Effects of lithium chloride as a potential radioprotective agent on radiation response of DNA synthesis in mouse germinal cells

Abstract

Mouse spermatogonial germ cells are highly sensitive to ionizing radiation. Lithium salts are reported to stimulate the postirradiation recovery of hematopoietic marrow cells. We have, therefore, examined whether administered lithium chloride (LiCl) would also be able to protect the mouse germinal cells against radiation injury. Taking DNA synthesis as an endpoint, our results show that the testicular DNA-specific activity in irradiated mice was higher by 61% on average when they had been pretreated with LiCl both 24 h and 1 h prior to gamma-irradiation (2.0 Gy). It was also observed that the DNA synthetic activity in the germinal cells fully recovered after LiCl pretreatment at doses of 40 mg per kg body weight prior to total body irradiation of 0.05-0.25 Gy, whereas at doses of 0.5-6.0 Gy, following the same procedure of LiCl pretreatment, only an incomplete recovery was observed. The dose reduction factor for LiCl is 1.84. The current findings indicate that pretreatment with LiCl provides considerable protection against radiation damage in mouse spermatogonia.

Lithium increases proliferation of hippocampal neural stem/progenitor cells and rescues irradiation-induced cell cycle arrestin vitro

“…To further validate that the increased size of the irradiated neurospheres after lithium treatment was due to increased numbers of proliferating cells, rather than hypertrophy, we assessed BrdU incorporation in NSPCs 48 hours after irradiation (Fig. 2C ), confirming that 3 mM LiCl recruits NSPCs into proliferation and restores the proliferative capacity halted after irradiation, as indicated by increased DNA synthesis also in vivo [ 30 , 63 ]. In support of this, the cell cycle distribution of NSPCs after irradiation revealed that the reduction of NSPCs in S phase could be rescued by 3 mM, but not 1 mM, LiCl treatment, with full restoration of proliferation as early as 6 hours after irradiation, and maintained protection at least up to 72 h after irradiation (Fig.…”