Characterization of contractile function in diabetic hypertensive cardiomyopathy in adult rat ventricular myocytes.
Characterization of contractile function in diabetic hypertensive cardiomyopathy in adult rat ventricular myocytes.
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DOI：
10.1006/jmcc.2001.1431
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发表时间：
2001-09
影响因子：
5
通讯作者：
L. Wold;D. P. Relling;P. Colligan;G. I. Scott;K. K. Hintz-K.;B. H. Ren;P. Epstein;J. Ren
中科院分区：
文献类型：
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作者：
L. Wold;D. P. Relling;P. Colligan;G. I. Scott;K. K. Hintz-K.;B. H. Ren;P. Epstein;J. Ren
糖尿病和高血压都会产生心肌功能障碍，从而加速心血管疾病的发病率和死亡率。两者的共存往往导致比单独任何一种过程更严重的心肌病。本研究的目的是在单个心肌细胞水平上表征糖尿病高血压心肌病的收缩功能。采用单次注射（55 mg/kg）链脲佐菌素（STZ）使成年自发性高血压大鼠（SHR）和正常Wistar-Kyoto大鼠（WKY）发生糖尿病。评估心室肌细胞的收缩特性，包括峰值缩短（PS）、峰值缩短时间（TPS）、至90%再强化时间（TR90）和最大缩短/再强化速度（+/-dL/d t）。实验动物表现出心脏增大，血糖和收缩压升高。与对照（WKY）相比，PS保持不变（SHR）、增强（WKY- stz）或降低（WKY- stz）。与WKY组相比，所有实验组的肌细胞都表现出延长的TPS和TR90，尽管只有高血压组（SHR, SHR- stz）的肌细胞与降低的+/-dL/d / t相关。此外，WKY- stz而不是SHR组或SHR- stz组的肌细胞对增加的细胞外Ca2+的反应性受损。与WKY组相比，SHR-STZ组肌细胞的刺激频率-峰值缩短反应曲线左移。这些结果证实了在多细胞水平上的观察结果，即糖尿病和高血压合并导致的心脏收缩功能损害比任何一种疾病单独造成的损害更大。
Diabetes and hypertension both produce myocardial dysfunction that accelerates cardiovascular morbidity and mortality. Coexistence of the two often results in a more severe cardiomyopathy than either process alone. The purpose of this study was to characterize the contractile function of diabetic hypertensive cardiomyopathy at the single myocyte level. Adult spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats were made diabetic with a single injection (55 mg/kg) of streptozotocin (STZ). Contractile properties of ventricular myocytes were evaluated, including peak shortening (PS), time-to-peak shortening (TPS), time-to-90% relengthening (TR90) and maximal velocities of shortening/relengthening (+/-dL/d t). The experimental animals exhibited enlarged heart size, elevated blood glucose and systolic blood pressure. PS was unchanged (SHR), enhanced (WKY-STZ) or depressed (SHR-STZ) compared to control (WKY). Myocytes from all experimental groups displayed prolonged TPS and TR90 compared to the WKY group, although only those from the hypertensive groups (SHR, SHR-STZ) were associated with reduced +/-dL/d t. Additionally, myocytes from the WKY-STZ but not the SHR or the SHR-STZ groups exhibited impaired responsiveness to increased extracellular Ca2+. Myocytes from the SHR-STZ group displayed a leftward shift of the stimulus frequency-peak shortening response curve compared to the WKY group. These results confirmed observations at the multicellular levels that combination of diabetes and hypertension results in a greater impairment of cardiac contractile function than is seen with either disease alone.