title: [Orexin A and neuropeptide Y levels in plasma and hypothalamus of rats with chronic renal failure].
abstract: 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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Nephrology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100730, China.
authors.forename: Jun-ling
authors.initials: JL
authors.lastname: Li
authors.forename: Fa-lei
authors.initials: FL
authors.lastname: Zheng
authors.forename: Hui-bing
authors.initials: HB
authors.lastname: Tan
authors.forename: Su-yan
authors.initials: SY
authors.lastname: Yin
authors.forename: Ji-hong
authors.initials: JH
authors.lastname: Yang
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Yu-fen
authors.initials: YF
authors.lastname: Bu
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000032:analysis* / Q000097:blood; D007031:Hypothalamus / Q000737:chemistry*; D047908:Intracellular Signaling Peptides and Proteins; D007676:Kidney Failure, Chronic / Q000378:metabolism*; D008297:Male; D009478:Neuropeptide Y / Q000032:analysis* / Q000097:blood; D009479:Neuropeptides / Q000032:analysis* / Q000097:blood; D000068797:Orexins; D051381:Rats; D017208:Rats, Wistar
chemical_list: D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D009478:Neuropeptide Y; D009479:Neuropeptides; D000068797:Orexins