Low-Level Laser Therapy Attenuates LPS-Induced Rats Mastitis by Inhibiting Polymorphonuclear Neutrophil Adhesion

• DOI: 10.1292/jvms.14-0061
• Publication Date: 2014-08-21T23:54:08Z
• Authors: Yueqiang WANG; Xianjing HE; Dandan HAO; Debin YU; Jianbin LIANG; Yanpeng QU; Dongbo SUN; Bin YANG; Keli YANG; Rui WU; Jianfa WANG
• Keywords: Lipopolysaccharides; 0301 basic medicine; Analysis of Variance; CD11b Antigen; Neutrophils; Immunology; Interleukin-1beta; Interleukin-8; Enzyme-Linked Immunosorbent Assay; Mastitis; Flow Cytometry; Intercellular Adhesion Molecule-1; Rats; 3. Good health; Platelet Endothelial Cell Adhesion Molecule-1; 03 medical and health sciences; Gene Expression Regulation; Animals; Female; L-Selectin; Low-Level Light Therapy; Rats, Wistar; DNA Primers

The aim of this study was to investigate the effects of low-level laser therapy (LLLT) on a rat model of lipopolysaccharide (LPS)-induced mastitis and its underlying molecular mechanisms. The rat model of mastitis was induced by inoculation of LPS through the canals of the mammary gland. The results showed that LPS-induced secretion of IL-1β and IL-8 significantly decreased after LLLT (650 nm, 2.5 mW, 30 mW/cm(2)). LLLT also inhibited intercellular adhesion molecule-1 (ICAM-1) expression and attenuated the LPS-induced decrease of the expression of CD62L and increase of the expression of CD11b. Moreover, LLLT also suppressed LPS-induced polymorphonuclear neutrophils (PMNs) entering the alveoli of the mammary gland. The number of PMNs in the mammary alveolus and the myeloperoxidase (MPO) activity were decreased after LLLT. These results suggested that LLLT therapy is beneficial in decreasing the somatic cell count and improving milk nutritional quality in cows with an intramammary infection.