Evaluation for functional correlation between prostaglandins and dopamine in regulation mechanisms of ADH release in the AV3V

AV3V 中 ADH 释放调节机制中前列腺素和多巴胺之间功能相关性的评估

基本信息

批准号：
08670076
负责人：
YAMAGUCHI Kenichi
金额：
$ 1.22万
依托单位：
NIIGATA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

项目摘要

1. The aims of reseach project were to examine roles of prostaglandins (PGs) synthesized in the anteroventral third ventricular region (AV3V) in regulation mechanisms of ADH release and cardiovascular system under hypovolemic condition, and to evaluate those of AV3V catecholamine receptors in mediating responses to PGE2. Experiments were conducted in conscious rats with cerebral and vascular cannulae implanted chronically.2. Blood of 1% of body weight was removed twice (H1 and H2) from the femoral artery. H1 increased plasma ADH (pADH) without affecting arterial pressure (AP) and heart rate (HR), whereas after H2 further augmentation of pADH were produced with conspicuous falls in AP and rises in plasma angiotensin II (ANGII). These homorrhages did not alter plasma osmolality or sodium, but increased plasma chloride and decreased plasma potassium.3. An inhibitor of PG synthesis meclofenamate (MCL) infused locally into the AV3V prevented the pADH responses to the bleeding, potentiated t … More hose of AP, and caused singnificant reduction of HR following H2. Other variable such as plasma ANGII were not influenced by MCL.These effects of MCL were not caused when it was infused into the nucleus accumbens, a region sligtlhy distant from the AV3V,or into the cerebral ventricle.4. When PGE2 was applied into the AV3V sites near infusion points of MCL,pADH,AP and HR increased singnificantly.5. Local infusion of dopamine (DA) and an alpha-adrenegic agonist phenylephrines (PHE) into the AV3V elicited transient augmentation of pADH.DA influenced none of the other variables, whereas PHE application caused concomitant reises of AP in approximately 50% of tests. The AV3V infusion of a beta-adrenergic agonist isoproterenol induced depressor and tachycardiac effects.6. The effects of PHE on both the pADH and AP were abolished by prior application of an alpha-adrenergic antagonist phenoxybenzamine into the AV3V.The effect of DA on pADH was blocked by the prior administration of a D1-DAergic antagonist SCH23390, but not by that of a D2-DAergic antagonist sulpiride. The application of these antagonists alone did not affect any of the variables including pADH.7. The AV3V infusion of phenoxybenzamine, SCH23390 and sulpiride were without significant effect on the PGE2-evoed responses of pADH,AP and HR.8. These results suggest that PGs formed in the AV3V may play important roles in regulating ADH release, AP and HR,and that the effects of PGE2 on these factors may not be mediated by AV3V catecholamine receptors, despite their ability to influence the factors. Less

1. 研究项目的目的是研究前腹侧第三脑室区（AV3V）合成的前列腺素（PGs）在低血容量条件下ADH释放和心血管系统的调节机制中的作用，并评估AV3V儿茶酚胺受体在介导反应中的作用实验在长期植入脑血管插管的清醒大鼠中进行。2．抽取体重1％的血液。 (H1 和 H2) H1 增加血浆 ADH (pADH)，但不影响动脉压 (AP) 和心率 (HR)，而 H2 后，pADH 进一步增加，AP 明显下降，血浆血管紧张素上升。 II (ANGII)。这些出血不会改变血浆渗透压或钠，但会增加血浆氯并降低血浆钾。3。 (MCL) 局部注入 AV3V 可以防止 pADH 对出血的反应，增强 AP 的反应，并导致 H2 后 HR 显着降低。其他变量（例如血浆 ANGII）不受 MCL 的影响。当它被注入距AV3V稍远的伏隔核或脑室时不会引起。4． MCL、pADH、AP和HR输注点附近的AV3V位点显着增加。5．局部输注多巴胺(DA)和α-肾上腺素激动剂去氧肾上腺素(PHE)引起pADH的短暂增强。5．变数，而 PHE 应用在大约 50% 的测试中导致 AP 伴随升高。 β-肾上腺素能激动剂异丙肾上腺素诱导的抑制和心动过速作用。 6. PHE 对 pADH 和 AP 的影响通过在 AV3V 中预先应用 α-肾上腺素能拮抗剂苯氧苯扎明而消除。 DA 对 pADH 的作用被先前的阻断。施用 D1-DAergic 拮抗剂 SCH23390，但不施用 D2-DAergic 拮抗剂单独应用这些拮抗剂不影响任何变量，包括pADH。7。苯氧苯扎明、SCH23390 和舒必利的AV3V 输注对pADH、AP 和HR 的PGE2 诱发反应没有显着影响。表明 AV3V 中形成的 PG 可能在调节 ADH 释放、AP 和 HR 中发挥重要作用，并且 PGE2 对这些的影响尽管 AV3V 儿茶酚胺受体对这些因素的影响能力较小，但这些因素可能不是由它们介导的。