Methadone Detection in Rat Myenteric Plexus: Comparison with Findings in the Central Nervous System by the Immunofluorescence Method

Abstract

Nonpregnant and pregnant rats were given methadone for varying time periods. Myenteric plexus was then examined for methadone by immunofluorescence and the results compared to similar studies of the central nervous system. Nonpregnant animals showed positive ganglion cells 2 weeks before methadone was detected in the brain. Additionally, maternal ganglion cells were more frequently positive than those of their offspring. These findings indicate fundamental differences in the response of peripheral and central neurons to methadone. Thus, studying the effects of opiates on isolated strips of bowel may be of little value in furthering understanding of the action of narcotics upon the brain.