TY - JOUR T1 - Protection from Cadmium Cytotoxicity by N-Acetylcysteine in LLC-PK<sub>1</sub> Cells JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 344 LP - 351 VL - 287 IS - 1 AU - Bambang Wispriyono AU - Masato Matsuoka AU - Hideki Igisu AU - Koji Matsuno Y1 - 1998/10/01 UR - http://jpet.aspetjournals.org/content/287/1/344.abstract N2 - N-acetylcysteine (NAC) has been known not only to stimulate synthesis of glutathione but also to affect the gene regulation. In our study, effects of NAC on the cytotoxicity of cadmium (Cd) were examined in LLC-PK1 cells. Preincubation and subsequent incubation with 1 mM NAC almost completely suppressed Cd-induced cellular damage evaluated either by trypan blue exclusion or lactate dehydrogenase leakage. This almost complete protection required the presence of NAC during Cd exposure. Treatment with 1 mM NAC increased the intracellular glutathione level approximately 2-fold. Inhibition of this increase by buthionine sulfoximine did not abolish the protection by NAC. One mM NAC also suppressed Cd-induced increase of c-Fos protein although NAC alone did not change the protein content. The inhibition of transcriptions by actinomycin D did not affect the protection by NAC. Thus, NAC-induced protection appeared to be independent of glutathione level or the transcriptional activation of genes including c-fos. However, treatment with NAC markedly lowered the uptake of Cd into cells although it did not affect the efflux clearly. Addition of NAC during the exposure to Cd suppressed Cd-induced cellular damage but the suppression decreased when the duration of the exposure without NAC increased. These results suggest that NAC-induced protection against Cd cytotoxicity is mainly due to the lowered uptake of Cd into the cells. The American Society for Pharmacology and Experimental Therapeutics ER -