Pituitary adenylate cyclase activating polypeptide (PACAP) increases cytosolic-free calcium concentration in folliculo-stellate cells and somatotropes of rat pituitary

Toshihiko Yada, Sandor Vigh, Akira Arimura

Research output: Contribution to journalArticle

54 Citations (Scopus)

Abstract

Pituitary adenylate cyclase activating polypeptide (PACAP) is a new member of the secretin/VIP peptide family. In order to identify pituitary target cells for PACAP, we examined the effect of PACAP on the cytosolic-free Ca2+ concentrations, [Ca2+]i, in cells using Fura-2 and a digital imaging system. In a concentration-dependent manner, PACAP increased [Ca2+]i in pituitary cells, from 10-11 to 10-8 M. Some cells responded to PACAP at 10-11 M, while others only at 10-8 M, showing a diversity among cells in the sensitivity to PACAP. Both PACAP and growth hormone-releasing factor (GRF) at 10-8 M increased [Ca2+]i in 25% and 33% of the total pituitary cells, respectively. About 38% of the GRF-responsive cells also responded to PACAP. Some of the cells that responded to PACAP were immunocytochemically identified as growth hormone (GH) cells or folliculo-stellate (FS) cells using antisera against GH or S-100 protein, respectively. The results indicate that both the folliculo-stellate cells and GH cells of the pituitary are the direct targets for PACAP, but the possibility that other cell types also respond to PACAP cannot be excluded.

Original languageEnglish
Pages (from-to)235-239
Number of pages5
JournalPeptides
Volume14
Issue number2
DOIs
Publication statusPublished - Jan 1 1993

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Keywords

  • Calcium
  • Folliculo-stellate cells
  • Fura-2
  • Immunocytochemistry
  • PACAP
  • Rat pituitary
  • Somatotropes

ASJC Scopus subject areas

  • Biochemistry
  • Physiology
  • Endocrinology
  • Cellular and Molecular Neuroscience

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