Establishment and characterization of the transformants stably-expressing MDR1 derived from various animal species in LLC-PK1.
OBJECTIVE
Stable transformants expressing human multidrug resistance 1 (MDR1), monkey MDR1, canine MDR1, rat MDR1a, rat MDR1b, mouse mdr1a, and mouse mdr1b in LLC-PK1 were established to investigate species differences in P-glycoprotein (P-gp, ABCB1) mediated efflux activity.


METHODS
The seven cDNAs of MDR1 from five animals were cloned, and their transformants stably expressing the series of MDR1 in LLC-PK1 were established. Transport studies of clarithromycin, daunorubicin, digoxin, erythromycin, etoposide, paclitaxel, propranolol, quinidine, ritonavir, saquinavir, verapamil, and vinblastine were performed by using these cells, and efflux activity was compared among the species.


RESULTS
Except for propranolol, all compounds showed efflux activity in all transformants, and were judged to be substrates of P-gp. There were slight interspecies and interisoforms differences in the substrate recognition. However, the efflux ratio among the series of the MDR1 stably expressing cells showed good correlation as represented between human and monkey MDR1, and poor correlation as represented between human MDR1 and mouse mdr1a, and human and canine MDR1.


CONCLUSIONS
Results in the present study indicate that all MDR1 stably expressing cells have efflux activity for various P-gp substrates, and that interspecies differences and similarities of the P-gp substrate efflux activity may exist.
Takeuchi
Toshiyuki
T
Development Research Center, Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, 2-17-85 Juso-Honmachi, Yodogawa-ku, Osaka, 532-8686, Japan. Takeuchi_Toshiyuki@takeda.co.jp
Yoshitomi
Sumie
S
Higuchi
Tomoaki
T
Ikemoto
Keiko
K
Niwa
Shin-ichi
S
Ebihara
Takuya
T
Katoh
Miki
M
Yokoi
Tsuyoshi
T
Asahi
Satoru
S
D018435:ATP Binding Cassette Transporter, Subfamily B / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D018528:ATP-Binding Cassette Transporters / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001692:Biological Transport; D017291:Clarithromycin / Q000378:metabolism; D004077:Digoxin / Q000037:antagonists & inhibitors / Q000378:metabolism; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D000882:Haplorhini; D006801:Humans; D007700:Kinetics; D018374:LLC-PK1 Cells; D051379:Mice; D004364:Pharmaceutical Preparations / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D013552:Swine; D014162:Transfection; D014700:Verapamil / Q000494:pharmacology; D014747:Vinblastine / Q000378:metabolism; D000097202:ATP-Binding Cassette Sub-Family B Member 4
D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D018528:ATP-Binding Cassette Transporters; D017291:Clarithromycin; D004077:Digoxin; D004364:Pharmaceutical Preparations; D012333:RNA, Messenger; D014700:Verapamil; D014747:Vinblastine; D000097202:ATP-Binding Cassette Sub-Family B Member 4; C095122:multidrug resistance protein 3