[The effect of lithium on the tissue levels of electrolytes and hyaluronic acid levels in the kidney papilla in the rat].

Injections of 0.2 M LiCl i. p. (1 ml/100 g/day) induced polydipsia in rats drinking tap water. The plasma lithium concentration and its content in the erythrocytes, skeletal muscles, renal tissue were significantly higher in the rats drinking tap water as compared with rats drinking saline. No significant differences in the body volume of extracellular fluid, muscle water, Na, K content and their muscle intracellular concentrations were noted between the "lithium" and the control rats. Na content in the plasma and the renal cortex--medullar Na gradient were decreased in the "lithium" rats drinking tap water. The hyaluronic acid content in renal papilla was increased in all rats receiving lithium injections. After an injection of ADH the papillary hyaluronic acid content markedly decreased in control rats while it decreased only insignificantly in "lithium" rats. The impairment of the ability of urine concentrating and polyuria in "lithium" rats seems to be partly connected with an enhancement of the polymerization degree of renal papillar hyaluronic acid.