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.

Histological structure of male rat pituitary gland following treatment with paracetamol singly or concomitantly with honey

Paracetamol, also known as acetaminophen, is one of the most commonly used drugs as an analgesic and anti-inflammatory. Paracetamol contains a phenol ring and an acetyl group raising the possibility that it might have sex steroid antagonist properties. A small proportion of the drug is metabolized into a reactive metabolite, which is normally detoxified by glutathione. Over dose might cause glutathione depletion and oxidative stress. Honey is considered as an antioxidant because of the presence of ascorbic acid, flavonoid and alpha-tocopherol. This work was carried out to investigate the morphological modifications that would occur in the pituitary gland of male rats in response to the administration of acetaminophen in therapeutic dose for one month duration and a possible protective effect of honey when given concomitantly with paracetamol. Thirty adult male albino rats were used. The animals were divided into three groups. Group I served as a control Group II were given paracetamol orally in a dose of 800 mg/kg/day for one month. Group III were given paracetamol in a similar dose and duration concomitantly with honey in a dose of 2.5 gm/kg/day orally. All the animals were sacrificed and the pituitary gland was dissected out and processed for general histological and ultrastructural examination of the pars distalis. The pars distalis of group II revealed variable structural changes in the gonadotrophs and somatotrophs. In group III the changes extended to involve the thyrotrophs. The most characteristic change was the excessive dilatation in ER. It is concluded that paracetamol influences the structure of pars distalis in a selective form. Honey modifies paracetamol effect, possibly via its ascorbic acid contents