Vitamin E ameliorates histological and immunohistochemical changes in the cerebellar cortex of alloxan-induced diabetic rats

Diabetes mellitus causes a variety of functional and structural disorders in the central nervous system. To describe structural, ultrastructural, and immunohistochemical changes in the cerebellar cortex of alloxan-induced diabetic rats and to determine the possible protective effect of vitamin E. The rats were divided into three equal groups at random: group A [control], group B [alloxan-induced diabetic rats], and group C [alloxan-induced diabetic rats that received vitamin E]. In rats of groups B and C, diabetes was induced by a single intraperitoneal injection of alloxan monohydrate. After 8 weeks, the rats of all groups were sacrificed and the cerebellum was dissected immediately and subjected to H and E stain, and immunostaining for glial fibrillary acidic protein [GFAP], and thin strips from the cortex were prepared and examined by transmission electron microscopy. Diabetic untreated rats showed shrunken Purkinje cells and apoptotic cells in the granular layer. Ultrastructurally, the nuclei of Purkinje cells were irregular and the cytoplasm contained numerous lysosomes, abnormal mitochondria, and dilated Golgi saccules. Myelinated nerve fibers showed splitting of myelin sheaths and wide axonal spaces. Immunohistochemically, a significant increase in the number of GFAP-positive astrocytes in diabetic untreated rats was found as compared with the control. These histological and ultrastructural alterations were ameliorated in vitamin E-treated diabetic rats. Moreover, a significant decrease in the number of GFAP-positive astrocytes was found in animals that received vitamin E as compared with diabetic untreated rats. Vitamin E can be used as an adjuvant therapy for the prevention and treatment of the central nervous system complications of diabetes

Ultrastructural changes in lactotrophs and somatotrophs of alloxan-induced diabetic rats and the possible protective effect of alpha-lipoic acid

Alteration in the cellular composition of the anterior pituitary gland could be involved in both prolactin and growth hormone disturbances in cases of poorly controlled diabetes. This study was conducted to investigate the ultrastructural changes in both somatotrophs and lactotrophs of diabetic rats and to investigate the possible protective effect of alpha-lipoic acid. Thirty adult male rats were randomly divided into three equal groups: group A [control], group B [alloxan-induced diabetic rats], and group C [alloxan-induced diabetic rats that received alpha-lipoic acid]. In rats of groups B and C, diabetes was induced by a single intraperitoneal injection of alloxan monohydrate. In animals of group C, alpha-lipoic acid was given intraperitoneally during the period of the experiment. Twelve weeks after induction of diabetes, specimens of the pituitary gland were processed for transmission electron microscopic examination and a morphometric study was conducted. Somatotrophs of diabetic rats showed condensed nuclei, dilated Golgi saccules, and dilated rough endoplasmic reticulum cisternae. Further, some lactotrophs showed corrugated or condensed nuclei, dilated Golgi saccules, and relatively fewer granules. In both somatotrophs and lactotrophs of diabetic rats, the number of cytoplasmic granules was significantly decreased as compared with that of control rats. In addition, a significant increase in the percentage of empty granules to the total number of granules was recorded. However, the total number of granules and the percentage of empty granules to the total number in both somatotrophs and lactotrophs were significantly reduced in diabetic rats treated with alpha-lipoic acid as compared with untreated diabetic rats. The spectrum of changes in lactotrophs and somatotrophs of uncontrolled diabetic rats was found to be corrected by alpha-lipoic acid and therefore alpha-lipoic acid is recommended as a form of adjuvant therapy for diabetes

Light and electron microscopic study of the corneal stroma during the healing process of alkali-induced ulcer

Corneal exposure to alkali is associated with defective clarity and impaired vision. This study was designed to describe structural and ultrastructural changes in the corneal storma following alkali-induced ulcer. Ten guinea pigs were anesthetized, and alkali burn was performed by touching a 4.0-mm-diameter applicator, a piece of sterile gauze, saturated with 1 mol/l sodium hydroxide on the corneas of the left eyes for 30 seconds. The right and left eyes were harvested. Corneas from the right side were used as controls. H and E-stained paraffin sections were prepared, and thin elongated strips from all the corneas were processed to be examined by transmission electron microscope. Two weeks after alkali burn, corneal stromal neovascularization with the appearance of postcapillary nevules was the most characteristic feature. This was associated with wide stromal spaces, inflammatory cellular infiltrate, activated fibroblasts, and irregularly deposited collagen. Despite corneal reepithelialization, stromal changes might account for defective clarity following exposure to alkali

Altered secretory activity in rat adrenal chromaffin cells after experimentally induced bronchial asthma and dexamethasone treatment: ultrastrucutral and biochemical study

It is generally accepted that chromaffin cells release their contents by both exocytosis and piecemeal degranulaltion [PMD]. Bronchial asthma and dexamethasone treatment might after this secretory activity. This study was designed to shed light on secretory activity in the normal adult rate chromaffin cells, in rats subjected to bronchial asthma and after treatment with dexamethasone. Rats were divided into three equal groups at random:group A[control], group B [asthmatic rats], and group C [dexamethasone-treated asthmatic rats]. In rats of group B, the chronic asthma model was established by an intraperitoneal injection and challenge with ovalbumin. In group C, the rats were pretreated with dexamethasone before each challenge. Serum epinephrine and norepinephrine levels were measured by enzyme-linked immunosorbent assay. Bronchoalveolar lavage fluid was examined for the total leukocytic count and paraffin sections from the lung were stained with H and E. Specimens of the adrenal medulla were examined by transmission electron microscope and were morphometrically analyzed. Significant decreases in serum epinephrine and norepinephrine levels were recorded in asthmatic rats and corrected after dexamethasone treatment. The total numbers of adrenaline and noradrenaline granules were significantly lower in asthmatic rats. Features of PMD manifested as tail-like projections, altered granules with eroded contents, partially empty granules, large completely empty containers, and small cytoplasmic vesicles were observed in control rats and were augmented in rats subjected to chronic asthma. Augmented features of PMD and biochemical changes in the conditions of chronic asthma could be corrected by dexamethasone treatment

L-carnitine attenuates testicular ischemia-reperfusion injury in rats

Testicular torsion might affect adolescent boys and adults and is considered one of the causes of reduced fertility. This study was carried out to describe late structural and ultrastructural changes in the rat testis following torsion/detorsion and to shed light on the possible protective effect of L-carnitine. Under general anesthesia, torsion was conducted by rotating the left testis 720 in a clockwise direction for 5 h followed by detorsion. The rats were divided into 3 equal groups: group I: Sham-operated control. Group II; torsion and detorsion were conducted as described. Group III; L-carnitine was injected intraperitoneally at a dose of 100 mg/kg, 1 h before detorsion. Seven days after detorsion, paraffin sections were obtained from the left testes of all groups and stained with hematoxylene and eosin and eendothelial nitric oxide synthase immunoreactivity. Fine specimens were processed to be examined with transmission electron microscope. Marked degenerative changes were seen in the seminiferous tubule manifested as irregularity of the basement membrane and cellular disarray. In addition, there were numerous apoptotic cells. An associated increase in eNOS immunoreactivity was detected. Ultrastructurally, spermatogonia appeared irregular and swollen with condensed nuclei. Spermatocytes showed relatively condensed nuclei and vacuoles that were variable in size and electron density. Sertoli cells appeared irregular with swollen mitochondria. In contrast, L-carnitine-treated animals exhibited less degenerative features and an unremarkable change in eendothelial nitric oxide synthase immunoreactivity. L-carnitine might be of benefit in treatment of testicular dysfunction resulting from torsion