Practolol: aspects of its metabolism and ocular binding in the hamster.
The metabolism and ocular binding of practolol were investigated after oral administration of 14C-practolol to hamsters treated with three modifiers of mixed-function oxidase activity: piperonyl butoxide, cobalt chloride or phenobarbitone. The major urinary metabolites of practolol were 3-hydroxypractolol and polar metabolites which included glucuronide conjugates. A number of unidentified metabolites constituted a minor portion of urinary radioactivity. Each pretreatment modified both the urinary excretion pattern (0-24 h) of practolol and its metabolites and also the metabolite profile of eye extracts 24 h after an oral dose. None of the modifiers of mixed-function oxidase activity had any significant effect on the ocular binding (both extractable and non-extractable components) of practolol and its metabolites. The results indicated that the non-extractable component was neither practolol nor 3-hydroxypractolol.
D000818:Animals; D003035:Cobalt / Q000494:pharmacology; D006224:Cricetinae; D005123:Eye / Q000378:metabolism*; D008297:Male; D008647:Mesocricetus; D006899:Mixed Function Oxygenases / Q000378:metabolism; D010634:Phenobarbital / Q000494:pharmacology; D010882:Piperonyl Butoxide / Q000494:pharmacology; D011217:Practolol / Q000378:metabolism* / Q000652:urine
D003035:Cobalt; D006899:Mixed Function Oxygenases; C018021:cobaltous chloride; D010882:Piperonyl Butoxide; D011217:Practolol; D010634:Phenobarbital