血管紧张素Ⅱ对大鼠下丘脑内血管升压素基因转录的影响  

EFFECT OF ANGIOTENSIN II ON VASOPRESSIN GENE TRANSCRIPTION IN THE HYPOTHALAMUS OF RATS

作　　者：陆利民[1] 宋后燕[1] 姚泰[1] 

机构地区：[1]上海医科大学生理学教研室,上海医科大学分子遗传学教研室

出　　处：《生理学报》1995年第4期373-380,共8页Acta Physiologica Sinica

基　　金：高等学校博士点专项科研基金;美国纽约中华医学基金

摘　　要：实验在雄性ＳＤ大鼠中进行，用核酸斑点杂交技术观察下丘脑组织中血管升压素（ＡＶＰ）基因转录水平变化，用异羟基洋地黄毒甙（ＤＩＧ）标记的２６个碱基长寡聚核苷酸作为检测探针。实验中观察到，用渗透压微泵向大鼠侧脑室内连续注射微量血管紧张素Ⅱ（０．２ｎｍｏｌ／ｈ）２ｄ后，可引起动物饮水量显著增加，下丘脑组织中ＡＶＰ基因转录水平升高，但无统计学显著意义。将实验动物每日饮水量限制在与对照动物相同的每日饮水量之后，侧脑室内注射ＡＮＧⅡ可导致下丘脑组织中ＡＶＰ基因转录水平显著升高。另外，给动物饮用２％ＮａＣｌ溶液或禁水后，也观察到下丘脑组织中ＡＶＰ基因转录水平升高。脑室内连续注射ＡＮＧⅡ受体拮抗剂Ｄｕｐ７５３（０．９ｎｍｏｌ／ｈ，６ｄ），或腹腔内注射血管紧张素转化酶抑制剂巯甲丙脯酸（Ｃａｐｔｏｐｒｉｌ５ｍｇ／（ｋｇ·ｄ）），不能阻断高渗刺激或禁水引起的下丘脑ＡＶＰ基因转录水平升高效应。上述实验结果表明，脑室内给予ＡＮＧⅡ可以使ＡＶＰ基因转录水平升高，在限制饮水的情况下，ＡＮＧⅡ的这种效应更为显著。另外，禁水引起的ＡＶＰ基因转录水平升高效应，看来并不需要内源性ＡＮＧⅡ参与。Experiments were carried out in male Sprague-Dawley rats. 3' -end digoxigeninlabeled 26 bp oligonucliotide probe was used to detect the vasopressin (AVP) mRNA in the hypothalamus.Dot blotting technique was used in the investigation of AVP gene transcription level.The results showed that continuous intracerebroventricular adminisiration (icv.) of angiotensin n at a rate of 0. 2 nmol/h for 2 days by using a miniosmotic pump resulted in a significant increase in daily water intake. An increase of AVP gene transcription level in the hypothalamus was also observed, but statistically insignifleant.When daily water intake was limited (25 ml/d), continuous icy. infusion of ANG Ⅱ caused a significant increase in hypothalamic AVP gene transcription. It was also observed that hypothalamic AVP gene transcription level increased after salt loading and dehydration. However, intraperitoneal application of angiotensin converting enzyme inhibitor captopril (5 mg/ (kg· d) ) or icy. nonpeptide angiotensin Ⅱ receptor antagonist Dup753 (0. 9 nmol/h) did not attenuate the increase of AVP gene transcription level induced by salt loading or dehydration. It is therefore suggested that the administration of ANG Ⅱ enhances AVP gene transcription in the hypothalamus, especially when water intake is limited. However, this increase does not involve the participation of endogenous ANG Ⅱ.

关 键 词：血管升压素 血管紧张素Ⅱ 基因转录 下丘脑 

分 类 号：R338.27[医药卫生—人体生理学]