Acid hydrolases stimulation

Simple formyjgmethionyl peptjge stimulate leukocyte movement and are chemotactic. Becker et al have synthesized a series of di-, tri-, and tetrapeptides, most of them being formyl methionyl peptides. These are chemotactic, stimulate phagocytosis of latex particles, and cause the selective release of lysosomal enzymes from PMN in the presence of cyto-chalasin B. There is a high degree of correlation between the ability of the peptides to enhance PMN movement and cause selective release of acid hydrolases. The presence of the formyl group on the methionine leads to a 3,000- to 30,000-fold increase in chemotactic activity. Further studies... 

One of early manifestations of neuropathy consists in a sharp (by 35 to 40%) reduction in conduction velocity of stimulation along peripheral nerves and a decrease in action potential amplitude of nerve, which are noted prior to the development of other clinical signs (ataxia, paresis, paralysis). The changes observed indicate the loss of excitability firstly by the A-6 thick fast-conducting nerve fibers [34, 36], In the pathogenesis of DNE induced by OPC, there take place an immunopathological component (the development of autoimmune process) [38,39], intensification in lipid peroxidation in neural tissue, labilization of lysosomal membranes, and activation of acid hydrolases [40, 41],... 

It is important to note that most of the results were obtained by treating animals with C. parvum before, simultaneously or just after the inoculation of tumor cells, although in one report (Fisher et al., 1975) antitumor effects of C. parvum were observed on well-implanted tumors. The antitumor effects were shown to be associated with the stimulation of cell-mediated immunity macrophage numbers were increased, their chemotaxis was enhanced, as well as the secretion of lysosomal acid hydrolase (Wilkinson,... 

Lysosomal Acid Hydrolase Biosynthesis Induciton of Stimulation... 

Fig. 3. Diagrammatic representation of the possible mechanisms underlying acid hydrolase induction. A. Endocytosis and/or phagolysosome formation stimulates ( intermediate) DNA-RNA mechanism. B. DNA-RNA machinery is stimulated through a membrane activated second messenger. C. Direct stimulation of protein-synthesizing system by inducer molecule.

A. Natube and Pathogenesis of Stimulation of Acid Hydrolase Synthesis... 

Controlled experimental situations have defined the presence and characteristics of stimulation of acid hydrolase activity. Table III summarizes the diverse nature of many of the inducing agents and the variability in acid hydrolases measured in representative organ systems. 

It is reasonable that the process of vesiculation occurs at an equilibrium rate, constant for each cell species and modified by the metabolic demands of the cells. We have suggested (Verity and Brown, 1968b), from maturation studies of cerebral lysosomal enzymes, that for a given rate of vesiculation, the enzyme complement of the primary lysosome is directly proportional to the individual rates of synthesis of the component enzymes. Such a hypothesis would account for the heterogeneity in acid hydrolase reaction to injury, the difference in maturation profiles of individual acid hydrolases, and the dysynchrony of acid hydrolase induction. Also suggested is a direct feedback mechanism whereby a stimulation of vesiculation may in turn induce increased enzyme synthesis, possibly through changes in membrane phospholipid metabolism. 

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