T. Sudo et al., Bradykinin and angiotensin II-induced [Ca2+](i) rise in cultured rat pituitary folliculo-stellate cells, J NEUROENDO, 13(11), 2001, pp. 942-950
Folliculo-stellate cells of the anterior pituitary are thought to modulate
pituitary hormone secretion through a paracrine mechanism. Angiotensin I! a
nd pituitary adenylate cyclase-activating polypeptide (PACAP) have previous
ly been shown to increase the intracellular Ca2+ concentration ([Ca2+](i))
of these cells. In the present study, we examined the effects of various pe
ptides such as bradykinin, angiotensin II, endothelin-1, PACAP, galanin and
neurotensin by Ca2+-imaging of folliculo-stellate cells in primary culture
. Bradykinin and angiotensin II increased [Ca2+](i) in folliculo-stellate c
ells. Both responses were completely suppressed by thapsigargin and were si
gnificantly suppressed by the phospholipase C inhibitor, U-73122. Ryanodine
did not significantly modify the responses. A B-2 antagonist and angiotens
in II receptor antagonist inhibited the response induced by bradykinin and
angiotensin II, respectively. Endothelin-1 and PACAP increased [Ca2+](i) in
fewer than 50% of folliculo-stellate cells but galanin and neurotensin did
not influence [Ca2+](i) in any of the folliculo-stellate cells tested. The
se results indicate that bradykinin and angiotensin II increase [Ca2+](i) i
n folliculo-stellate cells by activating phospholipase C through B2 recepto
r and AT(1) receptor, respectively, and that endothelin-1 and PACAP also in
crease [Ca2+](i) in some folliculo-stellate cells.