新生小牛肝组织胰岛素受体的功能

Functions of Hepatic Insulin Receptors in Neonatal Calves

检测7例胎龄276～284d、年龄7～11h的新生小牛肝组织胰岛素受体功能。用WGA－Setherose亲和层析法提纯肝组织胰岛素受体（Ins-R），观察受体125I-胰岛素特异性结合率;用Scatchard模型分析Ins－R数目及亲和性；以γ32P－ATP示踪底物多聚Glu4：Tyr1的磷酸化程度，了解胰岛素受体酪氨酸蛋白激酶（TPK）活性。同时检测血糖、皮质醇、胰高血糖素及胰岛素浓度，并分析各变量间的相关性。结果提示：肝组织Ins-R的TPK活性与年龄、胰岛素水平及胰岛素特异性结合率成正相关；新生小牛出生后不久肝组织Ins-R就具有一定的功能，且随着年龄增大而增强。

We assessed the functional characteristics of hepatic insulin receptors from seven newborn calves, whose gestation ages were 276 to 284 days, ages after birth were 7 to 11 hours.Insulin receptors from liver tissue were partially purified by affinity chromatography of WGA Sepharose. Insulin receptor number and affinity were observed with Scatchard analysis and tyrosine specific protein kinase activity were quantitated by the ability to phosphorylate substrate Glu4:Tyrl with y'P-ATP as tracer, meanwhile concentrations of blood glucose, plasma hydrocortisone, glucagon, and insulin were tested. The results showed hepatic insulin receptor TPK activity correlated positively with age after birth, insulin level and specific 125I-insulin binding. We suggest that hepatic insulin functions including its TPK activity established soon after birth and increased with growth in newborn calves.