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Results of chronopharmacological study of the circadian dependence of paracetamol toxicity and the extrapolation of obtained results to determine peculiarities in the daily activity of metabolic processes in rat liver are reported. The study was conducted on the model of acute paracetamol-induced hepatitis in both male and female rats in four diual periods: 03.00 a.m., 09.00 a.m., 15.00 p.m., and 21.00 p.m. The toxicity of paracetamol and the functional activity of liver were estimated by changes in markers of cytolytic activity of alanine aminotransferase (AIAT) and aspartate aminotransferase (AsAT) in blood serum, and the content of reduced glutathione (RG) in liver tissue. It is established that the degree of paracetamol toxicity and the level of hepatocyte RG are mutually dependent: the higher the content of RG in cells, the less pronounced toxic effect of xenobiotic is and vice versa, which is confirmed by correlation analysis (r = 0.43 - 0.94, depending on the circadian system of animals from control group). Extrapolation of results on the toxicity of paracetamol was used to reveal periods of the maximum and minimum functional activity of the liver. Acrophase of the functional activity of liver in rats corresponds to 15.00, and the antiphase of this activity in humans, to 01 - 03.

Acute, subacute, and chronic experiments were performed to examine the toxicity, specific action, analgetic, and physicochemical properties of suicrepan derived from the porcine duodenal mucosa and the hormone secretin contained in it. Suicrepan was found to be an effective pancreatic extrasecretory function stimulant, by showing therapeutical benefits in experimental pancreatitis and analgesic effects. The drug was demonstrated to display a low toxicity.

The pharmacological activity of a pediatric formulation of the phenolic hydrophobic drug propolis was studied in the experiments on albino rats of various age with toxic liver damages of various duration and in acute hepatic ischemia. In all models of hepatic abnormalities, the drug was found to show antioxidative properties which were moderate (30-60%). In addition, there were improvements in hepatic secretion of bile, cholic acids, and cholesterol. On the other hand, the membrane-stabilizing effect of the drug was exerted in not all the tested models of hepatic damage.

Melatonin was shown to produce a tocolytic effect in experiments on the isolated uterine horn in different experimental animals and on the whole body. The ability of melatonin to inhibit uterine contractility was confirmed by the studies of the effects of melatonin on oxytocin-induced myometrial contractions. It may be suggested that the antagonism between melatonin and oxytocin is uncompetitive.

The effects of glycosamine aminosugar on the processes of endotoxicosis and lipid peroxidation were thoroughly studied in rats with toxic pulmonary edema. There was a glycosamine-induced decrease in markers of endotoxicosis, such as medium-weight molecular peptides and malonic dialdehyde in serum and lung tissue. Administration of exogenous glucosamine resulted in its incorporation into the membranes of target organs, connective tissue and normalized the levels of endogenous N-acetyl-glucosamine, which finally determined antitoxic and antioxidative properties in this aminosugar.

The albino rat experiments studied the pharmacological action of oxycinnamic acid derivatives in acute tetrachloromethane-induced hepatic dystrophy and combined CCl4-ethanol-induced hepatic lesion. The tested agents were found to produce cholagogic, membrane-protective, and antioxidative effects in these hepatic abnormalities, thus improving the functional (cholate- and glycogen-synthetic) parameters of the liver.

A study was made of the action of the nonsteroidal antiinflammatory agent glucamin on the processes of oxidation and phosphorylation (OP) in isolated mitochondria of the liver. It has been established that glucamin does not exhibit the properties of a separator in the explored concentrations (10(-2)-10(-7) M). Unlike the standard drug voltaren that separates OP processes, it slightly enhances interaction of liver mitochondria which oxidize NAD-dependent substrates. The effect of voltaren is dose-dependent, being pronounced to a greater measure when succinate is applied as a substrate of mitochondria oxidation.