Itoh H, Nakao K, Yamada T, Morii N, Shiono S, Sugawara A, Saito Y, Mukoyama M, Arai H, Imura H
Second Division, Department of Medicine, Kyoto University School of Medicine, Japan.
Can J Physiol Pharmacol. 1988 Mar;66(3):255-61. doi: 10.1139/y88-044.
To elucidate the involvement of the brain renin-angiotensin system and the brain atrial natriuretic polypeptide (ANP) system in the regulation of ANP secretion from the heart, the effects of intracerebroventricular administration of angiotensin II and ANP on the plasma ANP level were examined in conscious unrestrained rats. The intracerebroventricular administration of angiotensin II at doses of 100 ng and 1 microgram significantly enhanced ANP secretion induced by volume-loading with 3-mL saline infusion (peak values of the plasma ANP level: control, 220 +/- 57 pg/mL; 100 ng angiotensin II, 1110 +/- 320 pg/mL, p less than 0.01; 1 microgram angiotensin II, 1055 +/- 60 pg/mL, p less than 0.01). The intracerebroventricular injection of angiotensin II at the same doses alone had no significant effect on the basal plasma ANP level. The enhancing effect of central angiotensin II on ANP secretion induced by volume-loading was significantly attenuated by pretreatment with the intravenous administration of the V1-receptor antagonist of vasopressin or with the intracerebroventricular administration of phentolamine. The intracerebroventricular administration of alpha-rANP(4-28) (5 micrograms) had no significant influence on the basal plasma ANP level; however, it significantly attenuated central angiotensin II potentiating effect of volume-loading induced ANP secretion. These results indicate that the brain renin-angiotensin system regulates ANP secretion via the stimulation of vasopressin secretion and (or) via the activation of the central alpha-adrenergic neural pathway, and that the brain ANP system interacts with the brain renin-angiotensin system in the central modulation of ANP secretion from the heart.(ABSTRACT TRUNCATED AT 250 WORDS)
为了阐明脑肾素 - 血管紧张素系统和脑心房钠尿肽（ANP）系统在调节心脏ANP分泌中的作用，在清醒自由活动的大鼠中研究了脑室内注射血管紧张素II和ANP对血浆ANP水平的影响。脑室内注射100 ng和1 μg剂量的血管紧张素II显著增强了3 mL生理盐水输注容量负荷诱导的ANP分泌（血浆ANP水平峰值：对照组，220±57 pg/mL；100 ng血管紧张素II，1110±320 pg/mL，p<0.01；1 μg血管紧张素II，1055±60 pg/mL，p<0.01）。相同剂量的血管紧张素II单独脑室内注射对基础血浆ANP水平无显著影响。静脉注射血管加压素的V1受体拮抗剂或脑室内注射酚妥拉明预处理可显著减弱中枢血管紧张素II对容量负荷诱导的ANP分泌的增强作用。脑室内注射α-rANP(4 - 28)（5 μg）对基础血浆ANP水平无显著影响；然而，它显著减弱了中枢血管紧张素II对容量负荷诱导的ANP分泌的增强作用。这些结果表明，脑肾素 - 血管紧张素系统通过刺激血管加压素分泌和（或）通过激活中枢α-肾上腺素能神经通路来调节ANP分泌，并且脑ANP系统在心脏ANP分泌的中枢调节中与脑肾素 - 血管紧张素系统相互作用。（摘要截短于250字）
