Electron microscopic study of the left caput epididymal epithelium of adult albino rats in an experimental left varicocele model

Varicocele is a vascular lesion characterized by dilatation and tortuosity of the pampiniform plexus of the spermatic cord. It is one of the most common causes of male infertility. Most studies have focused on testicular function. Meanwhile, there are limited data in the literature on its impact on the epididymal structure. The aim of this study was to assess the effect of an experimental left varicocele on the histological structure of the left caput epididymis of adult albino rats and the cauda epididymal sperm count. Forty adult male albino rats [220-250 g] were randomly allocated to four equal groups. In group I [control group], rats did not undergo any surgical intervention. In group II [sham-operated group], animals underwent sham operation. The rats of groups III and IV underwent partial ligation of the left renal vein to create a varicocele and were sacrificed after 4 weeks and 8 weeks, respectively. Left caput epididymal strips of five rats of each group were harvested and prepared for light and electron microscopic examinations. Sperm samples were obtained from the left cauda epididymides of the remaining animals of each group for sperm count, and the results were statistically analyzed. There was a positive correlation between the sperm count and the duration of varicocele. Group III rats revealed a significantly lower sperm count as compared with the control and sham-operated groups. A significantly greater reduction in the sperm count was found in group IV rats as compared with group III rats. Histologically, varicocele-induced left caput epididymal alterations mainly involved the principal cells. They included cytoplasmic vacuolation and widening of the intercellular spaces in semithin sections of group III rats. Ultrastructurally, increased vesicular and vacuolar contents of the apical cytoplasm along with dilatation of Golgi saccules and rough endoplasmic reticulum were observed. The tubular lumina depicted several retained defective spermatids and spermatozoa with retained cytoplasmic droplets. With an increase in varicocele duration [in group IV], apparent thinning out of the lining epithelium with few stereocilia was observed in semithin sections. Ultrastructurally, the principal cells revealed a relatively dense cytoplasm and rather heterochromatic nuclei. The lumina were bordered with short, sparse microvilli and showed several defective spermatozoa. Experimental left varicocele induces evident histological alterations of the ipsilateral caput epididymis of adult rats and also a reduction in the caudal sperm count, both of which are duration dependent

Histological and toxicological study on the effect of kojuc acid on the thyroid follicular cells of albino rats

Kojic acid is a natural substance, widely used as a food additive and preservative, in cosmetic preparations as a skin whitening agent, a plant growth factor as well as a chemical intermediate in pharmaceuticals. The goal of the present study was to clarify the impact of kojic acid on the thyroid follicular cells of male albino rats as well as the reversibility of its effect after withdrawal, both histologically and biochemically. A total of 30 adult male albino rats [120-150 g] were randomly divided among 3 equal groups. Group I [control group]: received isotonic saline orally for 4 weeks. Group II [treated group]: received kojic acid in a dose of 0.8g/kg b.w./day orally for 4 weeks. Group III [withdrawal group]: received kojic acid daily in the same dose and duration as in group II followed by its withdrawal for the next 4 weeks. By the end of the experimental periods, blood samples were collected for estimation of plasma triiodothyronine [T3], thyroxine [T4] and thyroid stimulating hormone [TSH] levels. Histological examination of toluidine blue-stained semithin sections, and ultrathin sections of the thyroid gland was also carried out. Statistical assessment of the biochemical parameters of group II rats showed significant reduction in T3 and T4 levels along with evident increase in TSH levels as compared to the control animals. Histologically, overt signs of hyperactivity affecting many thyroid follicles were encountered. It was represented by follicular cell hypertrophy and focal hyperplasia. Stratjfication of the lining follicular cells was also observed in some follicles. Many follicular cells exhibited dilatation of the rough endoplasmic reticulum [rER], cytoplasmic vacuolation, accumulation of numerous lysosomes and mitochondrial affection. Some follicular cells revealed signs of severe degeneration in the form of dense cytoplasm and small irregular dense nuclei. Withdrawal of kojic acid in group III rats resulted in return of the biochemical parameters as well as histological picture of the follicular cells to nearly normal control patterns. However, some follicular cells still revealed evident dilatation of the rER and many lysosomes. As well, few follicles were lined by more than one layer of follicular cells. Kojic acid exerted an evident toxic effect on the thyroid follicular cells. Although such effect was nearly completely reversible after kojic acid withdrawal, yet, it is recommended to restrict its use in food and cosmetic agents