In:
American Journal of Physiology-Endocrinology and Metabolism, American Physiological Society, Vol. 276, No. 1 ( 1999-01-01), p. E25-E33
Abstract:
Type 1 angiotensin II (ANG II) receptors play crucial roles in the regulation of blood pressure and fluid osmolarity, whereas the physiological roles of type 2 ANG II receptors (AT 2 ) remain unclear. Because AT 2 is expressed in atretic follicles where granulosa cells undergo apoptosis, we examined the space and time relationship between AT 2 expression and follicle atresia in vivo and the effect of AT 2 on follicle-stimulating hormone (FSH) actions in vitro. Binding studies, autoradiography, and RT-PCR of AT 2 revealed that the AT 2 content in granulosa cells was time dependently increased at both protein and mRNA levels in equine chorionic gonadotropin-treated immature female rats. This increase paralleled the progression of atresia. ANG II suppressed FSH-caused prevention of DNA fragmentation, increases in luteinizing hormone receptor content, and estrogen production through AT 2 in cultured granulosa cells. Moreover, FSH-induced stimulation of extracellular signal-regulated kinase activity, critical for cell survival, was inhibited by AT 2 stimulation. These results suggest that AT 2 mediates the progression of follicle atresia through granulosa cell apoptosis by inhibiting FSH actions.
Type of Medium:
Online Resource
ISSN:
0193-1849
,
1522-1555
DOI:
10.1152/ajpendo.1999.276.1.E25
Language:
English
Publisher:
American Physiological Society
Publication Date:
1999
detail.hit.zdb_id:
1477331-4
SSG:
12
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