ABSTRACT
The main purpose of this work was to construct an energy-dependent response curve of photobiomodulation on arterial pressure in hypertension animal model. To reach this objective, we have used a two-kidney one clip (2K-1C) rat model. Animals received acute laser light irradiation (660 nm) on abdominal region using different energy (0.6, 1.8, 3.6, 7.2, 13.8, 28.2, 55.8, and 111.6 J), the direct arterial pressure was measured by femoral cannulation, and systolic arterial pressure (SAP), diastolic arterial pressure (DAP), heart rate (HR), and time of effect were obtained. Our results indicated that 660 nm laser light presents an energy-dependent hypotensive effect, and 28.2 J energy irradiation reached the maximum hypotensive effect, inducing a decreased SAP, DAP, and HR (decrease in SAP: - 19.23 ± 1.82 mmHg, n = 11; DAP: - 9.57 ± 2.23 mmHg, n = 11; HR: - 39.15 ± 5.10 bpm, n = 11; and time of hypotensive effect: 3068.00 ± 719.00 s, n = 11). The higher energy irradiation evaluated (111.6 J) did not induce a hypotensive effect and induced an increase in HR (21.69 ± 7.89 bpm, n = 7). Taken together, our results indicate that red laser energy irradiation from 7.2 to 55.8 J is the effective therapeutic window to reduce SAP, DAP, MAP, and HR and induce a long-lasting hypotensive effect in rats, with effect loss at higher energy irradiation (111.6 J).
Subject(s)
Blood Pressure , Hypertension/physiopathology , Hypertension/radiotherapy , Low-Level Light Therapy , Animals , Blood Pressure/drug effects , Blood Pressure/physiology , Diastole/physiology , Heart Rate , Hypotension/physiopathology , Male , Rats, Wistar , Systole/physiologyABSTRACT
The purpose of this study was to evaluate the acute effect of photobiomodulation therapy (PBM) on arterial pressure in hypertensive and normotensive rats with application in an abdominal region. Normotensive (2K) and hypertensive (2K-1C) wistar rats were treated with PBM. Systolic arterial pressure (SAP), diastolic arterial pressure (DAP), mean arterial pressure (MAP) and heart rate (HR) were measured before, during and after PBM application. The nitric oxide (NO) serum concentration was measured before and after PBM application. Vascular reactivity study was performed in isolated thoracic aortas. Aluminum gallium arsenide (GaAlAs) diode laser was used, at 660nm wavelength and 100mW optical output. The PBM application induced a decrease of SAP in 2K-1C rats. In 2K rats, the PBM application had no effect on SAP, DAP and MAP. Moreover, the magnitude of hypotensive effect was higher in 2K-1C than in 2K rats. The PBM application induced a decrease of HR in 2K-1C and 2K, with higher effect in 2K-1C rats. In 2K-1C, the hypotensive effect induced by PBM was longer than that obtained in 2K rats. PBM application induced an elevation of NO concentration in serum from 2K-1C and 2K rats, with higher effect in 2K-1C. In isolated aortic rings PBM effect is dependent of NO release, and is not dependent of nitric oxide synthase (NOS) activation. Our results indicate that the abdominal acute application of PBM at 660nm is able to induce a long lasting hypotensive effect in hypertensive rats and vasodilation by a NO dependent mechanism.
Subject(s)
Arterial Pressure/radiation effects , Hypertension/radiotherapy , Lasers, Semiconductor/therapeutic use , Low-Level Light Therapy/methods , Nitric Oxide/blood , Animals , Aorta, Thoracic/metabolism , Aorta, Thoracic/radiation effects , Disease Models, Animal , Heart Rate/radiation effects , Hypertension/physiopathology , Male , Nitric Oxide Synthase/metabolism , Rats , Rats, Wistar , Time Factors , Vasodilation/radiation effectsABSTRACT
Sabe-se que o sedentarismo, associado a uma dieta nao balanceada tem grande importancia para o desenvolvimento de doencas cronico degenerativas. Por outro lado, o exercicio fisico tem sido um meio utilizado para o controle dessas doencas. Entretanto, pouco foi relatado sobre efeitos do exercicio de final de semana nocontrole das dislipidemias. Assim, o objetivo deste estudo foi observar respostas adaptativas ao exercicio de final de semana sobre o metabolismo das lipoproteinas em ratos machos alimentados com dieta hiperlipidica. Foram divididos em grupos 96 ratos machos adultos: dieta normocalorica (N) e hipercalorica (H), sedentario (S), treinado continuo (TC) e treinado de fim de semana (TFS), 5 e 2 sessoes semanais/90minutos/dia, respectivamente, por natacao. Durante todo o periodo experimental foram controlados: o peso e o consumo alimentar em gramas. Foram coletados, pesados e congelados o plasma (P), os tecidos adiposos barncos retropeitoneal (RET) e epididimal (EPI), tecido adiposo marron (TAM), musculo gastrocnemio (GAST), figado (FIG) e coracao (COR), para posteriores analises. Foram considerados significativos os valores de p<-0,05 a partir da analise de variancia `Anova Tree Way`. O treinamento de final de semana promoveu diminuicao significativa nos triglicerideos plasmaticos em animais hipercaloricos (SH 180,7+-13,9 vs TFSH97,2+-8,3). Os dois tipos de treinamento foram importantes no controle das dislipidemias em ratos alimentados com dieta hipercalorica, sendo observado aumento na concentracao de HDL colesterol em relacao aos respectivos animais sedentarios (SH 26,5+-2,0 vs TCH 35,7+-6,2 e TFSH 37,1+-1,2)
