Arachidonic Acid Release and Catecholamine Secretion from Digitonin‐Treated Chromaffin Cells: Effects of Micromolar Calcium, Phorbol Ester, and Protein Alkylating Agents

• Roy A. Frye

• Ronald W. Holz

抄録

The relationship between catecholamine secretion and arachidonic acid release from digitonin‐treated chromaffin cells was investigated. Digitonin renders permeable the plasma membranes of bovine adrenal chromaffin cells to Ca 2+ , ATP, and proteins. Digitonin‐treated cells undergo exocytosis of catecholamine in response to micromolar Ca 2+ in the medium. The addition of micromolar Ca 2+ to digitonin‐treated chromaffin cells that had been prelabeled with [ 3 H]arachidonic acid caused a marked increase in the release of [ 3 H]arachidonic acid. The time course of [ 3 H]arachidonic acid release paralleled catecholamine secretion. Although [ 3 H]arachidonic acid release and exocytosis were both activated by free Ca 2+ in the micromolar range, the activation of [ 3 H]arachidonic acid release occurred at Ca 2+ concentrations slightly lower than those required to activate exocytosis. Pretreatment of the chromaffin cells with N ‐ethylmaleimide (NEM) or p ‐bromophenacyl bromide (BPB) resulted in dose‐dependent inhibition of 10 μ M Ca 2+ ‐stimulated [ 3 H]arachidonic acid release and exocytosis. The IC 50 of NEM for both [ 3 H]arachidonic acid release and exocytosis was 40 μ M. The IC 50 of BPB for both events was 25 μ M. High concentrations (5–20 m M ) of Mg 2+ caused inhibition of catecholamine secretion without altering [ 3 H]arachidonic acid release. A phorbol ester that activates protein kinase C, 12‐ O ‐tetradecanoylphorbol‐13‐acetate (TPA), caused enhancement of both [ 3 H]arachidonic acid release and exocytosis. The findings demonstrate that [ 3 H]arachidonic acid release is stimulated during catecholamine secretion from digitonin‐treated chromaffin cells and they are consistent with a role for phospholipase A 2 in exocytosis from chromaffin cells. Furthermore the data suggest that protein kinase C can modulate both arachidonic acid release and exocytosis.

収録刊行物

• Journal of Neurochemistry

  Journal of Neurochemistry 44 (1), 265-273, 1985-01

  Wiley

キーワード

• Cellular and Molecular Neuroscience
• Biochemistry

詳細情報

• CRID: 1362262945549177728
• NII論文ID: 30014580517
• DOI: 10.1111/j.1471-4159.1985.tb07140.x
• ISSN: 14714159
• ISSN: 00223042
• Web Site: https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1471-4159.1985.tb07140.x
• Web Site: https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1471-4159.1985.tb07140.x
• データソース種別:
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  • CiNii Articles