Synergistic effect of rhTNF-alpha and rhIL-1 alpha in inducing anorexia in rats.
To investigate whether there is a synergistic effect of recombinant human tumor necrosis factor-alpha (rhTNF-alpha) and recombinant human interleukin-1 alpha (rhIL-1 alpha) in inducing anorexia, 32 rats with jugular catheters were studied (8 rats/group): controls received normal saline; the IL-1 group received rhIL-1 alpha (10 micrograms/kg); the TNF group received rhTNF-alpha (30 micrograms/kg); and the IL-1 + TNF group received the same concentration of both rhIL-1 alpha+rhTNF-alpha for 3 days; solutions were then switched to normal saline. No significant decrease in light- and dark-phase food intake occurred during infusion of subeffective rhTNF-alpha. Food intake was decreased on the first rhIL-1 alpha infusion day because of a decreased meal number during the dark phase. A significant decrease in food intake occurred with combined infusion of rhIL-1 alpha+rhTNF-alpha because of a reduction in meal number during dark phase and meal size during light phase. Our results show that rhIL-1 alpha and rhTNF-alpha, when administered concurrently, had a synergistic effect in inducing anorexia, suggesting that low concentrations of these cytokines as produced endogenously may have potential effects on other biological functions in vivo.
Yang
Z J
ZJ
Department of Surgery, University Hospital, State University of New York Health Science Center, Syracuse 13210.
Koseki
M
M
Meguid
M M
MM
Gleason
J R
JR
Debonis
D
D
D000818:Animals; D000855:Anorexia / Q000139:chemically induced / Q000503:physiopathology*; D001835:Body Weight / Q000187:drug effects; D002940:Circadian Rhythm; D003624:Darkness; D004357:Drug Synergism; D005247:Feeding Behavior / Q000187:drug effects*; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology*; D008027:Light; D008297:Male; D051381:Rats; D011916:Rats, Inbred F344; D011994:Recombinant Proteins / Q000494:pharmacology; D012016:Reference Values; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D007375:Interleukin-1; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha