Somatostatin receptors: identification and characterization in rat brain membranes.
Somatostatin receptors: identification and characterization in rat brain membranes.
复制标题
生长抑素受体：大鼠脑膜的鉴定和表征。
DOI：
10.1073/pnas.78.6.3930
复制
发表时间：
1981
影响因子：
11.1
通讯作者：
Patel,YC
中科院分区：
文献类型：
--
作者：
Srikant,CB;Patel,YC
我们已经确定和特点的十四肽生长抑素（SRIF;生长激素释放抑制因子）在大鼠脑中使用[125 I] Tyr 11]SRIF作为放射性配体的特异性受体。这些受体存在于从突触体的亚部分获得的膜中。来自大脑皮层的膜以高亲和力（Ka = 1.25 X 10（10）M-1）结合SRIF，并且具有0.155 X 10（-12）mol/mg的最大结合容量（Bmax）。阿片类药物或其他神经肽似乎都不会影响SRIF与脑细胞膜的结合。具有比SRIF更大生物效力的合成类似物--[D-Trp 8]SRIF、[D-Cys 14]SRIF和[D-Trp 8，D-Cys 14]SRIF--以比SRIF更大的亲合力与受体结合，而无活性类似物[（2 H）Ala 3]SRIF和[Ala 6]SRIF表现出低结合。受体密度与内源性生长抑素的比率在皮质、丘脑和纹状体中较高，在下丘脑中较低，在脑干和小脑中极低。因此，脑中的SRIF受体似乎是具有不同于内源性生长抑素的区域分布的独特的新型受体。
We have identified and characterized specific receptors for tetradecapeptide somatostatin (SRIF; somatotropin release-inhibiting factor) in rat brain using [125I]Tyr11]SRIF as the radioligand. These receptors are present in membranes obtained from a subfraction of synaptosomes. Membranes derived from cerebral cortex bind SRIF with high affinity (Ka = 1.25 X 10(10) M-1) and have a maximum binding capacity (Bmax) of 0.155 X 10(-12) mol/mg. Neither opiates nor other neuropeptides appear to influence the binding of SRIF to brain membranes. Synthetic analogs with greater biological potency than SRIF--[D-Trp8]SRIF, [D-Cys14]SRIF, and [D-Trp8, D-Cys14]SRIF--bind to the receptors with greater avidity than SRIF, whereas inactive analogs [(2H)Ala3]SRIF and [Ala6]SRIF exhibit low binding. The ratio of receptor density to endogenous somatostatin is high in the cortex, thalamus, and striatum, low in the hypothalamus, and extremely low in the brain stem and cerebellum. Thus, SRIF receptors in the brain appear to be a distinct, new class of receptors with a regional distribution different from that of endogenous somatostatin.