Effect of excess iodide on the structure of the thyroid gland of prepubertal male albino rats: a histological and immunohistochemical study

Excessive iodine intake is emerging as a new healthcare-related concern. Excess iodine is associated with a spectrum of effects on the thyroid. The aim of this study was to assess the effects of excess potassium iodide [KI] on the histological and immunohistochemical structure of the thyroid gland and evaluate the biochemical changes in thyroid hormones. Forty prepubertal male albino rats aged between 4 and 6 weeks were classified into two equal groups: group 1 [the control group], which was given distilled water, and group 2 [the KI-treated group], which was further subdivided into two equal subgroups. Subgroup 1a was given 0.1 mg KI/kg/day for 4 successive weeks and subgroup 1b was given 0.1 mg KI/kg/day for 8 successive weeks. At the end of the period, the animals were anesthetized and blood samples were collected for measurement of serum T3, T4, and thyroid-stimulating hormone. Thyroid glands were dissected out and processed for examination using light and electron microscopes. For light microscopic examination, the sections were stained with H and E and immunohistochemical analysis was carried out for localization of Fas. H and E-stained sections of the KI-treated subgroups showed highly significantly enlarged follicular cavities that were distended with vacuolated colloid. Most of the follicles were lined with flattened follicular cells with flattened nuclei. Follicular epithelial height was highly significantly decreased. Ultrastructurally, follicular cells showed dilatation of the cisternae of the endoplasmic reticulum, mitochondrial swelling, many electron-lucent zones, and collagen fibers in the interstitial spaces. Also, most of the nuclei were heterochromatic. Immunohistochemically, there was a highly significant increase in staining for Fas in the follicular cells of the treated subgroups. Biochemical assessment detected a nonsignificant decrease in T3 and T4 and a highly significant increase in the thyroid-stimulating hormone levels of the treated group. Excessive iodine intake affects thyroid structure and function. Hence, public iodine intake should be regulated to make sure that it is within optimal levels. Proper monitoring of the salt iodization program is essential. Also, drugs with high iodine content should be administered with caution

effect of maternal exposure to di-[2-ethylhexyl]-phthalate on the lung of albino rat offspring: a histological and immunohistochemical study

Introduction: Di-[2-ethylhexyl]-phthalate [DEHP] is present in a wide variety of medical devices. Infants are more susceptible than the general population

Aim of work: To investigate histological and immnohistochemical changes in the lung of newborn rats in response to mothers' exposure

Materials and methods: Twenty nonpregnant adult female albino rats were used. After pregnancy, on the 15[th] day of pregnancy, dams were divided into two equal groups: the control group received corn oil and the treated group received DEHP [500 mg/kg/day] from the 15[th] day of pregnancy and during the 1[st] three weeks of lactation. Fifteen offspring from each group were subdivided into three subgroups, 1, 2, and 3, which were sacrificed at the 2[nd], 7[th], and 21[st] postnatal day, respectively. Lung specimens were processed for light microscope [H and E and immunohistochemical staining of proliferating cell nuclear antigen] and electron microscope examination

Results: H and E-stained sections of treated lung on the 2[nd] day showed variable-sized saccules. Primary septa were significantly thicker than those of the control group. However, on the 7[th] day, focally dilated saccules with thin primary septa were observed. Saccules and secondary septa were fewer than those in the control group. On the 21[st] day, variable-sized alveoli and a significant increase in septal thickness were observed. Immunohistochemically, there was a significant increase in proliferating cell nuclear antigen-positive cells on both the 2[nd] day and the 21[st] day, whereas they decreased on the 7[th] day in comparison with the control group. Ultrastructurally, treated lung on the 2[nd] day showed a saccular wall with many layers of interstitial cells, some with shrunken nuclei, whereas on the 7[th] day, thin septa were observed. Type II pneumocytes and interstitial cells had heterochromatic shrunken nuclei, whereas on the 21[st] day, the presence of macrophages was observed in the lumen. Interstitials cells and type II pneumocytes showed heterochromatic nuclei and marked distortion of organelles

Conclusion: DEHP induced marked histological and immunohistochemical changes in the lung. Alternative plasticizers with less adverse impact could be used. Further studies on the possible protective effect of antioxidants are recommended

possible protective role of vitamin eon fluoride induced neurotoxicity in the frontal cortex of adult male albino rats: [histological and immunohistochemical study]

Sodium fluoride is commonly added to drinking water, tooth pastes and some mouth washes as decay preventive ingredient. However, it becomes toxic at long term exposure and leads to some adverse effects on various organs, including brain. Investigate the possible histological and immunohistochemical changes in the frontal cortex of sodium fluoride intoxicated rats and evaluate the possible protective role of vitamin E. Thirty-six adult mate albino rats were used in this study and divided equally into three groups: control, treated and prophylactic. Treated group comprised animals that received a daily oral dose of sodium fluoride [20mg/kg] for 4 weeks. Prophylactic group received a daily oral dose of sodium fluoride [20 mg/kg] concomitant with vitamin E [400mg/kg] for the same duration. At the end of experiment, the frontal cortex of Ml rats was processed for light and electron microscopic examination. lmmunohistochemical study was performed for detection of Glial Fibrillary Acidic Protein [GFAP] and Bcl-2. The obtained results were analyzed morphometrically and statistically. Light microscopic examination of treated group revealed that most nerve cells in the cortical layers were distorted in shape with deeply stained shrunken nuclei. The ullrastructural study exhibited apoptotic neurons with heterochromatic nuclei. Their cytoplasm contained dilated and fragmented cistemae of rough endoplasmic reticulum. Immunohistohemical study of this group revealed intense positive immunoreaction for GFAP in the cytoplasm and processes of astrocytes while weak reaction for Bcl-2 was observed in most of nerve cells. The prophylactic group displayed normal appearance of most of nerve cells in the conical layers and few cells appeared distorted. Positive immunoreaction for Bcl-2 was observed in many nerve cells and endothelium of blood vessels. Area percent of GFAP immunoreaction in astrocytes in all groups showed significant increase in the treated group when compared with the control or prophylactic groups. Chronic exposure to sodium fluoride results in histological and immunohistochemical changes on the neurons and glial tissue of frontal cortex. Furthermore, combined vitamin E supplementation has an ameliorating effect on these changes. So, dietary supplements of vitamin Ii maybe beneficial for populations at risk

Postnatal development of the albino rat renal cortex [histological study]

Renal development involves 2 basic processes: morphologic formation and acquisition of function. The aim of the present study was to obtain histological information about the postnatal development of the filtration barrier and to throw more light upon the concomitant developmental changes of the convoluted tubules in albino rat's renal cortex. Ten pregnant female rats were utilized. Fifteen of their off springs were taken and divided into 3 groups: Group A: studied at the 2[nd] day postnatal. Group B: studied at the 10[th] day postnatal. Group C: studied at the 21[st] day postnatal. Kidneys were removed then 5 micro m thick paraffin sections were obtained and stained with haematoxylin and eosin stain for light microscope study. Renal cortex was cut into minute pieces and prepared for electron microscope study. Light microscope examination of 2 days renal cortex exhibited two cortical zones. The subcapsular zone contained immature forms of the renal developmental stages; the juxtamedullary zone contained mature renal corpuscles. While, electron microscope examination showed podocytes with flat cytoplasmic sheets and foot processes. Endothelial cells had few fenestrations. The filtration barriers revealed double basement membrane. The lining cells of proximal tubules had few short apical microvilli, mitochondria randomly oriented and few basal infoldings. Also, those of distal convoluted tubules appeared with randomly oriented mitochondria and some basal infoldings. The light microscope examination of 10 days renal cortex showed disappearance of all immature forms and maturing glomeruli were observed. Electron microscope examination showed podocytes with its primary processes and foot processes. The endothelial cells showed numerous fenestrations. The filtration barriers revealed fused basement membranes with presence of outpockets. The lining cells of proximal tubules had numerous tall tightly packed apical microvilli. Mitochondria appeared lodged in the basal infoldings in both proximal and distal tubules. The light microscope examination of 21 days renal cortex revealed mature renal corpuscles with lobulated glomeruli. Electron microscope examination demonstrated mature glomeruli showing podocytes with numerous foot processes. The filtration barrier showed regular basement membrane with no outpockets. The endothelial cells appeared attenuated with numerous fenestrations. Proximal and distal tubules showed mature picture. It has been proposed that adult renal diseases may be determined by events that occurred during fetal development. Therefore, results of studies on renal development in experimental models need to be interpreted and correlated carefully with the concomitant functional changes