Menuelle P, Buc H A, Plas C
Biochim Biophys Acta. 1987 May 18;928(3):332-40. doi: 10.1016/0167-4889(87)90193-5.
The glycogenic effects of a glucose load (15 mM) and/or insulin (10 nM) were studied in 18-day-old fetal rat hepatocytes after 2 days of culture when medium contained 4 mM glucose. A glucose load led to a stimulation of [14C]glucose glycogen labelling (20 min) earlier than with insulin (30-40 min); maximal stimulations were 3-fold after 1 h for the glucose load and 5-fold after 2-3 h for insulin. Simultaneous addition of the two agents produced synergic effects. When insulin was added 4 h after a glucose load (or vice versa), a second glycogenic response was elicited: a further addition of the same glycogenic agent was ineffective. The early glycogenic effects (up to 2 h) also occurred in the presence of 10 microM cycloheximide, with, however, some decrease of insulin stimulation. The contribution of medium glucose to the glycogen formed for 2 days (67% in the absence of glycogenic agent) was clearly enhanced by a glucose load and to a lesser degree by insulin after a 4-h exposure (83 and 71%, respectively). This was accompanied by a related modification of the participation of glucogenic precursors such as fructose and galactose. Thus, acute glycogenic response to glucose and insulin appeared both synergic and independent, and quite different in several aspects in cultured fetal hepatocytes.
在含有4 mM葡萄糖的培养基中培养2天后，研究了葡萄糖负荷（15 mM）和/或胰岛素（10 nM）对18日龄胎鼠肝细胞的糖原生成作用。葡萄糖负荷比胰岛素（30 - 40分钟）更早地刺激了[14C]葡萄糖糖原标记（20分钟）；葡萄糖负荷1小时后的最大刺激为3倍，胰岛素2 - 3小时后的最大刺激为5倍。同时添加这两种物质产生协同作用。当在葡萄糖负荷后4小时添加胰岛素（或反之亦然）时，引发了第二次糖原生成反应：再次添加相同的糖原生成剂无效。早期糖原生成作用（长达2小时）在存在10 microM环己酰亚胺的情况下也会发生，不过胰岛素刺激会有所降低。葡萄糖负荷明显增强了培养基葡萄糖对2天内形成的糖原的贡献（在不存在糖原生成剂的情况下为67%），胰岛素在4小时暴露后对其贡献的增强程度较小（分别为83%和71%）。这伴随着生糖前体如果糖和半乳糖参与的相关改变。因此，对葡萄糖和胰岛素的急性糖原生成反应既表现出协同性又具有独立性，并且在培养的胎肝细胞的几个方面有很大不同。
