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A central role for KATP channels in arteriolar vasodilation and vasoconstriction signaling
Author(s) -
Dua Ashok K,
Junuzovic Jasna,
Murrant Coral L
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.5.a495-a
Subject(s) - pinacidil , vasodilation , vasoconstriction , chemistry , phenylephrine , arteriole , adenosine , potassium channel , acetylcholine , pharmacology , medicine , endocrinology , microcirculation , glibenclamide , biochemistry , blood pressure , diabetes mellitus
We tested for a central role of K ATP channels in vasoactivity of transverse arterioles (max diameter ≃ 40 μm) in an anesthetized hamster cremaster preparation in situ by testing whether 10 −5 M Glybenclamide (GLY, K ATP channel inhibitor) altered vasodilations induced by Acetylcholine (Ach, 10 −7 –10 −4 M); Adenosine (ADO,10 −9 –10 −4 M); S‐Nitroso‐N‐acetyl penicillamine (SNAP,10 −9 –10 −4 M) and vasoconstrictions induced by Phenylephrine (PHE 10 −9 –10 −4 M) and O 2 (10% and 21%). The effect of each compound was tested in the absence of GLY and again after 30 min of GLY incubation. Recovery from the effects of GLY was confirmed by repeating the experiment after 30 min washout of GLY. GLY significantly inhibited dilations produced by ACh at 10 −7 –10 −5 Mbut not 10 −4 M. GLY significantly inhibited dilations resulting from 10 −9 –10 −4 M ADO and 10 −9 –10 −4 M SNAP with less inhibition at higher concentrations. GLY inhibited all vasoconstrictions induced by O 2 and 10 −9 ‐ 10 −6 M PHE but not 10 −5 or 10 −4 M. The ability of 10 −7 –10 −4 M GLY to inhibit a 10 −6 M pinacidil (K ATP channel opener) dilation was used to test to indicate the lack of potential for non‐specific effects. Our data show that GLY inhibited a vasoactive component of each vasodilator and vasoconstrictor tested suggesting that K ATP channels play a central role in the vasoreactivity of arterioles. Supported by NSERC Canada and PREA.