Effects of epinephrine, clonidine, L-phenylephrine, and morphine on intestinal secretion mediated by Escherichia coli heat-stable enterotoxin in pig jejunum

Abstract

Perfusion of pig jejunum with Escherichia coli heat-stable enterotoxin (strain 1261) reversed net absorption of water and electrolytes to net secretion. Addition of the α-adrenergic agonists clonidine (5 × 10−7 M) or L-phenylephrine (5 × 10−6 M), or the opiate agonist morphine (3.6 × 10−6 M) to the perfusate reduced the secretory response to enterotoxin and stimulated absorption in normal jejunum. Epinephrine (5 × 10−5 M) did not stimulate absorption in controls but reduced chloride loss in the presence of enterotoxin. Mucosal sodium – potassium adenosine triphosphatase was unchanged but disaccharidase activity was decreased in the presence of enterotoxin. The results suggest that α-adrenergic agonists and opiate agonists may exert an antidiarrheal action by increasing net transport across intestinal epithelium.