论文部分内容阅读
目的:观察L精氨酸(LArg)对肾性高血压大鼠畸变产物耳声发射(DPOAE)的影响。方法:将二肾一夹(2K1C)型肾血管型高血压模型的大鼠24只分成模型对照组和LArg治疗组各12只;另设正常对照组12只。动物处死前检测DPOAE,并测定耳蜗组织超氧化物歧化酶(SOD)、丙二醛(MDA)和血浆内皮素(ET)的含量。结果:①与正常对照组比较,模型对照组SBP和血浆ET含量明显升高(分别P<0.01和P<0.05);耳蜗组织MDA平均含量明显升高(P<0.01);SOD活力明显下降(P<0.05)。在70dBSPL的高刺激强度下,3组各频率的DPOAE检出率均为100%;在低刺激强度(49dBSPL)下,模型对照组检出率明显降低,与正常对照组比较在各频率DPOAE检出率差异有统计学意义(P<0.05或P<0.01)。模型对照组在各频率DPOAE幅值均有所下降,与正常对照组比较差异有统计学意义(P<0.05或P<0.01)。②LArg治疗组与模型对照组比较,SBP和血浆ET含量均明显降低(均P<0.01);SOD活力明显高于模型对照组(P<0.05);耳蜗组织MDA平均含量明显低于模型对照组(P<0.01)。在低刺激强度(49dBSPL)下,LArg治疗组在各频率DPOAE检出率与模型对照组比较差异有统计学意义(P<0.05或P<0.01);DPOAE幅值在各频率与模型对照组比较均有所提高(P<0.05或P<0.01),而DPOAE潜伏期差异无统计学意义(P>0.05)。③LArg治疗组与正常对照组相比,上述各指标均无统计学意义(均P>0.05)。结论:①LArg可能通过改变大鼠内耳微循环而影响肾性高血压大鼠DPOAE;②LArg可以影响耳蜗组织自由基的代谢,并有利于氧自由基的清除,LArg对耳蜗组织氧自由基的清除并不改变其对DPOAE的影响。
Objective: To observe the effect of L-arginine (LArg) on distortion product otoacoustic emissions (DPOAE) in renal hypertensive rats. Methods: Twenty-four rats of 2K1C renal hypertension model were divided into model control group and LArg treatment group, with 12 rats in each group. Twelve rats were selected as normal control group. DPOAE was detected before sacrifice, and the levels of superoxide dismutase (SOD), malondialdehyde (MDA) and plasma endothelin (ET) were measured. Results: Compared with the normal control group, the content of SBP and ET in the model control group was significantly increased (P <0.01 and P <0.05, respectively); the average content of MDA in the cochlea was significantly increased (P <0.01); the activity of SOD was significantly decreased P <0.05). The detection rate of DPOAE was 100% under the high stimulus intensity of 70dBSPL, and the detection rate of DPOAE was lower at 49dBSPL. Compared with the normal control group, the detection rate of DPOAE at each frequency The difference was statistically significant (P <0.05 or P <0.01). The DPOAE amplitude of the model control group decreased at all frequencies, which was significantly different from the normal control group (P <0.05 or P <0.01). (2) Compared with model control group, the content of SBP and plasma ET in LArg treatment group were significantly decreased (all P <0.01); the activity of SOD was significantly higher than that in model control group (P <0.05); the average content of MDA in cochlear tissue was significantly lower than that in model control group P <0.01). The DPOAE detection rate at each frequency of LArg group was significantly lower than that of the model control group (P <0.05 or P <0.01) under the low stimulation intensity (49dBSPL); DPOAE amplitude at each frequency compared with the model control group (P <0.05 or P <0.01), while there was no significant difference in DPOAE latency (P> 0.05). (3) Compared with the normal control group, there was no significant difference in the above indexes between the LAg treatment group (all P> 0.05). Conclusion: (1) LArg may affect the DPOAE of renal hypertensive rats by altering microcirculation in the inner ear of rats; (2) LArg may affect the metabolism of free radicals in the cochlea and promote the scavenging of oxygen free radicals and LArg Does not change its impact on DPOAE.