Thermoregulatory responses in mice following acute administration of principal nitrogenous excretory substances.
This study was designed to assess the effects of some key excretory nitrogenous substances on body temperature and selected ambient temperature (Ta) in the mouse. In the first experiment, a dosage-response curve was developed to assess the effects of urea, creatinine, and ammonium chloride on colonic temperature at a Ta of 20 degrees C. All three substances elicited a drop in body temperature at a critical dosage. The threshold dosages were 3280 mg/kg for urea, 1279 mg/kg for creatinine, and 365 mg/kg for ammonium chloride. In a second experiment the selected Ta was monitored using a temperature gradient system. Mice were injected with dosages of the nitrogenous substances that had previously been shown to cause hypothermia at a Ta of 20 degrees C. Urea and ammonium chloride had no significant effect on the selected Ta nor on the colonic temperature after 90 min in the temperature gradient. Creatinine elicited a slight lowering of the selected Ta but had no effect on colonic temperature. The thermoregulatory responses to extremely toxic dosages of the nitrogenous substances appear to be quite dissimilar to that when animals are treated with xenobiotic compounds.
Gordon
C J
CJ
Neurotoxicology Division, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711.
D000643:Ammonium Chloride / Q000494:pharmacology*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D001833:Body Temperature Regulation / Q000187:drug effects*; D003404:Creatinine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D014508:Urea / Q000494:pharmacology*
D000643:Ammonium Chloride; D014508:Urea; D003404:Creatinine