Effects of ibuprofen on arylamine N-acetyltransferase activity in human colon tumor cells.
The inhibition of arylamine N-acetyltransferase (NAT) activity by ibuprofen was determined in a human colon tumour (adenocarcinoma) cell line. Two assay systems were employed, one with cellular cytosols (9000 g supernatant) and the other with intact colon tumour cell suspensions. The NAT activity in a human colon tumour cell line was inhibited by ibuprofen in a dose-dependent manner in both systems, i.e. the greater the concentration of ibuprofen in the reaction, the greater the inhibition of NAT activities in both systems. The data also indicated that ibuprofen decreases the apparent Km and Vmax of NAT enzyme from human colon tumour cells in both systems examined. This report is the first demonstration to show that ibuprofen affects human colon tumour cell NAT activity.
Chung
J G
JG
Department of Microbiology, China Medical College, Taichung, Taiwan, Republic of China.
Chang
H L
HL
Lin
W C
WC
Yeh
F T
FT
Hung
C F
CF
D015073:2-Acetylaminofluorene / Q000031:analogs & derivatives / Q000378:metabolism; D010129:4-Aminobenzoic Acid / Q000378:metabolism; D000230:Adenocarcinoma / Q000201:enzymology*; D000368:Aged; D001191:Arylamine N-Acetyltransferase / Q000187:drug effects / Q000378:metabolism*; D002273:Carcinogens / Q000378:metabolism; D003110:Colonic Neoplasms / Q000201:enzymology*; D004305:Dose-Response Relationship, Drug; D005449:Fluorenes / Q000378:metabolism; D006801:Humans; D007052:Ibuprofen / Q000494:pharmacology*; D008297:Male; D014407:Tumor Cells, Cultured