The Effect of Gallotannins and (+)-Catechin on the Stimulated Fluid Secretion on the Colon, Following a Rhein Perfusion in Guinea Pigs¹

Abstract

Using ^99mTc-EDTA as a non-absorbable volume marker, perfusion experiments on guinea pigs colon revealed the secretagogue effect of 0.7 mM rhein solution (circulating water increase x = + 2.8 ml/hour, SD 0.6 ml, N = 10). After omission of rhein, gallotannins in a 0.1% concentration effectively inclined the stimulated secretion, into absorption (x =-2.0 ml/hour, SD 0.4 ml, N = 4). Catechin (0.1%) had no marked effect. If a perfusion with tri-or pentagalloylglucose is preceding a rhein perfusion, the secretagogue effect of rhein is antagonised, although no absorption was detected. Catechin showed no activity. The addition of tri- or pentagalloylglucose to a rhein containing perfusate inclines significantly the observed secretion.