title: Regulatory effects of chronic low-dose morphine on nitric oxide level along with baroreflex sensitivity in two-kidney one-clip hypertensive rats.
abstract: BACKGROUND
  Opiates are traditionally used for treatment of some acute heart disorders. There are only few reports on the effects of long-term treatment of cardiovascular diseases with morphine. This study aimed to investigate the effects of chronic low-dose morphine use on the cardiovascular system in two-kidney one-clip (2K1C) hypertensive rats.
  
  
  METHODS
  Male Wistar rats were divided into two groups as the sham and 2K1C groups and each group was further subdivided into saline and morphine treatment subgroups. Blood pressure, heart rate, plasma rennin activity, serum nitric oxide concentration, and baroreflex sensitivity were measured.
  
  
  RESULTS
  Morphine significantly attenuated systolic blood pressure, diastolic blood pressure, and mean arterial pressure in the 2K1C animals. In addition, morphine decreased plasma rennin activity in the 2K1C group. Serum concentrations of nitric oxide were also decreased, and morphine prevented the reduction of nitric oxide. The baroreflex sensitivity was also improved following morphine administration in the 2K1C group.
  
  
  CONCLUSIONS
  According to the results presented in this study, chronic administration of low-dose morphine reduces regulated hypertension in the 2K1C rats, probably via a nitric oxide-dependent pathway.
authors.forename: Hossein
authors.initials: H
authors.lastname: Rezazadeh
authors.forename: Mohammadamin
authors.initials: M
authors.lastname: Hosseini Kahnouei
authors.forename: Gholamhossein
authors.initials: G
authors.lastname: Hassanshahi
authors.forename: Mohammad
authors.initials: M
authors.lastname: Allahtavakoli
authors.forename: Ali
authors.initials: A
authors.lastname: Shamsizadeh
authors.forename: Ali
authors.initials: A
authors.lastname: Roohbakhsh
authors.forename: Iman
authors.initials: I
authors.lastname: Fatemi
authors.forename: Mohammadreza
authors.initials: M
authors.lastname: Zarisfi
authors.affiliation: Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran. aapoursha@gmail.com.
authors.forename: Ali Asghar
authors.initials: AA
authors.lastname: Pourshanazari
mesh_terms: D000818:Animals; D017704:Baroreflex / Q000187:drug effects*; D001794:Blood Pressure / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D006978:Hypertension, Renovascular / Q000503:physiopathology*; D008297:Male; D009020:Morphine / Q000008:administration & dosage / Q000494:pharmacology*; D009294:Narcotics / Q000008:administration & dosage / Q000494:pharmacology*; D009569:Nitric Oxide / Q000378:metabolism*; D017208:Rats, Wistar; D012083:Renin / Q000378:metabolism; D013525:Surgical Instruments
chemical_list: D009294:Narcotics; D009569:Nitric Oxide; D009020:Morphine; D012083:Renin