Tyrosine phosphorylation is involved in Ca2+entry in human gingival fibroblasts

Yorimasa Ogata, Sumi Nakao, Emi Shimizu, Yuko Matsuda-Honjyo, Muneyoshi Yamazaki, Shunsuke Furuyama, Hiroshi Sugiya

Research output: Contribution to journalArticlepeer-review


Bradykinin (1 μM) and histamine (100 μM) evoked an initial transient increase and a subsequent sustained increase in intracellular Ca2+concentration ([Ca2+]i) in fura-2-loaded human gingival fibroblasts, which may be attributed to Ca2+release from intracellular stores and Ca2+entry from extracellular sites, respectively. In fibroblasts pretreated with tyrosine kinase inhibitors such as herbimycin A (1 μM) and tyrphostin 47 (20 μM),the sustained level of [Ca2+]iinduced by bradykinin and histamine increased, but not the initial peak level. In the absence of external Ca2+, bradykinin and histamine induced only the transient increase in [Ca2+]i, but a subsequent addition of Ca2+to the medium resulted in a sustained increase in [Ca2+]icaused by Ca2+entry. Thapsigargin, an inhibitor of Ca2+-ATPase in inositol 1,4,5-trisphosphate-sensitive Ca2+stores, mimicked the effect of bradykinin and histamine. In the fibroblasts pretreated with tyrosine kinase inhibitors, the bradykinin-, histamine- and thapsigargin-induced Ca2+entry was clearly enhanced, but not the transient [Ca2+]iincrease. Tyrosine phosphatase inhibitor benzylphosphonic acid (200 μM) had no effect on Ca2+entry or transient [Ca2+]iincrease. These results suggest that tyrosine phosphorylation is involved in Ca2+entry in human gingival fibroblasts.

Original languageEnglish (US)
Pages (from-to)689-693
Number of pages5
JournalCell Biology International
Issue number8
StatePublished - Aug 1 2003


  • Caentry
  • Human gingival fibroblasts
  • Tyrosine kinase inhibitor
  • Tyrosine phosphorylation

ASJC Scopus subject areas

  • Cell Biology


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