Isolated Perfused Livers:

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Isolated Perfused Livers  Application
FieldsEffect of Estradiol 17 beta-D
glucuronide, Rifampicin and a new Antimicrobial X
on the hepatic and biliary clearance of BSP,
studied using Isolated Perfused Rat Liver.
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Effect of Estradiol 17 beta-D glucuronide,
Rifampicin and a new Antimicrobial X on the
hepatic and biliary clearance of BSP, studied
using Isolated Perfused Rat Liver.
Rational Findings of phase III studies were
consistent with the hypothesis that a new
Antimicrobial X interferes with the transport of
conjugated bilirubin by a competitive inhibition
of the Mrp 2 potentiated by pre-existing
transport abnormalites related to the infectious
process.
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PROPOSED MECHANISM(S) FOR HYPERBILIRUBINEMIA
INDUCED BY XENOBIOTICS AS THE ANTIMICROBIAL DRUG.
PLASMA
BILE
(ATP)
Xenobiotic
GST
eff-
GSH
GS-Xenobiotic
Glu-Bilirubin
Mrp 2
Bilirubin
OATP
B-UGT 1
eff-
PgP
CYTOKINES
SEPSIS
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The aim of the study was

• - Compare the hepatobiliary transport of two Mrp
  2 substrates
• Estradiol-17 Beta D-glucuronide,
• Sulfobromophtalein.
• Use the most relevant substrate
• To test the influence of the Antimicrobial X
  .
• on the Mrp 2 hepatobiliary transport pathway.
• Initiate a comparative ex vivo study
• Antimicrobial X / Rifampicin .

Pierre Gires, A. Grelier, S. Martin, D Poulet
and Ph Rateau (DMPK/Preclinical Studies)
December 1999.
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STUDY DESIGN
Estradiol-17 Beta D-glucuronide, 0.45 1µM
3 IPRL BSP (8, 16 32 Mg) 3 IPRL
BSP on TR- rats (32 mg) 2 IPRL BSP
(32 mg) Antimicrobial X (15 43 mg/kg)
2 IPRL BSP (32 mg) GSH-Antimicrobial
X 2 IPRL 3H-Rifampicin (12 mg) 2
IPRL 3H-Rifampicin (12 mg ) BSP (32 mg)
2 IPRL 3H-Rifampicin (12 mg ) Antimicrobial X
(43 mg/kg) 2 IPRL
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Hepatobiliary transport of the Estradiol
17-Beta-glucuronide using IPRL.
PK parameters n3
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Hepatobiliary transport of the Sulfobromophtalein
BSP, using IPRL.
PK parameters
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Schematic model of hepatic P-gp and Mrp 2in
Estradiol 17-Beta-glucuronide transport and its
cholestasis

• As cholestatic effect occurs when high doses of
  E217G are administered gt (1µM), BSP was choosen
  as substrate.
• MDR1 substrates/modulators protect against
  beta-estradiol-17beta-D-glucuronide cholestasis
  in rat liver.
• 1 Cancer Res. 1996 Nov 156(21)4992-7

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Hepatic and biliary clearances of the
Sulfobromophtalein using IPRL with or without
Synercid infusion.
In order to mimic in vivo conditions,
Antimicrobial X was infused for 20 minutes at 15
43 mg/kg BSP bolus was injected 5 minutes
before the end of infusion.
45
65
60
PK parameters
BSP 32 mg
100
90
BSP 32 mg Antimicro X 43 mg/kg
80
70
60
50
Amount BSP ()
40
30
20
10
0
0
30
60
90
120
150
180
Time (hour)
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Influence of Antimicrobial X on the biliary
excretion of the BSP administered at 32 mg on
IPRL
BSP amount excreted in bile ()
90.00
80.00
70.00
60.00
50.00
excreted
40.00
30.00
20.00
10.00
0.00
BSP 32 mg
BSP 32 mg (TR- rats)
BSP 32 mg Anti X 15 mg/kg
BSP 32 mg AntiX 43 mg/kg
BSP 32 mg Anti X -GSH
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Influence of Anti X GSH metabolite on the
biliary clearance of the BSP administered at 32
mg on IPRL
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Effect of the Rifampicin on the hepatic and
biliary clearances of the Sulfobromophtalein
In lab Preliminary results
A. Oliven, H.M.Bassan results
Fig Inhibition by Rifampicin of the biliary
excretion of BSP as compare to controls
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CONCLUSION

• In the present investigation, we were able
• To confirm
• The role of the Mrp 2 in the biliary clearance of
  the BSP.
• as shown, using TR - rats, deficient in this
  transporter
• Our results suggest that
• Antimicrobial X interferes with Mrp 2 substrate
  as BSP
• This effect could be related with administered
  dose.
• Antimicrobial X (GSH-conjugate) could also
  interfere with the Mrp2.
• It could confirm the hypothesis of the Advisory
  Board, that Antimicrobial X interferes with the
  transport of conjugated bilirubin by a
  competitive inhibition of Mrp2 transporter.