大鼠肝脏、卵巢及肾上腺胰岛素受体结合性质的比较

Comparison of the binding characteristics of insulin receptors on ovary, adrenal and hepatic plasma membrane from rats

目的比较大鼠肝脏、卵巢和肾上腺胰岛素受体（ｉｎｓｕｌｉｎ ｒｅｃｅｐｔｏｒ， ＩＲ）的结合性质。方法放射配体结合分析法对ＩＲ的数目（用结合容量表示）与亲和力（用饱和常数表示）进行检测。结果大鼠肝脏、卵巢和肾上腺ＩＲ高亲和位点的结合容量分别为７．３５９×１０个／ｍｇ白质、８．０２９×１０个／ｍｇ蛋白质和６．４４０×１０个／ｍｇ蛋白质，饱和常数分别为６．１４７×１０Ｍ－１、１．５２７×１０Ｍ－１、１．０１０×１０Ｍ－１；ＩＲ低亲和位点的结合容量分别为２．４０３×１０个／ｍｇ蛋白质、２．４０３×１０个／ｍｇ蛋白质和２．２５７×１０个／ｍｇ蛋白质，饱和常数分别为２．９２０×１０Ｍ－１、２．００８×１０Ｍ－１和０．４３３×１０Ｍ－１。结论卵巢和肾上腺也存在丰富的ＩＲ，其数量与肝脏的相似，而饱和常数小于肝脏的ＩＲ。提示胰岛素对卵巢和肾上腺可能有重要的调节作用。

Objective To compare the binding characteristics of insulin receptors (IR) on ovary,adrenal and hepatic plasma membrane from rats. Methods The number and affinity of IR was detected by radioligand binding assay. Results Scatchard plot analyses showed that the receptor numbers for high affinity sites are 7. 359×10/mg protein, 8. 029× 10/mg protein and 6. 440×10/mg protein of liver,ovarian and adrenal plasma membrane with KD of 6.147×107 M-1, 1. 528×10, M-1, and 1. 010×107 M-1 that. The receptor numbers for low affinity sites are 2. 403×10/mg protein,2. 212×10/mg protein,and 2. 257×10/mg protein respectively with KD of 2. 920×10M-1,2. 008×10 M-1 and 0. 433×10sM-1. Conclusion There are abundent IR on ovary and adrenal just as many as those on liver, although the KD are smaller. It suggests that insulin may play an important regulatory role in ovary and adrenal.