Cotlier E, Davidson C
Ophthalmic Res. 1983;15(1):29-37. doi: 10.1159/000265234.
A system for isolation of capillaries from the retina has been adapted to biochemical studies in vitro. Insulin receptors were identified in human and calf retinal blood vessels. Binding of 125I insulin by calf retinal blood vessels takes place through high affinity (low capacity) and low affinity (high capacity) receptor sites. Insulin binding is inhibited by glucagon, and cGMP and proinsulin. Dissociation of insulin receptor protein or lipid with Triton X-100 or phospholipase results in significant decreases in 125I insulin binding by retinal blood vessels. Dissociation of insulin bound occurs only at 0 degrees C which may be due to rapid internalization of insulin at higher temperatures. Activities of cAMP and cGMP phosphodiesterases and cyclase of retinal vessels were not significantly changed by incubation with insulin. At high concentrations in the media human growth hormone stimulates and then inhibits I125 insulin binding by retinal capillaries.
一种从视网膜分离毛细血管的系统已被应用于体外生化研究。在人和小牛视网膜血管中鉴定出了胰岛素受体。小牛视网膜血管对125I胰岛素的结合通过高亲和力（低容量）和低亲和力（高容量）受体位点进行。胰高血糖素、cGMP和胰岛素原可抑制胰岛素结合。用Triton X-100或磷脂酶使胰岛素受体蛋白或脂质解离会导致视网膜血管对125I胰岛素的结合显著减少。胰岛素结合的解离仅在0℃时发生，这可能是由于胰岛素在较高温度下快速内化所致。视网膜血管的cAMP和cGMP磷酸二酯酶以及环化酶的活性在与胰岛素孵育后没有显著变化。在培养基中高浓度时，人生长激素会刺激然后抑制视网膜毛细血管对I125胰岛素的结合。
