de la Vega M T, Nunez A, Montano J A
Departmento de Fisiología, Biofisica y Neurociencias, Centro de Investigación y de Estudios Avanzados, México, D.F, México.
Neurosci Lett. 1996 Jul 26;213(1):29-32. doi: 10.1016/0304-3940(96)12824-x.
In cross-chopped slices from rat thalamus and in the presence of 10 mM LiC1, the cholinergic agonist carbachol stimulated the accumulation of total [3H]inositol phosphates ([3H]IP2 = [3H]IP1 + [3H]IP2 + [3H]IP3). Best-fit values for the concentration-response curve for carbachol after 60 min incubation yielded an EC50 of 44 +/- 6 microM, maximum effect of 199 +/- 6% of basal accumulation and Hill coefficient (nH) of 1.1 +/- 0.1. Carbachol-induced [3H]IPs accumulation was inhibited by 4-diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP; pKi 9.1) and the p-fluoro analogue of hexahydro-sila-difenidol (pF-HHSiD; pKi 8.1). Concentration-response curves for carbachol were shifted to the right in a parallel fashion by pirenzepine (100, 300 and 100 nM). A Schild plot of the data was linear (slope 0.95 +/- 0.04) and yielded a log KD for pirenzepine of -6.8 +/- 0.1. Taken together, these results suggest that carbachol-induced inositol phosphate accumulation in rat thalamus is mediated by muscarinic M3-receptors.
在大鼠丘脑的交叉切片中，在存在10 mM LiC1的情况下，胆碱能激动剂卡巴胆碱刺激了总[3H]肌醇磷酸酯（[3H]IP2 = [3H]IP1 + [3H]IP2 + [3H]IP3）的积累。孵育60分钟后，卡巴胆碱浓度 - 反应曲线的最佳拟合值得出EC50为44±6 microM，最大效应为基础积累的199±6%，希尔系数（nH）为1.1±0.1。卡巴胆碱诱导的[3H]IPs积累受到4 - 二苯基乙酰氧基 - N - 甲基哌啶甲碘化物（4 - DAMP；pKi 9.1）和六氢硅二苯哌啶的对氟类似物（pF - HHSiD；pKi 8.1）的抑制。哌仑西平（100、300和100 nM）使卡巴胆碱的浓度 - 反应曲线以平行方式向右移动。数据的施尔德图呈线性（斜率0.95±0.04），哌仑西平的log KD为 - 6.8±0.1。综上所述，这些结果表明卡巴胆碱诱导的大鼠丘脑肌醇磷酸酯积累是由毒蕈碱M3受体介导的。
