The apoptotic effect of a high dose of toluene on liver tissue during the acute phase: an experimental study.

The aim of this study is to investigate the acute toxic effects of high-dose toluene and its mechanisms on the liver tissue of toluene-treated rats. In this study, 16 adult male Wistar albino rats (200-220 g) were divided into two equal groups. Group I was used as a control group, while group II was exposed to high dose of toluene, 5200 mg/kg (6 ml/kg per gavage). After the 3-hour experimental period, blood samples and liver tissues were taken from the euthanized animals. Serum aspartate and alanine aminotransferase levels were assayed. Liver tissues were fixed in 10% neutral formalin, then embedded in paraffin and sectioned (5 µm thickness). Sections were stained with hematoxylin and eosin for histopathological examination. A terminal transferase dUTP nick end labeling assay was also done for the determination of apoptosis in liver tissues. For the determination of Bax and caspase-3 immunoreactivity, the sections were stained using avidin-biotin-peroxidase immunohistochemical method. The level of plasma transaminase was found to be increased in toluene administered rats. Additionally, slight degeneration of hepatocyte and mononuclear cell infiltration was observed in the liver tissue sections and a high (+++) immunoreactivity for Bax and caspase-3 protein was observed in the toluene group. This study showed that the high dose of toluene triggers apoptosis in the liver of rats via the mitochondrial pathway in acute period.

Does mitomycin-C increase collagen turnover as a modulator of wound healing in tracheostomyzed rats?

OBJECTIVES: This study aims to investigate the effect of mitomycin-C in the wound healing process on collagen synthesis in tracheostomyzed rats. MATERIALS AND METHODS: Fourteen healthy, in both sexes, mean weight of 270 g (range 250-300 g), Wistar-Albino type rats underwent tracheotomy and tracheal mucosa was damaged with micro-scissors on both sides of tracheostomyzed area. The rats were divided into two groups: The experimental group (group 1) received immediate topical application of mitomycin-C 0.2 mg/ml; the control group (group 2) received saline solution. The rats were sacrificed after a period of one month. Subsequently, the tracheostomyzed region was excised and vertically divided into the two parts. The level of hydroxyproline in the dry tissue was measured in one part of the tissue. Fibroblast count was performed in the other part of the tracheostomyzed region using the stereological method. RESULTS: The hydroxyproline level was much higher in the mitomycin-C group when compared to the control group (p<0.05). In contrary, the number of fibroblasts was lower in the mitomycin-C group than control group (p<0.05). CONCLUSION: When used in wound healing, mitomycin-C may increase collagen synthesis or quicken the wound healing process after one month.

Repeated dose of ketamine effect to the rat hippocampus tissue.

AIM: We aimed to determine the neurotoxic effect of repeated ketamine administration on brain tissue and if neurotoxic effect was present, whether this effect continued 16 days later using histological stereological method, a quantitative and objective method. MATERIALS AND METHODS: Female rats were divided into three groups, each containing five rats. Rats in Group I were given 0.9% saline solution 4 times a day for 5 days. The rats in Groups II and III were given ketamine as intraperitoneal injections. Rats in Groups I and II were sacrificed on 5(th) day while the ones in Group III on 21(st) day. Cornu ammonis (CA) and gyrus dentatus (GD) regions in hippocampus tissue of rats were studied using optic fractionation method. FINDINGS: There were significantly less number of cells in hippocampal CA and GD regions of rats from Groups II and III compared to the ones from Group I. Difference in cell number was also significantly higher in Group III than in Group II, but this difference was not as pronounced as the one between Groups III and I. CONCLUSION: Repeated ketamine doses caused neurotoxicity in rat hippocampus.

Beneficial effects of melatonin and BQ-123 on the rat testis damage caused by cigarette smoke.

BACKGROUND/AIM: Several studies have demonstrated that cigarette smoke has detrimental effects on testicular function. However, it is unknown whether melatonin or BQ-123 has beneficial effects on the rat testis damage caused by cigarette smoke. The aim of the present study was to investigate the beneficial effects of melatonin or BQ-123 on the testicular damage caused by cigarette smoke. MATERIALS AND METHODS: Twenty Wistar rats were randomly divided into 4 equal groups: control group (n = 5), cigarette smoke group (n = 5), melatonin group (n = 5), and BQ-123 group (n = 5). At the end of 4 weeks, all the rats were sacrificed for histopathological evaluation and subsequent stereological analysis. The optical fractionator counting method, the most efficient and unbiased method, was used to estimate the total number of spermatogonia and spermatocytes. RESULTS: All the control testes demonstrated complete spermatogenesis. There was a significant decrease in the germ cells of rats exposed to cigarette smoke for 4 weeks. After the application of melatonin or BQ-123, the total number of spermatogonia and spermatocytes in the testes was significantly higher. CONCLUSION: Based on these findings, melatonin and BQ-123 are able to minimize the degenerative effects of cigarette smoke by increasing the germ cell count.

Aquaporin-1 and aquaporin-3 expressions in the intervertebral disc of rats with aging.

OBJECTIVE: The intervertebral disc (IVD) undergoes biochemical and morphologic degenerative changes during the process of aging. Aquaporins (AQPs) are a family of water channel proteins that facilitate water and small solute movement in tissues and may have a potential role in the aging degeneration of IVDs. One of the important problems in understanding disc degeneration is to find cellular molecules which contribute to the pathogenesis of IVDs. XThe aim of this study was to demonstrate the expression of aquaporin 1 and 3 in nucleus pulposus (NP), annulus fibrosus (AF) cells of rat lumbar intervertebral discs from both young and aged animals using immunohistochemistry. MATERIAL AND METHODS: Twenty Wistar-albino rats were included in the study. The rats were separated into two groups: 2-month-old rats (n=10) as the young group, 18-month-old rats (n=10) as the old group. The intervertebral disc tissues obtained from the lumbar spine (L1-L4, 4 discs) were used for immunohistochemical staining of AQP-1 and 3. RESULTS: This study demonstrated that AQP-1 and AQP-3 immunoreactivity significantly decreased in NP and AF of aged rats compared to the young rats. CONCLUSION: We suggest that AQP-1 and 3 may contribute to the age related degeneration of the intervertebral disc.