Changes in intracellular content of glutathione and thiols associated with γ-glutamyl cycle during sperm penetration and pronuclear formation in rat oocytes

Hiroaki Funahashi, Naoya Bandoh, Shinobu Nakahira, She Hoon Oh, Seiji Tsuboi

Research output: Contribution to journalArticlepeer-review

6 Citations (Scopus)

Abstract

The content of glutathione and other thiols in rat eggs was examined during sperm penetration and pronuclear formation by high-performance liquid chromatography with fluorescence detection. Reduced glutathione (GSH) content was higher in unfertilised oocytes (8.50 ± 0.29 pmol/egg) and penetrated eggs with a decondensed sperm nucleus (DSH eggs; 7.72 ± 0.56 pmol/egg) than eggs at the pronuclear stage (PN eggs; 5.93 ± 0.10 pmol/egg). The content of oxidised glutathione (GSSG) was not different among experimental groups (152.6 ± 74.1 nmol/egg in unfertilised eggs, 146.0 ± 50.0 nmol/egg in DSH eggs and 39.7 ± 17.3 nmol/egg in PN eggs). The GSSG/GSH ratio did not change during fertilisation. Although the reduced cysteinylglycine content of eggs did not change among experimental groups, the oxidised form of cysteinylglycine increased (p < 0.025) between sperm decondensation (6.9 ± 1.5 nmol/egg in unfertilised oocytes and 10.1 ± 2.1 nmol/egg in DSH eggs) and pronuclear formation (40.5 ± 11.5 nmol/egg in PN eggs). Low contents of cystine were detected during fertilisation but cysteine and γ-glutamylcysteine were not detected in any treatment groups. These results demonstrate that GSH content in rat eggs decreases between sperm decondensation and pronuclear formation, probably due to the increased activity of γ-glutamyl transpeptidase.

Original languageEnglish
Pages (from-to)301-305
Number of pages5
JournalZygote
Volume7
Issue number4
DOIs
Publication statusPublished - Nov 1999

Keywords

  • Decondensation of spermatozoa
  • Fertilisation
  • Glutathione
  • Pronuclear formation
  • Rat eggs

ASJC Scopus subject areas

  • Developmental Biology
  • Cell Biology

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