Role of nitric oxide in vasodilation in upstream muscle during intermittent pneumatic compression.
This study investigated the dosage effects of nitric oxide synthase (NOS) inhibitor N(G)-monomethyl-L-arginine (L-NMMA) on intermittent pneumatic compression (IPC)-induced vasodilation in uncompressed upstream muscle and the effects of IPC on endothelial NOS (eNOS) expression in upstream muscle. After L-NMMA infusion, mean arterial pressure increased by 5% from baseline (99.5 +/- 18.7 mmHg; P < 0.05). Heart rate and respiratory rate were not significantly affected. One-hour IPC application on legs induced a 10% dilation from baseline in 10- to 20-microm arterioles and a 10-20% dilation in 21- to 40 microm arterioles and 41- to 70-microm arteries in uncompressed cremaster muscle. IPC-induced vasodilation was dose dependently reduced, abolished, or even reversed by concurrently infused L-NMMA. Moreover, expression of eNOS mRNA in uncompressed cremaster muscle was upregulated to 2 and 2.5 times normal at the end of 1- and 5-h IPC on legs, respectively, and the expression of eNOS protein was upregulated to 1.8 times normal. These increases returned to baseline level after cessation of IPC. The results suggest that eNOS plays an important role in regulating the microcirculation in upstream muscle during IPC.
Chen
Long-En
LE
The Orthopaedic Microsurgery Laboratory, Department of Surgery, Duke University Medical Center, Durham, North Carolina 27710, USA. chen0006@mc.duke.edu
Liu
Kang
K
Qi
Wen-Ning
WN
Joneschild
Elizabeth
E
Tan
Xiangling
X
Seaber
Anthony V
AV
Stamler
Jonathan S
JS
Urbaniak
James R
JR
D000009:Abdominal Muscles / Q000098:blood supply* / Q000201:enzymology; D000818:Animals; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007866:Leg; D008297:Male; D008833:Microcirculation / Q000187:drug effects; D009569:Nitric Oxide / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000235:genetics / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III; D011312:Pressure; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012016:Reference Values; D014664:Vasodilation / Q000502:physiology*; D019323:omega-N-Methylarginine / Q000494:pharmacology
D004791:Enzyme Inhibitors; D012333:RNA, Messenger; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III; C496316:Nos3 protein, rat