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

Histological and immunohistochemical changes in the adult rat testes after left experimental varicocele and possible protective effects of resveratrol

Varicoceles are present in about 30-50% of infertile men. However, the histological changes in the testes are not well-defined. Also, Resveratrol [RES] is a powerful antioxidant used recently in the treatment of infertility with other causes. So, this study aimed to elucidate the histological and immunohistochemical changes of both testes after left experimental varicocele and to evaluate the possible protective role of RES. This study included forty adult male albino rats divided into four equal groups: Control group [I]; sham-operated group [II]; left varicocele group [III] and left varicolcele+RES group [lv]. Varicocele was induced by partial ligation of the left renal vein. RES was orally administered to group IV in a dose of 20 mg/kg body weight every day for five weeks. At the end, all animals were sacrificed and testes were excised. Paraffin sections were prepared and stained with HandE, PAS reaction and immunohistochemical staining for proliferating cell nuclear antigen [PCNA]. PCNA-labeling index was calculated to assess spermatogenesis. Left experimental varicocele was shown to affect both ipsi-and contra-lateral testes. The changes in the ipsilateral testes were in the form of irregular degenerated seminefirous tubules with numerous blood vessels and thickened basement membranes. These changes were present in some tubules in the contralateral testes. PCNA-LI values were significantly lower than the control and sham-operated groups. Treatment with RES proved to improve these changes. Left experimental varicocele has deleterious effects on the structure of both testes and supplementation with RES in cases of infertility with varicocele may have a protective effect

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

Impact of experimental hypothyroidism and treatment with levothyroxin and zinc on the testis of adult albino rat: histological and immunohistochemical study

This study was performed to investigate the effects of experimental hypothyroidism on the testis and serum zinc level of adult rat and to compare the results of the different treatment regimens of levothyroxin and zinc. Twenty-five adult male albino rats were used. They were divided into: group I [control group] with five animals and Group II [experimental group] with twenty animals. All animals of group II received daily intraperitoneal injections of propyl-thiouracil for three weeks for induction of hypothyroidism. The rats were then divided into four equal subgroups which were given levothyroxin and/or zinc sulphate supplementation or no further treatment for the next two weeks. Serum levels of T3, T4, TSH and zinc were evaluated for all animals in days 22 and 36 from the beginning of the experiment. At the end, testes were collected and paraffin sections were prepared. The sections were stained with H and E, PAS reaction and immunohistochemical staining for proliferating cell nuclear antibodies [PCNA]. PCNA-labeling index was calculated to assess spermatogenesis. It was concluded that [i] serum zinc levels were significantly decreased in hypothyroid rats and testicular histology was affected in the form of decreased diameter and narrowing of the seminiferous tubules, interstitial oedema, congestion of the blood vessels, thickening of the basement membrane and decreased spermatogenesis; [ii] oral zinc per se had no effect of the testicular histology or spermatogenesis; [iii] treatment with levothyroxin alone increased serum zinc levels and spermatogenesis without reaching control levels; [iv] zinc deficiency might add to the detrimental effects of hypothyroidism in spermatogenesis and [v] optimal results were achieved with combined levothyroxin and zinc replacement therapy. It was recommended to assess thyroid hormone levels routinely in cases of male infertility. Also, further studies for the interactions between thyroid gland disorders and zinc homeostasis were suggested