Effect of somatostatin and atropine infusion on intestinal transit time and fructose absorption in the perfused human jejunum.

Somatostatin has previously been shown to reduce nutrient absorption from the human jejunum. These studies were designed to examine whether changes in intestinal motility may be responsible for the inhibitory effect of somatostatin on intestinal absorption. Using triple-lumen perfusion techniques in healthy volunteers, somatostatin infusion (8 micrograms/kg/h) prolonged mean transit time from 9 to 16 min in a 30-cm jejunal test segment as estimated from dye dilution curves. Somatostatin infusion significantly reduced jejunal fructose absorption. Atropine (10 micrograms/kg/h, i.v.) caused a similar prolongation of mean transit time in the perfused jejunum. However, unlike somatostatin, atropine significantly increased fructose absorption. The observation that somatostatin and atropine affect absorption in opposite ways while prolonging intestinal transit time in a similar fashion suggests that the effects of somatostatin and atropine are due to a direct influence on absorption at the mucosal level that is independent of any effect on intestinal motility.