No abstract available.
Animals ; Rats*

This study was carried out to investigate the ultrastructural findings of rats after administration of 0.5% lead acetate with drinking water. The Sprague-Dawley rats were divided into control and experimental groups. The control group was composed of 12 rats and was orally administered with 0.5% sodium acetate. The experimental group was composed of 36 rats and orally administered with 0.5% lead acetate. Two rats in the control group and four rats in the experimental group were sacrificed on day 2, and week 1, 2, 4, 6 and 8 after administration. The kidney was extirpated and examined by electron microscopy. The results obtained were as follows: The blood lead concentration in the experimental group began to increase from the second day after administration and it increased gradually until the 6th week and it decreased at the 8 week. The urinary excretion of delta-ALA also increased from the secondary and gradually increased up to the 8th week. On electron microscopic examination, the proximal tubular cells showed fat droplets, dilatation of the endoplasmic reticulum, mitochondrial swelling, increased numbers of secondary lysosomes and myelin figure-like residual bodies and intranuclear inclusion bodies. All these findings peaked at the eighth week after administration. Ultrastructural findings after Timm sulphide silver reaction revealed the lead granules in the proximal tubular lumen and between the microvilli of the proximal tubular cells without membrane-bounded. It can be concluded that most of the changes of micro-organelles are compatible with degenerative changes of lead exposure and passive diffusion of lead granules are involved in the proximal tubular cells.
Rats ; Animals

An experimental studies were carried out to observe the protective effects of malotilate, a new antihepatotoxic agent, on the chronic hepatic injury induced by CCl4 with or without ethanol. The rats used weighed about 200g were divided into 2 groups, 4 weeks & 8 weeks. Each group was given by orally with malotilate, 100 mg/kg, once a day, and was injected by subcutaneously with CCl4 1.5 mg/kg in a mixture with olive oil twice a week. Aqueous ethanol (20%) was administered in drinking water daily. The serochemical and histopathological studies were carried out in each experimental group. The results were as follows: 1. The chronic liver injuries induced by CCl4 with or without ethanol were significantly ameliorated by normalize serum values GOT, GPT. Alkaline phosphatase, Cholesterol, HDL-Cholesterol, and gamma glutamyl transpeptidase. 2. In Group of 4 weeks, malotilate manifested protective effects by significant inhibition of fatty changes, spotty necrosis and fibrosis in CCl4-intoxicated liver with or without additional ethanol. 3. In group of 8 weeks, malotilate significantly imoproved fatty changes, fibrogenic activity in the group administered with CCl4, followed by ethanol.
Rats ; Animals

No abstract available.
Animals ; Rats*

The purpose of this study is to investigate the morphologic changes of the sinusoidal endothelial cells and the associated structures of the cirrhotic rat liver induced by repeat intraperitoneal injections of N-diethylnitrosamine (DEN) (100 mg/kg/week). One day to 6 weeks later, rat livers were observed under the light, transmission and scanning electron microscopy, and immunostained with laminin antibody. Two weeks after DEN treatment, the fibrillar material in Disse's space was noted, and then a basement membrane-like structure was found at 4 weeks after treatment. Laminin was detected in perisinusoidal areas after 4 weeks. Laminin was strongly positive on the fibrous septum and in the sinusoidal wall of cirrhotic nodules after 6 weeks of treatment. The diameters and numbers of sinusoidal endothelial fenestrations did not change significantly until 2 weeks. They decreased within 4 weeks, and then the sinusoidal endothelium was poorly fenestrated at 6 weeks after DEN treatment. These results suggest that as fibrosis develops in cirrhosis, the deposit of extracellular matrix such as laminin within Disse's space is a major contributing factor in the structural alteration of sinusoidal endothelial cells, and the capillarization of the sinusoidal endothelial cells may be a contributor to impairment of the hepatic function in cirrhosis.
Rats ; Animals

Ion irradiation is a very promising tool to modify the chemical structure and physical properities of polymers. This study was aimed to evaluate the cellular adhesion to ion beam-irradiated surface of biodegradable poly-llactide(PLLA) membrane. The PLLA membrane samples were irradiated by using 35 KeV Ar+ to fluence of 5x10(13), 5x10(14) and 5x10(15)ion/cm2. Water contact angles to control and each dose of ion beam-irradiated PLLA membranes were measured. Cultured fetal rat calvarial osteoblasts were seeded onto control and each dose of ion beam-irradiated PLLA membranes and cultured. After 24 hours, each PLLA membranes onto which osteoblasts attached were examined by scanning electron microscopy(SEM). Osteoblasts were removed from each PLLA membrane and then, the vitality and the number of cells were calibrated. Alkaline phosphatase of detached cells from each PLLA membranes were measured. Ion beam-irradiated PLLA membranes showed no significantly morphological change from control PLLA membranes. In the measurement of water contact angle to each membrane, the dose range of ion beam employed in this study reduced significantly contact angles. Among them, 5x10(14) ion/cm2 showed the least contact angle. The vitalities of osteoblastes detached from each membranes were confirmed by flow cytometer and well attached cells with their own morphology onto each membranes were observed by SEM. A very strong improvement of the cell adhesion and proliferation was observed for ion beam-irradiated surfaces of PLLA membranes. 5x10(14)ions/cm2 exhibited the most strong effect also in cellular adherence. ALPase activities also tended to increase in ion beam-irradiated membranes but statistical differences were not found. These results suggested that ion beam irradiation is an effective tool to improve the adhesion and spreading behaviour of the cells onto the biodegradable PLLA membranes for the promotion of membrane-tissue integration.
Rats ; Animals

No abstract available.
Animals ; Rats*

No abstract available.
Animals ; Rats*

The pulmonary microvasculatures of rats were studied by injection replicas prepared from Mercox. This medium enabled us to easily obtain consistent, stable, and complete injected replicas of the pulmonary vasculature. In order to investigate the three dimensional structures of the tributaries of the bronchial artery, such as the capillary plexus and vasa vasorum, we performed a scanning electron microscopic(SEM) study of the vascular casts, using Mercox CL-2B as a media. The alveolar capillaries revealed hexagonal or pentagonal rings of vascular networks. In some areas, the vascular rings composed a square network, The bronchial tree was supplied by the bronchial arteries which form a coarse capillary extending as far as the terminal bronchioles. Occasionally the capillary plexus was connected with adjacent capillary networks in and around the alveolar walls. The walls of the pulmonary artery revealed only a single layer of the vasa vasorum, but those of the pulmonary vein were surrounded by more complicated and well developed vasa vasorum than the pulmonary arterial side. The mean diameters of the venous vasa vasorum are greater than the arterial vasa vasorum.
Rats ; Animals

Amiodarone, an antiarrhythmic drug, may exert pulmonary toxicity in some patients but the pathogenesis is not clear. This study was carried out to investigate the pathogenetic mechanism of pulmonary injury induced by amiodarone at dose of 100 mg/kg/day given to rats by intraperitoneal injection for 3 weeks. And the preventive effects of concomitantly injected steroid (10 mg/kg/day) on amiodarone induced pulmonary injury was also studied using bronchoalveolar lavage, light microscopy and transmission electron microscopy. The results obtained were summarized as follows: Mild lymphocytosis of bronchoalveolar lavage fluid was found in all experimental groups. Intracytoplasmic lamellar body formation was found in all types of pulmonary cells and type II pneumocytes revealed the earliest abnormal lamellar body formation. The capillary endothelial cells showed cellular swelling and detachment from underlying basement membrane at early phase of experiment and the edema of alveolar wall and interstitium were noted. Interstitial fibrosis and proliferation of type II pneumocytes were noted at late phase. The lungs of steroid injected groups revealed accumulation of lamellar bodies in all types of pulmonary cells but interstitial fibrosis was not occurred. These findings support the concept that amiodarone is responsible for a drug-induced phospholipidosis and directly toxic to pulmonary endothelial and epithelial cells. And steroid may regress the progression of amiodarone induced pulmonary injury.
Rats ; Animals