牛大脑前动脉和脑微血管系统培养的平滑肌细胞中的白三烯C4受体

Leukotriene C4 receptors in cultured smooth muscle cells from bovine anterior cerebral arteries and microcerebrovasculatures.

作者信息

Zeng G Q, Rui Y C, Sun D X, Shen Y A

机构信息

Department of Pharmacology, School of Pharmacy, Second Military Medical University, Shanghai, China.

出版信息

Zhongguo Yao Li Xue Bao. 1992 Nov;13(6):490-3.

PMID:1338860

Abstract

Specific receptors for leukotriene C4 (LTC4) were identified on smooth muscle cells isolated from bovine anterior cerebral arteries (BACASMC) and bovine microcerebrovasculatures (BMSMC). [3H]LTC4 specific bindings to both cells at a fixed input reached the maxima at 60 min and 20 min, respectively. With incremental inputs of radioligand and a constant cell number, [3H]LTC4 specific bindings reached a plateau indicative of a saturable binding site. Analysis of Scatchard plots demonstrated a single population of high-affinity binding sites in both cells. The dissociation constant (Kd) for BACASMC was 39.2 +/- 1.3 nmol.L-1 and its Bmax was 19.3 +/- 2.1 pmol/10(6) cells. For BMSMC, Kd = 2.0 +/- 0.4 nmol.L-1, Bmax = 157 +/- 13 fmol/10(6) cells. The specific [3H]LTC4 bindings was inhibited by unlabeled LTC4, LTD4 and FPL-55712 (an SRS-A antagonist). The inhibitory rates for BACASMC were 70.4% and 35.3% by LTC4 and FPL-55712 at 1 mumol.L-1, respectively. For BMSMC the inhibitory rates were 96.9%, 73.9%, and 44.9% by LTC4, LTD4, and FPL-55712 at 10 mumol.L-1, respectively.

摘要

在从牛大脑前动脉（BACASMC）和牛脑微血管（BMSMC）分离出的平滑肌细胞上鉴定出白三烯C4（LTC4）的特异性受体。在固定输入量下，[3H]LTC4与两种细胞的特异性结合分别在60分钟和20分钟时达到最大值。随着放射性配体输入量的增加和细胞数量恒定，[3H]LTC4的特异性结合达到平台期，表明存在可饱和的结合位点。Scatchard图分析表明两种细胞中均存在单一的高亲和力结合位点群体。BACASMC的解离常数（Kd）为39.2±1.3 nmol·L-1，其最大结合容量（Bmax）为19.3±2.1 pmol/10(6)个细胞。对于BMSMC，Kd = 2.0±0.4 nmol·L-1，Bmax = 157±13 fmol/10(6)个细胞。未标记的LTC4、LTD4和FPL-55712（一种SRS-A拮抗剂）可抑制[3H]LTC4的特异性结合。在1 μmol·L-1时，LTC4和FPL-55712对BACASMC的抑制率分别为70.4%和35.3%。对于BMSMC，在10 μmol·L-1时，LTC4、LTD4和FPL-55712的抑制率分别为96.9%、73.9%和44.9%。