小鼠肝组织中腺苷酸环化酶和环腺苷酸磷酸二酯酶比活力的研究

本文介绍腺苷酸环化酶(AC)和环腺替酸磷酸二酯酶(PDE)比活力的一种简单、快速测定法。以腺苷三磷酸(ATP)或环磷酸腺苷(cAMP)作为底物,同肝匀浆孵育时生成的或未消耗的 cAMP,用氧化铝柱层析法分离,以 Tris-HCl 缓冲液(pH7.4)洗脱,用分光光度法测定洗脱液中的 cAMP。根据 cAMP 的生成量和 cAMP 的消耗量分别表示 AC 和 PDE 活力。测定了小白鼠肝组织中 AC 和 PDE 比活力。上清液和沉淀中 AC 比活力分别为0.96和1.64单位/mg 蛋白质、PDE 比活力分别为2.06和0.50单位/mg 蛋白质,上清中 AC/PDE 比值为0.47,沉淀中比值为3.30。

THE STUDY ON ADENYLATE CYCLASE AND ADENOSINE 3',5'—CYCLIC PHOSPHATE PHOSPHODIESTERASE IN MOUSE LIVER

A simPle method for rapid assay of adenylate cyclase (AC) and adenosine 3`,5`-cyclic phosphate phosphodiesterase (PDE)in liver homogenate is described Using adenosine triphosphate (ATP)or adenosine 3`,5`-cyclic phosphate (cAMP ) as substrate,the cAMP formed or unhydrolyzed during incubation was se- parated with chromatography on aluminum oxide column end eluted with Tris-HCI buffer (pH7.4).The eiuted cAMP was measured spectrophotomcerically. The amou- nts of formed and hydrolyzed cAMP represented AC and PDE activities respec- tively. By the described method the specific activities of AC and PDE in superna- tent and precipitate of mouse liver were measured, wlth the amounts of AC being 0.96 and 1.64 units/rag protein and the amounts of PDE being 2.06 and 0.50 uni- ts/mg protein. The AC/PDE ratios of supernatant and precipitate were 0.47 and 3.30 respectively.