Micro computed tomographic and histopathological analysis of the effects of melamine exposure from the weaning period on bone development.

Melamine, which is used as a chemical in the industry, brings to mind the question of food safety due to its presence in the structure of plates, exposure to insecticides, and, most importantly, its addition to formula and pet foods years ago to provide false high protein positivity. This study aimed to examine the effects of exposure to low-dose melamine from the weaning period on bone development. Eighteen female rats (21 days old) were randomly divided into 3 groups. The first group (n = 6) received 0.1 ml saline, the second group (n = 6) and third group (n = 6) received 50 mg/kg and 75 mg/kg melamine in 0.1 ml saline for 21 days with oral gavage, respectively. After the 21 days application, animals were euthanized under anesthesia on the 45th day and right femur and tibia bones of the rats were taken and placed in 10% buffered formalin for histopathological and micro computed tomography (micro CT) examination. According to histopathologic, morphometric and micro CT analysis, there were not statistically significant differences in the thickness of physis plate (growth plate), compact bone, diaphysis, femur length and bone mineral density (BMD) of tibia between melamine and control groups (p > 0,05). However, the structure of the physis (growth) plates were deterioration in both 50 mg/kg and 75 mg/kg melamine groups. The structural integrity were irregular and even had cartilage areas that advanced towards the trabecular bone area. As a result, melamine exposure from the weaning period, when bone development is important, causes structural disruption of the physis plate (growth plate) with increasing doses.