RESUMO
BACKGROUND: Distal necrosis and inflammation are two of the most common health consequences of random-pattern skin flaps survival (SFS). Anti-inflammatory effects of spermidine have been identified in various studies. On the other hand, considering the involvement of the nitric oxide molecule in the spermidine mode of action and also its role in skin tissue function, we analyzed the possible effects of spermidine on the SFS and also, potential involvement of nitrergic pathway and inflammatory cytokine in these phenomena. METHODS: Each rat was pretreated with either a vehicle (control) or various doses of spermidine (0.5, 1, 3, 5, 10 and 30 mg/kg) and then was executed a random-pattern skin flap paradigm. Also, spermidine at the dose of 5 mg/kg was selected and one group rats received spermidine 20 min prior to surgery and one additional dose 1 day after operation. Then, 7 days after operations, interleukin (IL)-6, tumor necrosis factor (TNF)-α, interferon-gamma (IFN-γ), and nitrite levels were inquired in the tissue samples by ELIZA kit. Vascular endothelial growth factor expression was assessed by DAPI staining and fluorescent microscopes. The concentrations of three polyamines, including spermidine, spermine, and cadaverine, were analyzed using HPLC. RESULTS: Pretreatment with spermidine 5 mg/kg improved SFS considerably in microscopic skin H&E staining analysis and decreased the percentage of necrotic area. Moreover, spermidine exerted promising anti-inflammatory effects via the modulation of nitric oxide and reducing inflammatory cytokines. CONCLUSIONS: Spermidine could improve skin flaps survival, probably through the nitrergic system and inflammation pathways. This preclinical study provides level III evidence for the potential therapeutic effects of spermidine on SFS in rats, based on the analysis of animal models. Further studies are needed to confirm these findings in clinical settings. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .
RESUMO
Herein, the development of an ion-pair hollow fiber liquid-phase microextraction (IP-HF-LPME) procedure followed by capillary electrophoresis (CE) with indirect UV detection for the simultaneous extraction and determination of aliphatic biogenic amines including spermidine, spermine, and cadaverine in tissue samples of rat is described. In this study, tissue samples were firstly homogenized with a cold trichloroacetic acid solution then the developed method was applied to the supernatant resulting from tissue homogenization. Different CE separation and indirect UV detection conditions, as well as IP-HF-LPME extraction conditions were studied in detail and optimized. A 11 mmol L-1 imidazole solution containing 13 % (v/v) ethanol adjusted at pH 3.3 (by acetic acid) was the best running buffer for indirect UV detection of non-UV-absorbing amines. 1-Octanol in combination with salicylic acid, respectively as the membrane solvent and ion-pair reagent provided the highest extraction recovery for the studied amines. Method performances were established and good results of linearity, recovery, sensitivity, and repeatability were achieved for all the studied amines. Limits of detection were found to be between 2.8 and 4.5 ng mL-1 and limits of quantification were 15 ng mL-1 and the dynamic range was 15-2000 ng mL-1 for all three analytes.
