慢性肾功能衰竭大鼠下丘脑组织和血浆食欲素A及神经肽Y水平的变化及其意义

Orexin A and neuropeptide Y levels in plasma and hypothalamus of rats with chronic renal failure

目的 探讨大鼠慢性肾功能衰竭 (CRF)动物模型的下丘脑组织和血浆食欲素A及神经肽Y(NPY)水平的变化及其意义。方法 将 41只 2 0 0～ 2 50 g雄性Wister大鼠分为 :正常组、假手术组和CRF组。术后 4、 8、 1 2周分批断头处死大鼠 ,取血浆和下丘脑组织标本。用放射免疫法测定血浆和下丘脑组织食欲素A和NPY。用生化自动分析仪测定血清肌酐。结果 CRF大鼠术后4、 8和 1 2周血肌酐水平均高于假手术组。其术后 1 2周的血浆食欲素A水平高于假手术组 (2 64pg/ml± 62pg/mlvs 1 83pg/ml± 56pg/ml,P =0 0 39)。CRF大鼠术后 1 2周的下丘脑食欲素A水平明显低于假手术组 (1 0 5fmol/mg± 2 7fmol/mg湿重vs 1 7 4fmol/mg± 3 9fmol/mg湿重 ,P =0 0 2 3)。CRF大鼠术后 8周 (7 1 pmol/ml± 1 7pmol/mlvs 5 0 pmol/ml± 0 5pmol/ml,P =0 0 1 )和1 2周 (7 9pmol/ml± 1 1pmol/mlvs 4 8pmol/ml± 1 1 pmol/ml,P =0 0 0 0 8)的血浆神经肽Y水平高于假手术组 ,其术后 1 2周的下丘脑神经肽Y水平明显低于假手术组 (70fmol/mg± 2 3fmol/mgvs1 1 3fmol/mg± 31fmol/mg湿重 ,P =0 0 33)。 结论 (1 )CRF大鼠血浆食欲素A和NPY水平有逐渐增高趋势 ,肾功能减退可能导致食欲素A和NPY排泄障碍。 (2 )

Objective To explore the changes of orexin A and neuropeptide (NPY) in plasma and hypothalamus of rats with chronic renal failure (CRF) Methods 41 male Wister rats weighing 200～250 g were randomly divided into three groups: normal group, sham operation group, and CRF group (with the right kidney and 2/3 of the left kidney resected) A certain number of rats were decapitated 4, 8,and 12 weeks after respectively Their hypothalami were removed and blood collected Radioimmunoassay was used to measure the levels of orexin A and NPY in hypothalamus and plasma Automatic biochemical analyzer was used to measure the serum creatinine Results The serum creatinine level of CRF rats was both significantly higher than those of the sham operation rats at week 8 and week 12, respectively The plasma orexin A level of CRF rats at week 12 was 264 pg/ml±62 pg/ml, significantly higher than that of sham operation group (183 pg/ml±56pg/ml, P =0 039) The hypothalamus orexin A level of CRF rats were 10 5 fmol/mg±2 7 fmol/mg wet weight at week 12, significantly lower than that of sham operation rats(17 4 fmol/mg±3 9 fmol/mg wet weight, P =0 023) The plasma NPY levels of CRF rats at week 8 and week 12 were significantly higher than those of the sham operation rats (7 1 pmol/ml±1 7 pmol/ml vs 5 0pmol/ml±0 5 pmol/ml, P =0 01; and 7.9 pmol/ml±1 1 pmol/ml vs 4 8 pmol/ml±1 1 pmol/ml, P =0 0008) The hypothalamus NPY level of CRF rats at week 12 were 70 fmol/mg±23 fmol/mg wet weight, significantly lower than that of the sham operation rats (113 fmol/mg±31 fmol/mg wet weight, P =0 03) Conclusion Loss of renal function may diminish the excretion of orexin A and neuropeptide The lowering of hypothalamus orexin A and neuropeptide Y levels may be one of the causes inducing anorexia in CRF