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

Propranolol versus prazosin on some aspects of lipid metabolism in rats exposed to cigarette smoke: a biochemical, histological and histochemical study

The effects of prazosin and propranolol monotherapy on serum lipids were compared in rats exposed to cigarette smoke. Cigarette smoke exposure for two weeks resulted in a significant increase in serum triglycerides and LDL-cholesterol. Changes in total cholesterol / LDL-cholesterol ratio were not statistically significant. Prazosin monotherapy [0.5 mg/kg/day p.o. for two weeks] resulted in a decrease [insignificant] in serum triglycerides, total and LDL-cholesterol concentrations and total cholesterol/LDL-cholesterol ratio. Propranolol monotherapy [70 mg/kg/day p.o. for two weeks] resulted in a significant increase in serum triglycrides, total cholesterol and LDL-cholesterol, while the total cholesterol/LDL-cholesterol ratio. Propranolol monotherapy [70 mg/kg/day p.o. for two weeks] resulted in a significant increase in serum triglycerides, total cholesterol and LDL-cholesterol, while the total cholesterol/LDL-cholesterol ratio showed a significant drop. Cigarette smoke exposure in rats treated by prazosin resulted in attenuation of the deleterious effects of smoke on triglycerides and LDL-cholesterol. However, potentiation of the effects of exposure to cigarette smoke was noted in the propranolol treated group. Histological study of the liver in the different groups by H and E, and both the enzymatic [succinic dehydrogenase, non-specific esterase, alkaline and acid phosphatases] and the non-enzymatic histochemical [Sudan black B, OTAN and Schultz reactions] findings sustantiate thebiochemical data obtained. It is suggested that the effects of prazosin on serum lipids may be mediated, at least in part, by blocking an action of either the sympathetic nervous system or sirculating catecholamines that normally modulate lipoprotein metabolism and might mediate the lipid alterations induced by smoking. Furthermore, the data suggest that propranolol may induce significant, potentially atherogenic changes in lipid metabolism, whereas prazosin may represent an advantageous alternative as an antihypertensive agent, especially in smoking subjects with an already atherogenic lipoprotein profile

Effect of toxocara canis on histopathology and histochemistry of brain, liver and kidney of mice

Thirty-five albino mice were infected with Toxocara canis eggs. The larval count was done in the whole body and in each organ separately. Pieces of the brain, liver and kidney were examined histologically and histochemically for studying succinic dehydrogenase, alkaline phosphatase, acid phosphatase and nonspecific esterase