Abstract: | Systemic arterial hypertension (SAH) is considered to be the greatest risk factor for
the development of neuro-cardiovascular pathologies, thus constituting a severe
Public Health issue in the world.The Low-Level Laser Therapy (LLLT), or laser therapy, activates components of the
cellular structure, therefore converting luminous energy into photochemical energy
and leading to biophysical and biochemical reactions in the mitochondrial respiratory
chain. The LLLT promotes cellular and tissue photobiomodulation by means of changes
in metabolism, leading to molecular, cellular and systemic changes.The objective of this study was to analyze the action of low-level laser in the
hemodynamic modulation of spontaneously hypertensive rats, in the long term. Animals
(n = 16) were randomly divided into the Laser Group (n = 8), which received three
weekly LLLT irradiations for seven weeks, and into the Sham Group (n = 8), which
received three weekly simulations of laser for seven weeks, accounting for 21
applications in each group. After seven weeks, animals were cannulated by the
implantation of a catheter in the left carotid artery. On the following day, the
systemic arterial pressure was recorded. The Laser Group showed reduced levels of
mean blood pressure, with statistically significant reduction (169 ± 4 mmHg*
vs. 182 ± 4 mmHg from the Sham Group) and reduced levels of diastolic pressure
(143 ± 4 mmHg* vs. 157 ± 3 mmHg from the Sham Group), revealing a 13
and 14 mmHg decrease, respectively. Besides, there was a concomitant important
decline in heart rate (312 ± 14 bpm vs. 361 ± 13 bpm from the Sham
Group). Therefore, laser therapy was able to produce hemodynamic changes, thus
reducing pressure levels in spontaneously hypertensive rats. |