Background: Estrogen therapy is widely used nowadays in women to treat many postmenopausal symptoms but it may have some undesirable effects due to multiple organs affection. So, the aim of this study was to determine the effects of chronic estradiol treatment on the structure and function of the thyroid gland in ovarictomized rats as a model simulating menopause.

BackgroundSeveral 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. Aim of the workThe 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. Materials and methodsThirty 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&E, Masson's trichrome, and periodic acid-Schiff. The sections were also stained with an immunohistochemical stain against endotheliumderived nitric oxide synthase (eNOS). ResultsDiabetes 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. Conclusion NO increases in early diabetic kidney and ARB in the form of valsartan could be recommended for preventing the development of diabetic nephropathy.

Hypothesis: Several studies demonstrated that the patho-physiologic and morphologic changes in early diabetic nephropathy were mediated by either an increase or decrease in the nitric oxide (NO) production and/or activity. There are few reports suggesting a relationship between NO and renin-angiotensin system. Objectives: The present study was designed to determine the effects of early diabetic state on NO production and also to assess the protective effects of angiotensin receptor blockers (ARB) on these changes. Material and Methods: Thirty adult male albino rats were included in this study. Twenty were injected with streptozotocin for induction of diabetes. The other ten were injected with the vehicle and served as control. Two days after injection, the diabetic animals were randomly divided into two groups of ten 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 paraffin sections. The sections were stained with H & E, Masson trichrome and PAS reaction. Also, the sections were stained with immunohistochemical stain against endothelium-derived nitric oxide synthase (eNOS). Results: Diabetes induced histological changes in the form of glomerular hypertrophy,