Localization of angiotensin II receptor subtypes AT1 and AT2 in the pancreas of rodents

1997 ◽  
Vol 153 (2) ◽  
pp. 269-274 ◽  
Author(s):  
P S Leung ◽  
H C Chan ◽  
L X M Fu ◽  
P Y D Wong

Abstract Previous studies have demonstrated the existence of several key components of the renin–angiotensin system in the pancreas. In the present study, the localization of angiotensin II receptor subtypes, type I (AT1) and type II (AT2), in the mouse and the rat pancreas was studied by immunocytochemistry using specific antipeptide antibodies against the second extracellular loops of AT1 and AT2 receptors in conjunction with confocal laser scanning microscopy. In the mouse, immunoreactivity for AT1 and AT2 was observed predominantly in the endothelia of the blood vessels and the epithelia of the pancreatic ductal system. Similar distribution of immunoreactivity for AT1 and AT2 was also observed. However, the intensity of immunoreactivity for AT1 and AT2 was stronger in the rat than that found in the mouse pancreas. Much weaker immunostaining for both AT1 and AT2, as compared with that found in ductal regions, was also found in the acini of the rodent pancreas. Together with the previous findings, the present results suggest that AT1 and/or AT2 receptors may play a role in regulating pancreatic functions in the rodent. Journal of Endocrinology (1997) 153, 269–274

1992 ◽  
Vol 55 (5) ◽  
pp. 563-573 ◽  
Author(s):  
Brian P. Rowe ◽  
David L. Saylor ◽  
Robert C. Speth

Reproduction ◽  
2003 ◽  
pp. 425-435 ◽  
Author(s):  
K Mitsube ◽  
M Mikuni ◽  
M Matousek ◽  
U Zackrisson ◽  
M Brannstrom

The aim of the present study was to examine the roles of the angiotensin II receptor subtypes, AT(1) and AT(2), in ovulation, and to evaluate the contribution of angiotensin II-mediated pathways in regulation of ovarian blood flow. The AT(1)-specific antagonist, losartan, was administered alone or in combination with the AT(2)-specific antagonist, PD123319, to preovulatory rat ovaries perfused in vitro. Losartan (100 micromol l(-1)) did not affect the number of ovulations, whereas the combination of losartan (100 micromol l(-1)) and PD123319 (10 micromol l(-1)) inhibited ovulation. The angiotensin II antagonists did not affect the ovarian production of oestradiol, progesterone, prostaglandin E(2) (PGE(2)), PGF(2 alpha) or plasminogen activator activity. Ovarian nitric oxide production was inhibited by losartan. Ovarian blood flow was measured by laser Doppler flowmetry in vivo in preovulatory rat ovaries. Intrabursal injection of angiotensin II reduced ovarian blood flow of gonadotrophin-stimulated rats. Losartan had no effect on basal ovarian blood flow but completely blocked the angiotensin II-induced reduction. In contrast, treatment with PD123319 increased basal ovarian blood flow and failed to reverse the effect of exogenously administered angiotensin II, indicating that under physiological conditions, ovarian blood flow of the rat is negatively regulated by angiotensin II mainly through the action of AT(2). Taken together, these results indicate that two different types of angiotensin II receptor facilitate ovulation by cooperative mechanisms and that they regulate ovarian blood flow in a different manner.


1997 ◽  
Vol 66 (6) ◽  
pp. 416-425 ◽  
Author(s):  
C. Moreau ◽  
R. Rasolojanahary ◽  
A.J. Zamora ◽  
Alain Enjalbert ◽  
Claude Kordon ◽  
...  

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