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The monolayer culture of 3-day-old rat hepatocytes was treated by antimicrotubule agent colchicine after activation with isoproterenol. Alterations in the amount of lysosomes with the size of 1.0-2.5 and 3-6 mkm per cell were studied with light microscope after staining with the vital dye neutral red and after identification of acid phosphatase by plumbum precipitation in the frozen preparations. It was shown that isoproterenol application (20 microM) within 1.5 h did not change significantly the number of lysosomes sized 1.0-2.5 microns but stimulated the increase in the amount of lysosomes 3-6 mkm in size. The addition of 2.5 mM colchicine, after the isoproterenol treatment, decreases greatly the number of lysosomes with the size of 1.0-2.5 and 3-6 mkm. A considerable part of the large lysosomes can be resistant to the colchicine action. It is concluded that the microtubules play an important role in lysosome functioning.

The monolayer cultures of newborn rats hepatocytes were treated with substrate starvation (20 min.) anoxia accompanied with substrate starvation (1 h.), following rehabilitation (1 h.) and cooling (4 degrees C, 30 min). After the neutral red staining we have examined the alterations in lysosomes quantity and the development of phagocytosis; we also tested the hepatocytes distribution due to the amount of the second lysosomes per cell. We have shown that a short time pathological treatment caused a decrease in large lysosomes (1-3 microns) amount in significant portion of hepatocytes. There were neither increase in phagosomes amount per cell nor alterations in the quantity of cells, containing phagosomes. However a long time pathological treatment caused the increase in phagosomes and cells. We propose that initial stage of lysosomal apparatus alterations, connected with reduction of CAMP level, is accompanied by a stamping of large lysosomes.

Acid phosphatase activity, ATP and cyclic nucleotide levels were studied in primary cardiomyocyte cultures of newborn rats under hypoxic conditions. It was shown that incubation of cardiac cells in Eagle's medium supplemented with 10% calf serum during hypoxia (5% O2, 5% CO2, 90% N2) caused an hour later a decrease in lysosomal acid phosphatase activity, whereas free enzyme activity increased. The exposure of cells in Hanks salt solution to one hour hypoxia resulted in a 3-fold decrease of ATP level and further increase in free acid phosphatase activity. It was found that cAMP and cGMP levels do not depend on the presence of hypoxia. The mechanisms involved in the regulation of lysosomal membrane state are discussed.

Activity of some lysosomal enzymes was studied in the primary heart cell culture of newborn rats under conditions of hypoxia and in isolated ischemic perfused heart, in liver and heart tissues of dogs after traumatic shock and after experimental myocardium infarction as well as in liver tissue of rats after 10 min experimental heart arrest and during the postresuscitation period. Decrease in cAMP and elevation in cGMP levels, impairment of the adenylate cyclase hormonal regulation, decrease in activity of cAMP-dependent protein kinases were shown to correlate distinctly with an increase of acid hydrolases free activity in liver and heart cell cytoplasm of dogs with traumatic shock and with experimental myocardium infarction. Free activity of acid phosphatase was increased in primary heart cell culture under conditions of hypoxia and in isolated ischemic perfused rat heart. Intraperitoneal administration of cAMP-containing liposomes into the rats with 10 min heart arrest led to stabilization of liver lysosomal membranes within 1 hr of 4 hrs of the post-resuscitation period. The mechanisms involved in stabilization of lysosomal membranes are discussed.