Alterations in nitric oxide synthase isoforms in acute lower limb ischemia and reperfusion.
Alterations in nitric oxide synthase (NOS) are implicated in ischemia and ischemia-reperfusion injury. Changes in the 3 NOS isoforms in human skeletal muscle subjected to acute ischemia and reperfusion were studied. Muscle biopsies were taken from patients undergoing total knee replacement. Distribution of the specific NOS isoforms within muscle sections was studied using immunohistochemistry. NOS mRNA levels were measured using real-time reverse transcription-polymerase chain reaction and protein levels studied using Western blotting. NOS activity was also assessed using the citrulline assay. All 3 NOS isoforms were found in muscle sections associated with muscle fibers and microvessels. In muscle subjected to acute ischemia and reperfusion, NOS I/neuronal NOS mRNA and protein were elevated during reperfusion. NOS III/endothelial NOS was also upregulated at the protein level during reperfusion. No changes in NOS II/inducible NOS expression or NOS activity occurred. In conclusion, alterations in NOS I and III (neuronal NOS and endothelial NOS) at different levels occurred after acute ischemia and reperfusion in human skeletal muscle; however, this did not result in increased NOS activity. In the development of therapeutic agents based on manipulation of the NO pathway, targeting the appropriate NOS isoenzymes may be important.
Tsui
Janice C S
JC
Department of Surgery, Royal Free Hospital, London, UK. jcstsui@hotmail.com
Baker
Daryll M
DM
Shaw
Sidney G
SG
Dashwood
Michael R
MR
D000208:Acute Disease; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee; D015153:Blotting, Western; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D007150:Immunohistochemistry; D007511:Ischemia / Q000201:enzymology* / Q000235:genetics; D035002:Lower Extremity; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000098:blood supply* / Q000201:enzymology; D019001:Nitric Oxide Synthase / Q000032:analysis* / Q000235:genetics; D052248:Nitric Oxide Synthase Type I / Q000032:analysis; D052247:Nitric Oxide Synthase Type II / Q000032:analysis; D052250:Nitric Oxide Synthase Type III / Q000032:analysis; D020370:Osteoarthritis, Knee / Q000601:surgery*; D012333:RNA, Messenger / Q000032:analysis; D015424:Reperfusion / Q000009:adverse effects*; D015427:Reperfusion Injury / Q000201:enzymology* / Q000209:etiology / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014111:Tourniquets / Q000009:adverse effects*
D012333:RNA, Messenger; C496320:NOS1 protein, human; C496319:NOS2 protein, human; C496314:NOS3 protein, human; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III