Endocrine Abstracts

We have shown that repeated cold stress increases ovarian sympathetic tonus and induces typical polycystic ovary syndrome (PCOS) features. Lesion of the noradrenergic nucleus Locus Coeruleus decreases ovarian noradrenaline release and prevents stress-induced PCOS in rats exposed to chronic intermittent cold stress. The aim of this study was to assess whether the alterations on ovarian morphology, ovulation rate and hormonal secretion induced by cold stress could be prevented by the beta-adrenergic blocker propranolol. Female rats were exposed to repeated sessions of cold stress (4°C/3 h per day from monday to friday), during 4 weeks. The rats had free access to water (S groups) or water with propranolol (4 mg/kg; SP group). Then after, the animals were kept at room temperature for four additional weeks with free access to water. Unstressed animals were maintained at room temperature for 8 weeks with free access to water (US group) or water+propranolol in the first 4 weeks (US+P group). Rats were decapitated, trunk blood was collected for hormone measurements, the oviducts removed to assess the number of oocytes, and ovaries for histological analysis. In S group there was a decreased number of healthy preantral and antral follicles, an increased number of atretic preantral and antral follicles, pre-cystic and cystic follicles and follicles with hyperthecosis compared to US rats. The number of oocytes was reduced and estradiol and DHEA plasma levels were higher than in unstressed rats. Propranolol treatment per se did not alter the parameters evaluated in the US+P group but prevented the majority of alterations in the SP group. The number of all disarranged structures, oocytes and DHEA levels in propranolol treated rats were similar to the US rats. Therefore, blocking ovarian beta-adrenergic receptor was shown to be a good tool to prevent the onset of PCOS induced by sympathetic hyperactivation.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This work was supported, however funding details unavailable.