Biochemical Properties of the Ovarian Granulosa Cell Type 2-Angiotensin II Receptor

Angiotensin II (Ang II) receptors, estimated by the specific binding of the peptide Ang II receptor antagonist [125I][Sar1,Ile8]Ang II, are localized on multiple ovarian structures, including follicular granulosa cells. Using the Ang II receptor subtype-selective nonpeptide antagonists, DuP 753 [selective for the type 1 Ang II (AT1) receptor] and PD 123319 [selective for the type 2 Ang II (AT2) receptor], we show that follicular granulosa cells, in vivo and in vitro, exclusively express the AT2 receptor. To understand the function of Ang II in ovarian follicles, we compared the biochemical properties and transmembrane signaling pathways of the granulosa cell AT2 receptor with those properties generally associated with Ang II receptors found in the adrenal zona glomerulosa, where the AT1receptor predominates. The mol wt of the granulosa cell AT2 receptor (-79,000), estimated by affinity cross-linking studies, is similar to that of the adrenal zona glomerulosa Ang II receptor. Like the adrenal zona glomerul...