title: Effects of testosterone on mean arterial pressure and aquaporin (AQP)-1, 2, 3, 4, 6 and 7 expressions in the kidney of orchidectomized, adult male Sprague-Dawley rats.
abstract: We hypothesized that higher blood pressure in males than females could be due to testosterone effects on aquaporin (AQP) expression in kidneys.
  
  
  METHODS
  Orchidectomized adult male Sprague-Dawley (SD) rats received seven days subcutaneous testosterone treatment (125 μg/kg/day or 250 μg/kg/day), with or without flutamide or finasteride. Following completion of treatment, MAP was determined in rats under anaesthesia via carotid artery cannulation. In another cohort of rats, kidneys were removed following sacrifice and AQP-1, 2, 3, 4, 6 and 7 protein and mRNA levels were determined by Western blotting and Real-time PCR respectively. Distribution of AQP subunits' protein in the nephrons were visualized by immunofluorescence.
  
  
  RESULTS
  Testosterone caused MAP, AQP-1, 2, 4, 6 and 7 protein and mRNA levels in kidneys to increase while AQP-3 protein and mRNA levels in kidneys to decrease (p < 0.05). AQP-1 and 7 were found to be distributed in the proximal convoluted tubule (PCT) while AQP-2, 3, 4 and 6 were found to be distributed in the collecting ducts (CD). Effects of testosterone were antagonized by flutamide and finasteride.
  
  
  CONCLUSIONS
  Elevated expression of AQP-1, 2, 4, 6 and 7 under testosterone influence in kidneys could lead to increase H2O reabsorption which eventually lead to increase in blood pressure.
authors.affiliation: Department of Physiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: Su Yi
authors.initials: SY
authors.lastname: Loh
authors.affiliation: Department of Physiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: Nelli
authors.initials: N
authors.lastname: Giribabu
authors.affiliation: Department of Physiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: Khadijeh
authors.initials: K
authors.lastname: Gholami
authors.affiliation: Department of Physiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia. Electronic address: naguib.salleh@yahoo.com.my.
authors.forename: Naguib
authors.initials: N
authors.lastname: Salleh
mesh_terms: D000818:Animals; D020346:Aquaporins / Q000235:genetics* / Q000378:metabolism*; D001794:Blood Pressure; D015331:Cohort Studies; D018120:Finasteride / Q000737:chemistry; D005485:Flutamide / Q000737:chemistry; D005786:Gene Expression Regulation; D007684:Kidney Tubules / Q000378:metabolism*; D007685:Kidney Tubules, Collecting / Q000378:metabolism*; D008297:Male; D008856:Microscopy, Fluorescence; D009919:Orchiectomy; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013739:Testosterone / Q000737:chemistry*
chemical_list: D020346:Aquaporins; D012333:RNA, Messenger; D013739:Testosterone; D018120:Finasteride; D005485:Flutamide
keywords: Aquaporins; Blood pressure; Kidneys; Testosterone