SPECIFIC RADIOIMMUNOASSAYS FOR CODEINE AND MORPHINE - METABOLISM OF CODEINE TO MORPHINE IN RAT

  • 1 January 1977
    • journal article
    • research article
    • Vol. 17  (4) , 595-603
Abstract
Specific antisera to morphine were raised in response to immunization with a conjugate of N-carboxypropylnormorphine with bovine serum albumin (BSA). These antisera effectively distinguished changes in substituents at the 3 and 6 positions of the alkaloid, thus reducing cross-reactivity with codeine and morphine-3-glucuronide to negligible levels. The utility of these antisera was illustrated by their application in radioimmunoassay procedures, along with similarly specific anti-codeine sera to study the biotransformation of codeine to morphine in the rat. After oral codeine administration, serum morphine levels were low but significantly higher than codeine levels after 15 min, indicating rapid metabolism of codeine to morphine.