Neurohumoral control of villous motility

WA Womack, D Mailman, PR Kvietys… - American Journal of …, 1988 - journals.physiology.org
WA Womack, D Mailman, PR Kvietys, DN Granger
American Journal of Physiology-Gastrointestinal and Liver …, 1988journals.physiology.org
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 …
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.
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