STUDIES WITH OXYTHIAMINE TO MIMIC REPRODUCTION DISORDERS AMONG FISH EARLY-LIFE STAGES

Newly fertilised eggs of sea trout (Salmo trutta) were injected with t he thiamine antagonist oxythiamine or with oxythiamine in combination with 3,3',4,4'-tetra-chlorobiphenyl, (PCB #77), Rainbow trout (Oncorhy nchus mykiss) eggs were injected with PCB #77, A dea Ease in liver tra nsketolase activity was used as a biomarker to indicate a physiologica l deficiency in thiamine, Exposure to oxythiamine caused deformities i n the newly hatched larvae, as well as high mortality during the larva l stages. Exposure to oxythiamine in combination with PCB #77 caused a synergistic higher frequency of disorders. Analysis of liver transket olase activity in the larvae injected with PCB #77 indicated that PCB #77 did not decrease the half-life of thiamine in the offspring. The d ata obtained indicate that oxythiamine increased the sensitivity to PC B #77 in the offspring, however through mechanisms other than those ca using thiamine deficiency in feral fish. (C) 1998 Elsevier Science Ltd . All rights reserved.