Bile secretion in man. The effects of somatostatin, vasoactive intestinal peptide and secretin.
In 41 patients, operated upon for common bile duct stones, a temporary bile fistula was achieved by means of a T-tube and a Foley-catheter with an occludable balloon. To learn more about peptide control of bile secretion, 6-8 days after surgery, bile flow was studied before as well as during infusion of the three peptides somatostatin, vasoactive intestinal peptide and secretin. The findings, also presented in Figure 17, were: 1. During somatostatin infusion, bile secretion decreased by 30%, and bile lipid output was reduced by some 10%. The clearance of [14C]-erythritol decreased by 25%, indicating an effect on the bile acid-dependent canalicular bile secretion (Paper I). 2. Vasoactive intestinal peptide (VIP) increased bile secretion by 65%. The concentration of bile lipids decreased, whereas the output was uneffected. The bicarbonate concentration increased, and the concentrations of sodium and potassium were uneffected. [14C]-erythritol clearance was not influenced by VIP infusion. Thus, VIP stimulated bile secretion at the ductular level (Paper II). 3. VIP increased bile secretion by 60%, whereupon secretin increased it by another 70%. Neither of the two peptides effected bile acid output. Both VIP and secretin increased bicarbonate output, whereas only VIP increased the concentration. The clearance of [14C]-erythritol was uneffected by VIP infusion, but increased following secretin, as did the clearance of [14C]-mannitol. Thus, VIP stimulated bile secretion at the ductular level, whereas secretin seemed to stimulate bile secretion both at the ductular level and at the bile acid non-dependent canalicular level (Paper III). 4. Whereas VIP stimulated bile secretion, somatostatin decreased it by some 40%. Even when somatostatin was administered during VIP infusion, no reduction of the VIP-induced choleresis was seen. VIP increased both bicarbonate concentration and output, whereas somatostatin had the opposite effect. The concentration of chloride increased following VIP infusion, but decreased following somatostatin. The output of bile acids was not influenced by VIP infusion and decreased by somatostatin, whereas total lipid concentration increased during somatostatin infusion with a decrease when VIP was added. Thus, somatostatin acts on the bile acid-dependent canalicular bile secretion and also, to some extent, on the ductular secretion. The effects of the two peptides on bile secretion are independent of each other (Paper IV). 5. While fasting, 6-8 days after bile duct surgery, bile secretion averaged 290 microliters/min. Canalicular bile secretion, as measured by the clearance of [14C]-erythritol, constituted some 80% of total bile flow. Maximum de novo synthesis of bile acids was 8.7 mmol/24 h, implying a 8-9 fold stimulation due to interrupted enterohepatic circulation (Paper V). 6. No serious side effects from this method with temporary bile fistulas following bile duct surgery were found. Therefore, the method is recommended for further research on human bile secretion (Paper V).
Nyberg
B
B
Department of Surgery, Huddinge University Hospital, Karolinska Institutet, Stockholm, Sweden.
D001646:Bile / Q000378:metabolism*; D001652:Bile Ducts / Q000187:drug effects / Q000378:metabolism*; D002758:Cholangiography; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D012633:Secretin / Q000494:pharmacology*; D013004:Somatostatin / Q000494:pharmacology*; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology*
D012633:Secretin; D014660:Vasoactive Intestinal Peptide; D013004:Somatostatin