PT - JOURNAL ARTICLE AU - Chen-YĆ¼ Sung AU - E. Leong Way AU - Kenneth G. Scott TI - STUDIES ON THE RELATIONSHIP OF METABOLIC FATE AND HORMONAL EFFECTS OF <span class="sc">D,L</span>-METHADONE TO THE DEVELOPMENT OF DRUG TOLERANCE DP - 1953 Jan 01 TA - Journal of Pharmacology and Experimental Therapeutics PG - 12--23 VI - 107 IP - 1 4099 - http://jpet.aspetjournals.org/content/107/1/12.short 4100 - http://jpet.aspetjournals.org/content/107/1/12.full SO - J Pharmacol Exp Ther1953 Jan 01; 107 AB - No appreciable difference in D,L-methadone levels was observed in the tissues of normal and tolerant rats following administration of the compound. Liver slices from tolerant rats were found to metabolize D,L-methadone slightly less rapidly than those from normals. The urinary excretion of the compound in normal and in tolerant animals did not differ greatly but tolerant animals excreted a greater amount of a metabolic product of D,L-methadone. Muscle homogenate from tolerant animals bound D,L-methadone approximately to the same extent as that from normals. Adrenal hypertrophy and perhaps a slight decrease in thyroid activity were observed to accompany the development of tolerance to D,L-methadone. The possible relationships of these factors have been discussed.