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Inhibition of effects of flow on potassium permeability in single perfused frog mesenteric capillaries
Author(s) -
Kajimura M.,
Michel C. C.
Publication year - 1999
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1111/j.1469-7793.1999.201aa.x
Subject(s) - chemistry , medicine , forskolin , nitric oxide , intracellular , endocrinology , biophysics , adenosine , vasodilation , permeability (electromagnetism) , biology , biochemistry , in vitro , membrane
1 We have investigated the effects of various potential inhibitors on flow‐dependent K + permeability ( P K ) of single perfused mesenteric microvessels in pithed frogs. 2 Neither superfusion with a nitric oxide synthase inhibitor, N G ‐monomethyl‐L‐arginine (10 or 100 μmol l −1 ), nor the addition of indomethacin (30 μmol l −1 ) to both perfusate and superfusate reduced the positive correlation between P K and flow velocity ( U ). 3 In the presence of agents known to raise intracellular levels of adenosine 3′,5′‐cyclic monophosphate (noradrenaline, 8‐bromo‐cAMP and a combination of forskolin and rolipram) the slope of the relation between P K and U was no longer significant, so that P K was no longer flow dependent. 4 These results confirm that the flow dependence of P K is a biological process and not an artefact of measurement and suggest a role for intracellular cAMP rather than nitric oxide or prostacyclin in the flow‐dependent modulation of P K in frog mesenteric microvessels.