[Effect of exogenous thyroxin on renal ion-regulating and acid-secreting functions in white rats].

: Experimental hyperthyreosis was stimulated by intraventricular injections of sodium solithyroxin (T4) suspension on 1% starch gel during 10 days at a dose of 10 microg/100 g of body mass (n = 15) or 20 microg/100 g of body mass (n = 15). Renal function was tested by 5 % water loading after 24 hrs. since the last T4 injection. Urine and blood plasma samples were analyzed for creatinine; in addition, urine was analyzed for sodium and potassium ions of titrated acids, ammonium cations, and pH. Thyroxin was found to decrease creatinine clearance and expedite renal excretion of sodium and potassium ions irrespective of the amount of exogenous T4; at the same time, exaggerated excretion of titrated acids and ammonium cations correlated with T4 dose.