5-hydroxytryptamine and cholera secretion. Physiological and pharmacological studies in cats and rats.
The intestinal secretion evoked by close intra-arterial infusion of 5-hydroxytryptamine (5-HT) in cats was inhibited by tetrodotoxin, a drug abolishing action potentials. Furthermore, the intestinal secretion produced by placing a 2-mM 5-HT solution in the intestinal lumen of rats was inhibited by hexamethonium, a ganglionic receptor-blocking agent. These observations strongly indicate that 5-HT-induced secretion is, at least in part, neurally mediated. It was also shown that 5-HT receptors are involved in the pathophysiology of choleraic secretion, since the secretion was inhibited by making the experimental animal tachyphylactic against 5-HT. No effects of 5-HT tachyphylaxis were noted on fluid transport in normal intestines. The results are discussed in relation to a new hypothesis for the pathophysiology of cholera secretion.
D000818:Animals; D002415:Cats; D002772:Cholera Toxin / Q000378:metabolism*; D005260:Female; D006584:Hexamethonium Compounds / Q000494:pharmacology; D007413:Intestinal Mucosa / Q000378:metabolism*; D007422:Intestines / Q000294:innervation; D008297:Male; D010313:Partial Pressure; D051381:Rats; D011919:Rats, Inbred Strains; D011985:Receptors, Serotonin / Q000502:physiology; D012701:Serotonin / Q000494:pharmacology*; D013779:Tetrodotoxin / Q000494:pharmacology
D006584:Hexamethonium Compounds; D011985:Receptors, Serotonin; D012701:Serotonin; D013779:Tetrodotoxin; D002772:Cholera Toxin