Effect of monochromatic red helium-neon laser on the morphology of zymosan arthritis in rats

Histological and electron microscopy findings suggesting the effect of monochromatic coherent polarized red light on zymosan arthritis in rats are presented. The data obtained have confirmed that treatment of inflamed joints with laser rays exerts an evident therapeutic effect which is determined by activated function of macrophages and fibroblasts of the synovial membrane, resulting in a more rapid change of inflammation phases. Analysis of the cases where the rats were treated with ordinary red light has revealed no essential differences in the joints of the control and irradiated groups.     

Enzymes of cyclic nucleotide degradation in eye tissues during experimental ocular herpes

Activity of phosphodiesterases disintegrating cAMP and cGMP in the cornea, sclera and ciliary body was investigated in health and in different stages of experimental herpetic keratitis. The problems concerning the role of the cyclase system in the pathogenesis of herpetic keratitis and the possibility of applying some of the drugs to the disease treatment are discussed.     

Mitochondrial proteinases of the yeast Saccharomyces cerevisiae: electrophoretic detection, substrate specificity and sensitivity to inhibitors

The proteins of submitochondrial particles solubilized with 0.1% Triton X-100 were separated by polyacrylamide gel electrophoresis. Hydrolysis of several proteinase substrates was registered directly in the gel after completion of electrophoresis. According to the data obtained the inner mitochondrial membrane contains one or two enzymes which catalyze hydrolysis of cytochrome c as well as one or two enzymes splitting synthetic substrate of trypsin-like proteinases, e. g. N-alpha-benzoyl-L-arginine-p-nitroanilide (BAPA) and N-alpha-benzoyl-L-arginine-beta-naphthylamide (BANA). Submitochondrial particles were shown to catalyze hydrolysis of 3H-labelled cytochrome c. This activity is suppressed by the same inhibitors as the hydrolysis of mitochondrial translation products, i. e. phenyl-methylsulfonylfluoride, p-chloromercuribenzosulfonate, leupeptin and antipain. Presumably these two processes are catalyzed by the same enzyme localized in the inner mitochondrial membrane. Physiological functions of BAPA- and BANA-hydrolyzing enzyme(s) are still unclear.     

Investigation of the lipid dependence of pyrophosphatase activity from rat liver microsomes and hepatoma by phospholipase C

The lipid dependence of pyrophosphatase activity was studied by treatment of liver and hepatoma microsomes with phospholipase C from Cl. perfringens and B. cereus and a subsequent incorporation of various classes of phospholipids into the delipidated microsomes. Phospholipase C hydrolysis sharply lowers the pyrophosphatase activity of liver and hepatoma microsomes. The enzyme activity is restored after introduction of phospholipids into delipidated liver microsomes, the maximal effect being achieved on incorporation of phosphatidylcholine. All the phospholipids tested exerted the same reactivation effects on the delipidated microsomes of hepatoma. However, a more complete delipidation of hepatoma microsomes by phospholipase C hydrolysis and a subsequent organic solvent extraction revealed a specific dependence of the enzyme activity on phosphatidylserine.     

Mechanism of stabilization of synaptosomes with alpha-tocopherol during exposure to phospholipase A2

Changes in potential-dependent fluorescence were studied, using fluorescent probe di-S-C3-(5), in synaptosome suspensions exposed to phospholipase A2, alpha-tocopherol and its derivatives. Phospholipase A2 increased potential-dependent fluorescence, i.e. depolarization of synaptosome membranes. The damaging phospholipase A2 effect was prevented and/or abolished by alpha-tocopherol added to synaptosome suspensions before and after phospholipase A2. Alpha-tocopherol derivatives (2,2,5,7,8-pentamethyl-6-hydroxychromane and alpha-tocopheryl-acetate as well as 4-methyl-2,6-di-tert-butylphenol) failed to exert a protective effect on synaptosome membranes modified by phospholipase A2. It is suggested that alpha-tocopherol effect is determined by its interaction with fatty acids, with 6-hydroxy groups of chromanol nucleus and phytol chain being essential for the complex formation.     

Changes in superoxide dismutase activity in the presence of electron donors and acceptors

The activity of superoxide dismutase (SOD) from bovine erythrocytes was measured by the inhibition of nitrotetrazolium blue reduction rate in superoxide anion radical generation systems--xanthine/xanthine oxidase of NADH/phenazine methasulfate. The enzyme activity increases in the presence of compounds acting as electron donors in radical-involving reactions and decreased in the presence of compounds possessing the properties of electron acceptors. Activation of SOD by electron donors and its inhibition by electron acceptors was dependent on the concentration of the above compounds. In the absence of SOD electron donors and acceptors did not change the rate of tetrazolium blue reduction by superoxide anion radicals. The role of the new type of SOD regulation for the enzyme functioning in the cell is discussed.