Comparative study on the effect of antioxidants alpha-lipoic acid and N-acetyl cysteine on the structure of the renal tubules of diabetic rabbits

Hyperglycemia-induced oxidative stress plays a central role in the pathogenesis of diabetic complications. The therapeutic potential of antioxidants in the prevention and treatment of these complications is an emerging research area. The roles of alpha-lipoic acid [ALA] and N-acetyl cysteine [NAC] in the protection against oxidative stress in alloxan-induced diabetic rabbits were assessed both biochemically and histologically in this study. Thirty-two mature male rabbits were used in this study. They were divided into two groups: the control group [n=8] and the experimental [n=24] group; the experimental group was injected intraperitoneally with alloxan [180mg/ml/kg body weight]. After 3 weeks, this group [diabetic rabbits] was subdivided into three subgroups of eight rabbits each. The first one was left as the untreated diabetic subgroup; rabbits in the second and third subgroups were treated daily for 7 days with ALA and NAC [100 mg/ml/kg body weight], respectively. At the end of the experiment, blood and kidney sections were processed for biochemical and histological studies. The renal tubules showed degenerative and apoptotic changes, which were associated with increased DNA fragmentation and lipid peroxidation in the kidney tissues, as well as reduction in the capacity of the antioxidant defense system. However, treatment of diabetic rabbits with either ALA or NAC ameliorated diabetes-induced oxidative stress. ALA and NAC could be useful in the prevention and treatment of oxidative stress associated with hyperglycemia. This action seems to result mainly from direct scavenging of reactive oxygen species and restoring of the GSH [glutathione] redox state

Effect of low phosphate diet on the structure of the rat parathyroid and thyroid glands

Dietary phosphate restriction in patients with chronic renal insufficiency has been demonstrated to prevent the increase in serum parathyroid hormone [PTH] levels clinically. Besides, the effect of phosphate on serum PTH levels is reported to be independent of changes in the level of both serum calcium and vitamin D. To investigate the structure of the parathyroid and the thyroid glands in rats fed restricted phosphate diet. Three groups of adult Wistar rats were used in this study. Group I, served as control. They were fed with regular balanced diet containing normal [0.6%] phosphate, normal [0.6%] calcium diet. Groups II and Ill [the experimental groups], were fed low [0.02%] phosphate, normal [0.6%] calcium and low [0.02%] phosphate, low [0.02%] calcium diets respectively for 30 days. The morphology of the parathyroid and thyroid glands was studied, using light and electron microscopic techniques. The parathyroid glands of groups II and Ill were atrophied with connective tissue invasion and darkening of the chief cells. The chief cells revealed well developed Golgi and RER cisternae, and the cytoplasm contained numerous small granules containing particulate material. The thyroid follicles in group Ii animals appeared lighter in staining, whereas in group Ill, most of the follicular cells were darkened. However, the activation was focal in distribution. Active interaction between the thyroid follicular and the adjacent parafollicular cells was evident. Both the plasma and nuclear membranes of the follicular cells exhibited signs of interactions. The thyroid parafollicular cells in group H appeared dark and contained numerous secretory granules, whereas in group III they were pale and contained few granules. It can be concluded that phosphate restriction induces a direct atrophic effect on the parathyroid gland, independent of calcium level. On the other hand, phosphate restriction influences the thyroid parafollicular cells indirectly, most probably through modulating the blood calcium level. It can also be concluded that a mutual cooperation exists between the thyroid follicular and parafollicular cells

Morphological and morphometric study of cultured fibroblast from treated and untreated abnormal scar

To investigate the morphology of cultured fibroblasts derived from abnormal scars and compare it to those of human normal skin. This study was carried out in the Surgical Clinic, Faculty of Medicine, King Abdul-Aziz University, Jeddah, Kingdom of Saudi Arabia between December 2008 and March 2010. Fifty-two samples of hypertrophic and keloid scar were collected. An in vitro study was conducted in which fibroblasts from normal foreskin; abnormal scars were cultured, studied morphologically and morphometrically. There was a highly significant increase in the length and breadth of fibroblasts from the hypertrophic and keloid scars, and highly significant decrease in the bipolarity index compared to control. There was a significant increase in the mean cell area, mean nuclear area and nuclear/cytoplasmic ratio of fibroblast of hypertrophic and keloid scars compared to control. There was a significant decrease in the mean cell area and mean nuclear area of the fibroblast of the treated keloid scar [with all used modalities] compared to untreated ones. Morphologically, abnormal scar fibroblasts has abundant spreading cytoplasm with numerous processes and large nuclei. The cytoplasm, of some cells, contained clumped granules in the peri-nuclear region, numerous vacuoles, and dense vesicles. Morphological and morphometric study showed that hyperactive cultured fibroblasts was a characteristic feature of abnormal scars and the studied modalities of treatment reduced, but not completely nullify this activity

Ultrastructural study on the acini of the submandibular gland of adult experimentally diabetic male albino rat

The fine structure of the submandibular gland of male adult albino rats has been examined in control rats and in rats subjected to induced by alloxan for one, two and four months. All diabetic rats developed persistent hyperglycemia, lost weight, had atrophied testes and some of them became cachectic. Variable ultrastructural changes were evident in the affected acinar components even in early stages of diabetes induction of the experiment. It became more progressive after four months. The nuclei became irregular, electron dense and indented. There was a decrease in the amount of rough endoplasmic reticulum which appeared as fragmented strands. Accumulation of protein secretory material within the cytoplasm was followed by degenerative changes resulting in cell death. The presence of lipid droplets of variable sizes in basal cytoplasm was also noticed