Effect of erythropoietin on liver regeneration in an experimental model of partial hepatectomy.

BACKGROUND AND AIM: The liver shows remarkable regeneration ability after damage or resection. The main stimulant for hepatic regeneration is resection. Erythropoietin (EPO), which was initially used for anemia therapy, is today known as a general tissue protector owing to its anti-inflammatory, anti-oxidant, anti-apoptotic, and angiogenic properties. This study aims to investigate the effect of systemically administered EPO on liver regeneration after partial hepatectomy. METHODS: Forty-eight male Wistar albino rats were randomly split in two groups A and B consisting of 24 rats each. Standard 70% hepatectomy was performed on the rats in group A. The same surgical procedure was performed on the rats in group B, and they were additionally administered 3000 U/kg/subcutaneous EPO. The rats were sacrificed 24, 48, and 72 h after resection. The groups were compared in terms of biochemical, morphological, and histopathological parameters. RESULTS: The biochemical results showed that the administration of EPO decreased aspartate aminotransferase levels significantly (p < 0.05) at 24 h after hepatectomy. A comparison of the groups in terms of relative liver weight showed that EPO-treated groups exhibited a statistically significant increase (p < 0.05) for all three time periods. Histopathology results showed that in the EPO-treated groups, the mitosis index at 48 and 72 h, double nuclei cell number at 72 h, and proliferating cell nuclear antigen ratio at 48 h showed a significant increase (p < 0.05). CONCLUSION: Our study showed that systemically administering high-dose EPO increases regeneration by affecting the biochemical, morphological, and histopathological parameters after liver resection.

Effects of ebselen versus nimodipine on cerebral vasospasm subsequent to experimental subarachnoid hemorrhage in rats.

We investigated the effect of ebselen relative to nimodipine in an animal model of subarachnoid hemorrhage. Thirty Wistar albino rats were divided into 5 groups: G1, no intervention; G2, sham surgery without subarachnoid hemorrhage (SAH); G3, SAH only; G4, SAH plus nimodipine treatment; G5, SAH plus ebselen treatment. For G2 animals, physiological saline (0.9% NaCl) was injected into the cisterna magna. For G3, G4 and G5 animals, SAH was induced by injecting autologous non-heparinized blood into the cisterna magna. One hour after injection, G4 animals received nimodipine at 6-hour intervals and G5 animals received ebselen twice a day for 48 hours. After treatment, brain tissue and blood samples were taken for biochemical and histopathological examination. Mean malonyldialdehyde concentration was significantly higher in G3 than in G1 (p<0.0001), G2 (p=0.01), G4 (p=0.002) and G5 (p=0.014), and significantly higher in G5 than in G1 (p=0.013). Mean superoxide dismutase activity was significantly lower in G4 than in both G1 (p=0.025) and G2 (p=0.02). Mean wall thickness was significantly greater in G3 than in G1 (p<0.0001), G2 (p=0.01), G4 (p<0.0001) and G5 (p<0.0001). Mean wall thickness was also significantly greater in both G1 and G2 than in G4 (p<0.0014 and p<0.0001) and G5 (p<0.0001 and p<0.0001). Mean luminal diameter of the basilar artery was significantly smaller in G3 than in G2 (p=0.02), G4 (p<0.018) and G5 (p<0.001). Our results confirm that ebselen may have neuroprotective effects by acting to prevent vasospasm.

Is direct method of low density lipoprotein cholesterol measurement appropriate for targeting lipid lowering therapy?

OBJECTIVES: The aim of this study was to compare the Friedewald Formula with direct homogeneous low density lipoprotein cholesterol (LDL-C) assay for the detection of LDL-C levels. METHODS: Fasting serum samples were obtained for lipid analysis from 1001 patients. Total cholesterol (TC) and triglyceride (TG) levels were measured with enzymatic methods and the measurements of high density lipoprotein cholesterol (HDL-C) and LDL-C levels were detected using direct methods. RESULTS: The mean levels of serum TC, TG, HDL-C and LDL-C were detected with in the reference range. The LDL-C estimated by the Friedewald formula was significantly correlated (P<0.01) with the direct method but there was a negative bias among them. CONCLUSION: Laboratories cannot use direct method as a substitute for Friedewald formula because direct method has not been standardized in large populations and increase cholesterol assay costs.

The effect of sildenafil on an animal model for ischemic colitis.

INTRODUCTION: Sildenafil both enhances vasodilatation by relaxing the smooth muscle in the vessels and inhibits platelet aggregation. We have therefore examined the potential benefits of sildenafil on an animal model for ischemic colitis (IC). METHODS: Twenty-eight female Wistar albino rats weighing 250-300 g were randomized into three experimental groups as follows: in Group 1, animals were sham operated (n = 8) and received tap water; in Groups 2 and 3, the rats underwent a standardized surgical procedure to induce IC (n = 10 in each group). Group 2 animals served as the controls, receiving only tap water, while Group 3 animals received 10 mg/kg sildenafil per day as a single dose for a 3-day period. All animals were sacrificed 72 h after devascularization. To determine the severity of the ischemia, we scored the macroscopically visible damage, measured the ischemic area and scored the histopathology. Tissue malondialdehyde levels were also evaluated. RESULTS: The mean area of ischemic changes were 116.80 +/- 189.93 and 0.55 +/- 1.01 mm2 in Group 2 and 3 animals, respectively (p = 0.0001), while the macroscopically mean visible damage score decreased to 0.66 +/- 0.70 (p = 0.0001) for Group 3 animals. The Chiu scores were 0.00, 3.80 +/- 0.91 and 2.66 +/- 1.00 in Group 1, 2 and 3 animals, respectively. There was a statistically significant difference between Group 2 and 3 animals (p = 0.017). CONCLUSIONS: Our findings support the view that sildenafil leads to a improvement in IC due to its well-known effects on the vascular smooth muscle and on the microcirculatory hemodynamics.