Research

Rats with steroid-induced polycystic ovaries develop hypertension and increased sympathetic nervous system activity

Elisabet Stener-Victorin^1,2,3 , Karolina Ploj¹ , Britt-Mari Larsson¹ and Agneta Holmäng¹

¹  Cardiovascular Institute and Wallenberg Laboratory, Sahlgrenska Academy, Göteborg University, SE-413 45 Göteborg, Sweden

²  Department of Obstetrics and Gynaecology, Sahlgrenska University Hospital, Sahlgrenska, SE-413 45 Göteborg, Sweden

³  Institute of Occupational Therapy and Physical Therapy, Sahlgrenska Academy, Göteborg University, SE-405 30 Göteborg, Sweden

author email corresponding author email

Reproductive Biology and Endocrinology 2005, 3:44doi:10.1186/1477-7827-3-44

Published:	7 September 2005

Abstract

Background

Polycystic ovary syndrome (PCOS) is a complex endocrine and metabolic disorder associated with ovulatory dysfunction, abdominal obesity, hyperandrogenism, hypertension, and insulin resistance.

Methods

Our objectives in this study were (1) to estimate sympathetic-adrenal medullary (SAM) activity by measuring mean systolic blood pressure (MSAP) in rats with estradiol valerate (EV)-induced PCO; (2) to estimate alpha_1a and alpha_2a adrenoceptor expression in a brain area thought to mediate central effects on MSAP regulation and in the adrenal medulla; (3) to assess hypothalamic-pituitary-adrenal (HPA) axis regulation by measuring adrenocorticotropic hormone (ACTH) and corticosterone (CORT) levels in response to novel-environment stress; and (4) to measure abdominal obesity, sex steroids, and insulin sensitivity.

Results

The PCO rats had significantly higher MSAP than controls, higher levels of alpha_1a adrenoceptor mRNA in the hypothalamic paraventricular nucleus (PVN), and lower levels of alpha_2a adrenoceptor mRNA in the PVN and adrenal medulla. After exposure to stress, PCO rats had higher ACTH and CORT levels. Plasma testosterone concentrations were lower in PCO rats, and no differences in insulin sensitivity or in the weight of intraabdominal fat depots were found.

Conclusion

Thus, rats with EV-induced PCO develop hypertension and increased sympathetic and HPA-axis activity without reduced insulin sensitivity, obesity, or hyperandrogenism. These findings may have implications for mechanisms underlying hypertension in PCOS.