Hormonal adaptation to the stresses imposed upon sodium balance by pregnancy and lactation in the Yanomama Indians, a culture without salt
Oliver, W.J.; Neel, J.V.; Grekin, R.J.; Cohen, E.L.
Circulation 63(1): 110-116
1981
ISSN/ISBN: 0009-7322 PMID: 7002359 DOI: 10.1161/01.cir.63.1.110Document Number: 384600
The Yanomama Indians of northern Brazil and southern Venezuela, who are a "no-salt" culture, were studied for adjustments of sodium-related hormones to the stresses imposed on Na balance by pregnancy and prolonged lactation. Controls were similar observations in the Guaymi Indians of Panama, who have free access to salt. Urinary concentrations of Na were about 1 mEq/litre in male and female Yanomama, with 24-h excretion rates in the male subjects on average 1 mEq. The pregnant Yanomama had extremely high urinary concentrations of aldosterone. These were associated with higher plasma renin activities and serum aldosterone concentrations than in all other subjects. Although pregnant Guaymi had increases of serum and urinary aldosterone, they were significantly less than those of the Yanomama. Prolonged lactation in the Yanomama was associated with higher plasma renin activity and serum and urinary aldosterone concentration than the Guaymi, but not higher than those in nonlactating Yanomama women.