title: Independent regulation of periarteriolar and perivenular nitric oxide mechanisms in the in vivo hamster cheek pouch microvasculature.
abstract: OBJECTIVE
  We tested the hypothesis that differential stimulation of nitric oxide (NO) production can be induced in pre- and postcapillary segments of the microcirculation in the hamster cheek pouch.
  
  
  METHODS
  We applied acetylcholine (ACh) or platelet-activating factor (PAF) topically and measured perivascular NO concentration ([NO]) with NO-sensitive microelectrodes in arterioles and venules of the hamster cheek pouch. We also measured NO in cultured coronary endothelial cells (CVEC) after ACh or PAF.
  
  
  RESULTS
  ACh increased periarteriolar [NO] significantly in a dose-dependent manner. ACh at 1 microM increased [NO] from 438.1+/-43.4 nM at baseline to 647.9+/-66.3 nM, while 10 microM of ACh increased [NO] from baseline to 1,035.0+/-59.2 nM (P<0.05). Neither 1 nor 10 microM of ACh changed perivenular [NO] in the hamster cheek pouch. PAF, at 100 nM, increased perivenular [NO] from 326.6+/-50.8 to 622.8+/-41.5 nM. Importantly, 100 nM of PAF did not increase periarteriolar [NO]. PAF increased [NO] from 3.6+/-2.1 to 455.5+/-19.9 in CVEC, while ACh had no effect.
  
  
  CONCLUSIONS
  We conclude that NO production can be stimulated in a differential manner in pre- and postcapillary segments in the hamster cheek pouch. ACh selectively stimulates the production of NO only in arterioles, while PAF stimulates the production of NO only in venules.
authors.affiliation: Program in Vascular Biology, Department of Pharmacology and Physiology, UMDNJ-New Jersey Medical School, Newark, New Jersey 07101-1709 USA.
authors.forename: David D
authors.initials: DD
authors.lastname: Kim
authors.forename: Takehito
authors.initials: T
authors.lastname: Kanetaka
authors.forename: Ricardo G
authors.initials: RG
authors.lastname: Durán
authors.forename: Fabiola A
authors.initials: FA
authors.lastname: Sánhez
authors.forename: H Glenn
authors.initials: HG
authors.lastname: Bohlen
authors.forename: Walter N
authors.initials: WN
authors.lastname: Durá
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D001160:Arterioles / Q000187:drug effects / Q000378:metabolism; D002610:Cheek / Q000098:blood supply; D003331:Coronary Vessels; D006224:Cricetinae; D004730:Endothelium, Vascular / Q000166:cytology; D008839:Microelectrodes; D055806:Microvessels / Q000187:drug effects / Q000378:metabolism*; D009569:Nitric Oxide / Q000032:analysis / Q000096:biosynthesis*; D010972:Platelet Activating Factor / Q000494:pharmacology*; D014699:Venules / Q000187:drug effects / Q000378:metabolism
chemical_list: D010972:Platelet Activating Factor; D009569:Nitric Oxide; D000109:Acetylcholine