caa a22 4500 469081643 CHVBK 20180323132952.0 cr unu---uuuuu 170328e19920401xx s 000 0 eng 10.1007/BF00338068 doi (NATIONALLICENCE)springer-10.1007/BF00338068 In-vitro effects of angiotensin II on steroid production by hamster ovarian follicles and on ultrastructure of the theca interna [Elektronische Daten] [Patrick Kitzman, Reinhold Hutz] Summary: Angiotensin II (AII) is present in the mammalian ovary and has been correlated with atresia in follicles. Since the theca interna may be one site at which atresia is intiated, we wished to determine whether AII exerts an effect on theca interna from explanted ovarian follicles of hamsters. Hamsters were sacrified on the morning of proestrus, and ovaries were removed. Preovulatory follicles were excised from the ovaries, and cultured with one of the following components: medium alone (control); medium plus AII (1x10-6 M); the AII-receptor antagonist [Sar1, Ile8] AII (1x10-4 M); or AII plus antagonist. After 72 h, the follicles were processed for transmission electron microscopy (to determine quantities of theca interna organelles involved in the steroid synthetic pathway) or for protein determination (to normalize steroid production rates). The incubation medium was drawn off and analyzed by radioimmunoassay for progesterone, androstenedione, or estradiol-17β. There was a significant positive correlation (r=0.92, P<0.01) between follicular androstenedione secretion and area comprising theca interna smooth endoplasmic reticulum. In the theca interna, AII induced a two-fold and 1.6-fold increase in lipid droplet number and area comprising smooth endoplasmic reticulum, respectively (P<0.05). Excess antagonist negated the increase in cell or-ganelles and also reduced androstenedione secretion compared with AII alone (P<0.05). Most importantly, AII significantly augmented the ratio of androstenedione: estradiol-17β secretion by 44% over that of control. The ultrastructural changes observed in this study and the increase in the andostenedione: estradiol-17β production ratio are consistent with atresia-like changes in ovarian follicles. We believe, therefore, that AII is involved, possibly at its membrane receptor, in an aspect of the overall process of follicular atresia, operating in part at the level of the theca interna. Springer-Verlag, 1992 Angiotensin II nationallicence Ovarian follicles nationallicence Theca interna nationallicence Ultrastructure nationallicence Steroidogenesis nationallicence Atresia nationallicence Golden hamster (Rodentia) nationallicence Kitzman Patrick Deparment of Cell Biology, Neurobiology, and Anatomy, The Ohio State University, Graves Hall, 43210-1239, Columbus, OH, USA aut Hutz Reinhold Department of Biological Sciences, University of Wisconsin-Milwaukee, 53201-0413, Milwaukee, WI, USA aut Cell and Tissue Research Springer-Verlag 268/1(1992-04-01), 191-196 0302-766X 268:1<191 1992 268 441 https://doi.org/10.1007/BF00338068 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00338068 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Kitzman Patrick Deparment of Cell Biology, Neurobiology, and Anatomy, The Ohio State University, Graves Hall, 43210-1239, Columbus, OH, USA aut NATIONALLICENCE 700 1- Hutz Reinhold Department of Biological Sciences, University of Wisconsin-Milwaukee, 53201-0413, Milwaukee, WI, USA aut NATIONALLICENCE 773 0- Cell and Tissue Research Springer-Verlag 268/1(1992-04-01), 191-196 0302-766X 268:1<191 1992 268 441 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer