Zhong M, Zhang Y, Zhang W
Department of Senior Health Care, Qilu Hospital of Shandong University, Jinan 250012, China.
Zhonghua Yi Xue Za Zhi. 2001 Jun 10;81(11):669-72.
To elucidate the molecular mechanism underlying calcium handling in diastolic heart failure (DHF) from mRNA level and protein expression, including L-type calcium channel, sarcoplasmic reticulum (SR) Ca(2+)-ATPase, phospholamban, ryanodine receptor, calsequestrin.
DHF was produced in rabbits by abdominal aortic coarctation. The mRNA amounts of these calcium-handling genes were measured by RT-PCR, while the protein levels of SR Ca(2+)-ATPase and phospholamban were analyzed by Western blot analysis.
The content of calcium was significantly increased in myocardium of rabbits with DHF than in the myocardium of sham-operated rabbits. The SR Ca(2+)-ATPase activity of DHF rabbits was significantly reduced compared with that in sham-operated rabbits (21.1 micromol.mg(-1).h(-1) +/- 5.7 micromol.mg(-1).h(-1) vs 10.5 micromol.mg(-1).h(-1) +/- 2.8 micromol.mg(-1).h(-1), P < 0.01). RT-PCR analyses showed that the steady-state level of mRNA encoding the L-type calcium channel and SR Ca2+-ATPase was decreased significantly in rabbits with DHF compared with that in the sham-operated rabbits (micromol.mg(-1).h(-1)): 0.75 +/- 0.11 vs 1.20 +/- 0.33; 0.76 +/- 0.12 vs 1.24 +/- 0.38, P < 0.05). The SR Ca(2+)-ATPase mRNA level correlated negatively well with left ventricular relaxation time constant and left ventricular end-diastolic pressure (r = -0.81, -0.64, respectively, P < 0.05 approximately 0.01); the mRNA level of L-type calcium channel correlated negatively with left ventricular end-diastolic pressure (r = -0.74, P < 0.05). The mRNA level of ryanodine receptor correlated negatively with the left ventricular relaxation time constant too (r = -0.71, P < 0.05). Protein level of SR Ca(2+)-ATPase was significantly lower in rabbits with DHF than in the sham-operated rabbits (0.76 +/- 0.6 vs 1.02 +/- 0.09, P < 0.05), whereas the protein level of phospholamban was unchanged.
The L-type calcium channel and SR Ca(2+)-ATPase were down regulated in DHF. These changes may be a contributory factor for DHF.
从信使核糖核酸（mRNA）水平和蛋白质表达方面阐明舒张性心力衰竭（DHF）中钙处理的分子机制，包括L型钙通道、肌浆网（SR）Ca(2 +)-ATP酶、受磷蛋白、雷诺丁受体、肌集钙蛋白。
通过腹主动脉缩窄在兔身上制造DHF模型。用逆转录聚合酶链反应（RT-PCR）测量这些钙处理基因的mRNA量，同时用蛋白质印迹分析来分析SR Ca(2 +)-ATP酶和受磷蛋白的蛋白质水平。
与假手术兔的心肌相比，DHF兔心肌中的钙含量显著增加。与假手术兔相比，DHF兔的SR Ca(2 +)-ATP酶活性显著降低（21.1微摩尔·毫克(-1)·小时(-1)±5.7微摩尔·毫克(-1)·小时(-1)对10.5微摩尔·毫克(-1)·小时(-1)±2.8微摩尔·毫克(-1)·小时(-1)，P<0.01）。RT-PCR分析显示与假手术兔相比DHF兔中编码L型钙通道和SR Ca2 +-ATP酶的mRNA稳态水平显著降低（微摩尔·毫克(-1)·小时(-1)）：0.75±0.11对1.20±0.33；0.
