[Animal experiment studies on the effect of tris buffer and sodium bicarbonate. Effects on intracellular bicarbonate concentration in vivo. II].

Unrestrained male nephrectomised Sprague-Dawley rats were infused with 10 mmol per kg body weight THAM or sodium bicarbonate. In predetermined intervals up to 380 minutes arterial plasma pH (pHe) and pCO2 were monitored. In addition the intracellular bicarbonate concentration was determined before and after infusion of the agents. The following results were obtained: arterial pCO2 following THAM administration increases much more than following sodium bicarbonate infusion; arterial plasma pH following THAM application decreases rather rapidly compared to bicarbonate; intracellular bicarbonate concentration increases much more when sodium bicarbonate was infused; these results indicate that sodium bicarbonate is the more effective buffer substance for correction of extra-and intracellular acid-base disturbances than THAM. Sodium bicarbonate should be preferred in clinical practice.