Abstract

Background: Diazinon is an organophosphate that is broadly used as a pesticide to control insects and environmental pollutions. This toxic material is absorbed via inhalation, contact, or digestion and affects different tissues. Objectives: This research was a histomorphometric and immunohistochemical study of the fetal liver of mice after exposure to Diazinon. Materials and Methods: Twenty-five pregnant BALB/c mice (25-30 gr) were divided into five equal groups in the animal lab of Baqiyatallah University of Medical Sciences, Tehran, Iran. The normal group was without any intervention, and two sham groups received an emulsifier as 0.52 and 5.2 mu L/volume (5000 cc in desiccator) and two experimental groups received Diazinon 1.3 and 13 mu L/volume from the seventh to eighteenth days of pregnancy every other day via forty minutes of inhalation. The pregnant mice were killed on the eighteenth day of gestation and their fetuses were removed and evaluated for fetal growth and liver development. Five fixed fetuses were dehydrated through a series of graded ethanol, embedded in paraffin wax and their whole bodies were sectioned sagittally and stained via the hematoxylin-eosin method. Quantitative computer-assisted morphometric studies were done on the fetal liver tissues occupied by hepatocytes, blood islands, liver sinusoids, and apoptosis. Results: The mean crown-rump of the fetuses and their mean weight were increased in the experimental group as compared to the sham and normal groups, but the differences were not significant. The mean percentage of the hepatocyte area significantly increased in the experimental group as compared to the sham and control groups (P < 0.0001). However, the mean sinusoid area significantly decreased in the experimental group as compared to the sham and control groups. The mean percentage of the area occupied by apoptotic hepatocytes in the experimental group-13 mu L/volume (8.6143 +/- 1.00945) and 1.3 mu L/volume (6.1091 +/- 0.93093) - significantly increased as compared to the normal and sham groups (P < 0.0001). Conclusions: Our data showed that inhalation of Diazinon during pregnancy increased the hepatocyte area and hepatocyte apoptosis while it decreased the sinusoid area of the fetal liver.