Stimulation of DNA synthesis and pyrimidine deoxyribonucleoside transport systems in mouse glioma and mouse neuroblastoma cells by inorganic mercury

Abstract

Biochemical studies on effects of methylmercury and inorganic mercury on mouse glioma and neuroblastoma cells were carried out. Inorganic mercury accelerated DNA synthesis of mouse glioma cells at 10 −6 to 10 −5 m specifically in the middle log phase of the growth. Inorganic mercury facilitated the thymidine and deoxycytidine transports within a narrow range of concentration (1 to 2 × 10 −5 m), but no stimulation of transport was observed in the cases of purine deoxyribonucleosides. Inorganic mercury markedly inhibited both DNA synthesis and the transport systems of the precursors above 5 × 10 −5 m. On the other hand, methylmercury showed hardly any accelerating effects and markedly inhibited both the synthesis of DNA and the precursors' transport above 5 × 10 −5 m. In the case of mouse neuroblastoma cells, inorganic mercury stimulated DNA synthesis at 1 to 5 × 10 −6 m and also thymidine transport system at 1 to 2 × 10 −5 m.