Chronic exercise increases both inducible and endothelial nitric oxide synthase gene expression in endothelial cells of rat aorta.
Chronic exercise upregulates endothelial nitric oxide synthase (eNOS) gene expression. Whether the expression of inducible nitric oxide synthase (iNOS) is affected by exercise is unknown. We therefore investigated the effects of chronic exercise on iNOS and eNOS expression in isolated rat aortic endothelial and smooth muscle cells separately. Five-week-old male Wistar rats were randomly divided into control and exercise groups. After 10 weeks of running training, animals were sacrificed under ether anesthesia. The standard curve quantitative competitive reverse transcriptase-polymerase chain reaction method was used to quantify NOS mRNA expression in isolated endothelial/smooth muscle cells. To evaluate the functional role of iNOS, we examined phenylephrine-induced vascular responses with or without pretreatment with aminoguanidine. We found that (1) expression of iNOS and eNOS mRNA in endothelial cells was increased by chronic exercise and (2) chronic exercise blunted phenylephrine-induced vascular responses, probably by increasing NO release via iNOS. Our results show that chronic exercise increases both iNOS and eNOS gene expression in endothelium. These alterations may be partially responsible for the change in vascular response after exercise.
Yang
Ai-Lun
AL
Department of Physiology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
Tsai
Shaw-Jenq
SJ
Jiang
Meei Jyh
MJ
Jen
Chauying J
CJ
Chen
Hsiun-ing
HI
D000818:Animals; D001011:Aorta; D004730:Endothelium, Vascular / Q000166:cytology / Q000201:enzymology* / Q000502:physiology; D015870:Gene Expression; D008297:Male; D019001:Nitric Oxide Synthase / Q000235:genetics / Q000502:physiology*; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; D010656:Phenylephrine / Q000494:pharmacology; D010805:Physical Conditioning, Animal / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D015854:Up-Regulation; D014661:Vasoconstriction / Q000187:drug effects
D012333:RNA, Messenger; D010656:Phenylephrine; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; C496318:Nos2 protein, rat; C496316:Nos3 protein, rat