Amino acids a re required fo1' protein synthesis and energy sources in all living cell s. System L amino acid trans porters neutral amino aci cls i n a Na +' - independent manner. In ma 1ignan t tumors the L-type amino acid t ranspor te r 1(LA1'1), the first isoform 0 1' system L. is highly expressed to suppor t tumo1' cell growth. ln the present study, the expression 0 1' the system L amino acid transporter and BCH cytotoxicity were examined and compa red in both rat gli a l and C6 g lioma cel ls 1'he rat glia l cells expressed the L-type arnino acid t ra nsporter 2(LA1'2). the second isoform 이 system L, with its subu ni t 4F2hc. whereas the LA1'1 was not expressed. 1'he C6 glioma cells expressed LA1'1 with 4F2hc but not LA1'2 1'he [14C]L-leucine uptakes by the glial and C6 glioma cells were inhibi ted by BCH in a co ncent ration-d e pendant man ner wi th the lC50 values of 270.0 :t 13.7 μ M and 73.1 :t 4.5 μ M, respectively. 1'he cell g rowth was inh ibi ted by BCH in the time, concen tration-dependant manner in the gli al and C6 glioma cell s . 1'he rate of cell growth inhi bit ion induced by BCH in the C6 glioma cells was hi gh er than that in the gli al cells 1'hese results s uggesL that the tra ns ports of neutra l amino acids inc1uding several essenti al amino acids into rat g lial and C6 glioma cel ls a re for the most part mediated by LA1'2 and LA1'1, respectively. Therefore‘ the rat glia1 and C6 gJioma cells are excell ent tools for examing the proper ties of LA1'2 and LA1'1, respectively. Moreover, the spec너 i c inh ibi tion 0 1' LATl in cancel cells might be a new rationa le f'or anti -cancer therapy