title: Influence of decompression sickness on vasocontraction of isolated rat vessels.
abstract: Studies conducted in divers indicate that endothelium function is impaired following a dive even without decompression sickness (DCS). Our previous experiment conducted on rat isolated vessels showed no differences in endothelium-dependent vasodilation after a simulated dive even in the presence of DCS, while contractile response to phenylephrine was progressively impaired with increased decompression stress. This study aimed to further investigate the effect of DCS on vascular smooth muscle. Thirty-two male Sprague-Dawley rats were submitted to the same hyperbaric protocol and classified according to the severity of DCS: no-DCS (without clinical symptoms), mild-DCS, or severe-DCS (dead within 1 h). A control group remained at atmospheric pressure. Isometric tension was measured in rings of abdominal aorta and mesenteric arteries. Single dose contraction was assessed with KCl solution. Dose-response curves were obtained with phenylephrine and endothelin-1. Phenylephrine-induced contraction was observed in the presence of antioxidant tempol. Additionally, plasma concentrations of angiotensin II, angiotensin-converting enzyme, and thiobarbituric acid reactive substances (TBARS) were assessed. Response to phenylephrine was impaired only among mild-DCS in both vessels. Dose-response curves to endothelin-1 were impaired after mild-DCS in mesenteric and severe-DCS in aorta. KCl-induced contraction was affected after hyperbaric exposure regardless of DCS status in aorta only. These results confirm postdive vascular dysfunction is dependent on the type of vessel. It further evidenced that vascular dysfunction is triggered by DCS rather than by diving itself and suggest the influence of circulating factor/s. Diving-induced impairment of the L-type voltage-dependent Ca(2+) channels and/or influence of renin-angiotensin system is proposed.
authors.affiliation: EA4324-ORPHY Laboratory, Université de Bretagne Occidentale, Brest, France.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Mazur
authors.affiliation: EA4324-ORPHY Laboratory, Université de Bretagne Occidentale, Brest, France.
authors.forename: Kate
authors.initials: K
authors.lastname: Lambrechts
authors.affiliation: EA4324-ORPHY Laboratory, Université de Bretagne Occidentale, Brest, France.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Wang
authors.affiliation: EA4324-ORPHY Laboratory, Université de Bretagne Occidentale, Brest, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Belhomme
authors.affiliation: EA4324-ORPHY Laboratory, Université de Bretagne Occidentale, Brest, France.
authors.forename: Michael
authors.initials: M
authors.lastname: Theron
authors.affiliation: EA4324-ORPHY Laboratory, Université de Bretagne Occidentale, Brest, France.
authors.forename: Peter
authors.initials: P
authors.lastname: Buzzacott
authors.affiliation: EA4324-ORPHY Laboratory, Université de Bretagne Occidentale, Brest, France francois.guerrero@univ-brest.fr.
authors.forename: François
authors.identifier: http://orcid.org/0000-0002-0283-3503
authors.initials: F
authors.lastname: Guerrero
mesh_terms: D000804:Angiotensin II / Q000378:metabolism; D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D001011:Aorta / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D003665:Decompression Sickness / Q000378:metabolism / Q000503:physiopathology*; D004242:Diving / Q000502:physiology; D019332:Endothelin-1 / Q000378:metabolism; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D007703:Peptidyl-Dipeptidase A / Q000378:metabolism; D010656:Phenylephrine / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012084:Renin-Angiotensin System / Q000187:drug effects / Q000502:physiology; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology*; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology
chemical_list: D000975:Antioxidants; D019332:Endothelin-1; D017392:Thiobarbituric Acid Reactive Substances; D000804:Angiotensin II; D010656:Phenylephrine; D007703:Peptidyl-Dipeptidase A
keywords: aorta; contraction; decompression illness; diving; mesenteric artery; vascular smooth muscle