Wagner A C, Schäfer C, Williams J A
Department of Physiology, University of Michigan, Ann Arbor 48109.
Biochem Biophys Res Commun. 1992 Dec 30;189(3):1606-12. doi: 10.1016/0006-291x(92)90260-r.
The effects of the phosphatase inhibitors calyculin A and okadaic acid on amylase release from streptolysin-O permeabilized rat pancreatic acini were investigated. Both agents induced similar biphasic effects with moderate potentiation of calcium-stimulated amylase release at medium and strong inhibition at higher concentrations. Calyculin A was thirty times more potent than okadaic acid and at 100 nM totally inhibited calcium-induced amylase release while 3 microM okadaic acid reduced amylase release by 78%. 100nM calyculin A also completely inhibited GTP gamma S-potentiated amylase release and partially inhibited phorbol ester potentiated secretion. The data indicate that inhibition of a serine/threonine phosphatase, probably a type 1 phosphatase, leads to inhibition of calcium-induced amylase release in permeabilized pancreatic acini.
研究了磷酸酶抑制剂花萼海绵诱癌素A和冈田酸对经链球菌溶血素-O通透处理的大鼠胰腺腺泡淀粉酶释放的影响。两种药物均诱导出相似的双相效应，在中等浓度时对钙刺激的淀粉酶释放有适度增强作用，而在较高浓度时则有强烈抑制作用。花萼海绵诱癌素A的效力比冈田酸强30倍，在100 nM时完全抑制钙诱导的淀粉酶释放，而3 μM冈田酸使淀粉酶释放减少78%。100 nM花萼海绵诱癌素A也完全抑制GTPγS增强的淀粉酶释放，并部分抑制佛波酯增强的分泌。数据表明，抑制丝氨酸/苏氨酸磷酸酶（可能是1型磷酸酶）会导致通透处理的胰腺腺泡中钙诱导的淀粉酶释放受到抑制。
