Effect of dopamine and bromocriptine on rat ileal and colonic transport. Stimulation of absorption arid reversal of cholera toxin-induced secretion

M. Donowitz, G. Elta, L. Battisti, R. Fogel, E. Label-Schwartz

Research output: Contribution to journalArticle

Abstract

Water and electrolyte transport were determined in rat ileum and colon using the single-pass perfusion technique. Intraperitoneal dopamine caused prompt stimulation of both ileal and colonic water absorption. The dopamine effect was mediated by both specific dopamine and α2-adrenergic receptors. Haloperidol, a specific dopamine antagonist, and yohimbine, an α2-adrenergic antagonist, inhibited the effect of dopamine in ileal absorption; both antagonists alone had no effect on basal water transport. Bromocriptine (intravenous and intraluminal) stimulated ileal and colonic water absorption, which was inhibited by haloperidol and yohimbine, and reversed cholera toxin-induced ileal secretion. Magnitude and time-courses of the increased water absorption in ileal loops inoculated with cholera toxin were the same as in loops, inoculated with saline, suggesting that bromocriptine acted to reverse cholera toxin-induced secretion by stimulating absorption. Bromocriptine had no effect on the cyclic adenosine monophosphate increase caused by cholera toxin. We conclude (a) dopamine stimulates water absorption in vivo in rat ileum and colon; (b) this dopamine effect is via specific dopamine and α2-receptors; (c) bromocriptine stimulates water absorption in ileum and colon and also acts by dopamine and α2-receptors; and (d) bromocriptine reverses cholera toxin-induced secretion.

Original languageEnglish (US)
Pages (from-to)516-523
Number of pages8
JournalGastroenterology
Volume84
Issue number3
StatePublished - Mar 1983
Externally publishedYes

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ASJC Scopus subject areas

  • Hepatology
  • Gastroenterology

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