大鼠脂肪细胞β受体亚型的研究

Studies on subtype of β-adrenoceptor in rat adipocytes

用异丙肾上腺素（ＩＳＯＰ）和非典型β受体激动剂ＢＲＬ３７３４４作用于大鼠脂肪细胞，测定所产生的ｃＡＭＰ含量，结果二种激动剂的量效曲线相似。ＩＳＯＰ和ＢＲＬ３７３４４的ＥＣ５０分别为２．３×１０－７ｍｏｌ·Ｌ－１和２．０×１０－７ｍｏｌ·Ｌ－１，二者的ＥＣ８０都是１０－６ｍｏｌ·Ｌ－１。在普萘洛尔（ＰＲＯＰ）和选择性β１受体阻断剂ＣＧＰ２０７１２Ａ存在的情况下，ＩＳＯＰ的作用被阻断，ＰＲＯＰ与ＣＧＰ２０７１２Ａ的ＩＣ５０分别为２．０×１０－７ｍｏｌ·Ｌ－１和５．０×１０－８ｍｏｌ·Ｌ－１。但ＰＲＯＰ及ＣＧＰ２０７１２Ａ却难以阻断ＢＲＬ３７３４４的作用，只有在很高浓度（１０－４ｍｏｌ·Ｌ－１）时才能阻断其作用。上述结果表明大鼠脂肪细胞上存在着β１受体和非典型的β受体。

The level of cAMP reduced by β-adrenoceptor agonists,isoprenaline(ISOP) and BRL 37344 were determined in rat adipocytes.The study shows that the concentration-response curve (CRC) of ISOP and BRL 37344 are very similar, and the EC50 of ISOP and BRL 37344 are 2.3 × 10-7 mol·L-1 and 5.0 × 10-7mol·L-1respectively and the EC80 of both ISOP and BRL 37344 are 10-6 mol·L-1.In the presence of propranolol(PROP) and CGP 20712A,the effect of ISOP are blocked,and the IC50 of PROP and CGP 20712A are 2.0×10-7 mol·L-1and 5. 0 × 10-8 mol· L-1 respectively.The effect of BRL 37344 can hardly be antagonized by PROP and CGP 20712A but can be blocked by PROPand CGP 20712A only in very high concentration (10-4 mol· L-1).The result suggests thst there are β1-adrenoceptor and atypical β-adrenoceptor in rat adlpocytes.