Antioxidant enzyme systems in skeletal muscle atrophied by immobilization

To clarify the mechanism of oxidative stress in skeletal muscle atrophied by immobilization, we investigated the change of antioxidant enzyme activities in a typical slow red muscle, the soleus. Atrophied soleus muscles were collected from male Wistar rats (16 weeks old), one ankle joint of which had been immobilized in the fully extended position for 7 days. Also, soleus muscles were collected from intact age-matched rats as control. The activities of Mn-containing superoxide dismutase (Mn-SOD), Cu,Zn-containing superoxide dismutase (Cu,Zn-SOD), Se-dependent glutathione peroxidase (Se-GSHPx), glutathione S-transferase (GST), catalase, and glutathione reductase (GSSGRx) were measured. The activities of Cu,Zn-SOD, GST, and GSSGRx were significantly higher in atrophied muscles, while the others were unchanged. Increased Cu,Zn-SOD and unchanged Mn-SOD levels might reflect increased generation of superoxide anions in the cytoplasm rather than in the mitochondria. Owing to the enhancement of Cu,Zn-SOD and the unaltered Se-GSHPx and catalase activities, hydrogen peroxide is thought to be increased in the cytoplasm. Because there is also an increase of iron in the microsomes of atrophied muscles, the production of hydroxyl radicals, the most aggressive of radicals, might consequently be elevated.     

Studies on catalase, glutathione peroxidase and superoxidismutase activities in aging cells of Paramecium tetraurelia

The nature of the aging process has been the subject of considerable speculation. Now, some data indicate that free radical reactions going on continuously in the cells contribute to aging. Considering these data, we have investigated the activity of enzymes (catalase, glutathione peroxidase, superoxidismutase) present physiologically in the cell to limit to tolerable levels, the rate of free radicals or H2O2. These enzymes activities were assayed in Paramecium tetraurelia as clonal age increased. Catalase activity increases slightly during aging of paramecia, i.e. during maturity and senescence phases (20-150 fissions). No significant changes in glutathione peroxidase and superoxidismutase is found. Catalase activity was also assayed as a function of culture conditions. As the cells begin starving and the percentage of autogamous cells increases, catalase activity decreases. After autogamy, a large increase of catalase activity occurs during the sexual immaturity phase, i.e. during the first 20 fissions. By another way, H2O2 added in the culture medium (from 0 to 15 X 10(-5)M) causes an important increase of catalase activity (from 100 U.I. to 250 U.I.). The possible role of O-.2, OH. and H2O2 in aging is discussed.     

Localization of motoneurons innervating the muscle of the hard palate in the rat: A horseradish peroxidase study

Using the horseradish peroxidase-technique, the myotopical arrangement of motoneurons innervating the transverse palatine muscle in the rat was studied. It appears that this muscle is innervated by axons from cells located in the ipsilateral intermediate subnucleus of the facial motor nucleus. By nerve transection and electrophysiological experiments it is shown that the transverse palatine muscle is innervated by the inferior as well as the superior buccolabial branch of the facial nerve.     

A method to reduce glutathione peroxidase levels in primary endothelial cell cultures

The purpose of this study was to develop culture conditions that would reduce glutathione peroxidase activity in bovine mammary endothelial cells. Conditions of reduce glutathione peroxidase activity were produced in vitro by culturing cells in selenium-deficient media. Low selenium levels were achieved by reducing serum concentrations; however, levels of essential growth factors also were reduced by this method. Therefore, cell proliferation was promoted by supplementation with combinations of defined serum components including insulin, transferrin, linoleic acid, bovine brain extract, and human epidermal growth factor. Out of seven different formulas tested, F12K medium containing 2% fetal bovine serum, insulin, transferrin, and linoleic acid was found to be conducive for cell proliferation. Upon confluence, endothelial cells cultured under these conditions consistently displayed short passage rates, consistent cell numbers, and classic cobblestone morphology when grown in the presence or absence of supplemental selenium. Additionally, these cells retained typical endothelial cell characteristics such as uptake of 1,1-dioctadecyl-3,3,3,3-tetramethylindo-carb ocyanine perchlorate acetylated low-density lipoprotein and the expression of cell adhesion molecules and von Willebrand Factor.     

Ultrastructural myeloperoxidase activity and expression of myeloid-associated antigens in acute lymphoblastic leukemia

Ultrastructural myeloperoxidase (MPO) activity and myeloid-associated antigen (MyAg) expression were investigated in 12 adult patients with acute lymphoblastic leukemia (ALL). Ultrastructural MPO was detected by 3 different methods. Immunophenotyping was performed by flow cytometry, using a series of monoclonal antibodies. Ultrastructural MPO-positive blast cells were detected in 6 patients (50%). In 5 of these 6 patients, the methods detecting both MPO and platelet peroxidase (PPO) activities found MPO-positive blast cells more frequently than those detecting MPO activity alone. In 2 patients (17%), at least one kind of MyAg was positive. Ultrastructural MPO activity was detected more frequently than MyAg expression in ALL patients. This method of detecting PPO and MPO is recommended for detection of ultrastructural MPO-positive ALL.     

A lectin horseradish peroxidase study of the origin of ascending fibers in the medial forebrain bundle of the rat. The upper brainstem

The origins of projections within the medial forebrain bundle from the upper brainstem were examined with the horseradish peroxidase technique. Labeled cells were found in approximately 15 upper brainstem nuclei following injections of a conjugate of horseradish peroxidase and wheat germ agglutinin at various levels of the medial forebrain bundle. Labeled nuclei included (from caudal to rostral): dorsal and ventral parabrachial nuclei; Kolliker-Fuse nucleus; dorsolateral tegmental nucleus; A7 (lateral pontine tegmentum medial to lateral lemniscus); median and dorsal raphe nuclei; distinct group of cells oriented mediolaterally in the dorsal pontine tegmentum below the central gray; B9 (ventral midbrain tegmentum dorsal to medial lemniscus); retrorubral nucleus; nucleus of Darkschewitsch, interfascicular nucleus; rostral and caudal linear nuclei; ventral tegmental area; medial part of substantia nigra, pars compacta; and the supramammillary nucleus. With the exception of the ventral parabrachial nucleus, Kolliker-Fuse, A7, B9 and substantia nigra, pars compacta, each of the nuclei mentioned above sent strong projections along the medial forebrain bundle to the rostral forebrain. Sparse labeling was observed throughout the pontine and midbrain reticular formation. With the exception of the dorsal raphe nucleus, projections to the most anterior regions of the medial forebrain bundle (level of the anterior commissure) essentially only arose from presumed dopamine-containing nuclei-retrorubral nucleus (A8 area), interfascicular nucleus, rostral and caudal linear nuclei, substantia nigra pars compacta, and ventral tegmental area. Evidence was reviewed indicating that major forebrain sites of termination for these dopaminergic nuclei are structures that have been collectively referred to as the 'ventral striatum'. It is concluded from the present findings that several pontine and mesencephalic cell groups are in a position to exert a strong, direct effect on structures in the anterior forebrain and that the medial forebrain bundle is the main communication route between the upper brainstem and the forebrain.     

Use of glutathione inhibitors and glutathione transferases to overcome tumor resistance to cytostaticsin vivo

Preincubation of cells of BDF1 hybrid mice with P388 leukemia with doxorubicin and buthionine sulfoximine leads to the manifestation of a therapeutic effect of the antibiotic. Injection of buthionine sulfoximine and ethacrinic acid to mice with leukemia does not alter the therapeutic effect of the antibiotic. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 2, pp. 212–214, February, 1995 Presented by N. N. Trapeznikov, Member of the Russian Academy of Medical Sciences     

P糖蛋白和谷胱甘肽—S—转移酶在肾细胞癌中的表达

探讨肾细胞癌与多药耐药的关系，方法：应用免疫组化方法，检测４例术前未进行化疗的肾细胞癌和１６例正常肾组织中的Ｐ糖蛋白和谷胱甘肽－２转移－π表达。结果：Ｐ－ａｇ和ＧＳＴ－π外地１６例正常肾组织中的表达率均匀１００％，在４４例肾细胞癌组织中分别为６３．６５和５４．５％Ｐｇ，Ｐ－ｇｐ和／或ＧＳＴ－π阳性表达率为７９．５％。     

Physical training and fasting erythrocyte activities of free radical scavenging enzyme systems in sedentary men

Summary Effects of 10 weeks of physical training on free radical scavenging enzyme systems in erythrocytes were investigated in 7 sedentary healthy male students. The training consisted of running over 5 km, 6 times/week. Their maximum oxygen uptake and 12 min walk-run performance increased significantly after training. Of the antioxidant enzyme systems examined in the erythrocytes, both catalase activity and concentration and total glutathione reductase (GR) activity also showed significant increases following the training. The erythrocyte GR activity coefficient also increased significantly. These results suggest that chronic aerobic exercise increases riboflavin requirements and has some positive effects on antioxidative processes.