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IN UTERO 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN (TCDD) ALTERSREPRODUCTIVE MORPHOLOGY AND FUNCTION IN FEMALE RAT OFFSPRING
Citation:
Gray, L. AND J. Ostby. IN UTERO 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN (TCDD) ALTERSREPRODUCTIVE MORPHOLOGY AND FUNCTION IN FEMALE RAT OFFSPRING. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-95/518, 1995.
Description:
Recently, it was demonstrated that administration of TCDD during gestation permanently alters 'the reproductive potential of male rat and male hamster offspring. he objectives of this study were to determine if perinatal TCDD treatment altered sex differentiation and reproductive function of the female progeny. n this study, LE Hooded rats were dosed by gavage with 1 ug TCDD/kg on GD 8 or GD 15. n addition, Holtzman rats were exposed to TCDD to determine if the female progeny displayed malformations of the external genitalia and vaginal orifice as did LE rats. CDD-treated female LE offspring displayed a number of unusual developmental alterations. or example, many of the rats displayed clefting of the phallus with mild degree of hypospadias. n addition, most female progeny f rom the GD-15 TCDD-treatment group displayed a permanent "thread" of tissue across the opening of the vagina. imilar morphological alterations were noted in TCDD-exposed Holtzman rats. n the LE rat, vaginal and behavioral estrous cyclicity and estrous cycle-mediated running wheel activity were not affected by gestational TCDD treatment. n addition, when treated LE female offspring were mated to untreated males on the day of vaginal proestrus, female sexual behaviors (darting and lordosis @to mount ratios) were normal. owever, males had difficulty attaining intromission and vaginal bleeding was displayed by most TCDD-exposed female offspring during mating. urprisingly, TCDD-female progeny displayed normal levels of fertility over their entire reproductive life span.