Effects of intravenous versus intragastric glucose pretreatment on triglyceride secretion by perfused livers of fed rats.
The effects of the route of administration of 450 mg [U-14C]glucose to 250-g fed rats in vivo on the subsequent release of triglycerides from the perfused liver was studied. Livers were perfused for 180 min using a nonrecycling medium containing 10 mM glucose, 2 mM lactate, 0.2 mM pyruvate, and 100 microunits/mL porcine insulin. Biopsies were obtained at the beginning and end of the perfusions. The perfusate was collected and the secreted triglycerides were analyzed. Slower absorption of the intragastric glucose load contrasted with the rapid entry of the intravenous load; however, the total liver counts were not significantly affected by the route of glucose delivery. Hepatic glycogen concentration was also not significantly different, but the percent of total liver counts which was present in glycogen was significantly higher after intravenous glucose. The majority of the radioactivity in the livers of both groups of rats was present in water-soluble metabolites, with lesser amounts in triglycerides and phospholipids. Radioactivity in hepatic triglycerides declined significantly during perfusion only in the rats which had received glucose intravenously. The mean rate of triglyceride secretion from the livers of rats receiving the glucose intravenously was significantly lower than that of the rats receiving glucose intragastrically (0.21 +/- 0.05 vs. 0.97 +/- 0.28 mg/g liver per 180 min, p less than 0.05). The route of glucose administration affects both entry of glucose into the blood and subsequent hepatic triglyceride metabolism and secretion.
D000042:Absorption; D000818:Animals; D005260:Female; D005502:Food; D005947:Glucose / Q000008:administration & dosage*; D006003:Glycogen / Q000378:metabolism; D066298:In Vitro Techniques; D007275:Injections, Intravenous; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013270:Stomach; D014280:Triglycerides / Q000378:metabolism*
D010743:Phospholipids; D014280:Triglycerides; D006003:Glycogen; D005947:Glucose