[Properties of the adenylate cyclase system of isolated hepatocytes following freezing-thawing]

The effect of various regimen of freezing and thawing on the functional state of one of the most important receptor-regulatory cell systems, i. e. adenylate cyclase complex (ATP-pyrophosphate lyase cyclating E C 4.6.1.1.), has been studied on isolated rat hepatocytes. Basal and fluoride-stimulating activity and enzyme susceptibility to the regulatory effect of isoproterenol, adrenaline and noradrenaline were shown. Regardless of the regimen used, freezing and thawing decrease the stimulating effect of adrenergetic agents on adenylate cyclase system of isolated hepatocytes. The reason of it is probably the damage of a receptor site. The functional properties of catalytic enzyme subunit practically do not change. The results obtained show the necessity of correction of metabolic cell responses mediated by adenylate cyclase system during their freezing and thawing.