Antunes V R, Camargo G M, Saad R, Saad W A, Luiz A C, Camargo L A
Departamento de Fisiologia e Patologia, Faculdade de Odontologia, Universidade Estadual Paulista, Araraquara, SP, Brasil.
Braz J Med Biol Res. 1998 Dec;31(12):1597-600. doi: 10.1590/s0100-879x1998001200013.
In this study we investigated the effects of the injection into the supraoptic nucleus (SON) of non-peptide AT1- and AT2-angiotensin II (ANG II) receptor antagonists, DuP753 and PD123319, as well as of the arginine-vasopressin (AVP) receptor antagonist d(CH2)5-Tyr(Me)-AVP, on water and 3% NaCl intake induced by the injection of ANG II into the medial septal area (MSA). The effects on water or 3% NaCl intake were assessed in 30-h water-deprived or in 20-h water-deprived furosemide-treated adult male rats, respectively. The drugs were injected in 0.5 microliter over 30-60 s. Controls were injected with a similar volume of 0.15 M NaCl. Antagonists were injected at doses of 20, 80 and 180 nmol. Water and sodium intake was measured over a 2-h period. Previous administration of the AT1 receptor antagonist DuP753 into the SON decreased water (65%, N = 10, P < 0.01) and sodium intake (81%, N = 8, P < 0.01) induced by the injection of ANG II (10 nmol) into the MSA. Neither of these responses was significantly changed by injection of the AT2-receptor antagonist PD123319 into the SON. On the other hand, while there was a decrease in water intake (45%, N = 9, P < 0.01), ANG II-induced sodium intake was significantly increased (70%, N = 8, P < 0.01) following injection of the V1-type vasopressin antagonist d(CH2)5-Tyr(Me)-AVP into the SON. These results suggest that both AT1 and V1 receptors within the SON may be involved in water and sodium intake induced by the activation of ANG II receptors within the MSA. Furthermore, they do not support the involvement of MSA AT2 receptors in the mediation of these responses.
在本研究中，我们研究了向视上核（SON）注射非肽类AT1和AT2血管紧张素II（ANG II）受体拮抗剂杜普753（DuP753）和PD123319，以及精氨酸加压素（AVP）受体拮抗剂d(CH2)5-Tyr(Me)-AVP，对向内侧隔区（MSA）注射ANG II所诱导的水和3%氯化钠摄入的影响。分别在30小时禁水的成年雄性大鼠或20小时禁水并经速尿处理的成年雄性大鼠中评估对水或3%氯化钠摄入的影响。药物在30 - 60秒内以0.5微升的体积注射。对照组注射相同体积的0.15 M氯化钠。拮抗剂以20、80和180纳摩尔的剂量注射。在2小时内测量水和钠的摄入量。先前向SON注射AT1受体拮抗剂杜普753可降低向MSA注射ANG II（10纳摩尔）所诱导的水摄入量（65%，N = 10，P < 0.01）和钠摄入量（81%，N = 8，P < 0.01）。向SON注射AT2受体拮抗剂PD123319并未显著改变这些反应中的任何一个。另一方面，虽然向SON注射V1型加压素拮抗剂d(CH2)5-Tyr(Me)-AVP后水摄入量有所下降（45%，N = 9，P < 0.01），但ANG II诱导的钠摄入量却显著增加（70%，N = 8，P < 0.01）。这些结果表明，SON内的AT1和V1受体可能都参与了MSA内ANG II受体激活所诱导的水和钠摄入。此外，它们不支持MSA的AT2受体参与这些反应的介导作用。
