Banks M D, Sandberg M P, Fowler C J
Astra Pain Control AB, Department of Biochemical Pharmacology, Huddinge, Sweden.
Methods Find Exp Clin Pharmacol. 1995 Jan-Feb;17(1):15-21.
The effects of FLA99 and EWP840, two disulfiram analogs which potently inhibit Ins(1,4,5)P3 5-phosphatase, upon basal and thyrotropin-releasing hormone (TRH)-stimulated inositol (1,4,5)-trisphosphate (Ins(1,4,5)P3) levels were investigated. Neither test compound affected the characteristics of the [3H]Ins(1,4,5)P3 binding site used in the competitive protein binding assay of Ins(1,4,5)P3 levels. In rat GH3 pituitary cell suspensions, TRH (100 nM) produced a large and time-dependent increase in Ins(1,4,5)P3 concentration, the maximum response being obtained within 5 seconds of stimulation in these cells. Neither FLA99 (100, 300 and 1000 microM) nor EWP840 (100 microM) produced obvious effects on the Ins(1,4,5)P3 response to TRH stimulation. Higher concentrations of EWP840 (300 and 1000 microM) abolished the Ins(1,4,5)P3 response to TRH stimulation. The lack of effect of the 5-phosphatase inhibition in the cells may indicate that 5-phosphatase is not the major metabolic pathway of this second messenger in this cell line under the assay conditions used.
研究了两种二硫代氨基甲酸乙酯类似物FLA99和EWP840对基础和促甲状腺激素释放激素（TRH）刺激的肌醇（1,4,5）-三磷酸（Ins(1,4,5)P3）水平的影响，这两种化合物能有效抑制Ins(1,4,5)P3 5-磷酸酶。在Ins(1,4,5)P3水平的竞争性蛋白质结合测定中使用的[3H]Ins(1,4,5)P3结合位点的特性，两种测试化合物均未对其产生影响。在大鼠GH3垂体细胞悬液中，TRH（100 nM）使Ins(1,4,5)P3浓度产生了大量且随时间变化的增加，在这些细胞中，刺激后5秒内即可获得最大反应。FLA99（100、300和1000 microM）和EWP840（100 microM）对Ins(1,4,5)P3对TRH刺激的反应均未产生明显影响。较高浓度的EWP840（300和1000 microM）消除了Ins(1,4,5)P3对TRH刺激的反应。在细胞中5-磷酸酶抑制作用的缺乏可能表明，在所使用的测定条件下，5-磷酸酶不是该细胞系中这种第二信使的主要代谢途径。
