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SEX-LINKED CHANGES IN PHASE 1 BIOTRANSFORMATION OF PHENOL IN BROOK TROUT OVER AN ANNUAL REPRODUCTIVE CYCLE
Citation:
Kolanczyk, R C., L. E. Solem, A D. Hoffman, P. K. Schmieder, AND J M. McKim. SEX-LINKED CHANGES IN PHASE 1 BIOTRANSFORMATION OF PHENOL IN BROOK TROUT OVER AN ANNUAL REPRODUCTIVE CYCLE. Presented at Society of Toxicology Annual Meeting, Philadelphia, PA, March 19-23, 2000.
Description:
The microsomal metabolism of phenol (11 degrees C) over an annual reproductive cycle from June to December has been studied using fall spawning adult brook trout (Salvelinus fontinalis). Incubations were optimized for time, cofactor connection, pH, and microsomal protein concentration. Formation of phase I ring-hydroxylation metabolites, i.e., hydroquinone and catechol, was quantified by HHPLC with dual channel electrochemical detection. Sample preparation and chromatographic conditions were optimized toachieve the separation and sensitivity required for the analysis of these labile products. Metabolism of phenol over a range of substrate concentrations (1 to 150 mM) was quantified for calculation of Michaelis-Menten constants (Km and Vmax) for each month. Results indicate a nearly equal production of hydroquinone and catechol among males and females in late June. At the peak of maturity (October) there was an approximate ten fold greater production of ring-hydroxylation metabolites noted in females in comparison with males on a total liver basis. The increased production corelated with increased liver size and ovarian development in females. These experiments indicate the importance of quantifying changes in metabolic capacity, in response to large seasonal changes in physiology and biochemistry noted during sexual maturation and spawning.