TY - JOUR
T1 - Inhibition of initial transport rate of basolateral organic anion carrier in renal PT by BK and phenylephrine
AU - Gekle, Michael
AU - Mildenberger, Sigrid
AU - Sauvant, Christoph
AU - Bednarczyk, Dallas
AU - Wright, Stephen H.
AU - Dantzler, William H.
PY - 1999/8
Y1 - 1999/8
N2 - The effect of ligands for phospholipase C-coupled receptors and of protein kinase C (PKC) stimulation with phorbol ester [phorbol 12-myristate 13-acetate (PMA)] or 1,2-dioctanoyl-sn-glycerol on the activity of the basolateral organic anion transporter (OAT) in S2 segments of single, nonperfused rabbit proximal tubules (PT) was measured with the use of fluorescein and epifluorescence microscopy. The initial uptake rate (25 s, OAT activity) was measured in real time by using conditions similar to those found in vivo. Stimulation of PKC with PMA or 1,2-dioctanoyl-sn-glycerol led to an inhibition of OAT activity, which could be prevented by 10-7 mol/l of the PKC-specific inhibitor bisindolylmaleimide. The α1-receptor agonist phenylephrine as well as the peptide hormone bradykinin induced a reversible decrease of OAT activity, which was prevented by bisindolylmaleimide. The observed effect was not due to a decrease in the concentration of the counterion α-ketoglutarate or to impaired α-ketoglutarate recycling, because it was unchanged in the continuous presence of α-ketoglutarate or methyl succinate. We conclude that physiological stimuli can inhibit the activity of OAT in rabbit PT via PKC. The effect is not mediated by alterations in counterion availability but by a direct action on the OAT.
AB - The effect of ligands for phospholipase C-coupled receptors and of protein kinase C (PKC) stimulation with phorbol ester [phorbol 12-myristate 13-acetate (PMA)] or 1,2-dioctanoyl-sn-glycerol on the activity of the basolateral organic anion transporter (OAT) in S2 segments of single, nonperfused rabbit proximal tubules (PT) was measured with the use of fluorescein and epifluorescence microscopy. The initial uptake rate (25 s, OAT activity) was measured in real time by using conditions similar to those found in vivo. Stimulation of PKC with PMA or 1,2-dioctanoyl-sn-glycerol led to an inhibition of OAT activity, which could be prevented by 10-7 mol/l of the PKC-specific inhibitor bisindolylmaleimide. The α1-receptor agonist phenylephrine as well as the peptide hormone bradykinin induced a reversible decrease of OAT activity, which was prevented by bisindolylmaleimide. The observed effect was not due to a decrease in the concentration of the counterion α-ketoglutarate or to impaired α-ketoglutarate recycling, because it was unchanged in the continuous presence of α-ketoglutarate or methyl succinate. We conclude that physiological stimuli can inhibit the activity of OAT in rabbit PT via PKC. The effect is not mediated by alterations in counterion availability but by a direct action on the OAT.
KW - Bradykinin
KW - Isolated proximal tubule
KW - Kidney
KW - Organic anion transport
KW - Protein kinase C
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U2 - 10.1152/ajprenal.1999.277.2.f251
DO - 10.1152/ajprenal.1999.277.2.f251
M3 - Article
C2 - 10444580
AN - SCOPUS:0032879752
SN - 1931-857X
VL - 277
SP - F251-F256
JO - American Journal of Physiology - Renal Physiology
JF - American Journal of Physiology - Renal Physiology
IS - 2 46-2
ER -