|
|
||||||||
Instituto de Biología y Medicina Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas V, Obligado 2490, (1428) Buenos Aires, Argentina
We evaluated the effects of angiotensin II (ANG
II) and its antagonists on prolactin release, intracellular calcium
([Ca2+]i)
mobilization, and
[3H]thymidine uptake
in cells from normal rat pituitaries and from estrogen-induced
pituitary tumors. ANG II
(10
7 to
10
9 M) increased prolactin
release significantly in control and not in tumoral cells. In control
cells, ANG II (10
6 to
10
9 M) produced an
immediate spike of
[Ca2+]i
followed by a plateau. Spike levels rose significantly between 10
10 and
10
8 M ANG II, whereas the
onset of the spike was retarded with decreasing concentrations. In
tumoral cells, ANG II did not produce a spike phase even at
10
6 M. ANG II-induced
prolactin release and calcium mobilization were blocked by losartan
(AT1 receptor antagonist) and not
by PD-123319 (AT2 antagonist).
Finally, [3H]thymidine
uptake was not modified by ANG II
(10
7 to
10
10 M) or its antagonists
in either group. Our results suggest that chronic in vivo estrogenic
treatment alters in vitro pituitary response to ANG II. Alterations
might function to limit excessive prolactin secretion of hypersecreting
tumors. Besides, ANG II does not modify DNA synthesis in vitro of cells
from normal or tumor-derived hypophyses.
calcium; estrogen
This article has been cited by other articles:
![]() |
J. Vela, M. I. Perez-Millan, D. Becu-Villalobos, and G. Diaz-Torga Different kinases regulate activation of voltage-dependent calcium channels by depolarization in GH3 cells Am J Physiol Cell Physiol, September 1, 2007; 293(3): C951 - C959. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Paul, A. Poyan Mehr, and R. Kreutz Physiology of local Renin-Angiotensin systems. Physiol Rev, July 1, 2006; 86(3): 747 - 803. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Suarez, G. Diaz-Torga, A. Gonzalez-Iglesias, C. Cristina, and D. Becu-Villalobos Upregulation of angiotensin II type 2 receptor expression in estrogen-induced pituitary hyperplasia Am J Physiol Endocrinol Metab, May 1, 2004; 286(5): E786 - E794. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Suarez, G. Diaz-Torga, A. Gonzalez-Iglesias, J. Vela, A. Mladovan, A. Baldi, and D. Becu-Villalobos Angiotensin II phosphorylation of extracellular signal-regulated kinases in rat anterior pituitary cells Am J Physiol Endocrinol Metab, September 1, 2003; 285(3): E645 - E653. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. de Gasparo, K. J. Catt, T. Inagami, J. W. Wright, and Th. Unger International Union of Pharmacology. XXIII. The Angiotensin II Receptors Pharmacol. Rev., September 1, 2000; 52(3): 415 - 472. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. G. Iglesias, G. Diaz-Torga, V. Lux-Lantos, C. Libertun, and D. Becu-Villalobos Calcium influx and intracellular stores in angiotensin II stimulation of normal and hyperplastic pituitary cells Am J Physiol Endocrinol Metab, September 1, 1999; 277(3): E455 - E463. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |