title: The effect of ketamine/xylazine and carbon dioxide on plasma luteinizing hormone releasing hormone and testosterone concentrations in the male Norway rat.
abstract: The effect of a commonly used anaesthetic, ketamine/xylazine and/or carbon dioxide (CO(2)) on plasma luteinizing hormone releasing hormone (LHRH) and testosterone concentrations was determined in male Sprague-Dawley rats. These values were compared with values obtained from pre-anaesthetic control samples. Ketamine/xylazine treatment did not significantly affect testosterone concentrations. In contrast, LHRH started to decrease one hour after ketamine/xylazine administration and continued to significantly decrease after 24 h. In addition, in the CO(2) euthanasia-only group, LHRH concentrations were also significantly decreased. These results suggest that ketamine/xylazine anaesthesia followed by CO(2) euthanasia 24 h later is exerting a significant effect on LHRH concentrations 24 h after anaesthetizing, while only having a slight effect on testosterone, and that CO(2) is exerting an immediate significant effect on LHRH. In conclusion, LHRH analysis should be avoided after ketamine/xylazine anaesthesia and CO(2) euthanasia.
authors.affiliation: Health and Food Sector, HortResearch, East Street, PB 3123, Hamilton, New Zealand. egould@hortresearch.co.nz
authors.forename: E M
authors.initials: EM
authors.lastname: Gould
mesh_terms: D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D000778:Anesthetics, Dissociative / Q000494:pharmacology*; D000818:Animals; D000830:Animals, Laboratory; D002245:Carbon Dioxide / Q000494:pharmacology*; D007987:Gonadotropin-Releasing Hormone / Q000097:blood*; D007649:Ketamine / Q000494:pharmacology*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013739:Testosterone / Q000097:blood*; D014991:Xylazine / Q000494:pharmacology*
chemical_list: D000316:Adrenergic alpha-Agonists; D000778:Anesthetics, Dissociative; D002245:Carbon Dioxide; D014991:Xylazine; D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone; D007649:Ketamine