Involvement of interleukin-1 and interleukin-1 receptor antagonist in rat pituitary cell growth regulation.
Interleukin-1 (IL-1), one of the mediators of the interaction between the immune and the neuroendocrine system, is well known to modulate anterior pituitary hormone secretion. As IL-1 influences growth of various cell types, we investigated whether IL-1 is also a growth factor of pituitary cells. We demonstrate that IL-1 dose and time dependently inhibits the growth of normal rat pituitary cells under serum-free conditions. The inhibitory potencies of IL-1 alpha (ED50, 8 pg/ml) and IL-1 beta (ED50, 6 pg/ml) were nearly identical. In the presence of low amounts of serum, both IL-1 alpha (ED50, 130 pg/ml) and IL-1 beta (ED50, 90 pg/ml) were less effective in inhibiting growth. The IL-1-induced growth inhibition was IL-1 receptor mediated, because both IL-1 alpha- and IL-1 beta-mediated growth suppression could be completely reversed by the IL-1 receptor antagonist, the physiological counterpart of IL-1. In the mammosomatotroph GH3 rat pituitary tumor cell line, IL-1 failed to influence growth, indicating that either IL-1 receptors are missing or the IL-1 signaling pathway is uncoupled from the growth regulation. In contrast to growth, in our rat pituitary monolayer cell culture system, IL-1 did not affect ACTH, GH, or PRL secretion as described previously. This discrepancy suggests the involvement of different mechanisms in the IL-1-induced mediation of growth and hormone secretion.
Renner
U
U
Max-Planck Institute of Psychiatry, Clinical Institute, Munich, Germany.
Newton
C J
CJ
Pagotto
U
U
Sauer
J
J
Arzt
E
E
Stalla
G K
GK
D000324:Adrenocorticotropic Hormone / Q000378:metabolism; D000818:Animals; D000906:Antibodies / Q000276:immunology; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D013006:Growth Hormone / Q000378:metabolism; D006801:Humans; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1 / Q000276:immunology / Q000494:pharmacology*; D010904:Pituitary Gland, Posterior / Q000166:cytology* / Q000378:metabolism; D010911:Pituitary Neoplasms / Q000473:pathology; D011388:Prolactin / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins; D012016:Reference Values; D012795:Sialoglycoproteins / Q000276:immunology*
D000906:Antibodies; C507763:IL1RN protein, human; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1; D011994:Recombinant Proteins; D012795:Sialoglycoproteins; D000324:Adrenocorticotropic Hormone; D011388:Prolactin; D013006:Growth Hormone