Abstract
The polydipsia and polyuria were found in aged male rats of the inbred Wistar/Tw strain. Water intake and urinary volume (ml/day/100g BW) were markedly greater in 17-month-old males than in 6-month-old males. The urinary concentrations of electrolytes and glucose were lower in aged polydiptic male rats than in young males. After a single injection of antidiuretic hormone (ADH), water intake of aged polydiptic rats was temporarily lowered to the level of young rats receiving no ADH injection. This suggests that polydipsia and polyuria were the consequences, at least in part, of the insufficiency of ADH secretion.
