Jard S, Lombard C, Marie J, Devilliers G
Am J Physiol. 1987 Jul;253(1 Pt 2):F41-9. doi: 10.1152/ajprenal.1987.253.1.F41.
Mesangial cells respond to vasopressin by contraction and increased prostaglandin production. The purpose of the present study is to characterize vasopressin receptors from these cells. Glomeruli were isolated from rat kidneys and plated for explant growth of mesangial cells. Membranes were prepared from cells grown for 6 wk and tested for their ability to bind [3H]vasopressin (lysine vasopressin). These membranes contained a single class of specific vasopressin binding sites [equilibrium dissociation constant (Kd) = 10 +/- 1 nM, maximal binding capacity (Bmax) = 270 +/- 7 fmol/mg protein for 5 determinations]. Vasopressin induced a dose-dependent (apparent Kact value = 2 nM) accumulation of labeled inositol phosphates in myo[3H]inositol-prelabeled mesangial cells incubated in the presence of 10 mM of Li. Conversely, vasopressin failed to alter the adenylate cyclase activity of mesangial cell membranes. Competition experiments with a series of vasopressin structural analogues that have different degrees of affinity for V2-(renal), V1a- (vascular and hepatic), and V1b- (adenohypophyseal) receptors, indicated that vasopressin receptors from rat glomerular mesangial cells resemble the V1a- receptor subtype.
系膜细胞通过收缩和增加前列腺素生成对血管加压素产生反应。本研究的目的是对这些细胞中的血管加压素受体进行特性描述。从大鼠肾脏分离肾小球并铺板以进行系膜细胞的外植体生长。从生长6周的细胞制备膜，并检测其结合[³H]血管加压素（赖氨酸血管加压素）的能力。这些膜含有一类单一的特异性血管加压素结合位点[平衡解离常数（Kd）= 10 ± 1 nM，5次测定的最大结合容量（Bmax）= 270 ± 7 fmol/mg蛋白质]。在10 mM锂存在下孵育的用肌醇[³H]肌醇预标记的系膜细胞中，血管加压素诱导标记的肌醇磷酸酯呈剂量依赖性积累（表观Kact值 = 2 nM）。相反，血管加压素未能改变系膜细胞膜的腺苷酸环化酶活性。用一系列对V2-（肾脏）、V1a-（血管和肝脏）和V1b-（腺垂体）受体具有不同亲和力的血管加压素结构类似物进行的竞争实验表明，大鼠肾小球系膜细胞的血管加压素受体类似于V1a-受体亚型。
