Permissive role of alpha-tocopherol in the stimulation of aldosterone by sodium depletion in the guinea pig.
To investigate the role of vitamin E in aldosterone synthesis, in vivo and in vitro studies were done in alpha-tocopherol-depleted guinea pigs. Seventy-one days of low vitamin E intake ( < 5 mg/kg feed) reduced the concentration of alpha-tocopherol in serum, liver and adrenals to low levels with no signs of hypovitaminosis. Aldosterone secretion was stimulated by 15 days on a low sodium diet (200 mg/kg feed) in controls and vitamin E-depleted animals. Sodium depletion in controls stimulated plasma aldosterone by 335%. Vitamin E depletion reduced the stimulation of plasma aldosterone to only 112% (p < 0.05). In vitro aldosterone secretion by adrenal cells from sodium-depleted animals was 252% higher than secretion by cells from controls. This enhancement of in vitro aldosterone secretion following in vivo sodium depletion was abolished completely by combined in vivo vitamin E and sodium depletion (p < 0.05). No significant differences between groups were found for plasma renin activity, adrenocorticotrophin and serum potassium, suggesting that intra-adrenal mechanisms like damage by enhanced lipid peroxidation in alpha-tocopherol-depleted animals rather than changes in humoral aldosterone-regulating factors are the cause of the attenuated aldosterone response to sodium depletion.
Möbius
K
K
Department of Internal Medicine, Klinikum Benjamin Franklin, Freie Universität Berlin, Germany.
Redmann
A
A
Hiller
H H
HH
Oelkers
W
W
Bähr
V
V
D000324:Adrenocorticotropic Hormone / Q000097:blood; D000450:Aldosterone / Q000378:metabolism*; D000818:Animals; D006168:Guinea Pigs; D006854:Hydrocortisone / Q000097:blood; D008297:Male; D011188:Potassium / Q000097:blood; D012083:Renin / Q000097:blood; D012964:Sodium / Q000097:blood / Q000172:deficiency*; D013268:Stimulation, Chemical; D014810:Vitamin E / Q000502:physiology*; D014811:Vitamin E Deficiency / Q000097:blood; D014815:Vitamins / Q000378:metabolism
D014815:Vitamins; D014810:Vitamin E; D000450:Aldosterone; D000324:Adrenocorticotropic Hormone; D012964:Sodium; D012083:Renin; D011188:Potassium; D006854:Hydrocortisone