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Ischemic-reperfusion injury of the small intestine is an acute clinical condition with high mortality rate. This study describes the changes in levels of phenylalanine and tryptophan metabolites in intestinal homogenates and urine samples of Wistar male rats after 60 minutes of mesenteric ischemia and different reperfusion periods (1, 24, 30 hours) in comparison with a control group without the ischemia. The ischemic-reperfusion injury was quantified by the histopathological injury index. The levels of serotonin, epinephrine, and norepinephrine were determined in the intestinal homogenate and epinephrine, vanillylmandelic acid, and the 5-hydroxyindoleacetic acid was analyzed in urine using the HPLC method. The statistically significant increased level of serotonin, epinephrine and norepinephrine were detected in the intestinal samples after 24 hours of reperfusion (p

Diagnosis of bowel diseases is often difficult and time consuming since it is not always possible to obtain adequate information by the conventional diagnostic methods to set up a diagnosis and exclude nongastrointestinal causes of symptoms. The aim of this study was to investigate the structure of blood serum samples of patients with selected intestinal diseases. The blood serum samples of patients (N=35) with selected diagnoses (mesenteric thrombosis, inflammatory bowel disease, duodenal ulcers, sepsis, enterorrhagia, sigmoid colon resection, small intestine cancer) and of healthy subjects were evaluated by synchronous fluorescence fingerprint and atomic force microscopy. Autofluorescence of blood serum studied at λex = 280 nm showed significant decrease of fluorescence intensity in patients with all types of diseases affecting bowels in comparison with the healthy control patients. The blood serum surface of ill patients showed significant differences in comparison with control group samples after atomic force microscopy evaluation as well. Irregularly placed small globular units of irregular shape in small amounts are possible to observe in patients with intestine ischemia. Fluorescence analysis and atomic force microscopy showed the ability to rapidly reflect qualitative and quantitative changes of proteins in blood serum samples of patients. These sensitive methods could be beneficial for monitoring the progression of both acute or chronic bowel diseases.

The authors have studied the susceptibility of two key protective enzymes, glutathione peroxidase (GPX) and glutathione reductase (GR) to the reactive oxygen species (ROS) known to induce oxidative damage in vitro system containing Fe2+/EDTA. The ability of ROS scavanger stobadine to prevent oxidative damage was also studied. Incubation of GPX with Fe2+/EDTA resulted in the significant decrease in its enzyme activity while under the same condition the activity of GR was not changed. The presence of stobadine was effective in protecting GPX from the loss of its activity by in vitro oxidizing agents. The monitoring of the mitochondrial outer membrane dynamics by the method of synchronous fluorescence fingerprint showed that the membrane is involved in these processes. (Fig. 3, Ref. 35.)

The study investigated the prooxidative in vitro effect of various Fe(2+)-EDTA concentrations on biochemical parameters of the energetic metabolism of rat liver mitochondria. Fe(2+)-EDTA was added in concentrations 150, 300 and 400 mmol/mg of mitochondrial protein. The study included the investigation of consumption of oxygen in state 4 (without ADP addition) and in state 3 (with ADP addition), and the activities of ATP-ase, superoxide dismutase (SOD) and glutathione reductase. The mitochondrial outer membrane dynamics were simultaneously monitored by the method of synchronous fluorescence fingerprint. When compared with the control group, the results imply that in state 4, the addition of 150 mmol of Fe2+/mg of mitochondrial protein caused an insignificant increase in respiration to 104%, whereas in state 3, the oxygen consumption was insignificantly inhibited to 82%. The activity of ATPase was insignificantly raised to 105%, whereas the superoxide dismutase activity has decreased significantly to 77%. The activity of glutathione reductase increased significantly to 124%. The addition of 300 mmol of Fe2+/mg of mitochondrial protein has caused a significant inhibition of oxygen consumption to 67% in state 4 and to 31% in state 3. The activity of ATPase showed an insignificant elevation to 104%. The activity of superoxide dismutase was significantly reduced to 52% and that of glutathione reductase dropped to 72%. The addition of 400 Fe2+/mg of mitochondrial protein strongly diminished the oxygen consumption to 36% in state 4, and similarly to 37% in state 3. The activity of ATP-ase was significantly decreased to 39%, the superoxide dismutase activity diminished to 17% and glutathione reductase activity dropped to 37%. The monitoring of the mitochondrial outer membrane by the analysis of synchronous fluorescence fingerprint showed that the membrane is involved in these processes. (Fig. 5, Ref. 12.)