Using human umbilical cord endothelial cell cultures and a modified 3HTdR uptake technique, endothelial cell cytotoxic activity (ECA) has been demonstrated in sera of 95/130 patients with progressive systemic sclerosis (PSS), 14/20 patients with Raynaud syndrome (RS), 52/153 rheumatoid arthritis (RA), and 47/113 systemic lupus erythematosus (SLE) sera. ECA could be enriched by gel filtration from PSS sera in a molecular weight range of 5 k daltons. ECA was partially associated with serum proteins, mainly in the albumin containing fraction, albeit at a lower level of activity. In PSS, no relationship of ECA to the type of skin involvement was observed. ECA appears to be a low molecular weight mediator of, as yet, unknown origin.

Today, the problem of alcohol abuse is quite relevant around the world. According to the World Health Organization, alcohol abuse is one of the three causes of premature death and is one of the main etiological factors that that cause the development of chronic diseases of the liver and other organs. The severity of clinical manifestations and the prognosis of further dynamics of ongoing alcohol intoxication can be investigated by studying the composition of proteins in tissues, as it is known that this pathology has a pronounced protein dystrophy and active proteolysis. Although much is known today about the effects of alcohol on proteolytic systems, many questions still need to be explored, as proteomic studies can be used to find biomarkers and therapeutic targets for ethanol abuse. The aim of the study was: to investigate the proteolytic activity of blood plasma and liver of rats in chronic alcohol intoxication at 11 and 21 days of the experiment. The model of chronic alcohol intoxication was modeled on male rats – weight 180-200g by intragastric administration of 30% ethyl alcohol solution for 10 days on an empty stomach, at the rate of 2 ml per 100 g of animal weight. Total proteolytic activity, activity of metalloproteinases and serine proteinases were determined by the method of determining caseinolytic activity. The protein concentration was determined by the Bradford method. Statistical processing of the study results was performed by conventional methods of variation statistics. It was found that on the 11th day from the beginning of ethanol administration to rats, there was an increase in total proteolytic activity and activity of metetalloproteinases in blood plasma and liver.

Purpose: Hyperhomocysteinemia in children can develop as a result of genetic defects, endocrine abnormalities or under the influence of dietary factors. An elevated level of homocysteine is considered a risk factor for the progression of chronic kidney disease. The aim of the work was to investigate the indicators of oxidative stress in the homogenate of the kidneys of immature rats in control and with hyperhomocysteinemia. Methods: The concentration of reduced and oxidized glutathione, the activity of superoxide dismutase, catalase and nitric oxide synthase were determined. The model of hyperhomocysteinemia was reproduced on one-month-old male rats, which were kept on a standard vivarium diet. The experimental group was intragastrically administered by D,L-thiolactone homocysteine hydrochloride in a 1% starch solution at a dose of 200 mg/kg of body weight 1 per day for 8 weeks. The corresponding volume of 1% starch solution was injected into the control group of animals. The activity of superoxide dismutase, catalase and nitric oxide synthase were determined spectrophotometrically. Concentration of reduced and oxidized glutathione by fluorometric method. Results: It was established that upon hyperhomocysteinemia the concentration of reduced glutathione, the activity of superoxide dismutase, catalase, and nitric oxide synthase was decreased against the background of an increase in the concentration of oxidized glutathione in the homogenate of the kidneys of immature rats. Conclusions: The obtained results indicate that in the kidneys of immature rats, the development of oxidative stress occurs in the direction characteristic of adult animals. The obtained results indicate that in the kidneys of immature rats the development of oxidative stress resembles the adult animals. The obtained results showed a decrease in the concentration of reduced glutathione and the activity of antioxidant defense enzymes which may indicate the development of pathological processes in the kidneys

The study of biochemical processes in chronic alcohol intoxication is a topical issue of our time. A deeper understanding of the mechanism of action of proteinases in this pathological condition will help in the development and search for non-invasive diagnostic methods, thereby minimizing the risk of harming human health during complex diagnostic procedures. In our experiment, we investigated the general proteolytic activity, the activity of metalloproteinases and serine proteinases in the liver and kidneys of rats on an experimental model of chronic alcohol intoxication on days 1, 3, 7, and 11 of the experiment, as well as on days 21 and 28 after the cessation of ethanol administration. Male rats weighing 180–200 g were modeled for chronic alcohol intoxication by intragastric administration of 30% ethyl alcohol solution for 10 days on an empty stomach, at the rate of 2 ml per 100 g of animal weight. Liver and kidney homogenate by well-known methods. The concentration was determined by the Bradford method. The total proteolytic activity, the activity of metalloproteinases and serine proteinases were determined by the caseinolytic method with modifications. The total proteolytic activity, the activity of metalloproteinases and serine proteinases were determined by the caseinolytic method with modifications. It was shown that on the 3rd, 7th and 11th days of the experiment in the liver there was an increase in the total proteolytic activity and the activity of metalloproteinases. The activity of serine proteinases significantly increased on days 3 and 7 of the study. In the kidneys, a significant increase in all studied activities was observed only on the 3rd day. Such differences in the activities of metalloproteinases and serine proteinases can be associated with the different roles of these enzymes in physiological processes. Thus, we observed an increase in the activity of serine proteinases in acute intoxication, and in metalloproteinases in chronic intoxication.