Losartan ameliorates ovarian ischaemia/reperfusion injury in rats: an experimental study

This study aimed to investigate the protective and antioxidant role of losartan in ovarian ischaemia and ischaemia/reperfusion injury in an experimental ovarian torsion model. Thirty adult female rats were used. Rats were separated randomly into five groups; Group 1: sham group (abdominal wall was only opened and closed), Group 2: torsion group with 3-hour ischaemia using atraumatic vascular clips. Group 3: torsion + losartan group with 3-hour ischaemia 30 minutes after the administration of 40 mg/kg of losartan via oral gavage. Group 4: torsion-detorsion group with 3-hour ischaemia and 3-hour reperfusion (vascular clips were removed). Group 5: torsion-detorsion + losartan group with 3-hour ischaemia followed by administration of 40 mg/kg of losartan 30 minutes prior to a 3-hour detorsion/reperfusion. Ovarian tissue damage was scored by histopathological analysis. Ovarian tissue malondialdehyde (MDA) and plasma pentraxin 3 (PTX 3) levels were measured biochemically. In comparison with the sham group, both the torsion and torsion-detorsion groups had significantly higher scores for follicular degeneration, vascular congestion, oedema, haemorrhage, and leukocyte infiltration (p < .05). The aforementioned parameters significantly decreased in the torsion-detorsion + losartan group (p < .01) compared to those in the torsion-detorsion group. MDA and plasma PTX 3 levels were notably higher both in the torsion and torsion-detorsion groups compared with those in the sham group (p < .01). The current experimental ovarian torsion study suggests a protective role for losartan upon ischaemia and ischaemia/reperfusion injury in rat ovaries. Losartan may be a novel agent for decreasing ovarian ischaemia/reperfusion injury in ovaries.Impact statement What is already known on this subject? Among gynaecological emergencies, the diagnosis of ovarian torsion is highly difficult. A delayed diagnosis may lead to ovarian necrosis and subsequent loss of ovaries if timely surgical intervention is not performed, which is essential for the fertility and protection of ovarian functions in young patients. However, reperfusion of the ischaemic tissue might leads to more serious damage to the tissue than the damage caused by ischaemia. What the results of this study add? This study found that losartan, an Ang II type 1 receptor blocker which has been currently used for regulation of blood pressure, could be used experimentally to alleviate I/R injury in ovary through improving histological parameters, reducing tissue MDA and plasma PTX3 levels. To date, there is no study regarding the usage of losartan for alleviating I/R on ovary due to torsion.