Effects of prolonged dopamine infusion on the zona glomerulosa of sodium-restricted rats treated or not with prolactin: stereology and plasma hormone concentrations.
Prolonged sodium restriction was found to induce a notable hypertrophy of rat zona glomerulosa (ZG) cells and a significant rise in the basal plasma aldosterone concentration. Chronic prolactin administration significantly furthered the effects of sodium restriction. Dopamine infusion (3 mg/kg day for 7 days) did not apparently affect ZG morphology and function in the control rats, while it significantly counteracted the effects of sodium deprivation combined or not with prolactin administration. However, the action of dopamine was less intense in sodium-deprived rats treated with prolactin. These findings confirm the view that the dopaminergic system exerts a tonic inhibitory effect, modulated by the sodium balance, on the growth and secretory activity or rat ZG. Moreover, they suggest that the mechanism(s) underlying the antiadrenoglomerulotrophic action of dopamine in rats only partially involve(s) the well-known suppression of the hypophyseal release of prolactin.
Rebuffat
P
P
Dept. of Anatomy, University of Padua, Italy.
Belloni
A S
AS
Mazzocchi
G
G
Gottardo
G
G
Malendowicz
L K
LK
Nussdorfer
G G
GG
D000302:Adrenal Cortex / Q000187:drug effects*; D000450:Aldosterone / Q000097:blood*; D000818:Animals; D003345:Corticosterone / Q000097:blood*; D004039:Diet, Sodium-Restricted; D004298:Dopamine / Q000008:administration & dosage / Q000494:pharmacology*; D007262:Infusions, Intravenous; D008297:Male; D011388:Prolactin / Q000494:pharmacology*; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains
D000450:Aldosterone; D011388:Prolactin; D004298:Dopamine; D003345:Corticosterone