Intrinsic Pituitary Interleukin-1β Is Induced by Bacterial Lipopolysaccharide*

Using a specific antiserum recognizing recombinant rat interleukin-1β (IL-1β), immunoreactive material was localized to cytoplasmic granules in anterior pituitary endocrine cells and colocalized with TSH in thyrotropes. Authenticity was established by Northern blot hybridization using a specific rat IL-1β cRNA probe, revealing a 1.8-kilobase mRNA identical to that in the spleen. The marked increase in anterior pituitary IL- 1β message after the administration of bacterial lipopolysaccharide, raises the possibility that IL-1β may be involved in paracrine or autocrine regulation of pituitary function during infectious challenge. (Endocrinology 126: 3053–3058, 1990)