angiotensin-i and Polycystic-Ovary-Syndrome

Hyperandrogenism is a pivotal mediator in the pathogenesis of the polycystic ovary syndrome (PCOS), but the mechanisms of androgen excess in this condition are not fully understood. Angiotensin (Ang)-(1-7) is an active peptide of the renin-angiotensin system (RAS) that stimulates ovarian follicular growth and testosterone release in vitro.. To investigate whether Ang-(1-7), its receptor Mas and angiotensin-converting enzyme 2 (ACE2), the enzyme that converts Ang II into Ang-(1-7), are expressed in rat polycystic ovaries (PCO) and thus if this peptide system might be associated with excess androgen production in PCO.. A rat model that shares some features of PCOS such as disruption of folliculogenesis and multiple ovarian cyst formation was used in the study.. We found reduced levels of Ang-(1-7) and Mas receptor in PCO compared to normal ovaries. Also, ACE2 mRNA expression was reduced in PCO compared to ovaries of control rats (p < 0.05). PCO had high levels of estrogen and testosterone and increased mRNA for upstream enzymes of the steroidogenic cascade, but not of P450 aromatase.. These findings suggest that the ovarian ACE2-Ang-(1-7)-Mas receptor axis is inhibited and therefore may not be a co-factor of excess testosterone production in rat PCO.

Topics: Angiotensin I; Angiotensin-Converting Enzyme 2; Animals; Female; Peptide Fragments; Polycystic Ovary Syndrome; Proto-Oncogene Mas; Proto-Oncogene Proteins; Rats; Rats, Wistar; Receptors, G-Protein-Coupled; Signal Transduction

To explore the expression of renin-angiotensin system component (ACE-AngII-AT1/AT2 & ACE2-Ang-(1-7)-Mas) in endometrium of polycystic ovary syndrome (PCOS) patients and normal controls.. Thirty cases of normal endometrium in proliferative and secretory phases respectively were selected for the protein levels of AngII, AT1, AT2, ACE2, Ang-(1-7) and Mas through immunohistochemistry. And the specimens of proliferative endometrium from 15 PCOS patients and 15 normal controls respectively were prepared for the expressions of AT1, AT2, ACE2 and Mas mRNA through relative quantitative -polymerase chain reaction (RQ-PCR). The histological phases of endometria were confirmed by hematoxylin & eosin staining under microscope.. The expressions of AngII, AT1R, AT2R, ACE2, Ang-(1-7) and Mas showed periodical changes in endometrium throughout normal menstrual cycles and shared a similar trend. The expression was more pronounced in epithelial cells than that in stromal cells while it was also more dramatic in secretory phase than proliferative phase; The mRNA expressions of AT1, AT2, ACE2 and MAS were higher in PCOS endometrium than those in normal controls. Statistically significant differences existed between two groups (P < 0.01).. There is local existence of RAS in endometrium; Increased expressions of AT1 mRNA, AT2 mRNA, ACE2 mRNA and Mas mRNA in endometrium of PCOS may influence endometrial development and play a role in the pathological process of PCOS.

Topics: Adult; Angiotensin I; Angiotensin II; Angiotensin-Converting Enzyme 2; Case-Control Studies; Endometrium; Female; Humans; Peptide Fragments; Peptidyl-Dipeptidase A; Polycystic Ovary Syndrome; Proto-Oncogene Mas; Proto-Oncogene Proteins; Receptors, Angiotensin; Receptors, G-Protein-Coupled; Renin-Angiotensin System; Young Adult

Significantly higher values of systolic and diastolic arterial blood pressure as compared to the corresponding control group was found in a group of 31 patients with polycystic ovary syndrome (PCO) of age between 22 and 42 years (mean 34 years). It was demonstrated that the activity of the enzyme converting angiotensin I to angiotensin II (angiotensin converting enzyme, ACE) as determined by the spectrofluorometric method of Friedland and Silverstein did not differ significantly from that found in the control group. No significant correlation was also found between the ACE activity and the concentrations of testosterone, androstenedione, dehydroepiandrosterone, LH, FSH, prolactin and estradiol both in the patients and in the control group.

Topics: Adult; Angiotensin I; Angiotensin II; Blood Pressure; Female; Hormones; Humans; Peptidyl-Dipeptidase A; Polycystic Ovary Syndrome; Spectrometry, Fluorescence