Effects of mechano-gated cation channel blockers on Xenopus oocyte growth and development

N. C. Wilkinson, F. Gao, Owen Hamill

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

The putative role(s) of a mechanically gated (MG) cation channel in Xenopus oocyte growth, maturation, fertilization and embryogenesis has been examined. Using a pharmacological approach, we have tested the effects of the MG channel blockers, gadolinium, gentamicin and amiloride on the above developmental events. Our results indicate that oocyte maturation, fertilization and early embryogenesis (up to the free-swimming stage 45) can proceed normally in the presence of concentrations of agents that either completely abolish (i.e., ≤10 μM Gd3+) or partially block (i.e., 1 mm gentamicin) single MG channel activity as measured by patch-clamp recording. However, we also find that higher concentrations of Gd3+ (≤50 μM) can lead to an increased percentage (>20%) of axis-perturbed embryos compared with control (<1%) and that amiloride (0.5 mM) reduces the success of fertilization (from 100% to <50%) and increases mortality (by -75%) in developing embryos. Furthermore, we find that all three agents inhibit oocyte growth in vitro. However, their order of effectiveness (amiloride > gentamicin > Gd3+) is opposite to their order for blocking MG channels (Gd3+ >> gentamicin > amiloride). These discrepancies indicated that the drags effects occur by mechanisms other than, or in addition to, MG channel block. Our results provide no compelling evidence for the idea that MG channel activity is critical for development in Xenopus. This could mean that there are other mechanisms in the oocyte that can compensate when MG channel activity is blocked or that the protein that forms the channel can undergo additional interactions that result in a function insensitive to MG channel blockers.

Original languageEnglish (US)
Pages (from-to)161-174
Number of pages14
JournalJournal of Membrane Biology
Volume165
Issue number2
DOIs
StatePublished - Sep 15 1998

Fingerprint

Xenopus
Gentamicins
Growth and Development
Oocytes
Cations
Amiloride
Fertilization
Embryonic Development
Gadolinium
Embryonic Structures
Pharmacology
Growth
Proteins

Keywords

  • Amiloride
  • Development
  • Gadolinium
  • Gentamicin
  • Mechanosensitive channels

ASJC Scopus subject areas

  • Biophysics
  • Physiology
  • Cell Biology

Cite this

Effects of mechano-gated cation channel blockers on Xenopus oocyte growth and development. / Wilkinson, N. C.; Gao, F.; Hamill, Owen.

In: Journal of Membrane Biology, Vol. 165, No. 2, 15.09.1998, p. 161-174.

Research output: Contribution to journalArticle

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