Chronic inhibitory effect of insulin on plasma lipid concentrations in rats with transplanted pancreas.
BACKGROUND
Hyperinsulinemia, which is usually related to insulin resistance, is considered to be an important risk factor for coronary artery disease. Our study examines the influence of portal delivery of endogenous insulin after pancreas transplantation on plasma lipid metabolism, as compared with systemic delivery of insulin.


METHODS
Pancreas was transplanted heterotopically in normal rats by anastomosis of the donor portal vein to the recipient portal vein (PPTx) or inferior vena cava (CPTx) as an in vivo model of endogenous hyperinsulinemia.


RESULTS
The mean value of plasma insulin concentration of CPTx and PPTx rats was 149 and 165% that of control rats, whereas the plasma glucose concentration of CPTx and PPTx rats did not differ significantly from that of control rats. Plasma triglyceride (TG) concentrations were significantly lower in both PPTx and CPTx rats than control rats. During the intravenous glucose tolerance test, the area under the insulin concentration curves of CPTx and PPTx rats was 204 and 215% that of control rats, and they were correlated negatively with plasma TG concentrations. Plasma cholesterol and TG concentrations were significantly lower in PPTx rats than in control and CPTx rats.


CONCLUSIONS
Chronic hyperinsulinemia has a dose-dependent inhibitory effect on the regulation of plasma TG concentrations in rats with a transplanted pancreas. Significant lower lipid levels in PPTx rats than in CPTx rats suggest that portal delivery of insulin from the transplanted pancreas is relatively preventive for the atherosclerotic process as compared with systemic delivery of insulin.
Abe
H
H
Department of Surgery, Graduate School of Medicine, University of Tokyo, Japan.
Yamada
N
N
Ishibashi
S
S
Makuuchi
M
M
D000714:Anastomosis, Surgical; D000818:Animals; D019540:Area Under Curve; D001786:Blood Glucose / Q000378:metabolism; D002784:Cholesterol / Q000097:blood*; D008076:Cholesterol, HDL / Q000097:blood; D005951:Glucose Tolerance Test; D006946:Hyperinsulinism / Q000097:blood*; D007328:Insulin / Q000097:blood*; D008297:Male; D016035:Pancreas Transplantation / Q000379:methods / Q000502:physiology*; D011169:Portal Vein / Q000601:surgery; D051381:Rats; D011917:Rats, Inbred Lew; D012016:Reference Values; D014185:Transplantation, Isogeneic; D014280:Triglycerides / Q000097:blood*; D014682:Vena Cava, Inferior / Q000601:surgery
D001786:Blood Glucose; D008076:Cholesterol, HDL; D007328:Insulin; D014280:Triglycerides; D002784:Cholesterol