Effect of 2-mercaptopropionylglycine (MPG) on thyroid function in sub-lethally irradiated mice

The effect of MPG on radiation-induced odontogenic tissue metaplasia

This investigation monitored the effect of 2-mercaptopropionylglycine (MPG) in reducing radiation damage to the tooth-forming tissues. Fifty rats were exposed to x-ray doses of between 3 and 19 Gy directed toward the maxillary incisor germinal centers. Half of the animals were given an injection of MPG before irradiation, while the other rats were injected with saline solution. Administration of MPG did not significantly reduce the frequency of dentinal niche formation relative to the control teeth. The average lengths and percentage depths of the apicoincisal niches were statistically smaller in the groups treated with MPG. Although statistically significant, the mild protective effect of MPG was not clinically important because damage to the irradiated teeth was still extensive.

Evaluation of chemical protection against radiogenic osteodentin synthesis

The effect of the radioprotector 2-mercaptopropionylglycine (MPG) in preventing the synthesis of radiation-induced osteodentin was examined. Fifty rats were exposed to single x-ray doses of between 3 and 19 Gy localized to the maxillary incisor growth centers. Half of the animals received an injection of MPG before irradiation while saline was administered to the other rats. MPG produced statistically significant reductions in the severity of osteodentin generation, but not its frequency, at some radiation levels. The nature of osteodentin and possible mechanisms of chemical radioprotection by MPG are discussed.