Hano T, Shiotani M, Baba A, Nishio I, Masuyama Y
Department of Medicine, Wakayama Medical College, Japan.
Hypertens Res. 1995 Jun;18 Suppl 1:S141-3. doi: 10.1291/hypres.18.supplementi_s141.
The present study was performed in order to examine the effects of dopamine (DA) on renin release and to clarify which subtype of DA receptor, DA1 or DA2 contributes to renin release. Male Wistar rats aged seven weeks were used. Glomeruli were isolated by the modified Beierwaltes' sieving method and were transferred to a sealed chamber and superfused with Krebs-Ringer solution. In the first experiment, the changes in renin release induced by DA and the effects of a non-selective DA antagonist, haloperidol and a beta antagonist, propranolol on DA-induced renin release were examined. In the second experiment, the effect of a DA2 receptors antagonist, spiperone and of a DA1 receptor antagonist, SCH-23390 on renin release were investigated. Basal levels of renin release were 2.46 +/- 0.36 ng ATI/h/10(4) glomeruli (mean +/- SEM). DA caused a dose-dependent increase in renin release. The renin release induced by DA was inhibited by haloperidol but not by propranolol. The maximum level of renin release induced by 10(-5)M DA was 4.13 +/- 0.63 ng ATI/h/10(4) glomeruli. SCH-23390 at 10(-5)M caused significant suppression of DA-induced renin (p < 0.05). In contrast, 10(-5)M spiperone failed to suppress DA-induced renin release. These results suggest that DA induced renin release from isolated glomeruli through the DA1 receptors.
本研究旨在探讨多巴胺（DA）对肾素释放的影响，并阐明DA受体的哪种亚型（DA1或DA2）参与肾素释放。使用7周龄的雄性Wistar大鼠。通过改良的Beierwaltes筛分法分离肾小球，并将其转移至密封小室，用Krebs-Ringer溶液进行灌流。在第一个实验中，研究了DA诱导的肾素释放变化以及非选择性DA拮抗剂氟哌啶醇和β拮抗剂普萘洛尔对DA诱导的肾素释放的影响。在第二个实验中，研究了DA2受体拮抗剂螺哌隆和DA1受体拮抗剂SCH-23390对肾素释放的影响。肾素释放的基础水平为2.46±0.36 ng ATI/h/10(4)个肾小球（平均值±标准误）。DA引起肾素释放呈剂量依赖性增加。DA诱导的肾素释放被氟哌啶醇抑制，但未被普萘洛尔抑制。10(-5)M DA诱导的肾素释放最大水平为4.13±0.63 ng ATI/h/10(4)个肾小球。10(-5)M的SCH-23390可显著抑制DA诱导的肾素释放（p<0.05）。相反，10(-5)M的螺哌隆未能抑制DA诱导的肾素释放。这些结果表明，DA通过DA1受体诱导分离的肾小球释放肾素。
