do-Vale C F, Saad W A, Renzi A, Camargo G M, Queiróz R C, Silveira J E, Menani J V, Camargo L A
Departamento de Ciências Fisiológicas, Faculdade de Odontologia, Universidade Estadual Paulista, Araraquara, SP, Brasil.
Braz J Med Biol Res. 1995 Sep;28(9):999-1002.
We tested the effects of estradiol, progesterone and testosterone on water and salt intake induced by angiotensin II (ANG II) injected into the third ventricle of female Holtzman rats weighing 250-300 g. The water and salt ingestion observed after 120 min in the control experiments (injection of 0.5 microliter of 0.15 M NaCl into the third ventricle) was 1.6 +/- 0.3 ml (N = 10) and 0.3 +/- 0.1 ml (N = 8) in intact rats, respectively, and 1.4 +/- 0.3 ml (N = 10) and 0.2 +/- 0.1 (N = 8) in ovariectomized rats, respectively. ANG II injected in intact rats (4, 6, 12, 25, and 50 ng, icv, in 0.5 microliter saline) induced an increase in water intake (4.3 +/- 0.6, 5.4 +/- 0.7, 7.8 +/- 0.8, 10.4 +/- 1.2, 11.2 +/- 1.4 ml/120 min, respectively) (N = 43). The same doses of icv ANG II in intact rats increased the 3% NaCl intake (0.9 +/- 0.2, 1.4 +/- 0.3, 2.3 +/- 0.4, 2.2 +/- 0.3, and 2.5 +/- 0.4 ml/120 min, respectively) (N = 42). When administered to ovariectomized rats ANG II induced comparable amounts of water intake (4.0 +/- 0.5, 4.8 +/- 0.6, 6.9 +/- 0.7, 9.6 +/- 0.8, and 10.9 +/- 1.2 ml/120 min, respectively) (N = 43) but there was a significant decrease of 3% NaCl solution ingestion (0.3 +/- 0.1, 0.4 +/- 0.1, 0.8 +/- 0.2, 0.7 +/- 0.2, and 0.6 +/- 0.2 ml/120 min, respectively) (N = 44). Estrogen (50 micrograms), progesterone (25 ng), and testosterone (300 micrograms) were injected daily into ovariectomized rats for 21 days. Treatment with estrogen decreased the water intake and abolished the saline ingestion induced by icv injection of ANG II (12 ng) (2.8 +/- 1.2 and 0.3 +/- 0.1 ml/120 min, respectively) (N = 8). Treatment with progesterone also reduced the water intake (3.3 +/- 0.6 ml/120 min) (N = 8) and abolished the ANG II-induced saline ingestion (0.4 +/- 0.1 ml/120 min) (N = 8), but these effects were not observed with testosterone (6.4 +/- 0.8 and 2.2 +/- 0.3 ml/120 min, respectively) (N = 8). These results indicate that ANG II induces a greater increase in sodium intake in intact female rats than in ovariectomized rats and that estrogen and progesterone impair water and sodium intake in ovariectomized rats.
我们测试了雌二醇、孕酮和睾酮对体重250 - 300克雌性霍尔兹曼大鼠第三脑室内注射血管紧张素II（ANG II）所诱导的水和盐摄入的影响。在对照实验（向第三脑室注射0.5微升0.15 M NaCl）中，120分钟后观察到的完整大鼠的水和盐摄入量分别为1.6±0.3毫升（N = 10）和0.3±0.1毫升（N = 8），去卵巢大鼠分别为1.4±0.3毫升（N = 10）和0.2±0.1（N = 8）。向完整大鼠脑室内注射ANG II（4、6、12、25和50纳克，溶于0.5微升盐水中）会导致水摄入量增加（分别为4.3±0.6、5.4±0.7、7.8±0.8、10.4±1.2、11.2±1.4毫升/120分钟）（N = 43）。完整大鼠中相同剂量的脑室内ANG II会增加3% NaCl摄入量（分别为0.9±0.2、1.4±0.3、2.3±0.4、2.2±0.3和2.5±0.4毫升/120分钟）（N = 42）。当给去卵巢大鼠注射ANG II时，诱导出相当量的水摄入量（分别为4.0±0.5、4.8±0.6、6.9±0.7、9.6±0.8和10.9±1.2毫升/120分钟）（N = 43），但3% NaCl溶液摄入量显著减少（分别为0.3±0.1、0.4±0.1、0.8±0.2、0.7±0.2和0.6±0.2毫升/120分钟）（N = 44）。每天向去卵巢大鼠注射雌激素（50微克）、孕酮（25纳克）和睾酮（300微克），持续21天。雌激素治疗减少了水摄入量，并消除了脑室内注射ANG II（12纳克）所诱导的盐水摄入（分别为2.8±1.2和0.3±0.1毫升/120分钟）（N = 8）。孕酮治疗也减少了水摄入量（3.3±0.6毫升/120分钟）（N = 8），并消除了ANG II诱导的盐水摄入（0.4±0.1毫升/120分钟）（N = 8），但睾酮治疗未观察到这些效果（分别为6.4±0.8和2.2±0.3毫升/120分钟）（N = 8）。这些结果表明，ANG II在完整雌性大鼠中诱导的钠摄入量增加幅度大于去卵巢大鼠，并且雌激素和孕酮会损害去卵巢大鼠的水和钠摄入量。
