In order to develop a medical alternative to surgical ovarian
diathermy (OD) in
polycystic ovary syndrome (PCOS) more mechanistic information is required about OD. We therefore studied the cellular, molecular and vascular effects of
diathermy on the ovary using an established ovine model of PCOS. Pregnant sheep were treated twice weekly with
testosterone propionate (100 mg) from day 30-100 gestation. Their female offspring (n = 12) were studied during their second breeding season when the PCOS-like phenotype, with
anovulation, is fully manifest. In one group (n = 4) one ovary underwent
diathermy and it was collected and compared to the contralateral ovary after 24 hours. In another group a treatment PCOS cohort underwent
diathermy (n = 4) and the ovaries were collected and compared to the control PCOS cohort (n = 4) after 5 weeks. Ovarian vascular indices were measured using contrast-enhanced ultrasound and colour Doppler before, immediately after, 24 hours and five weeks after
diathermy.
Antral follicles were assessed by immunohistochemistry and ovarian stromal gene expression by quantitative RT-PCR 24 hours and 5 weeks after
diathermy.
Diathermy increased follicular atresia (P<0.05) and reduced
antral follicle numbers after 5 weeks (P<0.05). There was an increase in stromal CCL2 expression 24 hours after
diathermy (P<0.01) but no alteration in inflammatory indices at 5 weeks. Immediately after
diathermy there was increased
microbubble transit time in the ovarian microvasculature (P = 0.05) but this was not seen at 24 hours. However 24 hours after
diathermy there was a reduction in the stromal Doppler blood flow signal (P<0.05) and an increased ovarian resistance index (P<0.05) both of which persisted at 5 weeks (P<0.01; P<0.05). In the ovine model of PCOS, OD causes a sustained reduction in ovarian stromal blood flow with an increased ovarian artery resistance index associated with atresia of
antral follicles.