CCKA receptors mediate slow depolarizations in cultured mammalian sympathetic neurons

Steven R. Knoper, Alan G. Meehan, Sergey Purnyn, Jay S. Coggan, Todd L. Anthony, David L. Kreulen

Research output: Contribution to journalArticle

9 Scopus citations

Abstract

The effect of cholecystokinin octapeptide (CCK-8) was examined in guinea-pig celiac ganglion (CG) neurons in primary culture using standard intracellular recording techniques. Sulfated CCK-8 (CCK-8S; 1 μM) evoked slow depolarizing responses in 94% of CG neurons tested. In contrast, membrane potential was not affected by nonsulfated CCK-8 (CCK-8NS; 1 μM), CCK tetrapeptide (CCK-4; 1 μM), or gastrin (1 μM). The selective CCKA receptor antagonist L 364,718 potently inhibited CCK-8S-induced slow depolarizations(IC50 2.9 pM). In contrast, the selective CCKB receptor antagonist L 365,260 was a weak inhibitor of CCK-8S-induced slow depolarizations (IC50 1.3 μM). The depolarizing responses to CCK-8S were associated with an average increase in cell input resistance of 61%. Single electrode voltage clamp experiments indicated that CCK-8S-induced depolarizations were associated with a slow inward shift in holding current. Thus, the present findings indicate that guinea-pig cultured CG neurons are endowed with excitatory CCKA receptors the activation of which elicits a decrease in membrane conductance, thereby resulting in slow depolarizations.

Original languageEnglish (US)
Pages (from-to)65-69
Number of pages5
JournalEuropean Journal of Pharmacology
Volume232
Issue number1
DOIs
StatePublished - Feb 23 1993

Keywords

  • CCK receptors
  • Cholecystokinin
  • Electrophysiology
  • Primary cell culture
  • Slow depolarization
  • Sympathetic neurons (mammalian)

ASJC Scopus subject areas

  • Pharmacology

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