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METABOLISM OF [ 3 H]‐(±)‐ISOPRENALINE BY ISOLATED ATRIA AND CORONARY ARTERIES OF THE KITTEN
Author(s) -
CORNISH E.J.,
GOLDIE R.G.
Publication year - 1980
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1980.tb14564.x
Subject(s) - kitten , isoprenaline , medicine , coronary arteries , cardiology , chemistry , endocrinology , artery , cats , stimulation
1 Isolated coronary arteries of the kitten accumulated more unchanged isoprenaline and metabolized more amine than atria following incubation for 1 to 20 min with [ 3 H]‐(±)‐isoprenaline (25 ng/ml or 5 μg/ml). 2 Cortisol (10 or 80 μ m ), U‐0521 (120 μ m ) and oxytetracycline (100 μ m ) all reduced metabolite formation. 3 Cortisol inhibited ‘Iso Influx Min ’ (cellular isoprenaline accumulation plus total metabolite production). In contrast, it increased, decreased or did not alter accumulation of unmetabolized isoprenaline, depending upon the experimental conditions. 4 Isoprenaline accumulation was increased in atria and reduced in coronary arteries by U‐0521, while oxytetracycline reduced accumulation in coronary arteries at the high amine concentration. 5 It is concluded that in atria, cortisol inhibits metabolism and has differential effects on a number of extraneuronal compartments which accumulate isoprenaline. Both cortisol and U‐0521 appear to be extraneuronal uptake inhibitors and inhibitors of catechol‐ O ‐methyltransferase in coronary arteries. Oxytetracycline may have effects additional to inhibition of isoprenaline binding to connective tissue fibres.