Histological and immunohistochemical study of nitric oxide synthase and effects of angiotensin receptor blockade in early phase of diabetes in rat kidney

Several studies have demonstrated that the pathophysiological and morphological changes in early diabetic nephropathy were mediated by an increase or decrease in nitric oxide [NO] production and/or activity. There are few reports suggesting a relationship between NO and the renin-angiotensin system. The present study was designed to determine the effects of early diabetic state on NO production and also to assess the possible effects of angiotensin receptor blockers [ARBs] on these changes. Thirty adult male albino rats were included in this study. Twenty were injected with streptozotocin for induction of diabetes. The other 10 were injected with the vehicle and served as control. Two days after injection, the diabetic animals were randomly divided into two groups of 10 animals each. One group was given valsartan as an ARB and the other group received no further treatment. Three weeks later, all animals were sacrificed and the kidneys were processed for obtaining paraffin sections. The sections were stained with H and E, Masson's trichrome, and periodic acid-Schiff. The sections were also stained with an immunohistochemical stain against endothelium-derived nitric oxide synthase [eNOS]. Diabetes induced histological changes in the form of glomerular hypertrophy, increased glomerular matrix, focal areas of tubular atrophy, medullary congestion, and slight fibrosis. Immunostaining was present in the control kidney in the glomeruli and in the collecting tubules of the medulla. Diabetes induced a positive reaction in the proximal and distal convoluted tubules and increased immunoreactivity in the collecting tubules. Treatment with valsartan resulted in an improvement in the morphology of the kidney and a reduction in the intensity of eNOS immunostaining. NO increases in early diabetic kidney and ARB in the form of valsartan could be recommended for preventing the development of diabetic nephropathy

Effect of kupffer cell modulation in rat liver fibrosis: histological and immunohistochemical study

The process of Ito cell activation, which is thought to be the central pathogenic mechanism in liver fibrogenesis, may involve distinct interactions with Kupffer cells [KCs] mediated by various cytokines and growth factors. The aim of the present study was to determine whether targeting KC function using gadolinium chloride [GdC13] interferes with the carbon tetrachloride [CC14]-induced hepatic fibrosis. Thirty-six male rats were divided into CC14 alone [group I]; CC14+GdC13 [group II]; and control groups, and were given CC14 only [0.3ml/kg, sc]; CC14+GdC13 [10mg/kg, ip]; or vehicles or GdC13 alone, respectively, for either 1 or 8 weeks. Hepatic injury was assessed by histological evaluation of the liver tissue, and by serum AST and ALT determination. Collagen and reticular fiber content of the liver was determined in Masson's trichrome-stained and silver-impregnated sections, respectively. In addition, activated Ito cells were detected by alpha-SMA immunohistochemistry. As expected, CC14 alone treatment resulted in a significant increase in connective tissue deposition in the liver [fibrosis], with a significant elevation of serum liver enzymes; massive cell necrosis; and an increase in alpha-SMA immunoreactive cells, especially after 8 weeks. In contrast, such manifestations of hepatic injury were significantly attenuated by simultaneous GdC13 administration, especially the fibrous tissue deposition. However, extensive fatty changes and cell death were still observed in one specimen. Therefore, it could be concluded that modulation of macrophage function may be a useful approach in the treatment of hepatic fibrosis

Effect of ACE inhibiting therapy in ovarian hyperstimulation syndrome in the rat: histological and immunohistochemical study

Ovarian hyperstimulation syndrome [OHSS] has become a common problem since the introduction of assisted reproductive technologies and ovarian stimulation methods into infertility practice. The purpose of the present study was to investigate the possible effects of the angiotensin converting enzyme inhibitor enalapril in the ovarian hyperstimulation syndrome in a rat model. Thirty young adult virgin female rats were randomly divided into 2 experimental and one control groups of ten rats each. Ovarian hyperstimulation was induced in all experimental animals by using 30 IU FSH [sc] for 5 consecutive days, followed by 30 IU of hCG [im] on day 6. Oral enalapril tablets [2mg/kg] were given twice daily to ten rats only [group II] for 6 consecutive days. The remaining ten rats did not receive enalapril [group I]. Control animals received injections of saline solution to mimic the conditions of the study animals. Body weights of animals were recorded on days 1 and 8, and percentage of weight gain was calculated for each group. All animals were sacrificed on day 8, ovaries were removed and weighed to obtain ovarian weight. Histological changes in the ovaries were evaluated, and corpora lutea were counted to estimate the number of ovulations in each ovary. Blood samples were also taken to determine serum estradiol and progesterone levels. In addition, ovaries were subjected to immunohistichemical staining with anti-VEGF antibodies. Administration of the stimulation regimen to group I rats resulted in a significant increase in weight gain, ovarian weight, number of ovulations, serum estradiol and progesterone levels, as well as VEGF immunoreactivity in the ovaries, compared with the control rats. Moreover, a significant positive correlation between ovarian weight and body weight gain was also found in both experimental groups. Enalapril administration, in group II rats, significantly reduced all study parameters, including the VEGF immunohistochemical expression in the ovaries. Angiotensin converting enzyme inhibiting therapy with enalapril was significantly effective in reducing the severity of ovarian hyperstimulation syndrome in the rat model

Histological study on the effect of aluminium chloride on frontal cortex of adult male albino rats

Several studies implicated aluminium in the pathogenesis of many neurodegenerative disorders especially Alzheimer disease, although the underlying histopathological changes in the brain were not clear with many controversies. So we aimed to elucidate these histological, immunohistochemical and ultrastructural changes that might occur in the rat brain after aluminium exposure. In this study we used 18 adult male albino rats divided into 2 groups; a control group and an experimental group taking 600 mg/ kg aluminium chloride orally daily for 4 weeks. At the end of the fourth week, samples from the frontal cortex were obtained and stained with H and E, and glial fibrillary acidic protein [GFAP]. Other samples were processed for electron microscopic examination. Morphometric study was done for GFAP immunostaining. The group taking 600 mg/ kg aluminium chloride showed decreased body weight and had developed some neurological symptoms. Routine H and E revealed presence of some shrunken pyramidal cells with pyknotic nuclei; immunoreactivity for glial fibrillary acidic protein [GFAP] was decreased compared to control group. Ultrastructurally; some neurons showed shrunken nuclei, swelling and damage of the mitochondria and dilated saccules of Golgi apparatus and endoplasmic reticulum with the appearance of vacuolated areas in the cytoplasm with splitting of myelin sheath and degeneration of some nerve fibres. Aluminium in high doses can cause alterations in neurons and nerve fibers with decreased immunoreactivity for GFAP in astrocytes in the brain, so further studies would be needed to evaluate the effects of chronic exposure in apparently healthy individuals

Electron microscopic study on clara cells in the lung of adult mice in response to naphthalene injection

The present work aimed at studying the effect of intraperitoneal administration of naphthalene, an organic chemical, on nonciliated [Clara] cells in terminal bronchioles and lobar bronchi. Adult mice were divided into four groups, each given a single intraperitoneal injection of the following doses respectively [50, 100, 200 and 300 mg / kg] of naphthalene in corn oil. The animals were sacrificed 48 hours later. Retrograde recovery changes were studied fourteen days following naphthalene administration. Epithelial changes included cellular swelling, vacuolation and exfoliation of Clara cells. Minimal bronchiolar epithelial changes were observed in the first group [50 mg / kg]. In the second group [100 mg / kg], the number of Clara cells that showed vacuolation increased. In the third and fourth groups [200 and 300 mg / kg], almost all of the nonciliated eels lining terminal bronchioles were vacuolated and exfoliated. No detectable changes were noted in lobar bronchi except in the fourth group [300 mg / kg] where lobar bronchi showed vacuolation and exfoliation of Clara cells. Nonciliated cells in both terminal bronchioles and lobar bronchi resembled controls in recovery mice