Abstract
We have previously reported that restraint stress inhibits small intestinal motility in rats, and that the adrenergic β3-antagonist SR59230A administration recovered the inhibition. In the present study, we compared the effects of restraint stress and norepinephrine on small intestinal motility using α- and β-adrenergic antagonists. SR59230A did not recover the norepinephrine-induced inhibition of small intestinal motility. The norepinephrine-induced inhibition of small intestinal motility was recovered after administration of the α2-antagonist yohimbine, but not by α1-, β1-, and β2-antagonists. Considering these results, it is reasonable to assume that the mechanisms of inhibition of small intestinal motility due to restraint stress and norepinephrine treatment are different.
