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Effect of Potassium on the Release of [ 3 H]Noradrenaline from Rabbit and Human Pulmonary Artery
Author(s) -
Vizi Elek Sylvester,
Torok Tamas,
Magyar Kalman
Publication year - 1984
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1984.tb02735.x
Subject(s) - potassium , yohimbine , sodium , chemistry , stimulation , inhibitory postsynaptic potential , rabbit (cipher) , biophysics , endocrinology , medicine , biochemistry , biology , statistics , receptor , mathematics , organic chemistry , antagonist
The release of [ 3 H]noradrenaline ([ 3 H]NA) from rabbit and human isolated pulmonary artery has been measured. Removal of external potassium ions enhanced both the resting and stimulated release of [ 3 H]NA from the strips. On adding K + to tissues which had been suspended in K + ‐free Krebs solution, the release of [ 3 H]NA was reduced in both stimulated and unstimulated tissues. Selective inhibition of presynaptic α 2 ‐ ‐ adrenoceptors by yohimbine significantly potentiated the release of [ 3 H]NA evoked by stimulation in K + ‐free solution. The presynaptic inhibitory effect of NA was much less pronounced when the release was enhanced by the removal of external K + . Since the activity of Na,K‐ATPase may be affected by removing K + or by adding it to tissue previously kept in K + ‐free solution, the results may indicate involvement of the sodium pump in NA release.