OBJECTIVETo study the effects of low?intensity pulsed ultrasound (LIPUS) in promoting repair of cyclophosphamide (CTX)?induced ovarian injury in female rats.

METHODSFifty female SD rats were subjected to intraperitoneal injection of cyclophosphamide at 30 mg/kg for 5 consecutive days to induce premature ovarian failure. Successful modeling was achieved in 43 rats, which were then randomized into model group (21 rats) and treatment group (22 rats), with another 13 rats without any injections serving as the normal control group. The rats in the treatment group received low?intensity pulsed ultrasound treatment, and those in the other two groups received no interventions. The estrous cycle of the rats was monitored during the experiment, and all the rats were sacrificed 7 days after the treatment for analysis of serum estradiol (E), follicle stimulating hormone (FSH), anti?Mullerian hormone (AMH), morphological changes of the ovary and the number of follicles.

RESULTSCompared with those in the normal control group, the rats in the model group showed disorders in the estrous cycle, reduced number of follicles at all levels, significantly decreased serum Eand AMH, and increased serum FSH following CTX injection (P=0.01). Ultrasound treatment obviously promoted the recovery of estrous cycle, significantly increased the number of follicles and serum E(P=0.01), and decreased FSH (P=0.01) in the rats with CTX?induced ovarian injury, but AMH showed no significant changes after ultrasound treatment (P=0.50).

CONCLUSIONLow?intensity pulsed ultrasound can promote the repair of the CTX?induced ovarian injury in SD rats.