Basic amino acid transport in renal papilla: Microinfusion of Henle's loops and vasa recta

William H Dantzler, Stefan Silbernagl

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

To determine whether basic amino acids, like acidic and neutral amino acids, could be reabsorbed distal to tips of Henle's loops and recycled between loops and vasa recta in the renal papilla, we continuously microinfused ascending Henle's loops and vasa recta with 14C-labeled L-lysine (L-Lys; 1.28 mM) or L-arginine (L-Arg; 1.17 mM) and 3H-labeled inulin. We also determined percent of recovered radiolabel as intact amino acid. Like acidic and neutral amino acids, relative to inulin, ∼30% of L-Lys and ∼45% of L-Arg microinfused into Henle's loops were reabsorbed. However, whereas radiolabeled L-Lys reabsorption, like reabsorption of acidic and neutral amino acids, was not readily inhibited, radiolabeled L-Arg reabsorption was reduced to ∼25% by addition of unlabeled L-Arg (50 mM) or L-homoarginine (L-Homo-Arg) (50 mM) to infusate. This observation provides greater evidence for specific, carrier-mediated reabsorption for L-Arg than for acidic or neutral amino acids. About 36% (relative to inulin) of each of these amino acids microinfused into ascending vasa recta apparently was transferred directly into ipsilateral tubular structures (probably thin descending limbs of Henle's loops). Transfer of radiolabeled L-Arg was reduced to ∼8% by the inclusion of unlabeled L-Arg (50 mM) in infusate. Transfer of unlabeled L-Lys was unaffected by inclusion of unlabeled L-Lys (50 mM) in infusate but was reduced to ∼20% by inclusion of unlabeled L-Arg (50 mM) or L-Homo-Arg (50 mM) in infusate. These data suggest that L-Lys and L-Arg share transport system into ipsilateral loops but that the system has a greater affinity for L-Arg than L-Lys. Like acidic and neutral amino acids, basic amino acids apparently can be reabsorbed distal to tips of Henle's loops and recycled in the papilla.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Renal Fluid and Electrolyte Physiology
Volume265
Issue number6 34-6
StatePublished - Dec 1993

Fingerprint

Acidic Amino Acids
Neutral Amino Acids
Loop of Henle
Basic Amino Acids
Rectum
Inulin
Kidney
Hominidae
Homoarginine
Amino Acids
Lysine
Arginine

Keywords

  • Amino acid recycling
  • L-arginine
  • L-homoarginine
  • L-lysine
  • Rat papilla

ASJC Scopus subject areas

  • Physiology

Cite this

@article{ded38d2efc98412f9237dd8a06f8e001,
title = "Basic amino acid transport in renal papilla: Microinfusion of Henle's loops and vasa recta",
abstract = "To determine whether basic amino acids, like acidic and neutral amino acids, could be reabsorbed distal to tips of Henle's loops and recycled between loops and vasa recta in the renal papilla, we continuously microinfused ascending Henle's loops and vasa recta with 14C-labeled L-lysine (L-Lys; 1.28 mM) or L-arginine (L-Arg; 1.17 mM) and 3H-labeled inulin. We also determined percent of recovered radiolabel as intact amino acid. Like acidic and neutral amino acids, relative to inulin, ∼30{\%} of L-Lys and ∼45{\%} of L-Arg microinfused into Henle's loops were reabsorbed. However, whereas radiolabeled L-Lys reabsorption, like reabsorption of acidic and neutral amino acids, was not readily inhibited, radiolabeled L-Arg reabsorption was reduced to ∼25{\%} by addition of unlabeled L-Arg (50 mM) or L-homoarginine (L-Homo-Arg) (50 mM) to infusate. This observation provides greater evidence for specific, carrier-mediated reabsorption for L-Arg than for acidic or neutral amino acids. About 36{\%} (relative to inulin) of each of these amino acids microinfused into ascending vasa recta apparently was transferred directly into ipsilateral tubular structures (probably thin descending limbs of Henle's loops). Transfer of radiolabeled L-Arg was reduced to ∼8{\%} by the inclusion of unlabeled L-Arg (50 mM) in infusate. Transfer of unlabeled L-Lys was unaffected by inclusion of unlabeled L-Lys (50 mM) in infusate but was reduced to ∼20{\%} by inclusion of unlabeled L-Arg (50 mM) or L-Homo-Arg (50 mM) in infusate. These data suggest that L-Lys and L-Arg share transport system into ipsilateral loops but that the system has a greater affinity for L-Arg than L-Lys. Like acidic and neutral amino acids, basic amino acids apparently can be reabsorbed distal to tips of Henle's loops and recycled in the papilla.",
keywords = "Amino acid recycling, L-arginine, L-homoarginine, L-lysine, Rat papilla",
author = "Dantzler, {William H} and Stefan Silbernagl",
year = "1993",
month = "12",
language = "English (US)",
volume = "265",
journal = "American Journal of Physiology",
issn = "0363-6143",
publisher = "American Physiological Society",
number = "6 34-6",

}

TY - JOUR

T1 - Basic amino acid transport in renal papilla

T2 - Microinfusion of Henle's loops and vasa recta

AU - Dantzler, William H

AU - Silbernagl, Stefan

PY - 1993/12

Y1 - 1993/12

N2 - To determine whether basic amino acids, like acidic and neutral amino acids, could be reabsorbed distal to tips of Henle's loops and recycled between loops and vasa recta in the renal papilla, we continuously microinfused ascending Henle's loops and vasa recta with 14C-labeled L-lysine (L-Lys; 1.28 mM) or L-arginine (L-Arg; 1.17 mM) and 3H-labeled inulin. We also determined percent of recovered radiolabel as intact amino acid. Like acidic and neutral amino acids, relative to inulin, ∼30% of L-Lys and ∼45% of L-Arg microinfused into Henle's loops were reabsorbed. However, whereas radiolabeled L-Lys reabsorption, like reabsorption of acidic and neutral amino acids, was not readily inhibited, radiolabeled L-Arg reabsorption was reduced to ∼25% by addition of unlabeled L-Arg (50 mM) or L-homoarginine (L-Homo-Arg) (50 mM) to infusate. This observation provides greater evidence for specific, carrier-mediated reabsorption for L-Arg than for acidic or neutral amino acids. About 36% (relative to inulin) of each of these amino acids microinfused into ascending vasa recta apparently was transferred directly into ipsilateral tubular structures (probably thin descending limbs of Henle's loops). Transfer of radiolabeled L-Arg was reduced to ∼8% by the inclusion of unlabeled L-Arg (50 mM) in infusate. Transfer of unlabeled L-Lys was unaffected by inclusion of unlabeled L-Lys (50 mM) in infusate but was reduced to ∼20% by inclusion of unlabeled L-Arg (50 mM) or L-Homo-Arg (50 mM) in infusate. These data suggest that L-Lys and L-Arg share transport system into ipsilateral loops but that the system has a greater affinity for L-Arg than L-Lys. Like acidic and neutral amino acids, basic amino acids apparently can be reabsorbed distal to tips of Henle's loops and recycled in the papilla.

AB - To determine whether basic amino acids, like acidic and neutral amino acids, could be reabsorbed distal to tips of Henle's loops and recycled between loops and vasa recta in the renal papilla, we continuously microinfused ascending Henle's loops and vasa recta with 14C-labeled L-lysine (L-Lys; 1.28 mM) or L-arginine (L-Arg; 1.17 mM) and 3H-labeled inulin. We also determined percent of recovered radiolabel as intact amino acid. Like acidic and neutral amino acids, relative to inulin, ∼30% of L-Lys and ∼45% of L-Arg microinfused into Henle's loops were reabsorbed. However, whereas radiolabeled L-Lys reabsorption, like reabsorption of acidic and neutral amino acids, was not readily inhibited, radiolabeled L-Arg reabsorption was reduced to ∼25% by addition of unlabeled L-Arg (50 mM) or L-homoarginine (L-Homo-Arg) (50 mM) to infusate. This observation provides greater evidence for specific, carrier-mediated reabsorption for L-Arg than for acidic or neutral amino acids. About 36% (relative to inulin) of each of these amino acids microinfused into ascending vasa recta apparently was transferred directly into ipsilateral tubular structures (probably thin descending limbs of Henle's loops). Transfer of radiolabeled L-Arg was reduced to ∼8% by the inclusion of unlabeled L-Arg (50 mM) in infusate. Transfer of unlabeled L-Lys was unaffected by inclusion of unlabeled L-Lys (50 mM) in infusate but was reduced to ∼20% by inclusion of unlabeled L-Arg (50 mM) or L-Homo-Arg (50 mM) in infusate. These data suggest that L-Lys and L-Arg share transport system into ipsilateral loops but that the system has a greater affinity for L-Arg than L-Lys. Like acidic and neutral amino acids, basic amino acids apparently can be reabsorbed distal to tips of Henle's loops and recycled in the papilla.

KW - Amino acid recycling

KW - L-arginine

KW - L-homoarginine

KW - L-lysine

KW - Rat papilla

UR - http://www.scopus.com/inward/record.url?scp=0027717328&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0027717328&partnerID=8YFLogxK

M3 - Article

C2 - 8285216

AN - SCOPUS:0027717328

VL - 265

JO - American Journal of Physiology

JF - American Journal of Physiology

SN - 0363-6143

IS - 6 34-6

ER -