Regional distribution of free and sulfoconjugated catecholamines in the bovine adrenal cortex and medulla

Abstract

The intraadrenal distribution of free and sulfoconjugated catecholamines and the activity of the catecholamine sulfoconjugating enzyme phenolsulfotransferase in the bovine adrenal gland are described. In the adrenal cortex all three free catecholamines, epinephrine, norepinephrine, and dopamine, were detected in various concentrations. In the adrenal medulla, the relative proportion of the main adrenal catecholamines, free epinephrine and free norepinephrine, was found to be higher in the medullary sections derived from the subcortical areas where the ratio of epinephrine to norepinephrine was 8:1 than in the centre of the organ where norepinephrine levels reached those of epinephrine. Free dopamine, representing about 1.0% of the total catecholamine content was distributed in the same pattern as epinephrine or the sum of epinephrine and norepinephrine, revealing a significant positive correlation between regional dopamine and epinephrine plus norepinephrine (r = 0.97) as well as between dopamine and epinephrine (r = 0.96). Phenolsulfotransferase activity was present in both medulla and cortex. Dopamine sulfate was detected in relatively small concentration in all cortical and medullary layers, but norepinephrine sulfate and epinephrine sulfate were not present. The meaning of this distribution of individual catecholamines and phenolsulfotransferase activity in both cortex and medulla is discussed.