Acid-base balance following Tityus serrulatus scorpion envenoming in anaesthetized rats

In the present work the pH and arterial blood gases were measured in fasted and fed male albino rats, weighing 297 +/- 13 g, anaesthetized with uretha ne (1.4 g/kg, i.p.) before and after injection of T1 fraction from Tityus s errulatus scorpion venom, during 60 min. Arterial blood samples were collec ted at 0, 5, 15, 30 and 60 min for pH, pCO(2). pO(2), bicarbonate and base- excess analysis. The: data showed that the scorpion toxin induced a continu ous drop in the blood pH along the time. Hypercapnia and hypoxemia peaking at 30 min and followed by a recovery towards normal values at 60 min were a lso observed. A pronounced decrease in the blood bicarbonate levels at 60 m in and negative base-excess values along with time were evident at 60 min. The comparisons between fasted and fed animals have shown that in the last group the effects of scorpion toxin on the arterial blood gases were less p ronounced. We conclude that T1 fraction of Tityus serrulatus scorpion venom induces in anaesthetized rats an acute respiratory acidosis followed by me tabolic acidosis. (C) 2000 Elsevier Science Ltd. All rights reserved.