Inhibition of PAH transport by parathyroid hormone in OK cells: involvement of protein kinase C pathway.
We have previously shown that the p-aminohippurate (PAH) transport system in OK kidney epithelial cell line is under the regulatory control of protein kinase C. Parathyroid hormone (PTH) could activate protein kinase C, as well as protein kinase A, in OK cells. In the present study, the effect of PTH on PAH transport was studied in OK cells. PTH inhibited the transcellular transport of PAH from the basal to the apical side, as well as the accumulation of PAH in OK cells. Basolateral PAH uptake was inhibited by PTH in a dose- and time-dependent manner. Protein kinase A activators did not affect the transcellular transport or the accumulation of PAH. The PTH-induced inhibition of the accumulation of PAH was blocked by a protein kinase C inhibitor staurosporine. These results suggest that PTH inhibits the PAH transport in OK cells and that the messenger system mediated by protein kinase C, not protein kinase A, plays an important role in the regulation of PAH transport by PTH.
Nagai
J
J
Department of Pharmacy, Kyoto University Hospital, Faculty of Medicine, Kyoto University, Japan.
Yano
I
I
Hashimoto
Y
Y
Takano
M
M
Inui
K
K
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D003994:Bucladesine / Q000494:pharmacology; D002460:Cell Line; D002462:Cell Membrane / Q000502:physiology; D005576:Colforsin / Q000494:pharmacology; D007668:Kidney / Q000187:drug effects / Q000502:physiology*; D007700:Kinetics; D008353:Mannitol / Q000493:pharmacokinetics; D011493:Protein Kinase C / Q000378:metabolism*; D015290:Second Messenger Systems; D019311:Staurosporine / Q000494:pharmacology; D019379:Teriparatide / Q000494:pharmacology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D010130:p-Aminohippuric Acid / Q000493:pharmacokinetics*
D019379:Teriparatide; D005576:Colforsin; D015124:8-Bromo Cyclic Adenosine Monophosphate; D008353:Mannitol; D003994:Bucladesine; D011493:Protein Kinase C; D019311:Staurosporine; D013755:Tetradecanoylphorbol Acetate; D015056:1-Methyl-3-isobutylxanthine; D010130:p-Aminohippuric Acid