Heat stress‐induced B1 receptor synthesis in the rat: an ex vivo study

• Published in: British journal of pharmacology Vol. 125; no. 4; pp. 812 - 816
• Main Authors: Lagneux, Caroline, Innocenti‐Francillard, Patricia, Godin‐Ribuot, Diane, Bader, Mickael, Ribuot, Christophe
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.10.1998; Nature Publishing
• Subjects: [des‐Arg9]‐bradykinin; Animals; Aorta - metabolism; B1 receptor; Biological and medical sciences; Blood Pressure; Blotting, Southern; DNA, Complementary - chemical synthesis; Effects of various physical factors on living matter (vibrations, electric field, ultrasound, sound...); Endothelium, Vascular - drug effects; endotoxin; Fundamental and applied biological sciences. Psychology; Heat stress; Heat Stress Disorders - metabolism; In Vitro Techniques; Lipopolysaccharides - pharmacology; Male; mRNA; Muscle Relaxation - drug effects; Muscle, Smooth, Vascular - drug effects; Myocardium - metabolism; Oligonucleotides - chemical synthesis; Polymerase Chain Reaction; rat aorta rings; Rats; Rats, Wistar; Receptors, Adrenergic, beta-1 - metabolism; RNA - metabolism; RNA, Messenger - metabolism; Tissues, organs and organisms biophysics; Transcription, Genetic - drug effects; Heart; Rat; Rodentia; Smooth muscle; Biosynthesis; Gene expression; Endotoxin; Stress; Muscular relaxation; Vertebrata; Mammalia; Ex vivo; Blood vessel; Animal; Nitric oxide; Bradykinin; Thermal shock; Aorta; Circulatory system; Biological receptor
• ISSN: 0007-1188; 1476-5381
• DOI: 10.1038/sj.bjp.0702146

1 This ex vivo study was performed to characterize B1 receptor induction in rats submitted to heat stress. Changes in aortic isometric tension were recorded after a 90 min in vitro incubation with [des‐Arg9]‐bradykinin. B1 receptor mRNA were detected in aorta and heart using RT–PCR technique. 2 Aortic rings from sham rats did not respond to [des‐Arg9]‐bradykinin. In contrast, this agonist induced a concentration‐dependent relaxation of aortic rings from rats submitted to lipopolysaccharide (LPS) treatment or to heat stress 24 h earlier. 3 The concentration‐dependent relaxation induced by [des‐Arg9]‐bradykinin on aortic rings from heat‐stressed rats was abolished by [des‐Arg10]‐HOE 140, a selective B1 receptor antagonist. 4 In endothelium denuded aortic rings from heat‐stress rats, [des‐Arg9]‐bradykinin induced a concentration‐dependent constriction. 5 Pretreatment of intact aortic rings from heat‐stress rats with the cyclo‐oxygenase inhibitor, diclofenac (1 μM) did not prevent the concentration‐dependent relaxation in response to [des‐Arg9]‐bradykinin. In contrast, NO synthase inhibition with Nω‐nitro‐L‐arginine methyl ester (30 μM) totally prevented the vasorelaxant response. 6 B1 receptor mRNA were not detected in aorta and heart from sham animals but were present in tissue from heat‐stressed and LPS‐treated rats. 7 In conclusion, our results suggest that heat stress induces a transcriptional activation of the B1 receptor gene. The induction of B1 receptors leads to an endothelium‐ and NO‐dependent vasorelaxant response to [des‐Arg9]‐bradykinin. British Journal of Pharmacology (1998) 125, 812–816; doi:10.1038/sj.bjp.0702146