Freyse E J, Fischer U, Albrecht G, Marx S, Keilacker H
Central Institute of Diabetes Gerhardt Katsch, Karlsburg, GDR.
Diabetologia. 1987 Jun;30(6):402-8. doi: 10.1007/BF00292542.
The in vivo flux rates of glucose (6-3H-glucose) and of alanine (U-14C-alanine) were measured in insulin-dependent chronically diabetic dogs which were infused with insulin employing a bedside-type artificial B cell and either the peripheral or the portal venous route. In comparison with non-diabetic control animals the diabetic dogs had near-normal patterns of glucose metabolism and pancreatic glucagon regardless of the route of insulin administration. They also showed reduced basal portal but moderately elevated peripheral insulin levels on peripheral and near-normal peripheral values on portal insulin infusion. Both concentration and production rates of alanine were reduced on peripheral (0.142 +/- 0.016 mmol/l, 4.73 +/- 0.49 mumol.kg-1.min-1, p less than 0.05) but normal on portal insulin (0.206 +/- 0.030 mmol/l, 6.33 +/- 0.63 mumol.kg-1.min-1). The alanine clearance was slightly elevated or normal in the diabetic dogs, and the glucose production from alanine showed a strongly delayed response to an exogenous glucose load on either route of insulin administration. It is concluded that the peripheral hyperinsulinism during posthepatic insulin administration stimulates glucose utilisation to a normal extent, but inhibits the provision of amino groups in resting muscle. Alanine synthesis is thereby reduced, and the carbon moieties are shunted from glucose into circulating lactate. Long-term studies are needed to elucidate the role of the liver under these conditions.
采用床边型人工B细胞，通过外周或门静脉途径给胰岛素依赖型慢性糖尿病犬输注胰岛素，测量其体内葡萄糖（6-³H-葡萄糖）和丙氨酸（U-¹⁴C-丙氨酸）的通量率。与非糖尿病对照动物相比，无论胰岛素给药途径如何，糖尿病犬的葡萄糖代谢和胰高血糖素模式接近正常。在外周胰岛素输注时，它们的基础门静脉胰岛素水平降低，但外周胰岛素水平适度升高，门静脉胰岛素输注时外周胰岛素水平接近正常。外周丙氨酸的浓度和生成率均降低（0.142±0.016 mmol/L，4.73±0.49 μmol·kg⁻¹·min⁻¹，p<0.05），但门静脉胰岛素输注时正常（0.206±0.030 mmol/L，6.33±0.63 μmol·kg⁻¹·min⁻¹）。糖尿病犬的丙氨酸清除率略有升高或正常，无论胰岛素给药途径如何，丙氨酸生成葡萄糖对外源性葡萄糖负荷的反应均强烈延迟。结论是，肝后胰岛素给药期间的外周高胰岛素血症在正常程度上刺激葡萄糖利用，但抑制静息肌肉中氨基的供应。从而丙氨酸合成减少，碳部分从葡萄糖分流到循环乳酸中。需要进行长期研究以阐明在这些情况下肝脏的作用。
