前胡丙素对培养心肌细胞^（45）Ca^（2＋）摄入及细胞内游离钙的影响

Effect of Praeruptorin C on 45Ca2+ uptake and cytosolic-freeCa2+ in cultured myocardial cells of neonatal rat

利用培养的乳鼠心肌细胞测定细胞４５Ｃａ２＋的摄入及细胞内游离钙的浓度。结果表明，前胡丙素（Ｐｒａ－Ｃ）１０－１００μｍｏｌ·Ｌ－１依浓度抑制４５Ｃａ２＿的摄入，并抑制由３０μｍｏｌ·Ｌ－１ＫＣｌ所引起的４５Ｃｓ２＋摄入的增加，同时Ｐｒａ－Ｃ１００μｍｏｌ·Ｌ－１对去甲肾上腺素所诱发的４５Ｃａ２＿摄入的增加也有抑制作用。Ｐｒａ－Ｃ１０μｍｏｌ·Ｌ－１和维拉帕米１０μｍｏｌ·Ｌ－１能抑制细胞外高钾（３０，５０ｍｍｏｌ·Ｌ－１）引起的［Ｃａ２＋］ｉ的升高，同时Ｐｒａ－Ｃ３０ｍｏｌ·Ｌ－１和维拉帕米１０μｍｏｌ·Ｌ－１对去甲肾上腺素１０μｍｏｌ·Ｌ－１在无钙及含ＣａＣｌ２１．３ｍｍｏｌ·Ｌ－１的溶液中所引起的［Ｃａ２＋］，的增加也有抑制作用。提示前胡丙素对心肌细胞的作用与其阻滞钙通道有关。

Ca2+ uptake and [Ca2+], were measuredin cultured myocardial cells of neonatal rats. Praeruptorin C(Pra-C) 10-100 μmol· L-1 led to a progressive decrease of45Ca2+ uptake. Pra-C 10-100 μmol·L-1 inhibited the el-evation of 4sCa2+ uptake induced by 30 mmol· L-1 KCl.Pra-C 100 μmol· L-1 also had an inhibitory effect on theelevation of 45Ca2+ uptake induced by 10 μmol· L-1norepinephrine. Pra-C 10 μmol· L-1 and verapamil 10pmol · L-1 inhibited the KCl (30, 50 mmol · L-1)-induced[ Ca2+] i elevation by 27%, 31% and 55%. 58%,respectively, but did not change the [ Ca2+], while [ K+].was 5.4 mmol . Li. Pra-C 30 μmol· L-1 and verapamil10 μmol· L-1 could inhibit norepinephrine (lo μmol·L-1)induced [Ca2+]. elevation both in Ca2+-free and in 1.3mmol· L-1 Ca2+ solution. The results suggested that theeffect of Pra-C was related to its Ca2+ channel blockingaction in myocardial cells.