Connexin‐mimetic peptides dissociate electrotonic EDHF‐type signalling via myoendothelial and smooth muscle gap junctions in the rabbit iliac artery
AT Chaytor, LM Bakker, DH Edwards… - British journal of …, 2005 - Wiley Online Library
AT Chaytor, LM Bakker, DH Edwards, TM Griffith
British journal of pharmacology, 2005•Wiley Online Library1 Synthetic peptides corresponding to the Gap 26 and Gap 27 domains of the first and
second extracellular loops of the major vascular connexins (Cx37, Cx40 and Cx43),
designated as 43Gap 26, 40Gap 27, 37, 40Gap 26 and 37, 43Gap 27 according to Cx
homology, were used to investigate the role of gap junctions in the spread of endothelial
hyperpolarizations evoked by cyclopiazonic acid (CPA) through the wall of the rabbit iliac
artery. 2 Immunostaining and confocal microscopy demonstrated that gap junction plaques …
second extracellular loops of the major vascular connexins (Cx37, Cx40 and Cx43),
designated as 43Gap 26, 40Gap 27, 37, 40Gap 26 and 37, 43Gap 27 according to Cx
homology, were used to investigate the role of gap junctions in the spread of endothelial
hyperpolarizations evoked by cyclopiazonic acid (CPA) through the wall of the rabbit iliac
artery. 2 Immunostaining and confocal microscopy demonstrated that gap junction plaques …
- 1Synthetic peptides corresponding to the Gap 26 and Gap 27 domains of the first and second extracellular loops of the major vascular connexins (Cx37, Cx40 and Cx43), designated as 43Gap 26, 40Gap 27, 37,40Gap 26 and 37,43Gap 27 according to Cx homology, were used to investigate the role of gap junctions in the spread of endothelial hyperpolarizations evoked by cyclopiazonic acid (CPA) through the wall of the rabbit iliac artery.
- 2Immunostaining and confocal microscopy demonstrated that gap junction plaques constructed from Cx37 and Cx40 were abundant in the endothelium, whereas Cx43 was the dominant Cx visualized in the media.
- 3None of the Cx‐mimetic peptides affected endothelial hyperpolarizations evoked by CPA directly.
- 4When administered individually, 40Gap 27, 37,40Gap 26 and 37,43Gap 27, but not 43Gap 26, attenuated endothelium‐dependent subintimal smooth muscle hyperpolarization. By contrast, only 43Gap 26 and 37,43Gap 27 reduced the spread of subintimal hyperpolarization through the media of the rabbit iliac artery. The site of action of the peptides therefore correlated closely with the expression of their target Cxs in detectable gap junction plaques.
- 5The findings provide further evidence that the EDHF phenomenon is electrotonic in nature, and highlight the contribution of myoendothelial and homocellular smooth muscle communication via gap junctions to arterial function.
British Journal of Pharmacology (2005) 144, 108–114. doi:10.1038/sj.bjp.0706046
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