Effects of dimethylsulfoxide and pentoxifylline in the vitality of cutaneous flaps in rats / Efeitos do dimetilsulfóxido e da pentoxifilina na vitalidade de retalhos cutâneos em ratos

ABSTRACT Objectives: to verify the influence of dimethylsulfoxide and pentoxifylline on the vitality of cutaneous flaps in rats and the tissue repair process. Methods: were studied 30 Wistar rats, submitting them to a 2cm wide by 8cm long dorsal cutaneous flap, of caudal base. We distributed the animals in three groups: Control Group (n=10) with application gauze moistened with 0.9% Saline in the flap bed for 30 seconds; Dimethylsulfoxide group (n=10), with administration of 1ml of 5% dimethylsulfoxide divided into five injections of 0.2ml in the transition of the flap segments; Pentoxifylline group (n=10), with administration of pentoxifylline 20mg/kg, diluted to 1ml and divided into five injections of 0.2ml in the transition of the flap segments. Drugs were administered intraoperatively, in a single dose and subcutaneously. We observed the skin flaps for changes in color and texture. On the 10th postoperative day, we checked the dimensions of viable and necrotic tissues, followed by excision of the specimen for histological analysis. Results: the measurements of length of the viable and necrotic tissues between groups showed no differences. Histological analysis showed that the Dimethylsulfoxide group presented neovascularization, inflammatory infiltrate with leukocytes and more structured conjunctival stroma. The Pentoxifylline group showed neovascularization and inflammatory infiltrate, with moderate to intense granulation. The control group evolved with a higher rate of necrosis in the distal segment. Conclusion: dimethylsulfoxide and pentoxifylline influenced the vitality of the flap and the tissue repair process. However, they did not prevent necrosis macroscopically.

RESUMO Objetivos: verificar a influência do dimetilsulfóxido e da pentoxifilina na vitalidade e no processo de reparo tecidual de retalhos cutâneos em ratos. Método: foram estudados 30 ratos Wistar, nos quais foi confeccionado retalho cutâneo dorsal de 2cm de largura por 8cm de comprimento, de base caudal, e distribuídos em três grupos: Grupo Controle (n=10) com aplicação de gaze umedecida com solução salina a 0,9%, no leito do retalho, por 30 segundos; Grupo dimetilsulfóxido (n=10) com injeção de 1ml de dimetilsulfóxido a 5% divididos em cinco injeções de 0,2ml na transição dos segmentos do retalho; Grupo pentoxifilina (n=10) com injeção de 1ml pentoxifilina 20mg/kg, divididos em cinco injeções de 0,2ml na transição dos segmentos do retalho. Os fármacos foram administrados no transoperatório, em dose única e por via subcutânea. Os retalhos cutâneos foram observados quanto às alterações de cor e textura. No décimo dia de pós-operatório aferiu-se a dimensão do tecido viável e de necrose, seguido da exérese da peça para análise histológica. Resultados: a medida da dimensão de tecido viável e de necrose dos grupos não apresentou diferenças. A análise histológica mostrou que o grupo dimetilsulfóxido apresentou neovascularização, infiltrado inflamatório com leucócitos e estroma conjuntivo mais estruturado. O grupo pentoxifilina, mostrou neovascularização e infiltrado inflamatório com granulação moderada e intensa. O grupo controle evoluiu com maior índice de necrose no segmento distal. Conclusão: dimetilsulfóxido e pentoxifilina influenciaram na vitalidade do retalho e no processo de reparo tecidual. Entretanto, não evitaram a necrose macroscopicamente.

Antioxidant effect of Legalon(r) SIL in ischemia-reperfusion injury of rat skeletal muscle

PURPOSE: To evaluated the potential antioxidant agent Legalon (r) SIL (silibinin-C-2',3-bis(hydrogensuccinat)) in the skeletal muscle of rats. METHODS: IRI was achieved via tourniquet application in Wistar-albino rats. Experimental groups were chosen as (i) sham control, (ii) IRI (3+2 h), (iii) IRI and Legalon (r) SIL-50 (50 mg/kg/i.p.), (iv) IRI and Legalon (r) SIL-100 (100 mg/kg/i.p.), and (v) IRI and Legalon (r) SIL-200 (200 mg/kg/ i.p.). Muscle viability (evaluated by triphenyltetrazolium chloride dye method), malondialdehyde, superoxide dismutase, catalase, and glutathione peroxidase were assessed in muscle samples using a spectrophotometer. RESULTS: Although viability of the injured limb non-significantly declined in the IRI group, administration of Legalon (r) SIL did not prevent injury. However, dramatic increase observed in malondialdehyde levels in the IRI group was prohibited by Legalon (r) SIL in a statistically significant manner. In comparison with the sham-control group, IRI and Legalon (r) SIL administration did not cause any significant alterations in the levels of superoxide dismutase, catalase, and glutathione peroxidase. CONCLUSION: Although Legalon (r) SIL was not sufficient to prevent muscle injury in terms of viability, it is found to be an effective option to reduce reactive oxygen species-induced cell injury.

Analysis of effect isoxsuprine hydrochloride and nicotine in the Transverse Rectus Abdominis Myocutaneous flap (TRAM) in rats

PURPOSE: To evaluate the effects of isoxsuprine and nicotine on TRAM. METHODS: Forty eight 48 Wistar rats distributed into four Groups (n=12). All rats received medication managed daily for 20 days: saline solution (SA), nicotine solution (NI), isoxsuprine solution (IS) and nicotine solution (NI) + isoxsuprine solution (IS). On day 21st the rats were submitted to the caudally based, right unipedicled TRAM flap and after 48 hours, made the macroscopic evaluation of the surface of the flap, photographic documentation and collection of material for histology. Data from macroscopic evaluation were analyzed by ANOVA and microscopic evaluation by Kruskal-Wallis test, with significance level of 5%. RESULTS: In the macroscopic evaluation of isoxsuprine Group retail presented absolute numbers: final area (p=0.001*) and viable area (p=0.006*) with the highest values; necrosis (p=0.001*) had the lowest value. Microscopic examination revealed no significant findings in the study of TRAM under the action of isoxsuprine and nicotine to the percentage of necrosis in the left and right cranial and caudal regions. CONCLUSIONS: There was significant improvement in viability of TRAM using the isoxsuprine solution alone. No influence using nicotine alone and in association with isoxsuprine. .

Histological modification in TRAM flap in rats treated with pentoxifylline

PURPOSE: To investigate the blood vessels' concentration in TRAM flap's rat model, in the presence of pentoxifylline. METHODS: 32 male, Wistar-EPM rats were divided into two groups. Control group (C): 0.5 ml of saline, intraperitoneally, once a day, for seven days before flap elevation; PTX group (P): pentoxifylline (20mg/kg/day), intraperitoneally, for seven days before flap elevation. After that, they were submitted to a caudal unipedicle TRAM flap. On the fifth postoperative day, percentages of flap necrosis were determined via the "paper template" method and Tram flap's zone IV skin biopsies were taken for histological analysis. RESULTS: the mean percentage of flap necrosis in group C was 58.7 % and in group P, 31.1 (Wilcoxon test; p = 0.003). Mean capillary vessels number in zone IV's skin in C group was 33.4 and in P group was 71.9 (p=0.008). CONCLUSIONS: Pentoxifylline was effective reducing the necrosis in the caudal unipedicle TRAM flap in the rat as well as increasing the number of capillaries in an ischemic zone (zone IV). .

Effects of the topical administration of copaiba oil ointment (Copaifera langsdorffii) in skin flaps viability of rats

PURPOSE: To evaluate the effects of copaiba oil ointment (Copaifera langsdorffii) on dorsal skin flaps in rats. METHODS: Adult male rats (n=30) were distributed into three groups of ten animals each, as follows: GC - control; GCA - absolute control and GT - treated with copaiba ointment. The rats were subjected to dorsal cutaneous skin flap surgery and the animals from the GC and GT received post-operative treatment for eight consecutive days. The animals from the GCA group did not receive treatment while the animals from the GC group received daily topical treatment of ointment without the active ingredient and the animals from the GT group were daily treated with 10% copaiba oil ointment. At the end of each experimental period the lesions were evaluated according to the percentage of necrotic area. Then, fragments from cranial, median and caudal parts were fixed in Boüin's solution and processed for paraffin embedding. The morphology of histological sections (5µm) was evaluated and the number of leucocytes, fibroblasts and blood vessels was also analyzed. The data obtained were submitted to ANOVA test complemented by Tukey-Kramer test (p<0.05). RESULTS: The necrotic area was lower in the group treated with copaiba ointment when compared to the control groups (GCA>GC and GT), while the morphology showed larger granulation tissue with bulky fibroblasts and collagen fibers more arranged in the GT group. The morphometry showed a significant higher number of blood vessels in the median and caudal parts (GT>GCA and GC), leucocytes in the cranial part (GT>GC>GCA), and also fibroblasts in the median (GT and GC> GCA) and caudal parts (GT>GC and GCA) (p<0.05). CONCLUSION: The copaiba oil ointment favors angiogenesis and accelerates the viability of random skin flaps in rats.

Effects of silibinin and ethanol on skeletal muscle ischemia-reperfusion injury

PURPOSE: To investigate the potential beneficial effect of silibinin in ischemia-reperfusion injury (IRI) of skeletal muscle. METHODS: Under urethane anesthesia, four experimental groups were established in Balb/c mice: I) Sham-control, II) IRI (Tourniquet-induced) (2+1 h), III) IRI+ethanol (10%), and IV) IRI+silibinin (50 mg/kg/IP). The viability of muscle (left) was evaluated by the triphenyltetrazolium chloride dye method and calculated as the percentage of the contralateral control muscle (right). Malondialdehyde, superoxide dismutase, and catalase were measured in the gastrocnemius muscle via a spectrophotometer. RESULTS:The viability of gastrocnemius muscle in group II was significantly lower in comparison with that seen in group I. The administration of either ethanol or silibinin rendered the tissues to recover nearly to the baseline level. Additionally, malondialdehyde levels were higher in group II than those in group I. The application of silibinin prior to the reperfusion attenuated these to the control levels. However, malondialdehyde levels in the ethanol administrated group were reduced as well. The enhanced superoxide dismutase activity seen in the IRI group was not diminished in the animals treated with either silibinin or ethanol. Similarly, there were no differences between groups regarding the catalase activities. CONCLUSION: Ethanol seems to be effective in attenuating IRI in skeletal muscle and no definite conclusion can be made on silibinin effect.

Adiponectin effect on the viability of human endometrial stromal cells and mRNA expression of adiponectin receptors

Adiponectin is one of the most important adipokines secreted from fatty tissue that has a direct inhibitory effect on the development of cancer cells. Adiponectin plays an important role in human reproduction system and fertility of women. Adiponectin concentration decreases in women with endometriosis and endometrial cancer. The aim of the present study was to investigate the effect of adiponectin on human endometrial stromal cell [HESC] viability as well as mRNA expression of Adipo R1 and Adipo R2 receptors. In this experimental study, eight endometrial biopsies were taken and stromal cells were separated by enzymatic digestion and cell filtrations. Stromal cells of each biopsy were divided into four groups: control, 10, 100, and 200 ng/ml adiponectin concentrations. The effect of adiponectin on viability of the normal HESCs was studied by trypan blue staining and the relative expression levels of Adipo R1 and R2 were analyzed by semi-quantitative reverse transcription polymerase chain reaction [RT-PCR]. Data were analyzed by one way ANOVA and unpaired student's t test and p<0.05 was considered significant. Adiponectin decreased viability of normal human endometrial stromal cells in a dose and time dependent manner. Expression of Adipo R1 and Adipo R2 receptors did not change in the presence of adiponectin. Adiponectin can directly influence the viability of HESCs and decrease their viability, but it didn't change expression of adiponectin receptors

Effects of sildenafil on the viability of random skin flaps / Os efeitos do sildenafil na viabilidade de retalhos cutâneos randômicos

PURPOSE: To assess the viability of McFarlane skin flaps in rats with administration of sildenafil. METHODS: Twenty Wistar rats were distributed into two groups: Control (dorsal skin flap, subdermal application of saline solution at 0.9 percent) and Study (dorsal skin flap, subdermal application of sildenafil). Seven days after the surgery, flaps were photographed and graphically rendered. Then, they were analyzed with AutoCAD software. Three biopsies (proximal, medial and distal) of each flap were collected for histological analysis. RESULTS: Macroscopic analysis showed that animals of the study group had greater necrotic areas (p=0.003) in the dorsal skin flaps. Additionally, histological analysis of the distal third of these flaps showed a tendency to less granulated tissue formation in animals treated with sildenafil. CONCLUSION: Sildenafil subdermally was associated with lower viability of the random skin flap in rats.

OBJETIVO: Avaliar a viabilidade de retalhos cutâneos de ratos à McFarlane após a administração de sildenafil. MÉTODOS: Vinte ratos Wistar foram distribuídos em dois grupos: Controle (confecção do retalho cutâneo dorsal, aplicação subdérmica de solução salina a 0,9 por cento) e Estudo (confecção do retalho cutâneo dorsal, aplicação subdérmica de sildenafil). Sete dias após a operação, os retalhos foram fotografados e representados graficamente, para serem analisados com o programa AutoCad. Três biópsias (cranial, média e caudal) foram coletadas de cada retalho, para análise histológica. RESULTADOS: A análise macroscópica evidenciou que os animais do grupo Estudo apresentaram maiores áreas de necrose (p=0,003) nos retalhos cutâneos dorsais. Além disso, a análise histológica dos terços distais dos retalhos mostrou uma tendência à formação de menos tecido de granulação nos animais que receberam o sildenafil. CONCLUSÃO: O sildenafil subdérmico esteve associado com uma pior viabilidade tecidual dos retalhos cutâneos dorsais de ratos.