Kabadi U M
Medical Service, Veteran's Administration Medical Center, Des Moines, IA.
Metabolism. 1992 Feb;41(2):113-5. doi: 10.1016/0026-0495(92)90135-w.
The role of plasma glucose as a major regulator of glucagon secretion is well established. However, this feedback regulation appears to break down in several states in which a closer relationship is apparently evident between plasma glucagon and hepatic glycogen content. Therefore, we assessed plasma glucagon as well as glucose response (delta glucose) to intravenous (IV) bolus administration of 1 mg glucagon after an overnight fast (a reliable and accurate estimate of the magnitude of hepatic glycogen content) in a population of normal subjects and subjects with hepatic cirrhosis and hyperthyroidism, both of which are disorders characterized by hepatic glycogen depletion. Plasma glucose concentrations were not significantly different in either group. However, plasma glucagon and insulin concentrations were significantly increased and delta glucose significantly decreased in both cirrhotic patients and hyperthyroid patients as compared with normal subjects. Furthermore, a significant relationship (r = -.55, P less than .0001) was noted between delta glucose and plasma glucagon, but not plasma insulin. Therefore, we believe that pancreatic alpha-cell function may be dependent on hepatic glycogen content. Moreover, the primary action of glucagon may be to induce gluconeogenesis in the absence of hepatic glycogen stores due to declining insulin concentrations or insulin resistance.
血浆葡萄糖作为胰高血糖素分泌的主要调节因子，其作用已得到充分证实。然而，在几种状态下，这种反馈调节似乎失效，在这些状态下，血浆胰高血糖素与肝糖原含量之间的关系似乎更为密切。因此，我们在一组正常受试者以及患有肝硬化和甲状腺功能亢进症的受试者（这两种疾病均以肝糖原耗竭为特征）中，评估了空腹过夜后静脉推注1毫克胰高血糖素后的血浆胰高血糖素以及葡萄糖反应（葡萄糖变化量）（这是对肝糖原含量大小的可靠且准确的估计）。两组受试者的血浆葡萄糖浓度均无显著差异。然而，与正常受试者相比，肝硬化患者和甲状腺功能亢进患者的血浆胰高血糖素和胰岛素浓度均显著升高，葡萄糖变化量显著降低。此外，葡萄糖变化量与血浆胰高血糖素之间存在显著相关性（r = -0.55，P < 0.0001），但与血浆胰岛素之间无相关性。因此，我们认为胰腺α细胞功能可能依赖于肝糖原含量。此外，由于胰岛素浓度下降或胰岛素抵抗，在没有肝糖原储备的情况下，胰高血糖素的主要作用可能是诱导糖异生。
