Interleukin-1 beta enhances corticosterone secretion by acting directly on the rat adrenal gland.
Interleukin-1 (IL-1), a monokine released by activated monocytes during the acute phase of the inflammatory responses, has been reported to enhance hypophyseal ACTH release mainly by stimulating hypothalamic CRF secretion. We investigated a possible direct effect of IL-1 beta on the adrenal gland of the rat. IL-1 beta was found to dose-dependently (4-8 micrograms/kg) raise corticosterone (B) blood concentration in hypophysectomized rats, without inducing any significant increase in the level of circulating ACTH. IL-1 beta did not affect B production by either isolated rat inner adrenocortical cells or fragments of adrenocortical autotransplants lacking chromaffin cells, but dose-dependently (10(-8)-10(-6) M) enhanced that by adrenal slices including both cortex and medulla. The secretory effect of IL-1 beta (10(-6) M) was completely blocked by both alpha-helical-CRF (10(-6) M) and corticotropin-inhibiting peptide (10(-6) M), two competitive inhibitors which (at these concentrations) were able to annul B response of adrenal slices to CRF (10(-6) M) and ACTH (10(-8) M), respectively. In light of many findings indicating that adrenal medulla contains and releases CRF and numerous POMC-derived peptides (including ACTH), the hypothesis is advanced that the mechanism underlying the direct secretory effect of IL-1 beta on the adrenal gland may involve the activation of an intraadrenal CRF/ACTH system.
Andreis
P G
PG
Department of Anatomy, University of Padua, Italy.
Neri
G
G
Belloni
A S
AS
Mazzocchi
G
G
Kasprzak
A
A
Nussdorfer
G G
GG
D000311:Adrenal Glands / Q000378:metabolism*; D000324:Adrenocorticotropic Hormone / Q000037:antagonists & inhibitors / Q000494:pharmacology; D000818:Animals; D003345:Corticosterone / Q000378:metabolism*; D003346:Corticotropin-Releasing Hormone / Q000037:antagonists & inhibitors / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D007016:Hypophysectomy; D007375:Interleukin-1 / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D010446:Peptide Fragments / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains
D007375:Interleukin-1; D010446:Peptide Fragments; C069206:alpha helical corticotropin-releasing hormone; C026034:ACTH (7-38); D000324:Adrenocorticotropic Hormone; D003346:Corticotropin-Releasing Hormone; D003345:Corticosterone