Effects of cilostazol in kidney and skeletal striated muscle of Wistar rats submitted to acute ischemia and reperfusion of hind limbs / Efeitos do cilostazol em rim e musculatura estriada esquelética de ratos Wistar submetidos à isquemia aguda e reperfusão de membros posteriores

PURPOSE: To investigate the effect of cilostazol, in kidney and skeletal muscle of rats submitted to acute ischemia and reperfusion. METHODS: Fourty three animals were randomized and divided into two groups. Group I received a solution of cilostazol (10 mg/Kg) and group II received saline solution 0.9% (SS) by orogastric tube after ligature of the abdominal aorta. After four hours of ischemia the animals were divided into four subgroups: group IA (Cilostazol): two hours of reperfusion. Group IIA (SS): two hours of reperfusion. Group IB (Cilostazol): six hours of reperfusion. Group IIB (SS) six hours of reperfusion. After reperfusion, a left nephrectomy was performed and removal of the muscles of the hind limb. The histological parameters were studied. In kidney cylinders of myoglobin, vacuolar degeneration and acute tubular necrosis. In muscle interstitial edema, inflammatory infiltrate, hypereosinophilia fiber, cariopicnose and necrosis. Apoptosis was assessed by immunohistochemistry for cleaved caspase-3 and TUNEL. RESULTS: There was no statistically significant difference between groups. CONCLUSION: Cilostazol had no protective effect on the kidney and the skeletal striated muscle in rats submitted to acute ischemia and reperfusion in this model.

OBJETIVO: Investigar o efeito do cilostazol no rim e na musculatura esquelética de ratos submetidos à isquemia aguda e reperfusão. MÉTODOS: Quarenta e três animais foram aleatoriamente distribuídos em dois grupos. Grupo I recebeu solução de cilostazol (10 mg/Kg) e Grupo II recebeu solução fisiológica a 0,9% (SF), após ligadura da aorta abdominal. Decorridas quatro horas de isquemia os animais foram distribuídos em quatro subgrupos: Grupo IA (Cilostazol): duas horas de reperfusão. Grupo IIA (SF): duas horas de reperfusão. Grupo IB (Cilostazol): seis horas de reperfusão. Grupo IIB (SF): seis horas de reperfusão. Após a reperfusão, realizou-se nefrectomia esquerda e a retirada da musculatura de membro posterior. Os parâmetros histológicos estudados em rim foram cilindros de mioglobina, degeneração vacuolar e necrose tubular. Em músculo foram edema, infiltrado inflamatório, hipereosinofilia de fibras, cariopicnose e necrose. A apoptose foi avaliada por imunohistoquímica, através da caspase-3 clivada e TUNEL. RESULTADOS: Não houve diferença estatisticamente significante entre os grupos estudados. CONCLUSÃO: O cilostazol não teve efeito protetor sobre o rim e sobre a musculatura estriada esquelética em ratos Wistar submetidos à isquemia aguda e reperfusão no modelo estudado.

Pregabalin as a Neuroprotector after Spinal Cord Injury in Rats: Biochemical Analysis and Effect on Glial Cells

As one of trials on neuroprotection after spinal cord injury, we used pregabalin. After spinal cord injury (SCI) in rats using contusion model, we observed the effect of pregabalin compared to that of the control and the methylprednisolone treated rats. We observed locomotor improvement of paralyzed hindlimb and body weight changes for clinical evaluation and caspase-3, bcl-2, and p38 MAPK expressions using western blotting. On histopathological analysis, we also evaluated reactive proliferation of glial cells. We were able to observe pregabalin's effectiveness as a neuroprotector after SCI in terms of the clinical indicators and the laboratory findings. The caspase-3 and phosphorylated p38 MAPK expressions of the pregabalin group were lower than those of the control group (statistically significant with caspase-3). Bcl-2 showed no significant difference between the control group and the treated groups. On the histopathological analysis, pregabalin treatment demonstrated less proliferation of the microglia and astrocytes. With this animal study, we were able to demonstrate reproducible results of pregabalin's neuroprotection effect. Diminished production of caspase-3 and phosphorylated p38 MAPK and as well as decreased proliferation of astrocytes were seen with the administration of pregabalin. This influence on spinal cord injury might be a possible approach for achieving neuroprotection following central nervous system trauma including spinal cord injury.

Halothane effect on formalin-induced paw edema and flinching in rat

The formalin test is a model of injury-produced inflammatory pain. Anesthetics, in clinically relevant concentrations, affect neutrophils and immune suppression. This study was to determine whether halothane reliably inhibits inflammatory reaction and formalin induced pain behavior or does not. Rats were exposed to 100% oxygen (control) or halothane, respectively for 30 min and then 24 hr later five percent formalin test was assessed. The base values of the paw's diameter were obtained earlier, and then formalin induced edema was assessed by measuring diameters of the injected paws at 5 min, 1 hr, 4 hr and 24 hr after the injection. Nociceptive behavior was quantified by counting the number of times with the paw flinched at 5 min intervals for 60 min. The diameters of edema in the halothane group lessened more than those in the oxygen group at 1 and 24 hr in each following of the injection (p<0.05). The rats pre-administered with oxygen or halothane were similar appearances in nociceptive behaviors. It suggests that halothane anesthesia might inhibit slightly the inflammatory reaction with the formalin-induced edema but might not inhibit the formalin-induced pain behavior in the event of pre-administration halothane 24 hr earlier before the formalin test of rat.

Fatigue and contractile responses of rat hindlimb muscles following excessive dexamethasone administration.

Muscle weight, protein content and contractile performance (tetanic tension, fatigue and recovery) of extensor digitorum longus and soleus were investigated in rat following systemic administration of Dexamethasone (DX), 5 mg/kg/day for ten days. These animals showed marked reduction in food intake during the course of DX treatment. As a control, a group of food restricted (FR) rats receiving equal amount of food consumed by the DX treated rats was also studied along with the saline control group, to differentiate the effect of DX on muscle from that of dietary deficiency. There was a greater degree of atrophy (reduced muscle mass and protein content) of extensor digitorum longus in DX treated rats as compared to that of the FR rats. In-situ isometric tetanic tension per gram of muscle and per unit weight of protein was similar in both the muscles in the DX treated and the FR rats. There was increased fatiguability with reduced post fatigue recovery in both the muscles of DX treated rats as compared to the FR rats. The results indicate that besides atrophy of fast twitch muscles, DX increases the fatiguability and decreases the postfatigue recovery in both fast and slow muscles.