Interleukin-2 induces corticotropin-releasing hormone release from superfused rat hypothalami: influence of glucocorticoids.
The present work shows that interleukin-2 (IL-2) is able to increase in a dose-dependent manner (25-100 U/ml) CRF release from continuous perifused hypothalami. The effects of IL-2 and IL-1 on CRF secretion are potentiated by the simultaneous action of the two cytokines at the hypothalamus. The stimulatory effect of IL-2 on CRF secretion is significantly inhibited by the presence of dexamethasone in the perifusion medium. However, the CRF response to IL-2 was similar in adrenalectomized animals and sham-operated rats. It is suggested that the action of IL-2 on hypothalamic CRF secretion is integrated in the communication between the immune system and the hypothalamic-pituitary-adrenocortical axis, and that such action is subjected to glucocorticoid negative feedback modulation. The mechanism underlying the effect of IL-2 on CRF release is unknown, but arachidonic acid metabolites do not seem to be involved, since neither a lipooxygenase (nordihidrogueretic acid) nor a cyclooxigenase (indomethacin) inhibitor affected the hypothalamic secretory response to IL-2.
Cambronero
J C
JC
Cajal Institute, Consejo Superior de Investigaciones Científicas, Madrid, Spain.
Rivas
F J
FJ
Borrell
J
J
Guaza
C
C
D000315:Adrenalectomy; D000818:Animals; D003346:Corticotropin-Releasing Hormone / Q000378:metabolism*; D003907:Dexamethasone / Q000494:pharmacology*; D004357:Drug Synergism; D005938:Glucocorticoids / Q000502:physiology*; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism*; D007213:Indomethacin / Q000494:pharmacology; D007375:Interleukin-1 / Q000494:pharmacology; D007376:Interleukin-2 / Q000494:pharmacology*; D008297:Male; D009637:Masoprocol / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains
D005938:Glucocorticoids; D007375:Interleukin-1; D007376:Interleukin-2; D009637:Masoprocol; D003907:Dexamethasone; D003346:Corticotropin-Releasing Hormone; D007213:Indomethacin