Distribution of Pentazocine in Foetal and Maternal Mouse Tissues and of Radioactivity along the Gut of Mice Dosed with [³H]Pentazocine

Abstract

1. The concn. of pentazocine in the maternal and foetal tissues of the pregnant mouse was measured.

2. One hour after intra-muscular injection of pentazocine to the 19-day pregnant mouse, the levels of pentazocine were similar in maternal and foetal muscle (0.55 and 0.62 μg/g resp.). Corresponding values for maternal and foetal liver were 0.67 and 0.46 μg/g. The level of pentazocine in the placenta was 1.5 μg g.

3. Mice were killed at intervals after intra-muscular injection of [³H]pentazocine and the distribution of radioactivity along the alimentary tracts was demonstrated.

4. Bile and gut-contents of dosed mice contained conjugates of pentazocine and norpentazocine with small amounts of the conjugated pentazocine trans-alcohol. Traces of pentazocine, norpentazocine and of pentazocine trans-acid were detected in bile; in the gut contents small amounts of pentazocine and norpentazocine were detected with trace amounts of the trans-acid.