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Oxygen modulates contractile responses to potassium and prostaglandin F2 alpha in human pial arteries

Reinstrup, Peter LU ; Uski, Tore LU and Messeter, Kenneth (1992) In British Journal of Anaesthesia 68(2). p.187-192
Abstract
Oxygen may modulate cerebrovascular resistance, but its direct influence on human pial arteries is unknown. We have investigated the effects of varying oxygen tension (73, 30 and 8 kPa) in depolarized (potassium) and receptor stimulated (prostaglandin F2 alpha) isolated human pial arteries. Control responses were obtained at an oxygen tension of 30 kPa. Contractions induced by prostaglandin F2 alpha and potassium showed no significant difference in potency (unaffected EC50 values) at the different oxygen concentrations. In contrast, the maximum contractions (Emax) were dependent on the oxygen tension. Potassium-induced contractions were enhanced (Emax = 107 (SE 3)% of control contractions (P less than or equal to 0.01)) at an oxygen... (More)
Oxygen may modulate cerebrovascular resistance, but its direct influence on human pial arteries is unknown. We have investigated the effects of varying oxygen tension (73, 30 and 8 kPa) in depolarized (potassium) and receptor stimulated (prostaglandin F2 alpha) isolated human pial arteries. Control responses were obtained at an oxygen tension of 30 kPa. Contractions induced by prostaglandin F2 alpha and potassium showed no significant difference in potency (unaffected EC50 values) at the different oxygen concentrations. In contrast, the maximum contractions (Emax) were dependent on the oxygen tension. Potassium-induced contractions were enhanced (Emax = 107 (SE 3)% of control contractions (P less than or equal to 0.01)) at an oxygen tension of 73 kPa, whereas a reduction in tension to 8 kPa had no significant effect (97 (2)%). Prostaglandin F2 alpha-induced contractions were enhanced at 73 kPa (115 (6)%) (P = 0.02) and depressed at 8 kPa (96 (2)%) (P = 0.02). Reduction in oxygen tension induced a relaxation in depolarized and in receptor stimulated arteries, regardless of whether or not oxygen was replaced by nitrogen or by helium. Low oxygen tension relaxed arteries despite pretreatment with 2,4-dinitrophenol, an agent which blocks oxidative phosphorylation. It is concluded that a reduction in oxygen tension exerted a direct, although small, depressant effect on human pial arteries, and that this effect was not mediated exclusively by hyperpolarization or by inhibition of oxidative phosphorylation. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Arteries: cerebrovascular resistance, pial artery, stimulated contraction. Oxygen: tension.
in
British Journal of Anaesthesia
volume
68
issue
2
pages
187 - 192
publisher
Macmillan
external identifiers
  • pmid:1540463
ISSN
1471-6771
language
English
LU publication?
yes
id
952ce6e1-1671-4b67-8c95-472b260ba7f2 (old id 1106529)
alternative location
http://bja.oxfordjournals.org/cgi/reprint/68/2/187
date added to LUP
2008-08-11 16:29:17
date last changed
2016-04-15 19:24:20
@article{952ce6e1-1671-4b67-8c95-472b260ba7f2,
  abstract     = {Oxygen may modulate cerebrovascular resistance, but its direct influence on human pial arteries is unknown. We have investigated the effects of varying oxygen tension (73, 30 and 8 kPa) in depolarized (potassium) and receptor stimulated (prostaglandin F2 alpha) isolated human pial arteries. Control responses were obtained at an oxygen tension of 30 kPa. Contractions induced by prostaglandin F2 alpha and potassium showed no significant difference in potency (unaffected EC50 values) at the different oxygen concentrations. In contrast, the maximum contractions (Emax) were dependent on the oxygen tension. Potassium-induced contractions were enhanced (Emax = 107 (SE 3)% of control contractions (P less than or equal to 0.01)) at an oxygen tension of 73 kPa, whereas a reduction in tension to 8 kPa had no significant effect (97 (2)%). Prostaglandin F2 alpha-induced contractions were enhanced at 73 kPa (115 (6)%) (P = 0.02) and depressed at 8 kPa (96 (2)%) (P = 0.02). Reduction in oxygen tension induced a relaxation in depolarized and in receptor stimulated arteries, regardless of whether or not oxygen was replaced by nitrogen or by helium. Low oxygen tension relaxed arteries despite pretreatment with 2,4-dinitrophenol, an agent which blocks oxidative phosphorylation. It is concluded that a reduction in oxygen tension exerted a direct, although small, depressant effect on human pial arteries, and that this effect was not mediated exclusively by hyperpolarization or by inhibition of oxidative phosphorylation.},
  author       = {Reinstrup, Peter and Uski, Tore and Messeter, Kenneth},
  issn         = {1471-6771},
  keyword      = {Arteries: cerebrovascular resistance,pial artery,stimulated contraction. Oxygen: tension.},
  language     = {eng},
  number       = {2},
  pages        = {187--192},
  publisher    = {Macmillan},
  series       = {British Journal of Anaesthesia},
  title        = {Oxygen modulates contractile responses to potassium and prostaglandin F2 alpha in human pial arteries},
  volume       = {68},
  year         = {1992},
}