Use of insulin-like growth factor in the healing of open wounds in diabetic and non-diabetic rats

To analyze the effects of application of 1% and 3% insulin-like growth factor I (IGF-1) cream on the process of wound healing in induced skin lesions in diabetic and non-diabetic rats and evaluate its effect on expression of myofibroblasts. METHODS: Ninety-six Wistar adult male rats were divided into six groups, with 16 rats in each group, as follows: group 1: non-diabetic, untreated; group 2: non-diabetic, treated with 1% IGF-1 cream; group 3: non-diabetic, treated with 3% IGF-1 cream; group 4: diabetic, untreated; group 5: diabetic, treated with 1% IGF-1 cream; and group 6: diabetic, treated with 3% IGF-1 cream. In groups 4, 5, and 6, diabetes was induced by intravenous injection of alloxan. After diabetes had been induced, animals were mantained for 3 months. The experimental procedure consisted of the creation of a circular incision of 0.9 mm in diameter using a metal punch. Following this, wounds were treated daily according to the assigned treatment regimen. Groups 2 and 5 were treated with 1% IGF-1 cream, groups 3 and 6 with 3% IGF-1 cream, and groups 1 and 4 and the untreated groups with 0.9% saline solution. From each group, samples from 4 rats were taken at three, seven, 14, and 21 days after the injury. Samples were fixed in 10% formalin to prepare slides for histological analysis. Slides stained with hematoxylin-eosin (H&E) and Masson were observed vascular proliferation, mononuclear cells, polymorphonuclear cells, fibroblast proliferation, re-epithelialization, and collagen fibers. This study analyzed the expression of α-smooth muscle actin using specific antibodies to correlate the temporal expression of α-smooth muscle-specific actin (α-SM actin), a molecular marker for myofibroblast transformation. RESULTS: Macroscopic observation of wounds showed a more rapid re-epithelialization of wounds treated with IGF. Regarding acute inflammatory reactions, the results of the analysis of vascular.(AU)

Ischemic preconditioning attenuates remote pulmonary inflammatory infiltration of diabetic rats with an intestinal and hepatic ischemia-reperfusion injury

PURPOSE: To assess ischemic preconditioning (IPC) effects in pulmonary lesion in intestinal and hepatic ischemia-reperfusion (IR) injury models using diabetic rats. METHODS: Diabetes (DM) was induced in 28 male Wistar rats by alloxan (42 mg/kg, IV). After 28 days, severe DM rats were submitted to intestinal or hepatic IR injury with or without IPC. Intestinal IR (30 min of mesenteric artery occlusion and 30 min of reperfusion; n=6) and IPC groups (10 min ischemia, 10 min reperfusion, followed by intestinal IR; n=6), and Hepatic IR (30 min of hepatic pedicle occlusion and 30 min of reperfusion; n=5) and IPC groups (10 min ischemia, 10 min reperfusion, followed by hepatic IR; n=5), were compared to DM rats group (n=6). Plasmatic lactate, glycemia were measured before and after IR injury. Histomorphology of lung was performed counting inflammatory cells. Data was expressed in mean± SE. P<0.05. RESULTS: Glycemia and lactate were similar among groups. IPC did not interfere in these parameters. On histological evaluation, IR increased inflammatory cells infiltration in pulmonary parenchyma compared to control in both IR injury models. IPC attenuated inflammatory infiltration in lungs. CONCLUSION: Ischemic preconditioning protects against remote ischemia-reperfusion injury in lung on intestinal or hepatic ischemia-reperfusion model with acute diabetes.(AU)

Anastomotic healing in ileum and colon of alloxan-induced diabetic rats / Cicatrização de anastomoses realizadas no íleo e cólon de ratos diabéticos induzidos pela aloxana

PURPOSE: To investigate if diabetes mellitus may alter breaking strength (BS) and collagen content in ileum and colon anastomoses in rats. METHODS: Three-hundred Wistar rats were randomly assigned to 5 experimental groups, 60 per group: normal controls surgically manipulated (G1); normal controls submitted to ileum (G2) and colon (G3) anastomotic construction; diabetic rats submitted to ileum (G4) and colon (G5) anastomotic construction. Each group was further divided into 6 subgroups with 10 rats each for sacrifice at 0, 4, 7, 14, 21, and 30 days after surgery. All surgical procedures were performed 3 months after alloxan diabetes induction. BS was measured in all intestinal anastomoses. Fragments of ileum and colon anastomoses were taken for hydroxyproline concentration (HP) and total tissue protein (TP) dosages. RESULTS: Anastomotic BS was significantly decreased (P<0.05) in ileum and colon of G4 and G5 diabetic groups up to 7 and 14 days after surgery, respectively, compared with G2 and G3 normal control groups. Anastomotic HP and TP content did not significantly differ between diabetic and normal control operated groups in ileum or colon at all evaluation times. CONCLUSION: Experimental diabetes leads to impaired intestinal anastomotic strength during early surgical wound repair, but does not appear to be implicated with collagen synthesis capacity.(AU)

OBJETIVO: Investigar se o diabetes mellitus pode alterar a força de ruptura (FR) e o conteúdo de colágeno em anastomoses realizadas no íleo e cólon de ratos. MÉTODOS: 300 ratos Wistar foram distribuídos por sorteio em 5 grupos experimentais com 60 animais cada: controle normal manipulado cirurgicamente (G1); normais controles submetidos a anastomoses no íleo (G2) e cólon (G3); ratos diabéticos submetidos a anastomoses no íleo (G4) e cólon (G5). Cada grupo foi dividido em 6 subgrupos com 10 ratos cada para sacrifícios com 0, 4, 7, 14, 21 e 30 dias após as operações. Os procedimentos cirúrgicos foram realizados 3 meses após a indução do diabetes com aloxana. A FR foi medida em todas anastomoses intestinais. Fragmentos de anastomoses do íleo e cólon foram retirados para dosagens de hidroxiprolina (HP) e proteína tecidual total (PT). RESULTADOS: A FR teve significante redução (P<0,05) nos grupos diabéticos G4 e G5, até 7 e 14 dias após a operação, respectivamente, quando comparada à observada nos grupos controles G2 e G3. Não foram observadas diferenças significantes nas dosagens de HP e PT em ratos diabéticos e controles, tanto operados no íleo como no cólon, em todos os momentos de avaliação. CONCLUSÃO: O diabetes conduz a alterações da força de ruptura de anastomoses intestinais durante a fase inicial da reparação da ferida cirúrgica, porém, este fato parece não estar relacionado à capacidade de sintetizar colágeno.(AU)

Estudo comparativo entre cinco diferentes tratamentos sobre as alterações clínicas e laboratoriais do rato diabético induzido pela aloxana / Comparative study among five different treatments on the clinical and laboratory changes of the alloxan-induced diabetic rats

OBJETIVOS: Este estudo visa a analisar os efeitos, a longo prazo, de cinco diferentes tratamentos sobre o controle metabólico de ratos diabéticos aloxânicos. MÉTODOS: Foram analisados 7 grupos experimentais, com 50 ratos cada um, sendo: GN o grupo controle normal; GD o grupo controle diabético, sem tratamento; GI, GA e GIA os grupos tratados, respectivamente, com insulina, acarbose e associação insulina + acarbose; GTIL o grupo tratado com transplante de ilhotas de Langerhans; e o GTPD o grupo tratado com transplante pancreatoduodenal heterotópico. Parâmetros clínicos (peso, ingestão hídrica, ingestão alimentar e diurese) e laboratoriais (glicemia, glicose urinária e insulina plasmática) foram avaliados em todos os animais, no início do experimento, e após 1, 3, 6, 9 e 12 meses de seguimento. RESULTADOS: A exceção do GN, mortalidade foi observada em todos os grupos experimentais no seguimento de 12 meses (GD= 50 por cento; GI= 20 por cento; GA= 26 por cento; GIA= 18 por cento; GTIL= 4 por cento; GTPD= 20 por cento). Em GD, GI, GA e GIA os óbitos ocorreram por distúrbios metabólicos ou hidroeletrolíticos e/ou pneumonia, diarréia e caquexia; em GTIL e GTPD todos os óbitos ocorreram por falhas técnicas no pós-operatório até 72h. Animais dos grupos GI, GA e GIA tiveram melhora significativa (p < 0,05) de todos os parâmetros clínicos e laboratoriais observados em ratos diabéticos, sem diferença de efetividade entre os tratamentos. Porém, os resultados observados nestes grupos, biologicamente não foram comparáveis aos observados em GTIL e GTPD, onde observou-se correção completa, aos níveis normais, de todas as variáveis analisadas (p<0,01). CONCLUSÕES: Os tratamentos convencionais com insulina, acarbose e insulina + acarbose melhoraram o estado diabético grave dos ratos tratados, contudo, a eficácia dos tratamentos foi significativamente inferior à oferecida pelo GTIL e GTPD. (AU)