Low‐level Laser Therapy Decreased the Number of Ovarian Follicular Cysts in Polycystic Ovaries‐induced Rats

Abstract

Female rats induced to polycystic ovary (PCO) present ovarian alterations in both folliculogenesis and steroidogenesis. There are a reductions in the numbers of follicles and corpora lutea, in addition to the appearance of follicular cysts. Hyperandrogenemia is a consequence of steroidogenic alterations that induce irregular estral cycles and folliculogenesis. Low‐level laser therapy (LLLT) and light‐emitting diode (LEDs) therapy have been investigated and used in clinical practice concernig the biomodulation of cellular functions both in vivo and in vitro. The objective of this study was to analyze the effects of LLLT on the number of ovarian follicular cysts in PCO rats. Forty‐five female adult Wistar rats weighing 250–300 g were divided into control (n = 15), PCO (n = 15) and PCO/laser (n = 15) groups. PCO in the rats was induced by single injection of estradiol valerate (EV) (2 mg/kg/bw, i.m.). After PCO induction, the rats were divided into groups evaluated 30, 45, and 60 days after the injections. The animals were manually contained and irradiated with a laser (wavelength 808 nm, power 60 mW) using a dose of 3 Joules(J)/point for 18 seconds on the dorsal region, performing a transillumination on each ovary 3 times a week, totaling 6 J of energy per irradiated animal/per day of application. After sacrifice, the ovaries were collected for preparation and subsequent analysis of histological slides. The results were reported as means ± SEM. Statistically significant differences among the means for the treatment groups were identified using p<0.05. This study was approved by the local Animal Care and Use Committee (CEUA–UNIARA, protocol n° 019/16). The findings showed that the highest number of follicular cysts (6.33 ± 1.52) occurred in the PCO group 60 days after EV injection, while the lowest number of follicular cysts was observed in the control group (0.33 ± 0.57). The PCO animals submitted to LLLT for 60 days presented fewer (3 ± 1) follicular cysts than the PCO animals, but more follicular cysts than the control animals. The highest number of follicles was observed in the control group after 30 days (8 ± 1), while the lowest number was observed in the PCO group after 60 days (1.66 ± 0.57). The number of follicles found for the 60‐days PCO/laser group (6.66 ± 0.57) was higher than for the PCO group and equal to the control group. It could be concluded that the use of LLLT decreased the number of follicular cysts and increased the number of ovarian follicles in the PCO/laser group, compared to the PCO group, apparently restoring the ovarian folliculogenesis activity.Support or Funding InformationGrant #2016/02811‐4. São Paulo Research Foundation (FAPESP).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.