Avaliação da densidade óssea da mandíbula de ratos submetidos à exposição pré e pós-natal a resíduos organoclorados DDT e seus derivados

Abstract

EVALUATION OF MANDIBULAR BONE DENSITY IN RATS EXPOSED TO ORGANOCHLORINE RESIDUES DDT AND ITS DERIVATIVES DURING PRE- AND POSTNATAL PERIODS The increased use of pesticides in agriculture, combined with the long degradation time of their byproducts, has led to a range of environmental and public health issues. Recent epidemiological studies have provided evidence linking pre- and postnatal exposure to organochlorine pesticides with various adverse health outcomes. However, few studies have investigated the potential relationship between low-dose exposure to the organochlorine pesticide DDT (dichlorodiphenyltrichloroethane) and its residues with mineralogical alterations and changes in bone density. In this context, the objective of the present study was to evaluate transgenerational mandibular bone density in pubertal and adult rats subjected to pre- and postnatal exposure to low concentrations of organochlorine residues, specifically DDT derivatives. Following confirmation of pregnancy, female rats were randomly assigned to four experimental groups (n=6 per group) throughout gestation and lactation. The control group received ad libitum tap water, while the remaining groups also had ad libitum access to water, supplemented with the following organochlorine pesticides and their residues: the DDD group received tap water supplemented with DDD (dichlorodiphenyldichloroethane) at 0.0147 μM (0.0047 mg/L), and the DDE group received tap water supplemented with DDE (dichlorodiphenyldichloroethylene) at 0.0056 μM (0.0018 mg/L). The offspring (F1 generation) continued to receive the respective DDT residue formulations in their drinking water throughout development according to their assigned groups (Control, DDD, DDE). Likewise, the F2 generation was derived from the F1 generation and was subjected to the same DDT residue exposure. Evaluations of both F1 and F2 generations were conducted at 35 postnatal days (PND35) and 105 postnatal days (PND105). Following euthanasia, mandibles were collected and analyzed using computed tomography. Bone density measurements revealed no statistically significant differences among the evaluated groups (Control, DDD, DDE) in either generation (F1 and F2) at the assessed time points (PND35 and PND105). In conclusion, pre- and postnatal exposure to DDT and its derivatives at the evaluated concentrations did not result in significant alterations in mandibular bone density in first and secondgeneration rats. These findings highlight the need for further studies to elucidate the underlying mechanisms and potential long-term effects of low-dose organochlorine pesticide exposure on bone health and other health outcomes.