Modification of urinary potassium secretion following lithium in rats of different ages
Kersten, L.; Hofmann, B.; Bräunlich, H.
Agressologie 26(3): 253-256
1985
ISSN/ISBN: 0002-1148 PMID: 4037209 Document Number: 266423
In 5, 15, 33 and 105 day old rats the influence of Li (3 mmol/kg body wt; i.p.) on the active renal K secretion was investigated during a 3 h collecting period. In controls K was administered i.p. in different dosages: 3.8, 6 and 6.7 mmolK+/kg body wt. Following a K load there are distinct age differences in renal K excretion. Maximal transport capacity depends on age. However, following 6 mmol/kg body wt the transport system for K can be saturated in rats of all age groups. Li 3 mmol/kg body wt administered simultaneously with K leads to a dose-dependent inhibition of K secretion. The low Na excretion in K loaded rats of all age groups increased following simultaneous administration of Li. Especially in young rats the Na/K ratio is distinctly increased. Li can evidently be transported instead of K via the transcellular K transport mechanism (ATPase). But the enhanced Na excretion indicates that there are also relationships between renal excretion of Li and Na.