Skip to Main content Skip to Navigation
Journal articles

Hyperbaric-induced enhancement of noradrenaline-evoked contraction in rat thoracic aorta.

Abstract : The aim of this study was to investigate the effects of a high ambient pressure of He on vascular contraction induced by noradrenaline and to distinguish the effects of ambient pressure per se from those of increased pressure of inert gas. Rings of thoracic aorta were isolated from male Wistar rats. Isometric tension was measured in preparations exposed to 7.1 MPa (absolute pressure) of He. Dose-response curves for noradrenaline and contractions elicited by 120 mM KCl were compared with time-matched experiments performed at atmospheric pressure. The same protocol was also carried out under 7.1 MPa of N2. At the high pressure of He, the contraction elicited by noradrenaline was increased with no change in the response to K(+)-evoked depolarization. The tension developed in response to noradrenaline also increased under 7.1 MPa of N2 but the effects were less marked than during the He experiments. Moreover, the response to KCl was reduced in this circumstance. Hyperbaric conditions enhance the noradrenaline-induced contraction of rat aorta in vitro. This effect probably results from an action of pressure per se on activation of adrenoceptors. However, the hyperbaric-induced increase in vascular smooth muscle contraction is partially counteracted by high pressures of inert gases (N2, but also probably He), which impair the efficiency of the contractile machinery.
Complete list of metadatas

https://hal.univ-brest.fr/hal-00743429
Contributor : François Guerrero <>
Submitted on : Thursday, October 18, 2012 - 11:07:17 PM
Last modification on : Tuesday, March 6, 2018 - 1:22:06 AM

Identifiers

  • HAL Id : hal-00743429, version 1
  • PUBMED : 9257111

Collections

Citation

F. Guerrero, M. Lucciano, P. Joanny, Y. Jammes. Hyperbaric-induced enhancement of noradrenaline-evoked contraction in rat thoracic aorta.. Experimental Physiology, Wiley-Blackwell, 1997, 82 (4), pp.687-95. ⟨hal-00743429⟩

Share

Metrics

Record views

146