ABSTRACT

We investigated the possible toxic effects of melamine on muscle tissue in rats using biochemical, hematological and histopathological methods. We used three groups of female albino Wistar rats. The first group was given 0.1 ml saline. The second and third groups were given 50 and 75 mg/kg melamine dissolved in 0.1 ml saline, respectively, daily for 21 days. On day 45, all rats were sacrificed, and whole blood and plasma were analyzed for hematologic and biochemical characteristics. Muscle samples were stained with hematoxylin and eosin for histopathological investigation. Other sections were immunostained for matrix metalloproteinase-9 (MMP-9) and type IV collagen. We found a significant increase in the lymphocytosis-compliant leukocyte number in the 75 mg/kg melamine group compared to the other groups. We also found significant decreases in the hemoglobin levels and hematocrit values in the 75 mg/kg compared to the other groups. We found that the 75 mg/kg melamine group exhibited a significant increase in plasma aspartate aminotransferase (AST) activity compared to the other groups. Changes in plasma creatine kinase and lactate dehydrogenase activity were not statistically significant. Plasma AST activity and mean corpuscular hemoglobin levels were correlated with the lymphocyte:neutrophil ratio. We found mononuclear cell infiltration at the periphery of muscle bundles and in the connective tissue bundles in the melamine treated group. We found MMP-9 expression in muscle cell membranes and type IV collagen expression in degenerative connective tissue fibers. Whole blood, plasma and muscle tissue analysis indicated that the 75 mg/kg melamine group exhibited rhabdomyolysis that was associated with lymphocytosis and anemia. The underlying mechanisms by which melamine causes rhabdomyolytic effects remain unclear.

摘要

我们使用生化、血液学和组织病理学方法研究了三聚氰胺对大鼠肌肉组织可能产生的毒性作用。我们使用了三组雌性白化 Wistar 大鼠。第一组给予0.1毫升生理盐水。第二组和第三组分别每天服用 50 和 75 毫克/公斤的三聚氰胺溶解在 0.1 毫升生理盐水中，持续 21 天。在第45天，处死所有大鼠，分析全血和血浆的血液学和生化特征。肌肉样品用苏木精和伊红染色用于组织病理学研究。其他切片针对基质金属蛋白酶-9 (MMP-9) 和 IV 型胶原蛋白进行免疫染色。我们发现，与其他组相比，75 毫克/公斤三聚氰胺组的淋巴细胞增多顺应性白细胞数量显着增加。我们还发现，与其他组相比，75 mg/kg 组的血红蛋白水平和血细胞比容值显着降低。我们发现，与其他组相比，75 mg/kg 三聚氰胺组的血浆天冬氨酸转氨酶 (AST) 活性显着增加。血浆肌酸激酶和乳酸脱氢酶活性的变化无统计学意义。血浆 AST 活性和平均红细胞血红蛋白水平与淋巴细胞：中性粒细胞比率相关。我们在三聚氰胺治疗组的肌肉束周围和结缔组织束中发现单核细胞浸润。我们发现肌肉细胞膜中的 MMP-9 表达和退行性结缔组织纤维中的 IV 型胶原蛋白表达。全血，血浆和肌肉组织分析表明，75 mg/kg 三聚氰胺组表现出与淋巴细胞增多和贫血相关的横纹肌溶解症。三聚氰胺引起横纹肌溶解作用的潜在机制尚不清楚。