Malathion is an organophosphate pesticide widely used for agricultural crops and for vector control of Aedes aegypti. Humans are exposed to this environmental contaminant by ingesting contaminated food. The juvenile and peripubertal periods are critical for the postnatal development of the epididymis and are when animals are most vulnerable to toxic agents. Since juveniles and adolescents are developing under exposure to the insecticide malathion, the aim of the present study was to evaluate the effects of exposure to low doses of malathion on postnatal epididymal development in rats. Male Wistar rats were exposed to malathion daily via gavage at doses of 10 mg kg⁻¹ (M10 group) or 50 mg kg⁻¹ (M50 group) for 40 days (postnatal days (PNDs) 25–65). The control group received the vehicle (0.9% saline) under the same conditions. On PND 40, the epididymides were removed, weighed and used for histological analysis and determination of the inflammatory profile and sperm count. Sperm from the vas deferens were subjected to sperm motility analysis. The M50 group showed tissue remodelling in the caput and cauda epididymides and increased neutrophil and macrophage migration in the caput epididymis. The M10 group showed decreased motile spermatozoa and IL-6 levels in the caput epididymis. Both doses decreased the IL-1β level and altered the morphology of the same region. These results show that malathion exposure may impair postnatal epididymal development. Furthermore, alterations of the immune system in the epididymal environment are presented as new findings regarding the action of malathion on the epididymis.

马拉硫磷是一种有机磷酸盐农药，广泛用于农作物和埃及伊蚊的媒介控制。人体通过摄入被污染的食物而暴露于这种环境污染物中。幼年期和青春期期对附睾的产后发育至关重要，此时动物最容易受到毒物侵害。由于青少年和青少年在暴露于杀虫剂马拉硫磷下正在发育，因此本研究的目的是评估低剂量马拉硫磷对大鼠产后附睾发育的影响。雄性Wistar大鼠每天通过管饲法以10 mg kg ^-1（M10组）或50 mg kg ^-1的剂量暴露于马拉硫磷中（M50组）40天（产后天数（PND）25-65）。对照组在相同条件下接受了赋形剂（0.9％生理盐水）。在PND 40上，去除附睾，称重并用于组织学分析和确定炎症性状和精子数量。对输精管的精子进行精子活力分析。M50组在附睾和马尾附睾中显示组织重塑，在附睾的中性粒细胞和巨噬细胞迁移增加。M10组显示附睾附睾中活动精子和IL-6水平降低。两种剂量均降低了IL-1β水平并改变了同一区域的形态。这些结果表明，马拉硫磷暴露可能会损害出生后的附睾发育。此外，