The metabolism of canrenone in vitro by rat liver preparations

Abstract

1. The metabolism of [1-³H]canrenone, a primary metabolite of spironolactone and potassium canrenoate, by rat liver preparations in vitro has been investigated.

2. Canrenone was metabolized by 3-oxo-δ⁴-reduction to give 3α-hydroxy-5β-spirolactones, and also by a number of O₂ and NADPH-dependent microsomal hydroxylation reactions.

3. A major metabolic route requiring the presence of a microsomal fraction, but apparently independent of oxygen and NADPH, led to the formation of a number of compounds tentatively identified as trihydroxy-spirolactones.