Xylazine-ketamine-induced anesthesia in rats and its antagonism by yohimbine.
A combination of xylazine and ketamine was used to anesthetize 60 male rats, and then yohimbine was given to evaluate its reversing effect on xylazine-ketamine-induced anesthesia. In experiment A, xylazine (21 mg/kg of body weight) and ketamine (45 mg/kg) were admixed and administered IM to 12 Sprague-Dawley rats. Anesthesia lasted approximately 70 minutes. The xylazine-ketamine combination also induced polyuria, bradycardia, and bradypnea. When yohimbine (2.1 mg/kg) was given intraperitoneally 20 minutes after the xylazine-ketamine injection, the rats regained consciousness and righting reflexes within approximately 10 minutes. Yohimbine also reversed the bradycardia and bradypnea and appeared to reduce the polyuria induced by the xylazine-ketamine combination. In experiment B, xylazine (15.4 mg/kg) and ketamine (33 mg/kg) were admixed and given IM to 48 Holtzman rats. The combination induced surgical anesthesia for at least 30 minutes, during which a surgical procedure involving grafting a section of the sciatic nerve into the hypothalamus was performed. In rats in which yohimbine (1 mg/kg) was given intraperitoneally 45 to 60 minutes after xylazine-ketamine administration (before natural recovery from the anesthesia), the righting reflex was apparent in less than 10 minutes.
D000768:Anesthesia, General / Q000662:veterinary*; D000818:Animals; D006339:Heart Rate / Q000187:drug effects; D007649:Ketamine / Q000037:antagonists & inhibitors*; D008297:Male; D051381:Rats / Q000502:physiology*; D011919:Rats, Inbred Strains / Q000502:physiology; D012119:Respiration / Q000187:drug effects; D013843:Thiazines / Q000037:antagonists & inhibitors*; D014991:Xylazine / Q000037:antagonists & inhibitors*; D015016:Yohimbine / Q000494:pharmacology*
D013843:Thiazines; D014991:Xylazine; D015016:Yohimbine; D007649:Ketamine