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Bradykinin and Angiotensin II‐Induced [Ca 2+ ] i Rise in Cultured Rat Pituitary Folliculo‐Stellate Cells
Author(s) -
Sudo T.,
Sakuma Y.,
Kato M.
Publication year - 2001
Publication title -
journal of neuroendocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.062
H-Index - 116
eISSN - 1365-2826
pISSN - 0953-8194
DOI - 10.1046/j.1365-2826.2001.00699.x
Subject(s) - hepatic stellate cell , medicine , angiotensin ii , endocrinology , bradykinin , neurotensin , chemistry , bradykinin receptor , biology , receptor , neuropeptide
Folliculo‐stellate cells of the anterior pituitary are thought to modulate pituitary hormone secretion through a paracrine mechanism. Angiotensin II and pituitary adenylate cyclase‐activating polypeptide (PACAP) have previously been shown to increase the intracellular Ca 2+ concentration ([Ca 2+ ] i ) of these cells. In the present study, we examined the effects of various peptides such as bradykinin, angiotensin II, endothelin‐1, PACAP, galanin and neurotensin by Ca 2+ ‐imaging of folliculo‐stellate cells in primary culture. Bradykinin and angiotensin II increased [Ca 2+ ] i in folliculo‐stellate cells. Both responses were completely suppressed by thapsigargin and were significantly suppressed by the phospholipase C inhibitor, U‐73122. Ryanodine did not significantly modify the responses. A B 2 antagonist and angiotensin II receptor antagonist inhibited the response induced by bradykinin and angiotensin II, respectively. Endothelin‐1 and PACAP increased [Ca 2+ ] i in fewer than 50% of folliculo‐stellate cells but galanin and neurotensin did not influence [Ca 2+ ] i in any of the folliculo‐stellate cells tested. These results indicate that bradykinin and angiotensin II increase [Ca 2+ ] i in folliculo‐stellate cells by activating phospholipase C through B 2 receptor and AT 1 receptor, respectively, and that endothelin‐1 and PACAP also increase [Ca 2+ ] i in some folliculo‐stellate cells.