Chronic treatment with photobiomodulation decreases blood pressure and improves endothelial function in ovariectomized rats.

Menopause is a natural phase, related to the aging reproductive female, characterized by decreased production of hormones steroids, mainly estrogen, involved in multiple physiological process, including cardiovascular function. This estrogen decline can lead to the development of hypertension, as well as other cardiovascular diseases. Strategies therapeutics complementary he comes winning emphasis as option for management women's insurance at menopause, such as photobiomodulation. Photobiomodulation (PBM) is the application of no invasive low light sources level, normally in the forms of low level lasers therapy (LLLT) or light emitting diodes (LEDs) that present potentials benefits therapeutics in the treatment of inflammation and stress oxidative, favoring angiogenesis, improving function cardiac and remodeling tissue. The objective of this work was to evaluate the in vivo effects of photobiomodularion on cardiovascular parameters in ovariectomy-induced menopause in female rats. Twenty-six 70-day-old female Wistar rats were randomly assigned to three experimental groups: sham (SH), ovariectomized (OVX), and ovariectomized treated with photobiomodulation (OVX + PBM). The ovaries of all animals in the OVX groups were surgically removed at 12 weeks of age. The OVX + PBM group received photobiomodulation treatment with 5.6 Joules per point at six points on the abdominal region, using a power of 100mW at a wavelength of 660 nm, applied twice a week for two weeks. Blood pressure was measured using tail plethysmography, and endothelial function was assessed through vascular reactivity tests. At the end of the treatment period, the mean blood pressure in the OVX + PBM group was significantly lower than in the untreated OVX group. PBM treatment also improved endothelium-dependent vasodilation in aortic rings of OVX rats compared to the untreated OVX group, with no significant difference between the OVX + PBM and Sham groups. In addition, PBM increased serum nitric oxide (NO) levels compared to the OVX group. These results suggest that PBM treatment effectively reduced blood pressure, increased serum NO levels, and reversed endothelial dysfunction in ovariectomized rats.