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

Histological and immunohistochemical studies on the cerebellar cortex of adult male albino rats treated with griseofulvin

Griseofulvin was the first oral anti-fungal drug available for treatment of dermatophytosis. Neurological side effects including neuropathies, confusion, vertigo, eyesight disorders and fatigue may occur due to its use. Twenty adult male albino rats, each weighing 100-150 gm were used to study the toxic effects of griseofulvin administration on the histological structure of cerebellar cortex. They were classified equally into four groups. The first group: was used as a negative control group, the second group: was used as a positive control group, each rat was given 1 mL olive oil orally daily for 12 weeks, the third group: each rat was given griseofulvin orally [dissolved in olive oil in a dose of 2500 mg/kg body weight [1/20 of LD 50]for 6 weeks and the fourth group: each rat was given griseofulvin orally [dissolved in olive oil in a dose of 2500 mg/kg body weight [1/20 of LD 50] for 12 weeks. At the time of sacrifice all the animals were anaesthetized with ether inhalation and their cerebelli were carefully dissected and processed for paraffin sections then stained with hematoxylin and eosin, Weelecks procedure and modified aldehyde thionine technique to study the general structures. Immunohistochemical stain with astroglial marker antibody Glial Fibrillary Acid Protein was also used. In griseofulvin-treated animals of the third group, there was distortion of some Purkinje cells with loss of their dendritic arbirization and they were separated from each other. In treated animals of the fourth group, some Purkinje cells were more distorted and separated by wide spaces. The molecular layer appeared with scattered cells and less abundant nerve fibers in between. Immunohistochemically, tile treated animals of the third group showed Glial Fibrillary Acid Protein positive astrocytes in the molecular and granular layers. In the fourth group, there were Glial Fibrillary Acid Protein more positive astrocytes. The results of the current study revealed that, administration of griseofulvin for a long time induced adverse effects on the histological structure of the cerebellar cortex of adult male albino rats

Cardiotoxic and genotoxic effects of doxorubicin in albino rats

Doxorubicin [DXR] is a potent chemotherapeutic agent used in the treatment ofneoplastic diseases. To evaluate its cardiotoxicity and genotoxicity, it wasadministered orally for three successive weeks [three days a week] at a dailydose of 3.6 mg/kg body weight to a group of normal adult albino rats. At theend of the experiment, examination of the cardiac muscle of the treated ratsby light microscopic process showed areas of myocardial damage with separatedfoci of degenerated fibers, dilatation of blood vessels with increasedvasculature and areas of vascular degenerative changes between separatedirregular myofibrils. Electron microscopic study revealed, in addition to the above changes, a partial loss of myofibrils in some areas and degeneration in others, besides a disorganization of the nuclear membrane with nucleolusalternation and distension of blood capillaries. Increased vasculardegeneration and alternation of the interlocated discs were noted in manyareas with increased glycogen particles in-between the myofibrils. DXRinduced structural chromosomal aberration in the form of increased breaks andring chromosome formation, deletion of the short arm of acrocentricchromosome, and duplication of the long arm of metacentric chromosome, whilethe main numerical aberration was polyploidy chromosomal pattern

Light and electron microscopic studies of rabbit lungs in fresh water drowning and near-drowning

This study was designed to investigate the light and electron microscopic changes which occur in the lung of the rabbit in case of drowning and near-drowning. Thirty male healthy adult rabbits were used in this work. They were divided into three equal groups. The first group was used as a control group. The second group was anesthetized and endotracheal tube was introduced and 6 ml/kg of fresh water was instilled into the endotracheal tube. The animals were sacrificed after 29 minutes. The third group was also anesthetized and intubated, and fresh water was instilled into the endotracheal tube. Specimens from the lungs of the three groups were taken and processed for both light and electron microscopic processes. The results showed mainly vascular damage in near-drowning and marked alveolar cell damage in case of drowning