title: [Effects of simulated microgravity on L-ARG-NO-CGMP pathway of abdominal aorta in rats].
abstract: OBJECTIVE
  To investigate the effects of simulated microgravity on dilatory responsiveness and NOS expression of abdominal aorta in rats.
  
  
  METHODS
  Twenty male healthy SD rats, which body weight ranged from 300 g to 330 g, were divided into control group and simulated microgravity group randomly. After 4 weeks, using isolated arterial rings from rats, arterial dilatory responsiveness of abdominal aorta were examined in vitro. And the expression of nitric oxide synthase (NOS), including endothelial NOS (eNOS) and inducible NOS (iNOS), were observed by Western blot.
  
  
  RESULTS
  Dilatory responses of arterial rings to L-Arginine (10(-8)-10(-3) mol/L), and Acetylcholine mol/L) were decreased in simulated microgravity rats compared with that of controls; but dilatory responses of isolated aortic rings to sodium nitroprusside (mol/L) and 8-bromo-cGMP(mol/L) were similar in both simulated microgravity rats and control rats. The expression of both eNOS and iNOS had not showed significant differences between two groups.
  
  
  CONCLUSIONS
  The data indicate that endothelium dependent vasorelaxation in abdominal aortic rings are decreased by 4-week simulated microgravity, and this change may be result from altered NOS activity in endothelium.
authors.affiliation: Department of Aerospace Physiology, Xijing Hospital, Fourth Military Medical University, Xi' an 710032, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Ma
authors.forename: Xin-ling
authors.initials: XL
authors.lastname: Ren
authors.forename: Li-fan
authors.initials: LF
authors.lastname: Zhang
authors.forename: Xiao-wu
authors.initials: XW
authors.lastname: Ma
authors.forename: Jiu-hua
authors.initials: JH
authors.lastname: Cheng
mesh_terms: D000818:Animals; D001012:Aorta, Abdominal / Q000378:metabolism*; D001120:Arginine / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018474:Weightlessness Simulation
chemical_list: D009569:Nitric Oxide; D001120:Arginine; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; C496318:Nos2 protein, rat; C496316:Nos3 protein, rat; D006152:Cyclic GMP