Source:http://linkedlifedata.com/resource/umls/id/C0005576
MSH: The chemical alteration of an exogenous substance by or in a biological system. The alteration may inactivate the compound or it may result in the production of an active metabolite of an inactive parent compound. The alterations may be divided into METABOLIC DETOXICATION, PHASE I and METABOLIC DETOXICATION, PHASE II.,CSP: series of chemical alterations of an exogenous compound which occur within a biological system, as by enzymatic activity.