Influence of the HPA axis on the inflammatory response in cutaneous wounds with the use of 670-nm laser photobiomodulation

• Published in: Journal of photochemistry and photobiology. B, Biology Vol. 116; pp. 114 - 120
• Main Authors: Vilela, Deyla Duarte Carneiro, Chamusca, Flávia Villela, Andrade, Jorge Clarêncio Souza, Vallve, Maria Lourdes Farre, Gonzalez, Ana Cristina, Andrade, Zilton de Araújo, Medrado, Alena Ribeiro Alves Peixoto, Reis, Sílvia Regina de Almeida
• Format: Journal Article
• Language: English
• Published: Switzerland Elsevier B.V 05-11-2012
• Subjects: Adrenal Glands - physiopathology; Adrenal Glands - surgery; Adrenalectomy - adverse effects; Animals; CD4; CD4-Positive T-Lymphocytes - cytology; CD4-Positive T-Lymphocytes - immunology; CD45; CD8; CD8-Positive T-Lymphocytes - cytology; CD8-Positive T-Lymphocytes - immunology; Hypothalamo-Hypophyseal System - physiopathology; Inflammation - blood; Inflammation - immunology; Inflammation - physiopathology; Inflammation - surgery; Laser Therapy; Low-intensity laser therapy; Male; Rats; Rats, Wistar; Skin - immunology; Skin - injuries; Skin - physiopathology; T lymphocytes; T lymphocytes; CD4; CD45; CD8; Low-intensity laser therapy
• ISSN: 1011-1344; 1873-2682
• DOI: 10.1016/j.jphotobiol.2012.05.018

► Laser and tissue repair.
This study evaluated the influence of hypothalamic–pituitary–adrenal (HPA) axis in cutaneous wounds subjected to laser biomodulation. A total of 48 rats were divided into two groups: Group I (GI) with 24 adrenalectomized animals and Group II (GII) with 24 non-adrenalectomized animals. Each group was divided into two subgroups: the irradiated subgroup which laser was applied to four points at the edges of the wound (670nm laser, 9mW) and control subgroup. Rats in each subgroup were sacrificed at 24 or 72h. Adrenal glands were only removed from GI rats. Three days after adrenalectomy, a cutaneous wound was made. An immunohistochemical analysis was performed using anti-CD45 and anti-CD8 antibodies. Flow cytometry was used to count T lymphocytes and their subpopulations in blood. Decreases in the number of CD45-positive inflammatory cells and in the total numbers of CD8- and CD45-positive cells were observed in histological sections of adrenalectomized animals subjected to laser biomodulation at 24h. Similar results were observed for distribution of total lymphocytes in blood (p<0.05). The action of 670nm laser does not depend exclusively on HPA axis. It is believed that corticosteroid-promoting enzymes liberated in non-adrenal tissues may influence immune response under the influence of this type of phototherapy.