Anorexic effects of interleukin 1 in the rat.
Interleukin 1 (IL-1) administration produces anorexia. Among unanswered questions about this effect are 1) whether it plays a role in the cachexia associated with chronic infection and cancer, and 2) whether IL-1 acts directly on food intake or indirectly by first lowering the set point for body weight. To investigate these questions, rats were infused with recombinant IL-1 continuously for 14 days through osmotic minipumps. Tolerance to the anorexic effects of the infusion developed within a few days. Control experiments showed that neither loss of IL-1 potency nor failure in the delivery system were responsible for recovery of food intake. Prior weight reduction completely overrode the anorexic effects of IL-1; previously food-restricted rats were hyperphagic initially despite receiving IL-1. This result is consistent with the view that IL-1 lowers the set point for body weight, but the development of tolerance prevented the full evaluation of this interpretation.
Mrosovsky
N
N
Department of Zoology, University of Toronto, Ontario, Canada.
Molony
L A
LA
Conn
C A
CA
Kluger
M J
MJ
D000818:Animals; D001067:Appetite Depressants; D001835:Body Weight / Q000187:drug effects; D005247:Feeding Behavior / Q000187:drug effects; D005260:Female; D007263:Infusions, Parenteral; D007375:Interleukin-1 / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000494:pharmacology; D012016:Reference Values
D001067:Appetite Depressants; D007375:Interleukin-1; D011994:Recombinant Proteins