Zhu S Q, Kum W, Ho S K, Young J D, Cockram C S
Department of Medicine, Faculty of Medicine, Chinese University of Hong Kong, Shatin, N.T.
Brain Res. 1990 Oct 8;529(1-2):329-32. doi: 10.1016/0006-8993(90)90846-4.
Insulin receptor binding and effects upon uridine incorporation into nucleic acid were studied and compared to 3 insulin analogues, DPI, DPI-amide and DOI, in primary cultures of mouse astrocytes. From half-maximal inhibition of [125I]monoiodoinsulin binding (0.14 nM), the relative binding affinities of DPI, DPI-amide and DOI were 20%, 80% and 4% as compared with the native insulin, respectively. IC50 values were 158.5 nM for insulin, 199.5 nM for DPI-amide, 794.3 nM for DPI and 3980 nM for DOI. The corresponding relative potencies in stimulating [14C]uridine incorporation into TCA-insoluble material were 9% for DPI, 100% for DPI-amide and 1.1% for DOI. These findings are commensurate with data for these analogues in other insulin-sensitive tissues. It is concluded that the astrocyte insulin receptor has similar structural requirements to receptor in tissues outside the CNS, at least in terms of the involvement of the C-terminus of the insulin B-chain.
在小鼠星形胶质细胞原代培养物中，研究了胰岛素受体结合以及对尿苷掺入核酸的影响，并与3种胰岛素类似物DPI、DPI-酰胺和DOI进行了比较。从[125I]单碘胰岛素结合的半数最大抑制（0.14 nM）来看，与天然胰岛素相比，DPI、DPI-酰胺和DOI的相对结合亲和力分别为20%、80%和4%。胰岛素的IC50值为158.5 nM，DPI-酰胺为199.5 nM，DPI为794.3 nM，DOI为3980 nM。在刺激[14C]尿苷掺入三氯乙酸不溶性物质方面，相应的相对效力DPI为9%，DPI-酰胺为100%，DOI为1.1%。这些发现与这些类似物在其他胰岛素敏感组织中的数据一致。结论是，星形胶质细胞胰岛素受体与中枢神经系统外组织中的受体具有相似的结构要求，至少在胰岛素B链C末端的参与方面是如此。
