| reduction of cytochrome p4501a with age in atlantic tomcod from the st. lawrence estuary, canada: relationship with emaciation and possible effect of contamination. | this study reports a reduction of ethoxyresorufin-o-deethylase (erod) activity in large-sized, older atlantic tomcod (microgadus tomcod) collected in the st. lawrence estuary (quebec, canada) and investigates its relationship over a 4-year period to sex, gonadosomatic index (gsi), condition factor (cf) and cytochrome p4501a (cyp1a) mrna levels. in addition, the concentrations of polychlorinated biphenyls (pcbs) were measured in a subsample of fish. the reduction of erod activity with age was obs ... | 2004 | 15159050 |