Histological and histochemical study of the toxic effect of sodium fluoride and the possible protective role of sodium selenite on the convoluted tubules of the renal cortex of albino rats

Sodium fluaride is known as a specific and effective dental caries rohylactic agent and its systemic or local application is widely recommended in the recent years. It is also used as antihelminthic against roundworms, and for treatment of osteoporosis and otosclerosis in conjunction with calcium supplements and vitamin D. Moreover, it is used for water fluoridation, and as a rodenticide, disinfectant and fungicide. In recent years, acute and chronic toxicity of fluoride has been reported. The purpose of the recent study was to shed light on the histological [light and electron microcopic] and histochemical changes that might occur in the proximal and distal convoluted tubules of the renal cortex of albino rats following acute and chronic sodium fluoride [NaF] toxicity and to investigate the possible protective effect of sodium selenite [Na[2]SeO[3] administration on such toxicity. The present study was carried out on 80 adult male albino rats. They were divided into two main groups: acute NaF toxicity group and chronic NaF toxicity group, each of them included forty rats and was divided equally into four groups which were control group, NaF group, Na[2]SeO[3] group, and NaF and Na[2]SeO[3] group. In the acute toxicity group, NaF group received a single oral dose or NaF [135mg/kg body weight], Na[2]SeO[3] group received a single oral dose of Na[2]SeO[3] [0.35mg/kg body weight/day], while NaF and Na[2]SeO[3] group received a single oral dose of NaF [135mg/kg body weight] simultaneously with a single oral dose of Na[2]SeO[3] [0.35 mg/kg body weigh/day]. On he other hand, in chronic toxicity group, NaF group received NaF orally in a dose of 6mg/kg body weight/day, Na[2]SeO[3] group received Na+2+Se[SeO[3] orally in a dose of 0.35 mg/kg body weight/day, while NaF and Na+2+SeO[3] group received a daily oral dose of NaF [6mg/kg body weight/day] simultaneously with a daily oral dose of Na[2]SeO[3]]0.35mg/kg body weight/day] for three months. All rats were sacrificed 24 hours after their last dosing by decapitation after ether anesthesia Fresh specimens were taken from the renal cortex of each rat and prepared for the histological study [light microscopic examination using haematoxylin and eosin stain, and electron microscopic examination using the transmission electron microscope], and histochemical study [Periodic Acid-Schiff reaction]. The results of the present study revealed that there were marked histological and histochemical changes in the convoluted renal tubules following acute and chronic NaF toxicity. Moreover, sodium selenite was found to be a safe anti-oxidant, when used in appropriate dose, which could offer protection for the renal tissue in chronic NaF toxicity. Hence, it is recommended as a prophylactic agent given to workers highly exposed to sodium fluoride in their work place

Effects of electromagnetic fields on the skin of albino rats: a histological study

The aim of the present study was to evaluate the histological changes that might result from the long-term exposure to static and time varying electromagnetic fields [EM] of extremely low frequency on the skin of albino rats. This work was carried out on 15 adult male albino rats divided into three equal groups: Group I served as a normal control, group II was exposed to 10 mT static electromagnetic field two hours/day for one month and group III was exposed to 10 mT time varying electromagnetic field of extremely low frequency [50 Hz] for two hours/day for one month. By the end of the experiment, the animals were sacrificed by decapitation and specimens from the skin of each rat were taken and processed for electron microscopic and light microscopic examination by routine H and E, Gomoriis trichrome and orcein stains. The study concluded that the long-term exposure to magnetic fields may induce structural changes in the skin of albino rats being more prominent with time varying than with static electromagnetic field

Induced immunological Vasculitis in duodenum of albino rats: an ultrastructure study

Two groups of albino rats were included. The control group is formed of nine albino rats, divided into three subgroups: 1] Primed [sensitized] only by intraperitoneal injection of soybean protein emulsion, 2] duodenal tube feeding for 14 days by soybean protein hydrolysate only, and 3] oral feeding by soybean protein-free milk formula. The test group formed of nine albino rats were primed by intraperitoneal injection of soybean protein emulsion and challenged after one week by duodenal tube feeding of soybean protein hydrolysate for 14 days or till diarrhea developed. Results showed that all control groups showed no pathological abnormalities in their duodenum and did not develop diarrhea. The test group showed basically similar changes that varied in severity from mild, moderate to marked. The immunological findings were humoral and cellular immume reaction. Edema of the duodenum erythema and reduction in the size of the villi were seen morphologically. Ultrastructurally, deposition of immune complexes in the basement membrane leading to its thickening and irregularity, adhesion of leukocytes [PNLs, monocytes and lymphocytes] to the injured endothelium, edematous corium and inflammatory cellular infiltrate, increase in the number of lymphocytes going to the surface and congested plugged blood vessels were seen

Distribution of action filaments in spermatogenic cells and sertoli cells of mouse: an ultrastructural study

Study of the distribution of actin in spermatogenic cells and Sertoli cells of mouse might be important in elucidating how they may contribute to some of the processes that occur during spermatogenesis. Fifteen adult healthy male mice were used for this study. Testicular specimens were taken, fixed and processed for examination by a transmission electron microscope. Actin filaments were demonstrated in specific regions of the seminiferous epithelium. In spermatogenic cells, they occurred in the intercellular bridges between spermatogenic cells, in the subacrosomal spaces, and in the gap between the capitulum and the implantation fossa of differentiating spermatids. In Sertoli cells, they were abundant in ectoplasmic specialization and around the bulbar segment of tubulobulbar processes of late spermatids. At all of these sites, the filaments were related to the plasma membrane. The possible functional significance of actin filaments in such location was discussed