Influence of yohimbine on xylazine-induced depression of central nervous, gastrointestinal and cardiovascular function in the calf.
The antagonistic effect of yohimbine HCl (0.25 mg/kg IV), and alpha 2-adrenergic antagonist, on xylazine (0.05 mg/kg IV)-induced depression of central nervous and cardiovascular activity and rumen motility was studied in post-weaning calves. Yohimbine, administered 3 min post-xylazine, significantly decreased the duration of rumen amotility (38.3 +/- 4.2 min versus 14.0 +/- 2.2 min). Sedation, however, as monitored by the duration of fetlock knuckling in calves suspended in a body sling, was not shortened by yohimbine treatment. Yohimbine alone produced a significant tachycardia and led to a reduction of the duration of xylazine-induced bradycardia. Our data indicate that yohimbine produces a significant reversal of xylazine-induced rumen hypomotility at dosage levels that are without effect on sedation induced by this drug.
D000818:Animals; D002319:Cardiovascular System / Q000187:drug effects*; D002417:Cattle; D002490:Central Nervous System / Q000187:drug effects*; D003864:Depression, Chemical; D004064:Digestive System / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005769:Gastrointestinal Motility / Q000187:drug effects; D008297:Male; D012417:Rumen / Q000187:drug effects; D013843:Thiazines / Q000037:antagonists & inhibitors*; D014991:Xylazine / Q000037:antagonists & inhibitors*; D015016:Yohimbine / Q000494:pharmacology*
D013843:Thiazines; D014991:Xylazine; D015016:Yohimbine