Effect of sodium fluoride-induced toxicity on the renal cortex of lactating mice and their offspring: a light and electron microscopic study

Fluoride is commonly added to drinking water for its clarification and to reduce tooth decay. However, fluoride was shown to have cumulative toxic effects on various organs, including the kidneys. To investigate the impact of sodium fluoride toxicity of drinking water on the histological structure of the renal cortex of lactating mice and their suckling offspring. Forty mice [20 mothers and 20 of their offspring] were used in this study and divided equally into four groups: group I [control mothers]: allowed ad libitum access to tap water without any added sodium fluoride during pregnancy and lactation, group II [treated mothers]: drinking tap water containing NaF [0.5 g/L] from day 15 of pregnancy until day 14 after parturition, group III: [suckling offspring of control mothers] and group IV: [suckling offspring of treated mothers]. All mice were killed on postnatal day 14. Specimens were prepared for light microscope examination [hematoxylene and eosin and periodic acid-Schiff] and electron microscope examination. In addition, tubular epithelial height and tubular diameter were measured morphometrically and analyzed statistically. Examination of the renal cortex of treated mothers [group II] showed atrophic glomeruli with widened glomerular spaces. Tubules appeared dilated with decreased epithelial height as proved morphometrically. Tubular cells had a vacuolated cytoplasm and pyknotic nuclei. The apical brush border of many proximal tubules showed a weak and disrupted periodic acid-Schiff reaction. Ultrastructurally, some proximal lining cells showed heterochromatic nuclei, numerous cytoplasmic vacuolation of variable sizes and small scattered rounded mitochondria associated with loss of basal infoldings. However, the distal tubules maintained their basal infoldings and organized mitochondria. Podocyte foot processes were distorted and rested on a thickened glomerular basement membrane. The suckling offspring of the treated mothers showed less severe tubular injury than observed in their mothers as the tubular dilatation and the epithelial height were not affected significantly. Sodium fluoride induced various degrees of damage to the structure of renal cortex. The lactating mice renal cortices were severely affected compared to those of their suckling offspring. Thus, it is recommended to adjust the fluoride content in the municipal water supply and to avoid excess fluoride intake especially for lactating mothers

role of hormone replacement therapy on structural integrity of lacrimal gland in ovariectomized albino rats [histological and immunohistochemical study]

Sex steroid hormones are important regulators of lacrimal gland functions. In addition, dry eye syndrome is conmion in menopausal women. This work was conducted to demonstrate the role of hormone replacement therapy [HRT] on structural integrity of the lacrimal gland of ovariectomized rats. Thirty six adult female albino rats, were used in the present work divided into three equal groups: Group I [control] and group II [bilaterally ovariectomized rats] sacrificed 1 and 12 weeks following ovariectomy. The third group contained ovariectomized rats receiving HRT was subdivided into: Subgroup lila received estradiol benzoate and subgroup III b received androgen. Small pieces of the gland were obtained and processed for different histological and immunohistochernical stains. One week after ovariectomy the connective tissue septa was thickened. Collagen fibers were abundant with extensive cellular infiltration around dilated ducts and congested blood vessels. Some acinar cells were vacuolated and others contained darkly stained nuclei. Twelve weeks after ovarictomy, the acini were lined with low cuboidal cells and their lumina were widened with increased collagen fibers inbetween. In hormone treated group, the gland nearly regained its normal architecture, however few acinar cell nuclei showed hyperchrornatism. In estrogen treated group some interlobular septa were widened. Concerning fiRs inimunoreactivity, in group 11, the acinar cell nuclei showed strong positive reaction in the first week then the reaction was negative after 12 weeks. The immune reaction for ERs remained negative after the HRT. One week after ovariectomy, the immune reaction for bcl-2 was weak in the cytoplasm of ductal cells and moderate in interstitial cells. After 12 weeks, they became immune negative and after estrogen and androgen treatment marked rise in their bcl-2 immune reactivity was observed. Sex hormone balance was proved to be a crucial factor in maintaining structural and functional integrity of lacrirnal gland. So, future clinical therapeutic strategies based on estrogen and/or androgen replacement therapy for aged women and patients with premature ovarian failure could help in preventing or curing dry eye syndrome associated with lacrimal deficiency is adivsed

Histology and ultrastructural changes after enalapril injection in experimentally induced acute myocardial infarction in albino rats

Angiotensin converting enzyme inhibitors [ACEI] are still cautionary addressed in acute myocardial infarction. This study was carried out to elucidate how can enalapril [an ACEI] injection modulate the histological and ultrastructural features of acute left ventricular infarction in albino rats. In this study 25 albino rats were used. They were divided into control and experimental groups, which included renovascular hypertensive, acute infarcted group and enalapril-treated subgroups. From the previous findings it could be concluded that early intervention with enalapril in experimentally-induced acute left ventricular infarction would reduce the infarction areas and improve the ischemic injury