Yasujima M, Kanazawa M, Yoshida K, Kohzuki M, Watanabe H, Hiwatari M, Sato T, Abe K
Institute of Rehabilitation Medicine, Tohoku University School of Medicine, Narugo, Japan.
Tohoku J Exp Med. 1993 Apr;169(4):271-7. doi: 10.1620/tjem.169.271.
To assess potential roles of circulating levels of angiotensin II (Ang II) in the regulation of blood pressure in rats with reduced functional renal mass, we studied the blood pressure response to chronic infusion of Ang II at a subpressor dose in partially nephrectomized rats. Male Sprague-Dawley rats were subjected to 1/6, 2/6, 3/6, 4/6 and 5/6 nephrectomy, and sham operation a week before the infusion of Ang II at a rate of 400 micrograms/kg/day delivered intraperitoneally by osmotic minipumps for 14 days, or vehicle alone served as controls. Infusion of Ang II was associated with a slight but significant increase in systolic blood pressure in 1/6 nephrectomized rats (p < 0.05), whereas it did not induce a significant change in systolic blood pressure in sham-operated rats. Hypertension during Ang II infusion was more prominent in 2/6 nephrectomized rats than that in 1/6 nephrectomized rats (p < 0.05). However, there was no significant difference in hypertension during Ang II infusion among groups in 2/6, 3/6, 4/6 and 5/6 nephrectomized rats. Blood urea nitrogen and serum creatinine levels, endogenous creatinine clearance, urinary excretion of protein as indices of renal function, and urinary sodium excretion were not affected by chronic infusion of Ang II in 1/6, 2/6, 3/6, 4/6 and 5/6 nephrectomized, and sham-operated rats. There was also no significant difference in circulating levels of Ang II among Ang II infused-groups in 1/6 and 2/6 nephrectomized rats. These results indicate that elevated levels of circulating Ang II are capable of causing a sustained hypertension in rats with reduced functional renal mass.(ABSTRACT TRUNCATED AT 250 WORDS)
为了评估循环血管紧张素II（Ang II）水平在功能性肾质量减少的大鼠血压调节中的潜在作用，我们研究了部分肾切除大鼠对亚升压剂量的Ang II慢性输注的血压反应。雄性Sprague-Dawley大鼠接受1/6、2/6、3/6、4/6和5/6肾切除术，并在通过渗透微型泵以400微克/千克/天的速率腹膜内输注Ang II前一周进行假手术，持续14天，或仅用载体作为对照。在1/6肾切除的大鼠中，输注Ang II与收缩压轻微但显著升高相关（p<0.05），而在假手术大鼠中，它并未引起收缩压的显著变化。在2/6肾切除的大鼠中，Ang II输注期间的高血压比1/6肾切除的大鼠更明显（p<0.05）。然而，在2/6、3/6、4/6和5/6肾切除的大鼠组中，Ang II输注期间的高血压没有显著差异。作为肾功能指标的血尿素氮和血清肌酐水平、内生肌酐清除率、尿蛋白排泄以及尿钠排泄，在1/6、2/6、3/6、4/6和5/6肾切除以及假手术的大鼠中，不受Ang II慢性输注的影响。在1/6和2/6肾切除的大鼠中，Ang II输注组之间的循环Ang II水平也没有显著差异。这些结果表明，循环Ang II水平升高能够在功能性肾质量减少的大鼠中引起持续性高血压。（摘要截短至250字）
