Effect of physostigmine on plasma lactate and pyruvate in untrained/trained rats

Physostigmine (Phy) is metabolized to eseroline, a phenolic compound that appears to alter mitochondrial functions. The effect of Phy on recovery from exercise and on time course of plasma lactate and pyruvate levels following an acute bout of exercise (AE) was examined in untrained and trained (ET) rats. Phy alone elicited significantly higher plasma lactate and pyruvate levels than sedentary control. AE + Phy had a significantly higher plasma lactate and pyruvate levels compared to AE 2 min postadministration. From 5-30 min postexercise, lactate and pyruvate levels did not differ between these two acutely exercised groups. ET + Phy exhibited significantly lower levels of plasma lactate and pyruvate from 5-60 min postexercise compared to ET. The data show that the "additive" effect of Phy on postexercise plasma lactate and pyruvate levels can be attenuated by an enhanced fitness level in these rats.