Km. Kleinow et al., Distribution and inducibility of P-glycoprotein in the catfish: immunohistochemical detection using the mammalian C-219 monoclonal, MAR ENV RES, 50(1-5), 2000, pp. 313-317
Mounting evidence suggests that the P-glycoprotein (pgp) efflux pump may be
a modulator of bioavailability and a mode of excretion for xenobiotics. Im
munohistochemistry was utilized to examine the distribution and inducibilit
y of a pgp like protein in catfish. Immunoreactivity to the MDR C-219 monoc
lonal antibody was noted primarily in bile canaliculi or bile preductules o
f the liver, discrete areas of the extratubular region of the kidney and th
e columnar epithelia of the intestine. Regional differences in pgp content
were noted in the intestine with the distal region containing greater pgp l
evels than the proximal intestine. Dietary administration of vincristine, a
prototypic pgp inducer and beta -naphthoflavone an Ah agonist resulted in
induction of the C-219 immunoreactivity in the liver and the distal intesti
ne. These results are consistent in location and inducibility with pgp like
proteins and support a possible relationship to xenobiotic absorption and/
or excretion in the catfish. (C) 2000 Elsevier Science Ltd. All rights rese
rved.