Yamaguchi M, Momose K
Acta Endocrinol (Copenh). 1983 Dec;104(4):490-4. doi: 10.1530/acta.0.1040490.
The calmodulin dependency of calcitonin (CT) action on glucose-6-phosphatase and phosphyorylase alpha activities in the liver of rats was investigated. A single sc administration of CT (synthetic [A1,7] eel CT; 80 MRC mU/100 g body weight) produced significant increases in calcium content and glucose-6-phosphatase activity in the hepatic microsomes of intact and thyroparathyroidectomized rats. These increases in enzyme activity were significantly inhibited by W-7 (100 microM), with a concentration which showed maximal effect. However, this inhibition was less than 50% of the enzyme activity increased by CT administration. Meanwhile, CT produced significant increases in calcium content and phosphorylase alpha activity in the hepatic glycogen particles from intact rats. However, this increase in enzyme activity was not influenced significantly by W-7 (100 microM), suggesting that the calcium ion may directly activate the enzyme. These results suggest that the increase in microsomal glucose-6-phosphatase activity of rat liver mediated by cellular calcium following CT administration may partly depend on calmodulin.
研究了降钙素（CT）作用对大鼠肝脏中葡萄糖-6-磷酸酶和磷酸化酶α活性的钙调蛋白依赖性。单次皮下注射CT（合成的[A1,7]鳗鱼CT；80 MRC mU/100 g体重）可使完整和甲状旁腺切除大鼠肝脏微粒体中的钙含量和葡萄糖-6-磷酸酶活性显著增加。W-7（100 microM）可显著抑制这些酶活性的增加，该浓度显示出最大效应。然而，这种抑制作用小于CT给药增加的酶活性的50%。同时，CT可使完整大鼠肝脏糖原颗粒中的钙含量和磷酸化酶α活性显著增加。然而，W-7（100 microM）对这种酶活性的增加没有显著影响，表明钙离子可能直接激活该酶。这些结果表明，CT给药后细胞钙介导的大鼠肝脏微粒体葡萄糖-6-磷酸酶活性的增加可能部分依赖于钙调蛋白。
