effect of oral morphine consumption during pregnancy on the tongue development in the wistar rat embryos

background: morphine consumption during pregnancy could lead to defect and delay in nervous system development in the embryos. in the present study, development of the tongue of embryos whom their mothers received oral morphine during pregnancy have been studied. methods: female wistar rats (200-220 g) after pregnancy were divided randomly into the experimental and control groups. the control group received tap water whereas the experimental group received morphine (0.05 mg/ml) in their drinking waters. on the day 19, the pregnant rats were killed by chloroform overdose and the embryos were removed surgically and were fixed in formalin 10%. simultaneously, the rats’ bloods were collected for corticosterone measurement. weight and length of the embryos were determined. then the embryos’ heads were removed for tissue processing, cutting and hematoxylin- eosin staining. the subjects were evaluated using light microscope and motic software. number of the cells also counted. un-paired t-test applied for statistical analysis. results: plasma corticosterone level, embryos’ weight and length did not show any significant differences between  control and experimental groups. the large diameter of the tongue of the experimental group was decreased but the small diameter in two groups did not differ. tongue cells numbers in the experimental group were increased but their size decreased.  conclusion: decrease in the large diameter of tongue, increase in the cell number and decrease in cell size indicate the influence of morphine consumption during pregnancy on tongue development in the embryos.