LLLT at 670 nm positively influences all phases of rat skin wound healing.

ABSTRACT:The use of a simple and reproducible model is inevitable for objective statement of the effects of external factors on wound healing. Hence, present study was conducted to establish an excisional model of skin wound healing in corticosteroid treated, and streptozotocine induced diabetic rats as well as to standardized the semi-quantitative and quantitative evaluation of selected parameters. Round full thickness skin wounds were performed on the back of male Sprague-Dawley rats. Animals were sacrificed two, six, and fourteen days after surgery. Sections were stained with hematoxylin-eosin and van Gieson. Both semi-quantitative (wound reepithelization; presence of: inflammatory cells, fibroblasts, new wessels, and collagen) and quantitative methods (polymorphonuclear leucocytes/tissue macrophages ratio, percentage of re-epithelization, area of the granulation tissue) were used to evaluate the histological changes during wound healing. As compared to the control group the wound healing process of both experimental groups was decelerated. Interestingly, wound reepithelization and angiogenesis were significantly inhibited only in the steroid rats while epithelization was accelerated in diabetic rats. In conclusion, when compared to primary sutured wound healing it can be concluded that the excisional model is more appropriate for histological assessment of the effect of various factors on wound healing. In addition, administration of corticosteroids represents simple and inexpensive model of a complex skin wound healing impairment.

The aim of this study was to investigate the effect of a high‐fat (HF)/energy diet on the intestinal microbiota, the alkaline phosphatase (AP) activity, and related parameters of growth and obesity during the suckling and weaning periods in male Sprague‐Dawley rats. From birth, nutrition in suckling pups was manipulated by feeding rat dams either HF or a standard diet, and then after weaning, by exposure of experimental pups to the HF, and control rats to normal diet. On days 15, 20, 40 the numbers of 2 microbial groups, i.e., Bacteroides/Prevotella (BAC) and the Lactobacillus/Enterococcus (LAB) in the jejunum, were determined by fluorescent in situ hybridization technique, and the AP activity was assayed histochemically. During all investigated periods HF pups gained body fat more rapidly than control animals, but from weaning they displayed significantly stunted growth resulting in final body weight loss. Obesity in HF rats was also accompanied by higher LAB and lower numbers of BAC and with permanently higher AP activity. Correlation of these data showed significant negative correlation between LAB, AP, and weight gain and energy efficiency, and significant positive correlation of BAC and AP activity with body fat. These data support the concept that postnatal nutritional experience represents an important factor affecting the ontogeny of intestinal microbial communities and intestinal function. These acquired changes could be a component of regulatory mechanisms involved in adverse and/or positive consequences of HF diet for adiposity, body weight, and energy‐balance control in later life.