Kellum J M, Maxwell R J, Potter J, Kummerle J F
Surgery. 1986 Aug;100(2):445-53.
To determine whether mucosal serotonin (5-HT) is involved in the intestinal motility response to motilin, we studied the effects of intra-arterial infusions of motilin (5 X 10(-10) mol/L) in isolated, vascularly perfused segments of canine jejunum. Intraluminal pressures were continuously recorded through a perfused manometric catheter, and venous and luminal 5-HT levels were measured by radioimmunoassay. Luminal 5-HT output rose from a basal of 54 +/- 12 to a peak of 151 +/- 30 ng/min X 100 gm (p less than 0.01) with the motilin infusion. The earliest significant rise in luminal (5-HT), which occurred at 1 minute after the start of the motilin infusion, preceded the onset of phasic contractility. The rise in the motility index induced by motilin demonstrated a strong correlation (r = 0.72, p less than 0.01) with rises in luminal 5-HT output. 5-HT tachyphylaxis abolished the motility response to motilin; prior treatment with atropine abolished, while tetrodotoxin inhibited the luminal release of 5-HT. An infusion of exogenous 5-HT giving equivalent luminal 5-HT levels as induced by motilin led to similar phasic contractility and rise in the motility index. These findings suggest that motilin initiates phasic contractility in canine jejunum through the cholinergically mediated release of mucosal serotonin.
为了确定黏膜5-羟色胺（5-HT）是否参与了肠道对胃动素的运动反应，我们研究了在犬空肠分离的、血管灌注段中动脉内输注胃动素（5×10⁻¹⁰ mol/L）的作用。通过灌注测压导管连续记录腔内压力，并通过放射免疫测定法测量静脉和腔内5-HT水平。随着胃动素输注，腔内5-HT输出从基础值54±12上升至峰值151±30 ng/min×100 g（p<0.01）。腔内5-HT最早的显著升高发生在胃动素输注开始后1分钟，早于相性收缩的开始。胃动素诱导的运动指数升高与腔内5-HT输出升高呈强相关性（r = 0.72，p<0.01）。5-HT快速耐受消除了对胃动素的运动反应；预先用阿托品治疗可消除，而河豚毒素可抑制5-HT的腔内释放。输注外源性5-HT使腔内5-HT水平与胃动素诱导的水平相当，导致类似的相性收缩和运动指数升高。这些发现表明，胃动素通过胆碱能介导的黏膜5-羟色胺释放启动犬空肠的相性收缩。
