Denek L, Schwegler J S, Schaefer R M, Heidland A
Dept. of Nephrology, University of Würzburg, FRG.
FEBS Lett. 1990 Aug 20;269(1):226-8. doi: 10.1016/0014-5793(90)81160-p.
Chronic exposure (24 h) to parathyroid hormone (PTH) increases the intracellular proteolytic activity in cultured opossum kidney cells 2-fold at physiological PTH concentrations (10(-12) mol/l). This increase can be blocked by E-64, an inhibitor of thiol proteinases. The phorbol ester TPA mimicks the effect of PTH, whereas the calcium ionophore A23187 reduces the intracellular proteinase activity. Forskolin and dibutyrylic cAMP do not elevate proteinase activity. The protein kinase C inhibitor staurosporine is equally effective in blocking the TPA- and PTH-induced proteinase activity increase. These data indicate that PTH increases the intracellular thiol proteinase activity by an activation of protein kinase C and not by the cAMP dependent way.
在生理浓度的甲状旁腺激素（PTH，10⁻¹²摩尔/升）下，对负鼠肾细胞进行24小时的慢性暴露会使细胞内蛋白水解活性增加2倍。这种增加可被巯基蛋白酶抑制剂E-64阻断。佛波酯TPA可模拟PTH的作用，而钙离子载体A23187则会降低细胞内蛋白酶活性。福斯高林和二丁酰环磷腺苷不会提高蛋白酶活性。蛋白激酶C抑制剂星形孢菌素在阻断TPA和PTH诱导的蛋白酶活性增加方面同样有效。这些数据表明，PTH通过激活蛋白激酶C而非依赖环磷腺苷的方式增加细胞内巯基蛋白酶活性。
