AJP - Endocrinology and Metabolism, Vol 247, Issue 4 431-E435, Copyright © 1984 by American Physiological Society
Dopamine 3-sulfate inhibits aldosterone secretion in cultured bovine adrenal cells
K. Racz, N. T. Buu, O. Kuchel and A. De Lean
It has been demonstrated that dopamine inhibits the aldosterone (Aldo)
secretion in bovine adrenal cells in vitro. Because the majority of the
total circulating dopamine (DA) in bovine plasma (72%) is present in
sulfoconjugated form (6.8 +/- 3.4 pmol/ml) and free DA, DA sulfate, and
phenolsulfotransferase (PST) activity can be found in the bovine adrenal
cortex, we examined whether the inhibitory action of free DA on angiotensin
II- (ANG II) stimulated Aldo secretion by cultured bovine adrenal cells can
also be reproduced by sulfoconjugated DA analogues. Cells from the bovine
adrenal glands cultured for 3 days before testing responded to 10(-8) M ANG
II stimulation by a 10- to 12-fold increase in Aldo output. This
stimulatory effect was partially inhibited by the addition of free DA and
DA 3-sulfate, whereas DA 4-sulfate was inactive. Both free DA and DA
3-sulfate produced their maximal inhibitory effect at a concentration of
100 microM, with a decrease in Aldo secretion by 61% (free DA) and 44% (DA
3-sulfate). The slightly different inhibition curves for DA and for DA
3-sulfate on Aldo secretion cannot be explained by liberation of free DA
through hydrolytic processes because less than 1% free DA was detected
after the incubation of the cells with sulfoconjugated DA. These in vitro
findings suggest that DA 3-sulfate may be effective in complementing the
dopaminergic inhibition of Aldo secretion at the adrenal level.
