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

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 )CRF时下丘脑组织食欲素

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

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 approximately 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 5.0 pmol/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.