Toxic effects of molybdenum on the bones, nervous system and chromosomal pattern of adult male albino rats

ABSTRACT

Ammonium molybdate is an essential trace element in plants and animals as a cofactor for enzymes and also, it is an environmental pollutant. Sixty adult male albino rats were used to investigate the adverse effects of ammonium molybdate on the bone, brain, spinal cord and chromosomes. The rats were equally divided into 3 groups. The 1[st] group was left without treatment and used as a negative control group, the 2[nd] group was daily intragastrically administered saline for 30 days and was used as a positive control group and the 3[rd] group was daily intragastrically administered ammonium molybdate in a dose of 33 mg /kg body weight [1/10 of the lethal dose fifty] for 30 days. At the end of the study ten rats from each group were sacrificed, necropsied and specimens from the bone, brain and spinal cord were collected for histopathological examination. The remaining ten rats of each group were used for studying the chromosomal pattern of bone marrow cells. Histopathological examination of the rats of the 3[rd] group [ammonium molybdate group] showed reduction in the thickness of the bone trabeculae with formation of numerous osteoid fractures and fissures of the epiphysis and necrotic osteocytes. There is also separation between the cortical bone from the periosteum and the endosteum. The bone marrow cavity contains numerous large fat cells with lacked hemopoietic activity. The brain showed congestion of meningeal and cerebral blood vessels, edema, gliosis and neuronophagia. The spinal cord showed satillitosis, gliosis in the grey matter and encephalomalacia and demyelination in the white matter. Regarding cytogenetic study of the bone marrow cells, molybdenotic rats showed a significant increase in the incidence of chromosomal aberrations as terminal chromatid deletions, chromosomal fragments and ring chromosomes when compared with the control group. It could be concluded that, ammonium molybdate is genotoxic and can produce toxic effects on the bone, brain and the spinal cord of adult male albino rats