Investigação da ação disruptora da deltametrina sobre o sistema reprodutor de ratos (gerações f1 e f2)

Abstract

A deltamethrin is an insecticide belonging to the type II pyrethroid group, widely used without as a pest control in agriculture, industry, public health and in homes, but its indiscriminate and unprotected use has become a problem for population, since several pyrethroids had their action associated with disruption. Therefore, this work aimed to evaluate the possible disrupting actions of deltamethrin on the male and female reproductive systems of rats. Four female rats and two adult, nonbreeding male Wistar albino rats were used. The animals were placed for mating and the pregnant rats (F0 generation) were divided into 2 groups: treatment and control. From the 8th to the 14th day of pregnancy the treatment group received intraperitoneal injections of deltamethrin (0.01 mg / kg) and the control group received canola oil. Pregnant rats (F0 generation) were monitored daily and at 21 days postpartum weaning was performed (F1 generation), at 70 and 76 days of age, this generation was placed for procreation, and, as in the F0 generation, weaning was performed after 21 days of delivery (F2 generation). All the generations had the time of pregnancy, the number of pups and the sexual proportion between females and males evaluated. After euthanasia, the organs weight of the female and male reproductive systems and the integrity of the sperm plasma membrane were analyzed. Exposure to deltamethrin resulted in increased right-sided seminal vesicle weight in both generations and influenced uterine volume increase and right ovary decrease in subsequent generations, and decreased left ovary in F1 generation. The relative weight of the testes, vas deferens, left epididymis, left seminal vesicle and prostate, and the integrity parameter of the sperm plasma membrane did not change. Pregnancy time and number of pups in F1 generation were not affected and the proportion between females and males in both generations was similar. We can conclude that the exposure to deltamethrin altered anatomical aspects of weight of the right seminal vesicle, uterus and ovaries in subsequent generations. However, fertility patterns (number and sex ratio) remained unchanged.