Vassallo D V, Vasquez E C, Mill J G
Departamento de Ciências Fisiológicas, Universidade Federal do Espirito Santo, Vitória, Brasil.
Clin Exp Hypertens A. 1990;12(4):597-616. doi: 10.3109/10641969009073487.
Previous experiments using 15 days renovascular hypertensive rats and their sham operated uninephrectomized controls suggested a decrease in contractile force developed by the papillary muscles from uninephrectomized rats. Because of the implications of such findings two sets of experiments were performed. The first set 15 days after operations, compared four groups of Wistar male rats: uninephrectomized, sham operated controls and renovascular hypertensive 1K1C and 2K1C. In the second set of experiments the time course effects of uninephrectomy was analysed. The first four groups of animals showed that mean blood pressure was normal in both controls and uninephrectomized rats, but the 1K1C and 2K1C groups were hypertensive. Contractile performance was analysed 24 hours after hemodynamic studies from isometric contracting left ventricle papillary muscles. Results showed similar force development in controls, 1K1C and in 2K1C muscles. However, the muscles from uninephrectomized rats showed a significant contractile depression when compared to the other groups, even under different inotropic interventions, like isoproterenol or post-rest potentiation. The study of the time course effects of uninephrectomy showed that the contractile activity is depressed 7, 15 and 30 days after unilateral nephrectomy. The results suggest that the mechanical depression, whatever its underlying mechanism, is located at the contractile machinery level.
先前使用15日龄肾血管性高血压大鼠及其假手术单侧肾切除对照大鼠进行的实验表明，单侧肾切除大鼠乳头肌产生的收缩力有所下降。鉴于这些发现的潜在影响，进行了两组实验。第一组实验在手术后15天，比较了四组雄性Wistar大鼠：单侧肾切除组、假手术对照组以及肾血管性高血压1K1C和2K1C组。在第二组实验中，分析了单侧肾切除的时间进程效应。前四组动物显示，对照组和单侧肾切除大鼠的平均血压均正常，但1K1C和2K1C组为高血压。在进行血流动力学研究24小时后，对等长收缩的左心室乳头肌的收缩性能进行了分析。结果显示，对照组、1K1C组和2K1C组肌肉的力量发展相似。然而，与其他组相比，单侧肾切除大鼠的肌肉即使在不同的变力干预（如异丙肾上腺素或静息后增强）下，也表现出明显的收缩抑制。对单侧肾切除时间进程效应的研究表明，单侧肾切除后7天、15天和30天，收缩活动均受到抑制。结果表明，无论其潜在机制如何，机械性抑制均位于收缩机制水平。
