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Influence of halothane and isoflurane on the contractile responses to potassium and prostaglandin F2 alpha in isolated human pial arteries

Reinstrup, Peter LU ; Uski, Tore LU and Messeter, Kenneth (1994) In British Journal of Anaesthesia 72(5). p.581-586
Abstract
Volatile anaesthetics may modulate cerebrovascular resistance, but their direct actions on human cerebral arteries are unknown. In the present study, we have evaluated the effects of halothane and isoflurane at different MAC (0.4, 1.0 and 2.0) on contractions induced by depolarization (potassium) or receptor stimulation (prostaglandin F2 alpha) in isolated ring segments of human pial arteries. Neither halothane nor isoflurane had significant effects on potency (unaffected EC50 value) or the maximum response (Emax) in potassium-contracted arteries, even though there was a general tendency to attenuation of Emax. Similarly, the potency of prostaglandin F2 alpha was unchanged (unaffected EC50 value). However, the Emax value for prostaglandin... (More)
Volatile anaesthetics may modulate cerebrovascular resistance, but their direct actions on human cerebral arteries are unknown. In the present study, we have evaluated the effects of halothane and isoflurane at different MAC (0.4, 1.0 and 2.0) on contractions induced by depolarization (potassium) or receptor stimulation (prostaglandin F2 alpha) in isolated ring segments of human pial arteries. Neither halothane nor isoflurane had significant effects on potency (unaffected EC50 value) or the maximum response (Emax) in potassium-contracted arteries, even though there was a general tendency to attenuation of Emax. Similarly, the potency of prostaglandin F2 alpha was unchanged (unaffected EC50 value). However, the Emax value for prostaglandin F2 alpha at normocapnia (mean PCO2 4.3 (SEM 0.1) kPa, pH 7.41 (0.01)) and addition of halothane (0.4, 1.0 and 2.0 MAC) was significantly attenuated to 96 (2)%, 91 (3)% and 84 (4)% at the respective MAC concentrations. Isoflurane at 2 MAC and normocapnia also reduced Emax to 94 (3)%. During hypocapnia (PCO2 2.7 (0.1) kPa, pH 7.64 (0.01)), the vasodilator effect of halothane was reduced, whereas isoflurane at 0.4 and 1.0 MAC enhanced the contraction induced by prostaglandin F2 alpha. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Anaesthetics, volatile: enflurane. Anaesthetics, volatile: halothane. Brain: blood flow. Arteries: cerebral
in
British Journal of Anaesthesia
volume
72
issue
5
pages
581 - 586
publisher
Macmillan
external identifiers
  • pmid:8198913
ISSN
1471-6771
language
English
LU publication?
yes
id
c57c66a0-1690-4752-bcfb-248c85fb4a39 (old id 1108107)
alternative location
http://bja.oxfordjournals.org/cgi/reprint/72/5/581
date added to LUP
2008-07-23 14:04:20
date last changed
2016-04-15 19:44:02
@article{c57c66a0-1690-4752-bcfb-248c85fb4a39,
  abstract     = {Volatile anaesthetics may modulate cerebrovascular resistance, but their direct actions on human cerebral arteries are unknown. In the present study, we have evaluated the effects of halothane and isoflurane at different MAC (0.4, 1.0 and 2.0) on contractions induced by depolarization (potassium) or receptor stimulation (prostaglandin F2 alpha) in isolated ring segments of human pial arteries. Neither halothane nor isoflurane had significant effects on potency (unaffected EC50 value) or the maximum response (Emax) in potassium-contracted arteries, even though there was a general tendency to attenuation of Emax. Similarly, the potency of prostaglandin F2 alpha was unchanged (unaffected EC50 value). However, the Emax value for prostaglandin F2 alpha at normocapnia (mean PCO2 4.3 (SEM 0.1) kPa, pH 7.41 (0.01)) and addition of halothane (0.4, 1.0 and 2.0 MAC) was significantly attenuated to 96 (2)%, 91 (3)% and 84 (4)% at the respective MAC concentrations. Isoflurane at 2 MAC and normocapnia also reduced Emax to 94 (3)%. During hypocapnia (PCO2 2.7 (0.1) kPa, pH 7.64 (0.01)), the vasodilator effect of halothane was reduced, whereas isoflurane at 0.4 and 1.0 MAC enhanced the contraction induced by prostaglandin F2 alpha.},
  author       = {Reinstrup, Peter and Uski, Tore and Messeter, Kenneth},
  issn         = {1471-6771},
  keyword      = {Anaesthetics,volatile: enflurane. Anaesthetics,volatile: halothane. Brain: blood flow. Arteries: cerebral},
  language     = {eng},
  number       = {5},
  pages        = {581--586},
  publisher    = {Macmillan},
  series       = {British Journal of Anaesthesia},
  title        = {Influence of halothane and isoflurane on the contractile responses to potassium and prostaglandin F2 alpha in isolated human pial arteries},
  volume       = {72},
  year         = {1994},
}