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Influence of somatostatin on intestinal absorption
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EFFECT OF VIP INFUSION ON WATER AND ELECTROLYTEI~OVEMENTIN THE HUMAN DISTAL S~IALL BOWEL AND COLON G. J. Krejs. U n i v e r s i t y of Texas Health Science Center at Dallas, Southwestern lledical School, Dallas, Texas 75235 C l i n i c a l and experimental evidence suggests that elevated plasma VIP is the cause of the severe watery diarrhea in patients with pancreatic cholera syndrome. Careful studies of a few such patients revealed f l u i d secretion in the jejunum and near normal absorption in the ileum and colon. In these experiments we investigated the e f f e c t of elevated plasma VIP levels on water and ion transport in the ileum and colon. Pure porcine VIP (400 pmol/kg/h) was given intravenously to healthy subjects while t h e i r i n t e s t i n e was perfused with a plasma-like e l e c t r o l y t e s o l u t i o n . This VlP infusion rate has previousl y been shown to elevate plasma VIP from I 0 ± 3 to 7 5 ± I I p m o l / l i t e r (radioimmunoassay of Dr. S. R. Bloom). The table gives mean values (ml or meq/h, [-] absorption, [+] secretion; n = 5 , [ i l e u m ] , n : 4 [colon]). Water Sodium Potassium Chloride Bicarb. ILEUM: (30 cm)
Control VIP P
-60 +39 <0.05
-I0. I +5.3 <0.05
-0.34 +0.22 <0.05
-7.4 +3.6 <0.05
-2.7 +1.9 n.s.
COLON: Control -189 -33.9 +0.9 -33.3 -2.8 (entire VIP +II -0.2 +2.1 -6.4 +10.5 length) P. <0.02 <0.02 n.s. <0.01 n.s. In the ileum VIP i n f u s i o n induced water and ion secretion and in the colon NaCl absorption was reduced. Although so f a r not recognized in pancreatic cholera syndrome, these studies suggest that reduced absorption or secretion in the ileum and colon may c o n t r i b u t e to the pathogenesis of the severe watery diarrhea in such patients.
INFLUENCE OF SO~IATOSTATIN ON INTESTINAL ABSORPTION Laggner A., Prager J., Bayer M., Pointner H.
1
st
Dept. of ~!edizine,
Univ. of Vienna,
Austria
While the i n h i b i ~ r y effect of somatostatin (SST) on ~astrointestinal exocrine and endocrine secretion is well established the influence of this Dolypeptide on intestinal absorption is still matter of discussion. In a p r e v i o ~ r e p o r t we demonstrated that somatostatin inhibits the intestinal uptake and urine excretion of fluorescein-Na, a water soluble compound which is absorbed by diffusion through the intestinal wall. In further examinations we could demonstrate that SST blocks the increase of serum triglyceride levels following a test meal in normal subjects and in partially ~astrectomized patients. To further elucidate the mode of action of SST on fat absorption the influence of SST on intestinal alkaline phosphatase activity (lAP) in the duodenal juice was examined in 22 subjects undergoin~ diagnostic secretin-CCKtests, lAP in the duodenal juice is stimulated by i.v.infusion of secretinCCK. The i.v. administration of SST induces a distinct inhibition of lAP which is demonstrated not to be due to an exhaustion of the intestinal enzyme synthesis. As there is a functional relationship between fat absorption and lAP it is suggested that this inhibition of lAP may be one of the mechanisms by which SST inhibits intestinal fat absorption.
EFFECT OF VIP INFUSION ON WATER AND ELECTROLYTEI~OVEMENTIN THE HUMAN DISTAL S~IALL BOWEL AND COLON G. J. Krejs. U n i v e r s i t y of Texas Health Science Center at Dallas, Southwestern lledical School, Dallas, Texas 75235 C l i n i c a l and experimental evidence suggests that elevated plasma VIP is the cause of the severe watery diarrhea in patients with pancreatic cholera syndrome. Careful studies of a few such patients revealed f l u i d secretion in the jejunum and near normal absorption in the ileum and colon. In these experiments we investigated the e f f e c t of elevated plasma VIP levels on water and ion transport in the ileum and colon. Pure porcine VIP (400 pmol/kg/h) was given intravenously to healthy subjects while t h e i r i n t e s t i n e was perfused with a plasma-like e l e c t r o l y t e s o l u t i o n . This VlP infusion rate has previousl y been shown to elevate plasma VIP from I 0 ± 3 to 7 5 ± I I p m o l / l i t e r (radioimmunoassay of Dr. S. R. Bloom). The table gives mean values (ml or meq/h, [-] absorption, [+] secretion; n = 5 , [ i l e u m ] , n : 4 [colon]). Water Sodium Potassium Chloride Bicarb. ILEUM: (30 cm)
Control VIP P
-60 +39 <0.05
-I0. I +5.3 <0.05
-0.34 +0.22 <0.05
-7.4 +3.6 <0.05
-2.7 +1.9 n.s.
COLON: Control -189 -33.9 +0.9 -33.3 -2.8 (entire VIP +II -0.2 +2.1 -6.4 +10.5 length) P. <0.02 <0.02 n.s. <0.01 n.s. In the ileum VIP i n f u s i o n induced water and ion secretion and in the colon NaCl absorption was reduced. Although so f a r not recognized in pancreatic cholera syndrome, these studies suggest that reduced absorption or secretion in the ileum and colon may c o n t r i b u t e to the pathogenesis of the severe watery diarrhea in such patients.
INFLUENCE OF SO~IATOSTATIN ON INTESTINAL ABSORPTION Laggner A., Prager J., Bayer M., Pointner H.
1
st
Dept. of ~!edizine,
Univ. of Vienna,
Austria
While the i n h i b i ~ r y effect of somatostatin (SST) on ~astrointestinal exocrine and endocrine secretion is well established the influence of this Dolypeptide on intestinal absorption is still matter of discussion. In a p r e v i o ~ r e p o r t we demonstrated that somatostatin inhibits the intestinal uptake and urine excretion of fluorescein-Na, a water soluble compound which is absorbed by diffusion through the intestinal wall. In further examinations we could demonstrate that SST blocks the increase of serum triglyceride levels following a test meal in normal subjects and in partially ~astrectomized patients. To further elucidate the mode of action of SST on fat absorption the influence of SST on intestinal alkaline phosphatase activity (lAP) in the duodenal juice was examined in 22 subjects undergoin~ diagnostic secretin-CCKtests, lAP in the duodenal juice is stimulated by i.v.infusion of secretinCCK. The i.v. administration of SST induces a distinct inhibition of lAP which is demonstrated not to be due to an exhaustion of the intestinal enzyme synthesis. As there is a functional relationship between fat absorption and lAP it is suggested that this inhibition of lAP may be one of the mechanisms by which SST inhibits intestinal fat absorption.