Womack W A, Mailman D, Kvietys P R, Granger D N
Department of Physiology, College of Medicine, University of South Alabama, Mobile 36688.
Am J Physiol. 1988 Aug;255(2 Pt 1):G162-7. doi: 10.1152/ajpgi.1988.255.2.G162.
A quantitative videomicroscopic method was used to examine neurohumoral control of villous motility. Intraduodenal instillation of saline, 0.4% hydrochloric acid, or acidified predigested food did not cause a significant change in villous contraction frequency in an isolated segment of jejunum. Villous motility in the jejunum of fed dogs, from which the chyme had been removed, was not greater than that in fasted dogs (2.9 +/- 0.3 vs. 3.4 +/- 0.5 contractions/min). Furthermore, acid extracts of the duodenal mucosa did not produce an increase in jejunal villous motility when injected intravenously. These data argue against the existence of a humoral stimulant of villous motility (villikinin). Vagotomy caused only a small (20%) and transient (10 min) decline in villous motility. Vagal stimulation at 5, 10, and 20 Hz caused villous motility to increase by 24 +/- 7, 23 +/- 9, and 32 +/- 10%, respectively. Atropine blocked the effects of vagal stimulation. Section of the periarterial (sympathetic) nerves did not alter villous contractile activity. Stimulation of the periarterial nerves at 5, 10, and 20 Hz caused villous contraction frequency to decline by 41 +/- 5, 45 +/- 5, and 38 +/- 10%, respectively. This inhibition appears to involve both alpha- and beta-adrenergic receptors and a reduction in blood flow. Neither atropine, alpha-blockade, nor beta-blockade produced a sustained alteration in basal contraction frequency.
采用定量视频显微镜方法研究绒毛运动的神经体液控制。向十二指肠内滴注生理盐水、0.4%盐酸或酸化的预消化食物，在空肠分离段中并未引起绒毛收缩频率的显著变化。已清除食糜的喂食犬空肠中的绒毛运动，并不比禁食犬的绒毛运动更强（分别为2.9±0.3次/分钟和3.4±0.5次/分钟）。此外，十二指肠黏膜的酸提取物静脉注射后，并未使空肠绒毛运动增加。这些数据表明不存在绒毛运动的体液刺激物（绒毛收缩素）。迷走神经切断术仅使绒毛运动出现小幅（20%）且短暂（10分钟）的下降。以5、10和20赫兹频率刺激迷走神经，分别使绒毛运动增加24±7%、23±9%和32±10%。阿托品可阻断迷走神经刺激的作用。切断动脉周围（交感）神经并未改变绒毛的收缩活动。以5、10和20赫兹频率刺激动脉周围神经，分别使绒毛收缩频率下降41±5%、45±5%和38±10%。这种抑制作用似乎涉及α和β肾上腺素能受体以及血流量的减少。阿托品、α受体阻断剂或β受体阻断剂均未使基础收缩频率产生持续改变。
