Nicotine impact on rat substantia nigra compacta / 대한해부학회지

Nicotine neuronal interactions exert an adverse potential in some brain regions and a significant link has been established between tobacco smokeicotine and vascular impairment. This work addresses nicotine impact on various components of the substantia nigra compacta (SNc) in rat. Twenty adult male Albino rats were divided equally into two groups: Group I, vehicle-control group (received saline [1 ml/kg body weight intra peritoneally] for 11 days). Group II; nicotine group (received 1.5 mg/kg body weight/day Sc) for 11 days. Nicotine levels were detected in the serum. Specimens were taken from the mid brain, processed and examined using biochemical, immunohistochemical, ultrastructural and morphometric techniques. In nicotine group, biochemical analysis revealed reduction in total antioxidant capacity (TAC), decrease in dopamine and malondialdehyde (MDA) levels. The mean number of light cells, and the mean surface area of nerve cells/field were significantly reduced, with an increase of dark cells were found in nicotine group compared to control.Immunoreactivity in nicotine group revealed an increase in neuronal α-synuclein, reduction in tyrosine hydroxylase enzyme, an increase in caspase 3 and ultrastructure changes suggestive of neuronal apopto. The blood capillaries were markedly affected. Nicotine induced endothelial and pericytic apoptotic changes, irregular lumena and indistinct endothelial junctional complex. Nicotine administered subcutaneously in a small dose may have a deleterious effect on SNc, mainly involving dopaminergic neurons and blood capillaries. This effect seems to be secondary to an oxidative stress that might be produced by reduced TAC and increased MDA levels.

Nicotine impact on rat substantia nigra compacta / 대한해부학회지

Nicotine neuronal interactions exert an adverse potential in some brain regions and a significant link has been established between tobacco smokeicotine and vascular impairment. This work addresses nicotine impact on various components of the substantia nigra compacta (SNc) in rat. Twenty adult male Albino rats were divided equally into two groups: Group I, vehicle-control group (received saline [1 ml/kg body weight intra peritoneally] for 11 days). Group II; nicotine group (received 1.5 mg/kg body weight/day Sc) for 11 days. Nicotine levels were detected in the serum. Specimens were taken from the mid brain, processed and examined using biochemical, immunohistochemical, ultrastructural and morphometric techniques. In nicotine group, biochemical analysis revealed reduction in total antioxidant capacity (TAC), decrease in dopamine and malondialdehyde (MDA) levels. The mean number of light cells, and the mean surface area of nerve cells/field were significantly reduced, with an increase of dark cells were found in nicotine group compared to control.Immunoreactivity in nicotine group revealed an increase in neuronal α-synuclein, reduction in tyrosine hydroxylase enzyme, an increase in caspase 3 and ultrastructure changes suggestive of neuronal apopto. The blood capillaries were markedly affected. Nicotine induced endothelial and pericytic apoptotic changes, irregular lumena and indistinct endothelial junctional complex. Nicotine administered subcutaneously in a small dose may have a deleterious effect on SNc, mainly involving dopaminergic neurons and blood capillaries. This effect seems to be secondary to an oxidative stress that might be produced by reduced TAC and increased MDA levels.

Morphology of cat vomeronasal organ non-sensory epithelium during postnatal development / 대한해부학회지

The vomeronasal organ has an important role in mammal's social and sexual behaviours. In addition, it mediates defensive behavior through detection of protein pheromone homologues. In this work, a detailed morphological description of the postnatal development of the non-sensory epithelium (NSE) lining the vomeronasal duct (VND) of the female cat is provided using various histological techniques. The study focused on newborn, 2 weeks, 4 weeks, and 8 weeks of postnatal ages using four animals for each age. We report here for the first time that three types of NSE line the rostral segment of the VND; nonkeratinized stratified squamous epithelium, stratified cuboidal epithelium, and ciliated pseudo stratified columnar ciliated epithelium with goblet cells and that the VND undergoes 90° a change in its its axis from the vertical position caudally to the horizontal position rostral. The NSE which lines the lateral side of the VND middle segment is consists of cliated pseudostratified columnar epithelium without goblet cells. In addition to basal cells, the NSE contains ciliated and three types of nonciliated columnar epithelial cells (dark, light, and unstained). Mitotic figures were observed only in the basal cells layer during the first 2 weeks of postnatal development. Intraepithelial invading inflammatory cells were uncommon. Scanning electron microscopy revealed unevenly distributed long cilia intermingled with microvillar processes and intervening short microvillar processes. These projecting cilia and microvilli revealed a gradual increase in their height during development toward maturity.

Effect of nicotine on the structure of cochlea of guinea pigs / 대한해부학회지

Smoking has been positively associated with hearing loss in human. However, its effect on the cochlea has not been previously evaluated. Aim of work is to investigate the effect of nicotine, which is the primary pharmacological component of tobacco, on the structure of the cochlea of adult male guinea pigs. Fifteen male guinea pigs were classified into two groups: group I (control) and group II (nicotine treated group). Group II was further subdivided into two subgroups; IIA and IIB according to the dose of nicotine (3 mg/kg and 6 mg/kg, respectively). The cochlea was harvested and processed for light microscopy, transmission electron microscopy and scanning electron microscopy. Nicotine administration induced damage of outer hair cells which were distorted in shape with vacuolated cytoplasm and heterochromatic nuclei. Topography revealed damage of the stereocilia which included disorganization, bent and limp or complete loss and expansion of the surrounding supporting cells. These changes were more pronounced in the basal turn of the cochlea and mainly involved the outer hair cells. High dose induced more damage and resulted in protrusion of the apical poles of hair cells (blebing), particularly the outer two rows. Nicotine is proved to be harmful to the cells of the cochlea, particularly the outer hair cells of the basal turn. High doses induce blebing of hair cells.

Harderian gland of adult and aged male guinea pig a histological and ultrastructural study

The Harderian gland [HG] was studied in mature [4 months] and aged [2 years] male guinea pigs with light and electron microscopic techniques. The glandular tissue showed yellow green autofluorescence. The gland is surrounded by a collagenous capsule. It consisted of compound tubuloalveoli lined by a single layer of epithelial cells and possessing myoepithelial cells within their basal lamina. Semithin sections revealed two types of secretory cells; light and dark. Ultrastructurally three types of secretory cells could be recognized: type IA, type IB and type II. Type IA cells were the most readily observable one. The contained numerous lipid vacuoles, but no secretory vesicles. Type IB cells characteristically possessed numerous secretory vesicles with dense core. Type II cells exhibited light cytoplasm containing an elaborate SER, few lipid vacuoles and dilated RER cisternae. The gland is characterized by a specialized duct system within its substance. The gland structure showed several aging changes. These included invasion of the parenchyma with inflammatory cells, frequent detection of both plasma cells and mast cells, degeneration in both the secretory and the myoepithlial cells, increased deposition of connective tissue fibers as well as appearance of numerous immature blood capillaries. The results indicate that the guinea pig HG possesses several peculiar morphological features that deserve further investigations