Intracellular cystine loading causes proximal tubule respiratory dysfunction: Effect of glycine

A. Sakarcan, R. Aricheta, M. Baum

Research output: Contribution to journalArticle

27 Scopus citations

Abstract

The present study examined proximal tubu­lar respiration in control proximal tubules and proximal tubules loaded with cystine using 2 mmol/L cystine di­methyl ester. Basal oxygen consumption was significantly less in cystine-loaded tubules (20.6 ± 0.5 versus 12.1 ± 0.6 nmol 02min-1mg protein-1, p < 0.001). In the presence of 10-4 mol/L ouabain, an inhibitor of the NaK ATPase, oxygen consumption was 10.2 ± 0.7 nmol O2·min-1·mg protein-1 in control tubules and 11.4 ± 1.0 nmol O2·min-1 mg·protein-1 in cystine-loaded tubules. Thus, proximal tubular intracellular cystine loading specifically inhibits oxygen metabolism directed toward transport. Compared with control proximal tubules, cystine-loaded proximal tubules also had a lower rate of 02 consumption when the cells were permeabilized to sodium with nystatin and when mitochondrial respiration was uncoupled. Glycine, an amino acid that is cytoprotective to hypoxic proximal tubule injury, ameliorated the repiratory dysfunction ob­served in cystine-loaded tubules.

Original languageEnglish (US)
Pages (from-to)710-713
Number of pages4
JournalPediatric Research
Volume32
Issue number6
DOIs
StatePublished - Dec 1992

    Fingerprint

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health

Cite this