Insulin inhibits voltage-dependent calcium influx into rod photoreceptors

Jr Stella S.L., E. J. Bryson, W. B. Thoreson

Research output: Contribution to journalArticle

20 Scopus citations

Abstract

Insulin inhibits the ERG b-wave and modulates L-type calcium currents (ICa) in various preparations. We therefore examined insulin's effects on ICa and depolarization-evoked [Ca2+]i increases in rod photoreceptors. Insulin inhibited ICa and caused a dose-dependent reduction in the depolarization-evoked Ca2+ influx with an EC50 of 2.1 nM. Tyrosine kinase inhibitors, lavendustin A (100nM) and genistein (10μM), prevented insulin from reducing the depolarization-evoked Ca2+ increase in rods. Their less active analogues, lavendustin B and daidzein, had similar effects. An insulin receptor-specific tyrosine kinase inhibitor, HNMPA-(AM)3 (50μM), prevented insulin (30 nM) from reducing the depolarization-evoked Ca2+ increase in rods. The results suggest that insulin inhibits Ca2+ influx through voltage-dependent ICa in rod photoreceptors via tyrosine kinase activity.

Original languageEnglish (US)
Pages (from-to)947-951
Number of pages5
JournalNeuroReport
Volume12
Issue number5
StatePublished - Apr 17 2001

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Keywords

  • Calcium channel
  • Calcium imaging
  • Fura-2
  • HNMPA-(AM)
  • Insulin
  • Lavendustin A and B
  • Retinal slice
  • Rod
  • Tyrosine kinase

ASJC Scopus subject areas

  • Neuroscience(all)

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