The effects of cyclooxygenase inhibitors on tumor-induced anorexia in rats.
BACKGROUND
Interleukin-1 (IL-1) and tumor necrosis factor (TNF) are potent induces of prostaglandin (PG) synthesis and injection of PGE, IL-1, or TNF decreases food intake in healthy animals, whereas the anorexigenic effects of injected IL-1 and TNF are blocked by inhibitors of PG synthesis. It has been hypothesized that host secretion of IL-1 and TNF contribute to tumor-induced anorexia. This study was undertaken to determine whether administration of PG inhibitors alters food intake in anorectic rats implanted with Walker 256 carcinoma.


METHODS
Groups of six tumor-bearing rats were implanted with slow-release pellets containing ibuprofen, indomethacin, or acetylsalicylic acid. Food intake, tumor growth, and body temperature were monitored for 14 days and compared with control tumor-bearing animals implanted with placebo pellets.


RESULTS
Tumor growth was associated with anorexia, fever, weight loss, and increased leukocyte secretion of IL-1 and TNF. Indomethacin and ibuprofen retarded tumor growth 30-40% and lowered body temperature compared with controls, but had no effect on food intake or body weight of tumor-bearing animals.


CONCLUSIONS
Prostaglandins do not mediate tumor-induced anorexia.
McCarthy
D O
DO
University of Wisconsin-Madison, School of Nursing 53792.
Daun
J M
JM
D000818:Animals; D000855:Anorexia / Q000209:etiology*; D001835:Body Weight / Q000187:drug effects; D002279:Carcinoma 256, Walker / Q000473:pathology / Q000503:physiopathology*; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology*; D004435:Eating / Q000187:drug effects; D007375:Interleukin-1 / Q000378:metabolism; D008297:Male; D009368:Neoplasm Transplantation; D011453:Prostaglandins / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
D016861:Cyclooxygenase Inhibitors; D007375:Interleukin-1; D011453:Prostaglandins; D014409:Tumor Necrosis Factor-alpha