The effect on intestinal calcium absorption of somatostatin in man

Somatostatin has been detected in the gastrointestinal tract and has been shown to have wide actions on gastrointestinal function. Using an isotope method with 51Cr as a stool marker, we have examined the absorption of 47Ca in 9 healthy volunteers with and without infusion of cyclic somatostatin (250 microgram/h for 2 hours). Both serum and faecal measurements show reduced 47Ca-absorption during somatostatin infusion, net absorption falling from 53.0 +/- 14% without to 40.4 +/- 13% with somatostatin. Possible explanations are discussed with special emphasis on the possibility of an inhibition of active calcium transport, which may be a more general mode of somatostatin action.