From the Departments of Pharmacology and Nutritional Sciences (E.G., F.Y.) and Physiology (M.C.G.), University of Kentucky, Lexington.
Hypertension. 2019 Oct;74(4):1014-1020. doi: 10.1161/HYPERTENSIONAHA.119.12906. Epub 2019 Aug 5.
Obesity-related hypertension is a major public health concern. We recently demonstrated that plasma levels of the soluble form of the prorenin receptor (sPRR) were elevated in obesity-associated hypertension. Therefore, in the present study, we investigated the contribution of sPRR to blood pressure (BP) elevation in the context of obesity. High fat-fed C57BL/6 male mice were infused with vehicle or sPRR (30 µg/kg per day) via subcutaneously implanted osmotic minipump for 4 weeks. BP parameters were recorded using radiotelemetry devices. Male mice infused with sPRR exhibited higher systolic BP and mean arterial pressure and lower spontaneous baroreflex sensitivity than mice infused with vehicle. To define mechanisms involved in systolic BP elevation, mice were injected with an AT1R (Ang II [angiotensin II] type 1 receptor) antagonist (losartan), a muscarinic receptor antagonist (atropine), a β-adrenergic antagonist (propranolol), and a ganglionic blocker (chlorisondamine). Losartan did not blunt sPRR-induced elevation in systolic BP. Chlorisondamine treatment exacerbated the decrease in mean arterial pressure in male mice infused with sPRR. These results demonstrated that sPRR induced autonomic nervous dysfunction. Interestingly, plasma leptin levels were increased in high fat-fed C57BL/6 male mice infused with sPRR. Overall, our results indicated that sPRR increased systolic BP through an impairment of the baroreflex sensitivity and an increase in the sympathetic tone potentially mediated by leptin in high fat-fed C57BL/6 male mice.
肥胖相关性高血压是一个主要的公共卫生问题。我们最近证明,肥胖相关高血压患者的前肾素受体可溶性形式(sPRR)的血浆水平升高。因此,在本研究中,我们研究了 sPRR 在肥胖背景下对血压升高的贡献。通过皮下植入的渗透微型泵向高脂肪喂养的 C57BL/6 雄性小鼠输注 vehicle 或 sPRR(每天 30μg/kg)4 周。使用无线电遥测设备记录血压参数。与输注 vehicle 的小鼠相比,输注 sPRR 的雄性小鼠的收缩压和平均动脉压升高,而自发的压力反射敏感性降低。为了确定与收缩压升高相关的机制,向小鼠注射了 AT1R(血管紧张素 II [血管紧张素 II] 型 1 受体)拮抗剂(氯沙坦)、毒蕈碱受体拮抗剂(阿托品)、β-肾上腺素能拮抗剂(普萘洛尔)和神经节阻滞剂(氯米铵)。氯沙坦不能阻断 sPRR 引起的收缩压升高。氯米铵处理加剧了输注 sPRR 的雄性小鼠的平均动脉压降低。这些结果表明 sPRR 引起自主神经功能障碍。有趣的是,输注 sPRR 的高脂肪喂养的 C57BL/6 雄性小鼠的血浆瘦素水平升高。总的来说,我们的结果表明,sPRR 通过损害压力反射敏感性和增加交感神经张力来增加收缩压,这可能是由肥胖喂养的 C57BL/6 雄性小鼠中的瘦素介导的。