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Relationship between effects of ouabain on accumulation and efflux of noradrenaline in tissue slices
Abstract:
The primary goal of this investigation was to identify the mechanism by which ouabain decreases accumulation of noradrenaline by tissue slices. Secondary goals were: 1) to construct the concentration-effect curve for the action of ouabain to increase efflux of noradrenaline from tissue slices, and 2) to determine whether species sensitivity exists for the action of ouabain on efflux. In tissues from dogs and guinea-pigs, the concentration-effect curves were steep, a characteristics of many actions of digitalis. Dogs were approximately an order of magnitude more sensitive than guinea-pigs. The effect of ouabain to increase efflux appears to be the primary mechanism by which the drug decreases accumulation of noradrenaline by tissue slices. Ouabain may increase efflux from two different intraneuronal compartments. The intraneuronal site appears to be dependent upon the concentration of ouabain.
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