Introduction: Cardiac remodeling after myocardial infarction, is associated with progressive ventricular dysfunction and cardiovascular death. The purpose of this study was to examine the effect of endurance exercise training on morphological changes in rat heart tissue following experimental myocardial infarction. Materials and methods: Rats used in this experiment (8-10 weeks old, 235 ± 5 g body weight) after homogenization according to body weight, were randomly divided to three groups: Healthy (Sham), control (Sedentary) and endurance training groups. Myocardial infarction was induced by subcutaneous injection of isoprenaline (150 mg/kg) in two consecutive days with an interval of 24 hours. Endurance training initiated 2 days after infarction and continued for 4 weeks. In order to assess the necrosis lesion and fibrosis tissue, Hematoxylin-Eosin and Masson's trichrome staining were used, respectively. Data were analyzed by using one-way analysis of variance (ANOVA) at P< 0.05 level. Results:The results indicated that subcutaneous injection of isoprenaline, induced myocardial infarction in rat heart tissue. Rate of necrotic lesion in the Endurance training group was significantly higher than Sedentary (control) group (P=0.005).Also, the size of fibrosis tissue in the Endurance training group was significantly higher than the sedentary (control) group (P= 0.001). Conclusion: In general, results of this study showed that 4 weeks of endurance exercise training after myocardial infarction exacerbate tissue injury in rat heart.

BackgroundMast cells are one of the characteristic factors in angiogenesis, growth, and metastatic spread of tumors. Further studies are suggested to determine the type of these cells which might be useful in the assessment of biological nature of the tumor and its future treatment modality. Few studies have evaluated mast cell infiltration in visceral tumors, especially uterine tumors.Case presentationIn this study, age, sex, death rate, and histologic patterns were in agreement with those of previous reports on canine mast cell tumors. Cytopathology assays are widely used to prognosticate canine uterine mast cell tumors (MCT). There is limited information about these prognostic assays used on MCT that arise in the uterine. The anisocytosis and anisocytosis and giant cells were present in the tumor. Furthermore, the tumor had nuclear atypia with scattered multinucleated cells and prominent nucleoli and tumor were classified as poorly granulated. Under microscopic examination, we observed diffuse infiltration and proliferation of tumor cells from the uterine different area and the infiltrative characteristics and distribution patterns of neoplastic cells were observed. This tumor consisted of sheets and cords of uniform round cells with discrete cytoplasmic margins. Microscopically, the neoplastic masses were poorly-demarcated and lacked capsules and tumor cell usually showed a distinct cell boundary. Nevertheless, the neoplastic cells were located between collagen bundles forming small clusters and sheets and had large, centrally located, round to ovoid nuclei. In addition, eosinophils were scattered among the mast cells at the periphery of the masses. The presence of eosinophils and the observation, at high magnification, of cells with cytoplasmic metachromatic granules.ConclusionBased on these findings, a diagnosis of poorly-differentiated mast cell tumor was made and data histologic grading was available for tumor. Neoplasm was poorly differentiated or gradeIII.