Heat-induced increases in endothelial NO synthase expression and activity and endothelial NO release

• Published in: American journal of physiology. Heart and circulatory physiology Vol. 285; no. 1; pp. H333 - H340
• Main Authors: Harris, M. Brennan, Blackstone, Michele A, Ju, Hong, Venema, Virginia J, Venema, Richard C
• Format: Journal Article
• Language: English
• Published: United States 01.07.2003
• Subjects: Animals; Cattle; Cell Survival - physiology; Cells, Cultured; Coloring Agents; Endothelium, Vascular - enzymology; Endothelium, Vascular - metabolism; Endothelium, Vascular - physiology; Gene Expression Regulation, Enzymologic - physiology; Heat-Shock Response - physiology; HSP70 Heat-Shock Proteins - biosynthesis; HSP90 Heat-Shock Proteins - biosynthesis; Immunoblotting; In Vitro Techniques; Male; Muscle Contraction - drug effects; Muscle, Smooth, Vascular - physiopathology; Nitric Oxide - metabolism; Nitric Oxide Synthase - biosynthesis; Nitric Oxide Synthase - metabolism; Nitric Oxide Synthase Type III; Phenylephrine - pharmacology; Precipitin Tests; Rats; Rats, Sprague-Dawley; Trypan Blue; Vasoconstrictor Agents - pharmacology
• ISSN: 0363-6135; 1522-1539
• DOI: 10.1152/ajpheart.00726.2002

1 Vascular Biology Center, 2 Department of Pediatrics, 3 Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta, Georgia 30912-2500 Submitted 20 August 2002 ; accepted in final form 18 March 2003 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°C, 42°C, or 45°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°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°C. eNOS activity and maximal bradykinin-stimulated NO release was significantly increased 24 h after heat shock at 42°C. Heat shock in rats (core temperature: 42°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 N G -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. endothelium; heat shock; rat; heat shock proteins Address for reprint requests and other correspondence: M. Brennan Harris, Vascular Biology Center, Medical College of Georgia, 1459 Laney Walker Blvd., CB3207, Augusta, GA 30912-2500 (E-mail: bharris{at}mail.mcg.edu ).