An improvement in acute wound healing in rats by the synergistic effect of photobiomodulation and arginine / 한국실험동물학회지

In this probe, at first we examined the best route and dosage of arginine administration on wound healing in an excisional wound model in rats. Next, we intend to assess the impact of photobiomodulation (PBM) and arginine, individually and together, on the wound healing. In the pilot study, an excisional wound was made in each of 24 rats. There were 4 groups. Group 1 was the control group. In groups 2 and 3, wounds were topically treated with arginine ointments (ARG.) 2% and 5%, respectively. In group 4, arginine was injected (ARG. INJ.,i.p.). In the main phase, in 24 new rats, an excisional wound was made. There were 4 groups: group 5 served as the control. Wounds in group 6 were topically treated with ARG 2%. Wounds in group 7 were subjected to PBM. Wounds in group 8 were treated with PBM+ARG. 2%. On day 15, wound area measurement, wound strength, and stereological examination were performed. In the pilot study, we found that the ARG 2% ointment significantly decreased wound area than ARG. 5%, ARG. INJ. and control groups, and significantly increased wound strength compared to the control and ARG.5% groups. In the main phase, a significant decrease of wound area in all treatment regimens was induced. PBM + ARG. 2% and PBM treatment regimens significantly improved wound strength and almost all stereological parameters, compared to the control and ARG. 2% groups. PBM + ARG. 2% induced anti-inflammatory and angiogenic activities, and hastened the wound healing process in an excisional wound model in rats.

Effects of bone marrow mesenchymal stem cells-conditioned medium on tibial partial osteotomy model of fracture healing in hypothyroidism rats

Background: Hypothyroidism is associated with dysfunction of the bone turnover with reduced osteoblastic bone formation and osteoclastic bone resorption. Mesenchymal stem cells [MSCs] secrete various factors and cytokines that may stimulate bone regeneration. The aim of this study was to determine the effects of MSCs-conditioned medium [CM] in hypothyroidism male rats after inducing bone defect

Methods: In this study, 24 male rats were randomly assigned to three groups: [I] hypothyroidism + bone defect [HYPO], [II] hypothyroidism + bone defect + CM [HYPO + CM], and [III] no hypothyroidism + bone defect [control]. Four weeks after surgery, the right tibia was removed, and immediately, biomechanical and histological examinations were performed

Results: The results showed a significant reduction in bending stiffness [32.64 +/- 3.99], maximum force [14.63 +/- 1.89], high stress load [7.59 +/- 2.31], and energy absorption [12.68 +/- 2.12] at the osteotomy site in hypothyroidism rats in comparison to the control and hypothyroidism + condition medium groups [p < 0.05]. There was also a significant decrease in the trabecular bone volume [3.86 +/- 3.88] and the number of osteocytes [5800 +/- 859.8] at the osteotomy site in hypothyroidism rats compared to the control and hypothyroidism + condition medium groups [p < 0.01 and p < 0.02, respectively]

Conclusion: The present study suggests that the use of the CM can improve the fracture regeneration and accelerates bone healing at the osteotomy site in hypothyroidism rats

effects of pentoxifylline on the wound healing process in a rat experimental pressure sore model

The present study used a histological evaluation method to examine the effects of pentoxifylline [PTX] on healing an experimentally-induced pressure sore in a rat model. There were 36 adult male rats used in this study. Under general anesthesia and sterile conditions, we used forceps to create one pressure sore on each rat. A double layer of folded skin from the dorsal region was held with the highest forceps pressure grade for two hours, followed by 30 minutes of relaxation. This was repeated 12 times over three consecutive working days, and created a pressure sore after seven days. Next, rats were randomly divided into three control and three experimental groups. The experimental groups received intraperitoneal injections of PTX [50 mg/kg] for 14, 21, and 28 days after the pressure sore was created. Control groups received a similar volume of saline solution. Rats were euthanized, after which samples were extracted from the wound area and prepared for light microscopy examination. We calculated the number of neutrophils, macrophages, fibroblasts, blood vessel sections, and thicknesses of the newly formed epidermis and dermis. Although the values of some studied parameters were higher in the experimental group, there were no significant differences noted between the experimental and control groups. In this study PTX did not increase any histological parameters. Thus, the effects of PTX on the pressure sore model seem to result from different mechanisms

Evaluating the effects of pentoxifylline administration on experimental pressure sores in rats by biomechanical examinations / 한국실험동물학회지

This study used a biomechanical test to evaluate the effects of pentoxifylline administration on the wound healing process of an experimental pressure sore induced in rats. Under general anesthesia and sterile conditions, experimental pressure sores generated by no. 25 Halsted mosquito forceps were inflicted on 12 adult male rats. Pentoxifylline was injected intraperitoneally at a dose of 50 mg/kg daily from the day the pressure sore was generated, for a period of 20 days. At the end of 20 days, rats were sacrificed and skin samples extracted. Samples were biomechanically examined by a material testing instrument for maximum stress (N mm2), work up to maximum force (N), and elastic stiffness (N/mm). In the experimental group, maximum stress (2.05+/-0.15) and work up to maximum force (N/mm) (63.75+/-4.97) were significantly higher than the control group (1.3+/-0.27 and 43.3+/-14.96, P=0.002 and P=0.035, respectively). Pentoxifylline administration significantly accelerated the wound healing process in experimental rats with pressure sores, compared to that of the control group.