Global ischemia impairs ATP-sensitive K+ channel function in cerebral arterioles in piglets

F. Bari, Thomas M. Louis, Wei Meng, David W. Busija

Research output: Contribution to journalArticle

75 Citations (Scopus)

Abstract

Background and Purpose: Indirect evidence from studies in which calcitonin gene-related peptide was used indicates that anoxic stress suppresses functioning of cerebral vascular ATP-sensitive K+ channels. The purpose of this study was to directly examine effects of total global ischemia on cerebral arteriolar dilator responses to activators of ATP- sensitive K+ channels. Methods: We measured pial arteriolar diameters in anesthetized piglets using a closed cranial window and intravital microscopy. Baseline diameters were approximately 100 μm. Arteriolar responses to aprikalim (10-8 and 10-6 mol/L), a pharmacological activator of ATP- sensitive K+ channels, and iloprost (0.1 and 1 μg/mL), a physiological activator of these channels, were determined before and 1, 2, and 4 hours after a 10-minute period of total global ischemia. Ischemia was caused by increasing intracranial pressure. Results: Before ischemia, aprikalim dilated cerebral arterioles by 7±2% at 10-8 mol/L and by 25±4% at 10-6 mol/L (n=5). At 1 hour after ischemia, aprikalim did not cause significant dilation at either dose (3±2% at 10-8 mol/L and 7±4% at 10-6 mol/L: P2 were intact after ischemia. Conclusions: Ischemia transiently eliminates cerebral arteriolar dilation to activation of ATP-sensitive K+ channels; arteriolar responses are suppressed at 1 hour and return toward normal over 2 to 4 hours. In addition, reduced responsiveness can be prevented by prior treatment with indomethacin.

Original languageEnglish
Pages (from-to)1874-1881
Number of pages8
JournalStroke
Volume27
Issue number10
Publication statusPublished - Oct 1996

Fingerprint

Arterioles
Ischemia
Adenosine Triphosphate
Dilatation
Iloprost
Calcitonin Gene-Related Peptide
Intracranial Pressure
Brain Ischemia
Indomethacin
Blood Vessels
Pharmacology
aprikalim

Keywords

  • cerebral blood flow
  • indomethacin
  • oxygen radical
  • pigs
  • prostaglandins

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Neuroscience(all)

Cite this

Bari, F., Louis, T. M., Meng, W., & Busija, D. W. (1996). Global ischemia impairs ATP-sensitive K+ channel function in cerebral arterioles in piglets. Stroke, 27(10), 1874-1881.

Global ischemia impairs ATP-sensitive K+ channel function in cerebral arterioles in piglets. / Bari, F.; Louis, Thomas M.; Meng, Wei; Busija, David W.

In: Stroke, Vol. 27, No. 10, 10.1996, p. 1874-1881.

Research output: Contribution to journalArticle

Bari, F, Louis, TM, Meng, W & Busija, DW 1996, 'Global ischemia impairs ATP-sensitive K+ channel function in cerebral arterioles in piglets', Stroke, vol. 27, no. 10, pp. 1874-1881.
Bari, F. ; Louis, Thomas M. ; Meng, Wei ; Busija, David W. / Global ischemia impairs ATP-sensitive K+ channel function in cerebral arterioles in piglets. In: Stroke. 1996 ; Vol. 27, No. 10. pp. 1874-1881.
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