title: Effect of ghrelin on renal erythropoietin production in chronic hypoxic rats.
abstract: OBJECTIVE
  Ghrelin, a 28 amino acid peptide, has diverse effects in body organs. Erythropoietin is a key mediator in increasing the red blood cells during hypoxia. Previously, we have shown that ghrelin has a polycythemic effect. In the present study, we evaluated the effect of ghrelin on erythropoietin gene expression with the aim to find out the mechanism of its effect.
  
  
  METHODS
  Thirty two adult male Wistar rats were divided randomly into four groups. The hypoxic condition was induced by placing the rats into the hypoxic chamber with 11% oxygen for two weeks. Saline- and ghrelin-treated control rats remained in room with a regular air conditions. Erythropoietin gene expression was measured by real-time reverse transcription-polymerase chain reaction (RT-PCR). Plasma erythropoietin was measured by enzyme linked immunosorbent assay (ELISA).
  
  
  RESULTS
  After 2-weeks of hypoxia, erythropoietin transcripts and erythropoietin plasma levels were significantly increased in hypoxic animals compared with control animals. Ghrelin treatment decreased both plasma erythropoietin and erythropoietin gene expression only in the hypoxic rats.
  
  
  CONCLUSIONS
  Our data indicate that ghrelin might induce polycythemia through an erythropoietin-independent manner. However, to confirm this hypothesis and to find out the precise mechanism of this phenomenon further investigations are needed.
authors: H
authors: H
authors: Feizi
authors: K
authors: K
authors: Rajaee
authors: R
authors: R
authors: Keyhanmanesh
authors: M R
authors: MR
authors: Aliparasti
authors: S
authors: S
authors: Almasi
authors: M R
authors: MR
authors: Alipour
mesh_terms: D000818:Animals; D002908:Chronic Disease; D004921:Erythropoietin / Q000097:blood / Q000235:genetics*; D015870:Gene Expression / Q000187:drug effects; D054439:Ghrelin / Q000378:metabolism* / Q000494:pharmacology; D006400:Hematocrit; D000860:Hypoxia / Q000188:drug therapy / Q000378:metabolism*; D007668:Kidney / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar
chemical_list: D054439:Ghrelin; D004921:Erythropoietin