Portal v peripheral hyperinsulinemia and very low density lipoprotein triglyceride kinetics.

The effect of subcutaneously delivered insulin on the kinetics of rat plasma triglycerides was compared to that of intraperitoneally delivered insulin. The former route delivered insulin primarily extrahepatically and the latter, intraportally. In comparison to the intraperitoneally delivered insulin, the subcutaneously delivered insulin was associated with a higher peripheral serum insulin, lower serum glucose, lower serum FFA, lower serum triglycerides, and similar rate of triglyceride secretion. The activity of adipose tissue lipoprotein lipase was directly related to the serum insulin concentration. The pattern of serum triglycerides and lipoprotein lipase in the rats receiving subcutaneous insulin suggested that their rate of triglyceride removal exceeded that seen in the rats receiving intraperitoneal insulin. These observations indicate that the route of insulin delivery can influence the balance between the hepatic and extrahepatic effects of insulin on triglyceride kinetics.