Catecholamine, dopamine-beta-hydroxylase and atrial natriuretic factor content in separate heart chambers of cardiomyopathic hamsters

Since previous investigations have suggested a relationship between atrial natriuretic factor (ANF) and dopamine-beta-hydroxylation, cardiomyopathic hamsters were studied for atrial and ventricular catecholamine (CA) and dopamine-beta-hydroxylase (D beta H) content as correlates to a parallel finding of markedly decreased atrial but increased ventricular ANF concentrations in these animals. It was noted that, with progressive cardiomyopathy, the reduced tissue norepinephrine (NE) content paralleled the declining D beta H activity in the atria. In the ventricles, however, the progressively-decreasing NE content was associated with an increase of D beta H. These data indicate that the NE depletion is mediated by different mechanisms in the ventricles and atria. They do not support a simple relationship between NE depletion and tissue D beta H activity or between the latter and tissue ANF concentrations.