Beck A, Grasmugg B, Singer E, Bacher S, Raberger G
Cardiovasc Res. 1985 Nov;19(11):721-6. doi: 10.1093/cvr/19.11.721.
The effects of a continuous iv infusion (osmotic minipumps) of angiotensin II (80 ng . kg-1 . min-1) and isoprenaline (10 ng . kg-1 . min-1) lasting 28 days were studied in six normotensive, conscious dogs. The parameters measured were systolic and diastolic blood pressure, heart rate, levels of angiotensin II, renin activity, aldosterone and antidiuretic hormone in plasma, baroreceptor reflex sensitivity and body weight. The treatment resulted in an approximately sevenfold increase in plasma angiotensin II level from 62.9 +/- 24.5 pg . ml-1 to 455.3 +/- 95.6 pg . ml-1. Systolic and diastolic blood pressure, measured for the first time 2 days after implanting the minipumps, were markedly increased throughout the infusion period (pretreatment value: 123.8 +/- 5.3/68.3 +/- 3.8 mmHg; after 2 days: 159.8 +/- 12.0/100.5 +/- 9.8 mmHg; after 28 days: 159.8 +/- 7.1/98.3 +/- 6.4 mmHg, whereas the heart rate remained unchanged due to the combined effects of angiotensin II and the concomitantly given isoprenaline. A high correlation was found between angiotensin II level in plasma and mean arterial blood pressure (r = 0.846; p less than 0.001). Furthermore, plasma renin activity was markedly suppressed by the treatment, and aldosterone levels rose. Plasma antidiuretic hormone levels were found to be unchanged at the chosen sampling time. A decrease in baroreceptor reflex sensitivity accompanied the development of the hypertensive state. There was also a loss of body weight during the infusion of angiotensin II and isoprenaline. The data provide evidence for the usefulness of the presented experimental protocol as an alternative model of arterial hypertension in chronically instrumented, conscious dogs.
在6只血压正常、清醒的犬中，研究了持续28天静脉输注（渗透微型泵）血管紧张素II（80 ng·kg-1·min-1）和异丙肾上腺素（10 ng·kg-1·min-1）的效应。测量的参数包括收缩压和舒张压、心率、血浆中血管紧张素II、肾素活性、醛固酮和抗利尿激素水平、压力感受器反射敏感性和体重。治疗使血浆血管紧张素II水平从62.9±24.5 pg·ml-1增加至约7倍，达到455.3±95.6 pg·ml-1。在植入微型泵2天后首次测量的收缩压和舒张压在整个输注期间均显著升高（治疗前值：123.8±5.3/68.3±3.8 mmHg；2天后：159.8±12.0/100.5±9.8 mmHg；28天后：159.8±7.1/98.3±6.4 mmHg），而由于血管紧张素II和同时给予的异丙肾上腺素的联合作用，心率保持不变。血浆血管紧张素II水平与平均动脉血压之间存在高度相关性（r = 0.846；p＜0.001）。此外，治疗显著抑制了血浆肾素活性，醛固酮水平升高。在所选择的采样时间，血浆抗利尿激素水平未发生变化。压力感受器反射敏感性降低伴随着高血压状态的发展。在输注血管紧张素II和异丙肾上腺素期间体重也有所减轻。这些数据证明了所提出的实验方案作为长期植入仪器、清醒犬动脉高血压替代模型的有效性。
