A clinical form of sepsis induced by cecal ligation and puncture (CLP) was caused in order to monitor the concentration of enzymes (alanine aminotransferase -ALT, aspartate aminotransferase -AST, lactate dehydrogenase -LDH, amylase and creatine kinase -CK) in the rat blood. Experiments were performed on male Wistar rats, weighing on average 215±25 g. The rats were divided into four groups. In the first three groups (n=28 per group), sepsis was induced by pure culture of Escherichia coli (EC) or Staphylococcus aureus (SA) and mixed culture (MK) of caecum, while the fourth group included 20 control rats who underwent an abdominal incision. Blood was taken in time intervals of 12, 24, 72 and 120 hours.During the experimental protocol, we identified significant changes of all monitored enzymes in the serum of infected rats. After a period of 12 hours there was a significant increase in ALT (all rats with sepsis), AST and LDH (rats in the MK group) levels, while a decrease was noted in the concentration of amylase (EC, SA). Similarly, 24 hours after the CLP procedure, a significant decrease of amylase (MK) and AST (SA) was recorded, while serum LDH level varied significantly from elevated (EC, SA) to reduced (MC) values. Finally, at the time intervals of 72 and 120 hours the concentration of nearly all monitored enzymes has shown a decline, while significance was noted in lowering of ALT (MK), AST (SA, EC) and amylase (SA) levels. Statistical significance could not be observed in the change of CK levels at any of examined time points.

The purpose of the investigation was to induce the clinical form of sepsis in rats by inoculation of pure cultures of certain species of microorganisms into the ligated caecum. The experiments were performedon 104 Wistar strain male rats of 190-240 goody weight. The rats were divided into four groups three of which contained 28 animals each and one control group of 20 animals. In order to monitor the development of sepsis, rats were killed at 12,24, 72 and 120hafterthe surgical intervention. Clinically apparent sepsis in two groups of rats was induced in the following way: the previously emptied, tied off and washed out caecum was inoculated with pure cultures of Escherichia coli or Staphylococcus aureus. In the third group, sepsis was produced by the caecal content of the tied off and punctured caecum (a mixed culture of microorganisms). A false surgical intervention was performed in the control group by opening the abdomen. Clinically manifest symptoms of sepsis, such as higher body temperature, diarrhoea, anorexia, tachycardia tachypnoea, changes in appearance and behaviour, were observed in all the rats, from 24 to 120 h after surgery. Bacteriological findings in the blood and parenchyma! organs of the investigated rats, in the model of sepsis induced by the gram-negative bacterium E.coli, showed the presence of E.coli at all times from 12-120 h after inoculation. In the model of sepsis caused by Staphylococcus aureus this gram-positive bacterium was detected in the blood and tissue samples from 12 to 72 h after inoculation. In the model of sepsis induced by mixed bacterial cultures (E.coli, Proteus mirabilis Enterococcus spp) only E.coli was detected in the blood and parenchyma! organ samples at all the monitored time.s from 12 to 120 h, whereas P. mirabilis and Enterococcus spp. were detected only during the first 24 h of the experiment

Although brain complications in sepsis are not rare, early pathophysiologic events had not been made clear yet. We have considered antioxidative components-glutathione peroxidase (GSHPx) activity and reduced glutathione (GSH) concentration in two brain integrative centers, i.e the brain stem (BS) and thalamus. Sepsis was induced in adult male Wistar rats (200-250 g) by cecal ligation and perforation (CLP) with inoculation of Escherichia coli suspension (ATCC 25922) (n=40). The control group was sham operated (n=40). For each time point (0, 12, 24 and 72 hours) after treatment, ten animals within each group were decapitated. In BS, GSHPx activity increased at 12 and 24 hours after CLP, while in the thalamus, GSHPx activity increased at 72 hours, compared to controls. In BS, GSH concentration decreased at the 12th and 24th hour, and in the thalamus it decreased at the 72nd hour. Changed oxidative status in BS, recorded as soon as the 12th hour, reflects a prompt reaction of the central nervous system. This could be of great consequence for disturbed vasomotor response during sepsis.

The number of leucocytes and immunocompetent cells, was investigated during a clinical form of sepsis in rats. The experiments were carried out on 104 male rats, Wistar strain, of body weight 190 to 240 g. The rats were divided into four groups: three with 28 animals and one control group with 20 animals. The animals were killed 12, 24, 72 or 120 hours after surgical intervention. This consisted of caecal ligation and puncture (CLP), with inoculation of mixed bacteria or pure cultures of Escherichia coli or Staphylococcus aureus. They induced similar changes in the total leukocyte counts and percentages of different white blood cells. The significant leucopenia in the first half (early sepsis) of the examined period preceded significant leukosis in the rats with sepsis in the second half of the experiment (late sepsis). Also there were significant alterations in the numbers of granulocytes and agranulocytes. Neutrophilia and lymphopenia dominated during the whole period

The goal of this work was to induce clinical sepsis in rats in order to measure the following biochemical parameters (glucoses, triglycerides, cholesterol, total proteins, albumins and creatinine). The experiments were done on 104 male Wistar rats, body weight 190 to 240 g. The rats were divided in four groups. Treated groups consisted of 28 animals while in the control groups there were 20 animals. Animals were observed and sacrificed at 12, 24, 72 and 120 hours after surgery. In this model of sepsis (cecal ligation and puncture - CLP) with pure and mixed bacterial cultures, significant changes were noticed in all biochemical parameters. Significant hypoglycemia, hypercholesterolemia, decreased concentration of urea and increased concentration of creatinine were found in the first half of the experiment in all groups of rats with sepsis (at 12 and 24 hours). Hyperproteinemia and hypotriglyceridemia reached statistically significant values at 24 h in the groups of rats in which sepsis was induced with pure bacteria culture. In the other half of the experiment significant hypoalbuminemia was found in all rats with sepsis (at 71 and 120 h). [Projekat Ministarstva nauke Republike Srbije, br. TR 31071