Lipid A fever in cats.
In unanaesthetized cats the effect of lipid A on rectal temperature and on prostaglandin E2 (PGE2) activity in cisternal cerebrospinal fluid (c.s.f.) was examined. Lipid A was injected either intravenously or into the cerebral ventricles. 2. Lipid A injected intravenously in a dose of 1--4 mug/kg produced longlasting fever which was more often biphasic than monophasic. With a second injection a much shorter but usually hither monophasic response was produced. The cat was then for a time insensitive to I.V. lipid A but when the injections were repeated at 24 hr intervals brisk monophasic fevers were again produced. The threshold dose of I.V. lipid A lay between 0-1 and 0-3 mug/kg. 3. Lipid A injected into the cerebral ventricles in a dose of 100 ng or 1 mug produced long-lasting monophasic fever. No tolerance developed; the same or only slightly diminished responses occurred on repeated injections. The threshold dose was between 5 and 20 ng. 4. A cat rendered insensitive to I.V. lipid A gave its normal fever response to injection of lipid A into the cerebral ventricles. 5. The fever produced by lipid A injected I.V. or into the cerebral ventricles was associated with the appearance of, or a rise in PGE2 activity in c.s.f. 6. Both the fever and the PGE2 activity in c.s.f. produced by lipid A injected intravenously or into the cerebral ventricles were brought down and prevented by I.P. injections of aspirin, paracetamol, or indomethacin.
D000082:Acetaminophen / Q000494:pharmacology; D000818:Animals; D001241:Aspirin / Q000494:pharmacology; D001831:Body Temperature / Q000187:drug effects*; D002415:Cats; D005260:Female; D007213:Indomethacin / Q000494:pharmacology; D007275:Injections, Intravenous; D007276:Injections, Intraventricular; D008055:Lipids / Q000008:administration & dosage / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000008:administration & dosage / Q000494:pharmacology; D008297:Male; D011458:Prostaglandins E / Q000134:cerebrospinal fluid; D012475:Salmonella
D008055:Lipids; D008070:Lipopolysaccharides; D011458:Prostaglandins E; D000082:Acetaminophen; D001241:Aspirin; D007213:Indomethacin