가토(家兎)에서 xylazine의 혈압하강(血壓下降) 효과(效果)에 대한 yohimbine의 길항작용(拮抗作用)

Antagonism of xylazine-induced hypotensive effect by yohimbine in rabbits

Xylazine is commonly used for anesthesia in veterinary medicine and various adverse effects are developed. To examine if the severe hypotensive response associated with xylazine-induced anesthesia might be resulted from the stimulation of presynaptic alpha-2 adrenoceptors or the increase of vagal tone, effects of yohimbine, atropine and atropine with vagotomy on xylazine-induced severe and long-lasting hypotensive responses were investigated in rabbits. The results were summarized as follows: 1) Intravenously injected xylazine(1mg/kg)-induced hypotensive responses were inhibited by yohimbine(p<0.001). 2) Intravenously injected xylazine(1mg/kg)-induced hypotensive responses were not changed by atropine. 3) Intravenously administered xylazine(1mg/kg)-induced hypotensive responses are not changed by atropine with vagotomy. These results indicate that xylazine is thought to cause severe hypotensive response during anesthesia primarily by stimulating presynaptic alpha-2 adrenoceptors and other receptors or mechanisms may participate in the hgpotensive response of xylazine.