Rapid Communication: The Role of P‐Type Calcium Channels in the Depolarization‐Induced Activation of Nitric Oxide Synthase in Frontal Cortex

Sudarkodi Alagarsamy, Gyorgy Lonart, Kenneth M. Johnson

Research output: Contribution to journalArticle

15 Scopus citations


Abstract: In this study we demonstrate that 50 mRS K+ stimulates the conversion of L‐[3H] arginine to L‐[3H] citrulline and that this effect is blocked by 10 μM AT‐nitro‐l‐arginine, a nitric oxide synthase inhibitor, and Ca2+‐free conditions. Amiloride (1 mM) and low Na+ conditions were used to test the possible involvement of the Na+‐Ca2+ exchanger. These treatments were without effect. The calcium channel blockers 10 mRS Mg2+, 100 μM Cd2+, and 10 mRS Co2+ also blocked the K+ response, suggesting the involvement of voltage‐dependent calcium channels (VDCCs). The specific VDCC involved seems to be the P type, as funnel‐web spider toxin blocked the response whereas 200 μMNi2+, 10 μM nifedipine, and 100 nMω‐conotoxin did not.

Original languageEnglish (US)
Pages (from-to)400-403
Number of pages4
JournalJournal of neurochemistry
Issue number1
StatePublished - Jan 1994



  • Calcium channel
  • Frontal cortex.
  • Funnel‐web spider toxin
  • Nitric oxide synthase
  • Potassium chloride
  • P‐channel

ASJC Scopus subject areas

  • Biochemistry
  • Cellular and Molecular Neuroscience

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