【摘要】 目的：通过外源给予自发性高血压大鼠室旁核(paraventricular nucleus,PVN)血红素氧合酶1(heme oxygenase-1, HO-1)的激活剂Hemin和抑制剂ZnPPIX,观察PVN中内质网GRP78表达含量变化，探讨室旁核HO-1对自发性高血压大鼠内质网应激的影响。方法：选取8周龄健康雄性WKY大鼠和SHR大鼠，随机分为WKY+aCSF、WKY+Hemin、WKY+ZnPPIX、SHR+aCSF、SHR+Hemin、SHR+ZnPPIX组，每组10只。Hemin组PVN中给予Hemin, ZnPPIX组给予ZnPPIX,其余组给予人工脑脊液(aCSF),持续给药4 w。采用尾动脉无创测量平均动脉压(MAP),采用ELISA法检测PVN中HO-1、血浆NE水平，采用Western blot法检测PVN中内质网GRP78蛋白水平表达，免疫荧光法检测PVN中内质网GRP78阳性神经元表达。结果：(1)与WKY+aCSF组相比，SHR+aCSF组MAP水平明显升高(P<0.01);与SHR+aCSF组相比，SHR+Hemin组MAP水平明显下降(P<0.01);而SHR+ZnPPIX组MAP、NE水平明显升高(P<0.01)。(2)与WKY+aCSF组相比，SHR+aCSF组NE﹑HO-1水平升高(P<0.05);与SHR+aCSF组相比，SHR+Hemin组NE﹑HO-1水平下降(P<0.05);而SHR+ZnPPIX组NE﹑HO-1水平明显升高(P<0.05)。(3)WB结果表明，与WKY+aCSF组相比，SHR+aCSF组PVN内质网中GRP78表达明显升高(P<0.01);与SHR+aCSF组相比，SHR+Hemin组PVN内质网中GRP78表达明显下降(P<0.05);而SHR+ZnPPIX组GRP78表达明显升高(P<0.05)。(4)IF结果表明，与WKY+aCSF组相比，SHR+aCSF组PVN内质网中GRP78表达明显升高(P<0.05);与SHR+aCSF组相比，SHR+Hemin组PVN内质网中GRP78表达明显下降(P<0.05);而SHR+ZnPPIX组GRP78表达明显升高(P<0.05)。结论：室旁核HO-1可能通过抑制PVN内质网中GRP78表达，进而抑制外周交感神经活动来改善自发性高血压。更多还原

【Abstract】 Objective: By exogenously administering hemin(an activator of heme oxygenase-1, HO-1) and ZnPPIX(an inhibitor of HO-1) to the paraventricular nucleus(PVN) of spontaneously hypertensive rats, this study observed changes in the expression levels of endoplasmic reticulum GRP78 in the PVN to explore the impact of HO-1 in the PVN on endoplasmic reticulum stress in spontaneously hypertensive rats.Methods: Eight-week-old healthy male WKY rats and SHR rats were selected and randomly divided into WKY+aCSF, WKY+Hemin, WKY+ZnPPIX, SHR+aCSF, SHR+Hemin and SHR+ZnPPIX groups, with 10 rats in each group. Hemin was administered to the PVN in the Hemin group, ZnPPIX was administered in the ZnPPIX group, and artificial cerebrospinal fluid(aCSF) was administered in the remaining groups for a continuous duration of 4 weeks. The mean arterial pressure(MAP) was noninvasively measured via the tail artery. The levels of HO-1 in the PVN and plasma norepinephrine(NE) were detected using ELISA. The protein expression level of endoplasmic reticulum GRP78 in the PVN was detected using Western blot, and the expression of endoplasmic reticulum GRP78-positive neurons in the PVN was detected using immunofluorescence. Results:(1) Compared with the WKY+aCSF group, the MAP level in the SHR+aCSF group was significantly increased(P<0.01); compared with the SHR+aCSF group, the MAP level in the SHR+Hemin group was significantly decreased(P<0.01); while the MAP and NE levels in the SHR+ZnPPIX group were significantly increased(P<0.01).(2) Compared with the WKY+aCSF group, the NE and HO-1 levels in the SHR+aCSF group were increased(P<0.05); compared with the SHR+aCSF group, the NE and HO-1 levels in the SHR+Hemin group were decreased(P<0.05); while the NE and HO-1 levels in the SHR+ZnPPIX group were significantly increased(P<0.05).(3) The Western blot results showed that compared with the WKY+aCSF group, the expression of GRP78 in the endoplasmic reticulum of the PVN in the SHR+aCSF group was significantly increased(P<0.01); compared with the SHR+aCSF group, the expression of GRP78 in the endoplasmic reticulum of the PVN in the SHR+Hemin group was significantly decreased(P<0.05); while the expression of GRP78 in the SHR+ZnPPIX group was significantly increased(P<0.05).(4) The immunofluorescence results showed that compared with the WKY+aCSF group, the expression of GRP78 in the endoplasmic reticulum of the PVN in the SHR+aCSF group was significantly increased(P<0.05); compared with the SHR+aCSF group, the expression of GRP78 in the endoplasmic reticulum of the PVN in the SHR+Hemin group was significantly decreased(P<0.05); while the expression of GRP78 in the SHR+ZnPPIX group was significantly increased(P<0.05). Conclusion: HO-1 in the paraventricular nucleus may improve spontaneous hypertension by inhibiting the expression of GRP78 in the endoplasmic reticulum of the PVN, thereby inhibiting peripheral sympathetic nerve activity.更多还原