title: Endogenous and exogenous heptadecapeptide gastrin transport across the pig liver.
abstract: In vivo studies in the pig showed no net loss or gain of endogenous porcine gastrin during transport across the liver in fasting animals. Infusion of synthetic human heptadecapeptide gastrin (G-17) in doses of 0,25, 0,5 and 1,0 microgram/kg/min raised circulating gastrin levels to those found in the postprandial state. At no time was there a loss or gain of immunologically determined gastrin across the liver. Changes in the molecular size of gastrin, however, suggested that qualitative but not quantitative effects followed the administration of G-17 in vivo. The disappearance of gastrin from the circulation was biphasic, with an initial half-life of 3 minutes and a slower phase suggesting recirculation or multicompartment equilibration. The distribution at equilibrium was +/- 20% of body weight calculated from arterial levels, but 30-40% if portal or hepatic venous values were used. The mean blood production rate was +/- 125 microgram/day but the portal contribution was only 30 microgram/day, suggesting an important alternative source of gastrin.
mesh_terms: D000818:Animals; D005260:Female; D005755:Gastrins / Q000097:blood / Q000378:metabolism*; D008099:Liver / Q000098:blood supply / Q000378:metabolism*; D008297:Male; D010477:Perfusion; D011863:Radioimmunoassay; D013223:Statistics as Topic; D013552:Swine / Q000378:metabolism*
chemical_list: D005755:Gastrins