不同浓度的降钙素基因相关肽对培养的乳鼠心室肌细胞的影响

Effects of different concentrations of calcitonin gene related peptide on cultured anoxic ventricular myocardial cells of neonate rats

作者用培养的乳鼠原代心室肌细胞，建立缺氧模型，对缺氧前、缺氧１２０ｍｉｎ时，心肌细胞膜流动性、￣（５１）铬（￣（５１）Ｃｒ）释放率及细胞内钙、镁含量的变化及三种不同浓度的降钙素基因相关肽（ＣＧＲＰ）对缺氧过程的影响进行了观察．结果显示：缺氧１２０ｍｉｎ时，心肌细胞膜流动性（η：１．７７±０．０８对１．２２±０．１１），￣（５１）Ｃｒ释放率（１２．０３％±１．０５％对２０．０４％±１．２７％）均较缺氧前明显升高（Ｐ＜０．０１），而细胞内钙（１．９４±０．５１ｍｇ／ｇ对１．４０±０．０４ｍｇ／ｇｐｒｏｔｅｉｎ），镁（３．５２±０．２０ｍｇ／ｇ对２．１０±０．１９ｍｇ／ｇｐｒｏｔｅｉｎ）含量明显降低（Ｐ＜０．０５，０．０１）．１×１０＿（－８）ｍｏｌ／ＬＣＧＲＰ可降低缺氧时心肌细胞膜流动性（η：１．２２±０．１１对１．５６±０．０７），￣（５１）Ｃｒ释放率（２０．０４％±１．２７％对１４．６６％±２．１１％），减少镁的丢失（２．１０±０．１９ｍｇ／ｇ对３．０８±０．２２ｍｇ／ｇｐｒｏ－ｔｅｉｎ）；１×１０（－９）ｍｏｌ／Ｌ有部分作用，而１×１０（－７）ｍｏｌ／Ｌ则无此作用．三种不同浓度的ＣＧＲＰ对缺氧时细胞内钙的?

In the present experiment,an anoxia model was established by using primary cultured ventricular myocardial cells of neonate rats.The myocyte membrane fluidity,￣(51)Cr release rate and intracellular calcium and magnesium contents were measured before and after 120 min anoxia and the effects of different concentra-tions of calcitonin gene related peptide(CGRP)on the anoxic myocardial cells were studied.The findings showed that myocyte membrane fluidity(η)and ￣(51)Cr release rate significantly increased from 1.77 ±0. 08,12.03%±1. 05%to 1.22±0.11,20.04%± 1.27%,respectively(P<0.01) and contents of myocyte calci-um,magnesium decreased from 1.94 ±0. 51mg/g,3.52±0. 20 mg/g to 1.40±0. 04 mg/g,2.10±0.19 mg/g protein respectively(P<0.05,0.01)after 120 min anoxia. CGRP at a concentration of 1×10(-8) mol/L was able to reduce the myocyte membrane fluidity(η)from 1.22±0. 11 to 1. 56±0. 07,￣(51)Cr release rate from 20. 04%±1. 27%to 14. 66%±2.11%and the loss of magnesium from 2. 10 ±0. 19 mg/g to 3. 08±0. 22 mg/g protein after 120 min anoxia. CGRP at a concentration of1× 10￣(-9) mol/L had partial effects, while CGRP at a concentration of 1×10￣(-7)mol/L had no affection.The three different concentrations of CGRP had less af-fect on the loss of calcium after 120 min anoxia. The results showed that CGRP at a appropriate concentra- tions might lessen the damages of anoxic myocardial cellssuggesting that CGRP may have a protective func-tion to myocardial cells afflicted with anoxic injury. The function is related with concentrations of CGRP:CGRP at lower concentrations has a protective effect,while CGRP at higher concentrations may not have.