Sodium, potassium and aldosterone content of human milk during the first postnatal week.
In an attempt to obtain information about the hormonal control of the sodium content of human milk, simultaneous determinations were performed of the Na, K and aldosterone concentrations in milk samples collected from 6 mothers on the 2nd, 4th and 6th days after delivery. Na concentration (p less than 0.01), Na/K ratio (p less than 0.01) and aldosterone concentration (p less than 0.01) decreased significantly with advancing lactation. The rate of daily aldosterone excretion, however, rose considerably from 4.8 +/- 0.9 ng/day (mean +/- SE) on the 2nd to 12.2 +/- 1.6 ng/day on the 6th day post partum (p less than 0.01). A significant negative correlation was found between daily aldosterone excretion and Na concentration (p less than 0.05), as well as between aldosterone excretion and Na/K ratio (p less than 0.05) in human milk during the first week after delivery. It is suggested that the rate of aldosterone excretion may be of importance in the regulation of the Na concentration in human milk.
D000450:Aldosterone / Q000032:analysis*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008895:Milk, Human / Q000032:analysis*; D049590:Postpartum Period; D011188:Potassium / Q000032:analysis*; D011247:Pregnancy; D012964:Sodium / Q000032:analysis*; D013997:Time Factors
D000450:Aldosterone; D012964:Sodium; D011188:Potassium