Effects of interleukin-1 infused into brain are antagonized by alpha-MSH in a dose-dependent manner.
Interleukin-1 (IL-1) in the brain stimulates the pituitary-adrenal axis and markedly suppresses cellular immune responses. alpha-Melanocyte-stimulating hormone (alpha-MSH) introduced into the ventricular system simultaneously with IL-1 blocked these effects of IL-1 in a dose-dependent manner, with 10 ng of alpha-MSH totally blocking the elevation of plasma ACTH and corticosterone and suppression of Natural Killer (NK) cell activity produced by a dose of IL-1 (100 pg) that otherwise causes maximal effects. In that IL-1 has been shown to promote production of alpha-MSH, these results suggest that actions of IL-1 in brain are under negative feedback control and, consequently, that the effects of this cytokine in brain are of biological significance.
Weiss
J M
JM
Duke University Medical Center, Department of Psychiatry, Durham, NC 27710.
Sundar
S K
SK
Cierpial
M A
MA
Ritchie
J C
JC
D000324:Adrenocorticotropic Hormone / Q000097:blood; D000818:Animals; D001921:Brain; D003345:Corticosterone / Q000097:blood; D004305:Dose-Response Relationship, Drug; D007267:Injections; D007276:Injections, Intraventricular; D007375:Interleukin-1 / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D007694:Killer Cells, Natural / Q000187:drug effects; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013238:Stereotaxic Techniques; D000521:alpha-MSH / Q000494:pharmacology*
D007375:Interleukin-1; D000521:alpha-MSH; D000324:Adrenocorticotropic Hormone; D003345:Corticosterone