Transient exposure to environmentally realistic concentrations of di-(2-ethylhexyl)-phthalate during sensitive windows of development impaired larval survival and reproduction success in Japanese medaka

This study monitored the long-term effects of transient exposure to DEHP in early life stages (F0 generation) and its subsequent fertilization success in F1 generation using Japanese medaka, Oryzias latipes, as model organism. Embryos (4 hour post-fertilization, 4 hpf) of Japanese medaka were exposed to 0.001 ppb, 0.1 ppb, or 10 ppb DEHP for 21 days and returned to control water (without DEHP) for maturation (4 months old). At day 9 of the exposure study, mortality was significantly increased in medaka embryos (before hatching) treated with 0.001 ppb and 10 ppb DEHP. Continual exposure of young hatchlings for an additional 12 days (a total of 21 days of exposure) resulted in a significant increase in mortality in fish exposed to 0.001 ppb, 0.1 and 10 ppb DEHP. Significant reduction in egg production was observed in adult female medaka (4 months old) with prior exposure to 0.1 ppb and 10 ppb DEHP for 21 days during early development. Fertilization and hatching success were also significantly reduced in breeding pairs with prior exposure to 0.001 ppb, 0.1 ppb and 10 ppb DEHP during early life stage. Histological analysis of adult male gonads revealed a significant decline in mature sperm count accompanied by an increase in interstitial space in fish exposed to 0.1 ppb and 10 ppb DEHP during early development. Likewise, the amount of vitellogenic (mature) oocytes observed in the ovaries of adult female with transient exposure to 0.1 ppb and 10 p...
Source: Toxicology Reports - Category: Toxicology Source Type: research