Heat-induced increases in endothelial NO synthase expression and activity and endothelial NO release.
Endothelial nitric oxide (NO) synthase (eNOS) is regulated by heat shock protein 90 (HSP90), a heat-inducible protein; however, the effect of heat shock on eNOS expression and eNO release is unknown. Bovine aortic endothelial cells were incubated for 1 h at 37 degrees C, 42 degrees C, or 45 degrees C and cell lysates were evaluated with the use of Western blotting. We observed a 2.1 +/- 0.1-fold increase in eNOS protein content, but no change in HSP90 content, HSP70 content, or HSP90/eNOS association, 24 h after heat shock at 42 degrees C. We also observed a 7.7 +/- 1.5-fold increase in HSP70 protein content, but did not observe a change in eNOS or HSP90 24 h after heat shock at 45 degrees C. eNOS activity and maximal bradykinin-stimulated NO release was significantly increased 24 h after heat shock at 42 degrees C. Heat shock in rats (core temperature: 42 degrees C, 15 min) resulted in a significant increase in aortic eNOS, HSP90, and HSP70 protein content. The aorta from heat-shocked rats exhibited a decreased maximal contractile response to phenylephrine, which was abolished by preincubation with NG-nitro-l-arginine. We conclude that prior heat shock is a physical stimulus of increased eNOS expression and is associated with an increase in eNOS activity, agonist-stimulated NO release, and a decreased vasoconstrictor response.
Harris
M Brennan
MB
Department of Pediatrics, Medical College of Georgia, Augusta, GA 30912-2500, USA. bharris@mail.mcg.edu
Blackstone
Michele A
MA
Ju
Hong
H
Venema
Virginia J
VJ
Venema
Richard C
RC
D000818:Animals; D002417:Cattle; D002470:Cell Survival / Q000502:physiology; D002478:Cells, Cultured; D004396:Coloring Agents; D004730:Endothelium, Vascular / Q000201:enzymology / Q000378:metabolism* / Q000502:physiology*; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D018840:HSP70 Heat-Shock Proteins / Q000096:biosynthesis; D018841:HSP90 Heat-Shock Proteins / Q000096:biosynthesis; D018869:Heat-Shock Response / Q000502:physiology*; D015151:Immunoblotting; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000503:physiopathology; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000096:biosynthesis* / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III; D010656:Phenylephrine / Q000494:pharmacology; D011233:Precipitin Tests; D051381:Rats; D017207:Rats, Sprague-Dawley; D014343:Trypan Blue; D014662:Vasoconstrictor Agents / Q000494:pharmacology
D004396:Coloring Agents; D018840:HSP70 Heat-Shock Proteins; D018841:HSP90 Heat-Shock Proteins; D014662:Vasoconstrictor Agents; D010656:Phenylephrine; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III; C496316:Nos3 protein, rat; D014343:Trypan Blue