Independent regulation of periarteriolar and perivenular nitric oxide mechanisms in the in vivo hamster cheek pouch microvasculature.
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.
Kim
David D
DD
Program in Vascular Biology, Department of Pharmacology and Physiology, UMDNJ-New Jersey Medical School, Newark, New Jersey 07101-1709 USA.
Kanetaka
Takehito
T
Durán
Ricardo G
RG
Sánhez
Fabiola A
FA
Bohlen
H Glenn
HG
Durá
Walter N
WN
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
D010972:Platelet Activating Factor; D009569:Nitric Oxide; D000109:Acetylcholine