PKC regulation of organic anion secretion in perfused S2 segments of rabbit proximal tubules

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Abstract

To examine the role of protein kinase C (PKC) in organic anion (OA) secretion, we used epifluorescence microscopy to study steady-state transepithelial secretion of 1 μM fluorescein (FL) by isolated perfused S2 segments of rabbit renal proximal tubules. Addition of 100 nM phorbol 12- myristate 13-acetate (PMA), a known PKC activator, to the bathing medium decreased steady-state secretion of FL by ~30% after 25 min. This inhibition was irreversible and, indeed, increased to ~40% at 25 min following removal of PMA [10 μM 1,2-dioctanoyl-sn-glycerol (DOG) produced a comparable inhibition]. The inhibition produced by PMA was blocked when 100 nM of either staurosporine (ST) or bisindolylmaleimide I (BIM), both known PKC inhibitors, was added to the bath for a 20-min preexposure followed by the addition of PMA. ST or BIM alone had no significant effect on FL secretion, suggesting that the basal FL secretion rate was not under influence of PKC. Addition of 1 μM of either the peptide hormone bradykinin (BK) or the α1-receptor agonist phenylephrine (PE), both of which stimulate PKC via a ligand- receptor-PKC coupling reaction, to the bath also inhibited FL secretion by ~22 and ~27%, respectively. However, the inhibition was completely reversible after removal of BK or PE. Pretreatment of tubules with 100 nM BIM eliminated the inhibition of FL secretion produced by exposure to PE. We conclude that PKC negatively regulates the net secretion of OAs in rabbit renal proximal tubules. The data indicate that BK or catecholamines can play a physiological role in regulating OA secretion via PKC activation.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Renal Physiology
Volume278
Issue number1 47-1
StatePublished - Jan 2000

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Protein Kinase C
Anions
Fluorescein
Rabbits
Acetates
Bradykinin
Phenylephrine
Proximal Kidney Tubule
Staurosporine
Baths
Peptide Hormones
Protein C Inhibitor
Protein Kinase Inhibitors
Catecholamines
Microscopy
Ligands
phorbol-12-myristate
bisindolylmaleimide I

Keywords

  • 1,2-dioctanoyl-sn-glycerol
  • Bisindolylmaleimide I
  • Bradykinin
  • Fluorescein
  • Organic anion/dicarboxylate exchanger
  • Phenylephrine
  • Phorbol 12-myristate 13- acetate
  • Staurosporine
  • Transepithelial transport in real time

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

Cite this

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title = "PKC regulation of organic anion secretion in perfused S2 segments of rabbit proximal tubules",
abstract = "To examine the role of protein kinase C (PKC) in organic anion (OA) secretion, we used epifluorescence microscopy to study steady-state transepithelial secretion of 1 μM fluorescein (FL) by isolated perfused S2 segments of rabbit renal proximal tubules. Addition of 100 nM phorbol 12- myristate 13-acetate (PMA), a known PKC activator, to the bathing medium decreased steady-state secretion of FL by ~30{\%} after 25 min. This inhibition was irreversible and, indeed, increased to ~40{\%} at 25 min following removal of PMA [10 μM 1,2-dioctanoyl-sn-glycerol (DOG) produced a comparable inhibition]. The inhibition produced by PMA was blocked when 100 nM of either staurosporine (ST) or bisindolylmaleimide I (BIM), both known PKC inhibitors, was added to the bath for a 20-min preexposure followed by the addition of PMA. ST or BIM alone had no significant effect on FL secretion, suggesting that the basal FL secretion rate was not under influence of PKC. Addition of 1 μM of either the peptide hormone bradykinin (BK) or the α1-receptor agonist phenylephrine (PE), both of which stimulate PKC via a ligand- receptor-PKC coupling reaction, to the bath also inhibited FL secretion by ~22 and ~27{\%}, respectively. However, the inhibition was completely reversible after removal of BK or PE. Pretreatment of tubules with 100 nM BIM eliminated the inhibition of FL secretion produced by exposure to PE. We conclude that PKC negatively regulates the net secretion of OAs in rabbit renal proximal tubules. The data indicate that BK or catecholamines can play a physiological role in regulating OA secretion via PKC activation.",
keywords = "1,2-dioctanoyl-sn-glycerol, Bisindolylmaleimide I, Bradykinin, Fluorescein, Organic anion/dicarboxylate exchanger, Phenylephrine, Phorbol 12-myristate 13- acetate, Staurosporine, Transepithelial transport in real time",
author = "Apichai Shuprisha and Ron Lynch and Stephen Wright and Dantzler, {William H}",
year = "2000",
month = "1",
language = "English (US)",
volume = "278",
journal = "American Journal of Physiology",
issn = "0363-6143",
publisher = "American Physiological Society",
number = "1 47-1",

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TY - JOUR

T1 - PKC regulation of organic anion secretion in perfused S2 segments of rabbit proximal tubules

AU - Shuprisha, Apichai

AU - Lynch, Ron

AU - Wright, Stephen

AU - Dantzler, William H

PY - 2000/1

Y1 - 2000/1

N2 - To examine the role of protein kinase C (PKC) in organic anion (OA) secretion, we used epifluorescence microscopy to study steady-state transepithelial secretion of 1 μM fluorescein (FL) by isolated perfused S2 segments of rabbit renal proximal tubules. Addition of 100 nM phorbol 12- myristate 13-acetate (PMA), a known PKC activator, to the bathing medium decreased steady-state secretion of FL by ~30% after 25 min. This inhibition was irreversible and, indeed, increased to ~40% at 25 min following removal of PMA [10 μM 1,2-dioctanoyl-sn-glycerol (DOG) produced a comparable inhibition]. The inhibition produced by PMA was blocked when 100 nM of either staurosporine (ST) or bisindolylmaleimide I (BIM), both known PKC inhibitors, was added to the bath for a 20-min preexposure followed by the addition of PMA. ST or BIM alone had no significant effect on FL secretion, suggesting that the basal FL secretion rate was not under influence of PKC. Addition of 1 μM of either the peptide hormone bradykinin (BK) or the α1-receptor agonist phenylephrine (PE), both of which stimulate PKC via a ligand- receptor-PKC coupling reaction, to the bath also inhibited FL secretion by ~22 and ~27%, respectively. However, the inhibition was completely reversible after removal of BK or PE. Pretreatment of tubules with 100 nM BIM eliminated the inhibition of FL secretion produced by exposure to PE. We conclude that PKC negatively regulates the net secretion of OAs in rabbit renal proximal tubules. The data indicate that BK or catecholamines can play a physiological role in regulating OA secretion via PKC activation.

AB - To examine the role of protein kinase C (PKC) in organic anion (OA) secretion, we used epifluorescence microscopy to study steady-state transepithelial secretion of 1 μM fluorescein (FL) by isolated perfused S2 segments of rabbit renal proximal tubules. Addition of 100 nM phorbol 12- myristate 13-acetate (PMA), a known PKC activator, to the bathing medium decreased steady-state secretion of FL by ~30% after 25 min. This inhibition was irreversible and, indeed, increased to ~40% at 25 min following removal of PMA [10 μM 1,2-dioctanoyl-sn-glycerol (DOG) produced a comparable inhibition]. The inhibition produced by PMA was blocked when 100 nM of either staurosporine (ST) or bisindolylmaleimide I (BIM), both known PKC inhibitors, was added to the bath for a 20-min preexposure followed by the addition of PMA. ST or BIM alone had no significant effect on FL secretion, suggesting that the basal FL secretion rate was not under influence of PKC. Addition of 1 μM of either the peptide hormone bradykinin (BK) or the α1-receptor agonist phenylephrine (PE), both of which stimulate PKC via a ligand- receptor-PKC coupling reaction, to the bath also inhibited FL secretion by ~22 and ~27%, respectively. However, the inhibition was completely reversible after removal of BK or PE. Pretreatment of tubules with 100 nM BIM eliminated the inhibition of FL secretion produced by exposure to PE. We conclude that PKC negatively regulates the net secretion of OAs in rabbit renal proximal tubules. The data indicate that BK or catecholamines can play a physiological role in regulating OA secretion via PKC activation.

KW - 1,2-dioctanoyl-sn-glycerol

KW - Bisindolylmaleimide I

KW - Bradykinin

KW - Fluorescein

KW - Organic anion/dicarboxylate exchanger

KW - Phenylephrine

KW - Phorbol 12-myristate 13- acetate

KW - Staurosporine

KW - Transepithelial transport in real time

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M3 - Article

C2 - 10644661

AN - SCOPUS:0033964120

VL - 278

JO - American Journal of Physiology

JF - American Journal of Physiology

SN - 0363-6143

IS - 1 47-1

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