Histological and immunohistochemical study on rat spleen in experimentally induced liver cirrhosis

The present study aimed to examine the histological changes in the spleen of rats with liver cirrhosis, and to determine the immunohistochemical expression of endothelial nitric oxide synthase [e-NOS], and its upstream effectors; tumor necrosis factor [TNF-alpha] and vascular endothelial growth factor [VEGF]. Twenty male adult albino rats were divided into two equal groups. The first was control. In the second group, liver cirrhosis was induced by intraperitoneal [ip] injection of thioacetamide 200 mg/kg twice weekly for 12 weeks. Splenic index [spleen weight / body weight] was determined and the spleens of rats which developed liver cirrhosis were subjected to the following stains: hematoxylin and eosin [H and E], silver impregnation, and immunostaining with specific antibodies for e-NOS, TNF-alpha and VEGF. Quantitative assessments were carried out using image analyzer with statistical analysis of the results. Splenic sections of cirrhotic rats showed in addition to congestion of venous sinuses, significant increase in reticular fibers in capsule and trabeculae as well as throughout the red pulp. The percentages of red pulp and fibrous trabeculae areas were significantly higher in cirrhotic rats, while the percentage of the white pulp areas was significantly smaller. Immunohistochemical staining of both e-NOS and TNF-alpha in spleen sections of group II rats were significantly lower than control, while VEGF immunostaining was significantly higher. Splenomegaly in liver cirrhosis was not only congestive but there was also significant increase of reticular fibers, red pulp area and angiogenesis. Moreover, nitric oxide [NO] reduction resulting from suppression of e-NOS and TNF-alpha seen in this study contributed to the increased volume of the spleen

Protective effect of Ginkgo biloba against experimental cardiotoxicity induced by isoproterenol in adult male albino rats a histological and biochemical study

The present study was designed to investigate whether Ginkgo biloba [GB] might protect the heart against myocardial injury induced by isoproterenol [ISO] on the basis of its effects on biochemical and histological parameters. Twenty four adult male albino rats [180-200 g] were used in this study. They were divided into 4 equal groups of six rats each. Group I was the control group and group II received ISO [85 mg/kg body weight [bw], subcutaneously [S.C.] for two consecutive days to induce myocardial injury. Group III received GB [200 mg/kg bw] orally by gastric gavage daily for 21 days while group IV received GB [200 mg/kg bw] orally daily for 21 days in addition to ISO [85 mg/kg bw], S.C. on the 20th and 21st day from starting GB. After 24 hours, rats were sacrificed and the levels of cardiac marker enzymes [creatine kinase-CK] and its myocardial isoenzyme [CK-MB]] were assessed in serum. Heart specimens were processed for light and electron microscopic examination. Administration of GB before ISO significantly prevented ISO-induced elevation of serum cardiac marker enzymes. Light and electron microscopic findings of the heart pretreated with GB revealed a well preserved normal morphology of cardiac muscle with minimal evidence of myocardial injury when compared to ISO-treated hearts. This study demonstrated that GB had a significant effect in the protection of heart against myocardial injury induced by ISO. This beneficial effect was mostly related to its antioxidant property. The results of the present investigation may trigger an interest towards the use of GB in myocardial infarction