An escape phenomenon from water and sodium retention induced by propranolol in rats.

Rats given a daily dose of propranolol 45 mg/kg b.wt retain water and sodium for 4 days, escaping during the 5th and 6th days in which their excretions are larger than basal values. Afterwards, in the period studied, they make a new retention and clearing is less accentuated. No relationship could be found between these retentions and plasma renin activity or renal renin content.