretion by cultured rat pituitary cells after 24–72 hr incubation whereas 15 pM of IL-1β was not effective. Treatment with IL-1β for 12–48 hr did not affect intracellular content of FSH. However, treatment with 0.15 and 1.5 nM of IL-1β for 72 hr significantly suppressed intracellular content of FSH whereas various doses of IL-1β incubated with the cells for 12–72 hr showed no effect on the intracellular content of LH. Pretreatment with IL-1β for 48 hr inhibited both GnRH-mediated LH and FSH secretions by the pituitary. The secretion of FSH and LH mediated by an activator of protein kinase C, phorbol 12-myristate 13-acetate, was also significantly suppressed by pretreatment with IL-1β for 48 hr. These results suggest that (a) IL-1β has opposite effects on the secretion of LH and FSH and (b) pretreatment with IL-1β suppresses GnRH-mediated stimulation of LH and FSH by the pituitary and this suppressive effect of IL-1β may involve the suppression of a protein kinase C-dependent mechanism.