5-Hydroxytryptamine release into dog intestinal vasculaturel

BURXS, T. F., AND J. P. LONG. .pHydroxytryptamine release into dog intestinal vasculature. Am. J. Physiol. 21 I (3) : 6x g-625+ I 966. -The juxtaintestinal arteries of isolated intestinal segments of dogs were perfused with Krebs bicarbonate solution and the effluent solution from the vein was either collected or directly superfused over other test organs. By use of isolated superfused rat uteri, thin-layer chromatography, and comparative fluorescence spectra, the venous effluent was demonstrated to contain 5-HT. Continuous estimation of 5-HT concentration in the effluent was accomplished by means of a flow-through cuvette in a spectrophotofluorometer. Various stimuli, including scratching the serosal surface of the isolated intestinal segment, intraarterial administration of acetylcholine, and increasing intraluminal pressure, were found to markedly increase 5-HT release. The release of 5-WT may be involved in physiological activity of the intestine, perhaps being involved in the peristaltic reflex, or may supply additional 5-HT for blood platelet transport.