MEDICINSKI GLASNIK Official publication of the Medical Association of Zenica-Doboj Canton, Bosnia and Herzegovina Volume 15, Number 2, August 2018. ISSN 1840-0132 ¥ Published and copyright by: Medical Assotiation of Zenica-Doboj Canton; Address: Zenica, 72000, Bulevar kralja Tvrtka 14, Bosnia and Herzegovina; tel./fax: +387 32 444 270; Email: ljkozedo@bih.net.ba, medicinskiglasnik@gmail.com, web site: http//www.ljkzedo.ba For ordering information please contact: Jasenko Zilo, ljkozedo@bih.net.ba; Access to this journal is available free online trough: www.ljkzedo.ba The Journal is indexed by MEDLINE, EMBASE (Exerpta Medica), Scopus, EBSCO; ISSN 1840-0132 DTP by: Graphic and web design studio “B Panel” Zenica, Zmaja od Bosne bb, www.bpanel.ba, e-mail: info@bpanel.ba, tel. +387 32 441 290, 441 291; Printed by: Graforad Zenica, Zmaja od Bosne bb, 72000 Zenica, mob. 063 038 782; e-mail: graforad@gmail.com Printanje podrzao "Grad Zenica" mailto:ljkozedo@bih.net.ba mailto:medicinskiglasnik@gmail.com http://www.ljkzedo.ba mailto:ljkozedo@bih.net.ba http://www.ljkzedo.ba http://www.bpanel.ba mailto:info@bpanel.ba mailto:graforad@gmail.com Medicinski Glasnik Official Publication of the Medical Association of Zenica-Doboj Canton Bosnia and Herzegovina EDITOR-IN-CHIEF Selma Uzunovic, Zenica, Bosnia and Herzegovina DEPUTY EDITOR Besim Pmjavorac, Tesanj, Bosnia and Herzegovina MANAGING EDITOR Tarik Kapidzic, Zenica, Bosnia and Herzegovina EDITORS Solmaz Abdolrahimzadeh, Rome, Italy Luiz Ronaldo Alberti, Belo Horizonte, Brazil Mutay Aslan, Antalya, Turkey Adem Balic, Tuzla, Bosnia and Herzegovina Dubraka Bartolek, Zagreb, Croatia Branka Bedenic, Zagreb, Croatia Iva Christova, Sofia, Bulgaria Asja Celebic, Zagreb, Croatia Josip Culig, Zagreb, Croatia Filip Culo, Zagreb, Croatia Jordan Dimanovski, Zagreb, Croatia Branko Dmitrovic, Osijek, Croatia Davorin Banic, Slavonski Brod, Croatia Ines Drenjancevic, Osijek, Croatia Harun Drljevic, Zenica, Bosnia and Herzegovina Mukaddes Esrefoglu, Istanbul, Turkey Ivan Fistonic, Zagreb, Croatia Roberta Granese, Messina, Italy Simona Gurzu, Tirgu Murey Romania Diane Medved Harper, Louisville, United State Lejla Ibrahimagic-Seper, Zenica, Bosnia and Herzegovina Tatjana file, Ajman, United Arab Emirates Slobodan M. Jankovic, Kragujevac, Serbia Vjekoslav Jerolimov, Zagreb, Croatia loan Jung, Tirgu Mure§, Romania David Kovacevic, New Haven, United States Sven Kurbel, Osijek, Croatia Snjezana Pejicic, Banja Luka, Bosnia and Herzegovina Belma Pojskic, Zenica, Bosnia and Herzegovina Besim Pmjavorac, Tesanj, Bosnia and Herzegovina Asja Prohic, Sarajevo, Bosna Hercegovina Velimir Profozic, Zagreb, Croatia Radivoje Radic, Osijek, Croatia Amira Redzic, Sarajevo, Bosnia and Herzegovina Halima Resic, Sarajevo, Bosnia and Herzegovina Suad Sivic, Zenica, Bosnia and Herzegovina Sonja Smole-Mozina, Ljubljana, Slovenia Vladimir Simunovic, Mostar, Bosnia and Herzegovina Ekaterine Tskitishvili, Liege, Belgium Aylin Tiirel Ermertcan, Manisa, Turkey Adrij ana Vince, Zagreb, Croatia Jasmina Vranes, Zagreb, Croatia EDITORIAL ASSISTANT Hakija Beculic, Zenica, Bosnia and Herzegovina Proofreaders: Glorija Alic (English) Secretary: Jasenko Zilo MEDICINSKI GLASNIK Official Publication of the Medical Association of Zenica-Doboj Canton, Bosnia and Herzegovina Volume 15, Number 2, August 2018 Free full-text online at: www.ljkzedo.com.ba, and www.doaj.org (DOAJ, Directory of Open Access Journals) Original article g7 A study of enterocyte membranes during activation of apoptotic processes in chronic carrageenan- induced gastroenterocoiitis Anton Tkachenko, Dmytro Marakushyn, Iuliia Kalashnyk, Yevgen Korniyenko, Anatolii Onishchenko, Tatyana Gorbach, Oksana Nakonechna, Yevgen Posokhov, Alexander Tsygankov 93 Diagnostic and prognostic value of procalcitonin in patients with sepsis Sehveta Mustafic, Selmira Brkic, Besim Prnjavorac, Albina Sinanovic, Humera Porobic-Jahic, Sabina Salkic 101 A relation of serum homocysteine, uric acid and C-reactive protein level in patients with acute myocardial infarction Marijana Markovic Boras, Adlija Causevic, Ivica Brizic, Ivanka Miknlic, Marina Vasilj, Nevenka Jelic- Knezovic 109 The role of metabolic therapy with trimetazidine in effort tolerance in patients with ischemic heart disease Una Suljic, Besim Prnjavorac, Tamer Bego, Maja Malenica, Tanja Dujic, Irfan Prnjavorac, Adlija Causevic, Lejla Saranovic 115 High-density lipoprotein cholesterol, apolipoprotein E and atherogenic index of plasma are associated with risk of chronic kidney disease Jasmina Smajic, Sabaheta Hasic, Senija Rasic 122 Outcomes of intrahospital antimicrobial stewardship programs related to prevention of Clostridium difficile infection outbreaks Biljana Mijovic, Milena Dubravac-Tanaskovic, Maja Racic, Janja Bojanic, Slobodan Stanic, Dusica Bankovic Lazarevic 132 Antimicrobial effectiveness of polyhexamethylene biguanide on Enterococcus faecalis, Staphylococcus epidermidis and Candida albicans Ivana Medvedec Mikic, Livia Cigic, Darko Kero, Danijela Kalibovic Govorko, Goranka Prpic Mehicic, Arjana Tambic Andrasevic, Paris Simeon 139 Antibacterial potential of Croatian honey against antibiotic resistant pathogenic bacteria Ivana Gobin, Goranka Crnkovic, Maja Magdalenic, Gabrijela Begic, Ana Babic, Drazen Lusic, Darinka Vuckovic 145 Significance of diffusion weighted imaging (DWI) as an improving factor in contrast enhanced magnetic resonance imaging (MRI) enterography in evaluation of patients with Crohn’s disease Bilal Imsirovic, Enver Zerem, Alma Efendic, Alma Mekic Abazovic, Omar Zerem, Muhamed Djedovic 152 Comparison of Goldmann applanation, non-contact, dynamic contour and tonopen tonometry measurements in healthy and glaucomatous eyes, and effect of central corneal thickness on the measurement results Aydm Yildiz, Tekin Yasar 158 The association of factor V G1961A (factor V Leiden), prothrombin G20210A, MTHFR C677T and PAI-1 4G/5G polymorphisms with recurrent pregnancy loss in Bosnian women Amela Jusic, Devleta Balic, Aldijana Avdic, Maja Podanin, Adem Balic 164 Congenital nasolacrimal duct obstruction: caesarean section vs. vaginal delivery Aydm Yildiz 168 Effects of early diagnosis of the wrist over-use syndrome on the treatment Adnana Talic-Tanovic, Edina Tanovic, Mevludin Mekic, Ivanka Madar - Simic, Adnan Papovic, Hadzan Konjo 174 The predictive value of the clinical sign of limited hip abduction for developmental dysplasia of the hip (DDH) Svemir Custovic, Sahmir Sadie, Aleksandar Vujadinovic, Asmir Hrustic, Mahir Jasarevic, Amer Custovic, Ferid Krupic http://www.ljkzedo.com.ba http://www.doaj.org 179 Patients’ experience regarding informed consent in elective and emergency surgeries Olivera Peric, Marinko Misic, Dejan Tiric, Nikolina Penava, David Busic, Vajdana Tomic 186 Observational multicenter study of efficacy of paroxetine film-coated tablet in the treatment of anxiety disorder Alma Dzubur Kulenovic, Amra Memic Serdarevic, Zebra Halilovic, Haris Masnic, Amra Bahto, Belma Kapo, Daniela Delic, Amila Hadzimuratovic 192 The effect of changing one’s country of residence on the decision to become an organ donor: the experience of religious immigrant women living in Sweden Ferid Krupic, Sahmir Sadie, Svemir Custovic, Mahir Jasarevic, Mirsad Fazlic, Kristian Samuelsson 199 Quality of care for patients with diabetes done by family medicine team during the period 2013-2016 Larisa Gavran, Salih Tandir, Suad Sivic, Fatima Topcic Medicinski Glasnik is indexed by MEDLINE, EMBASE (Exerpta Medica), EBSCO and Scopus ORIGINAL ARTICLE A study of enterocyte membranes during activation of apoptotic processes in chronic carrageenan-induced gastroenterocolitis Anton Tkachenko1, Dmytro Marakushyn2, iuliia Kalashnyk3, Yevgen Korniyenko4, Anatolii Onishchenko1, Tatyana Gorbach1, Oksana Nakonechna1, Yevgen Posokhov5, Alexander Tsygankov5 department of Biochemistry, Kharkiv National Medical University, department of Physiology, Kharkiv National Medical University, department of Otorhinolaryngology3, Kharkiv National Medicai University, department of Human and Animal Physiology, V. N. Karazin Kharkiv National University, department of Organic Chemistry, Biochemistry and Microbiology, The National Technical University “Kharkiv Polytechnic Institute” ; Kharkiv, Ukraine ABSTRACT Corresponding author: Anton Tkachenko Department of Biochemistry, Kharkiv National Medical University Nauky av. 4, 61022 Kharkiv, Ukraine Phone: +380 50 109 45 54; Fax: +380 57 700 41 32; E-mail: antontkachenko555@gmail.com ORCHID ID: http://www.orcid.org/0000- 0002-1029-1636 Original submission: 20 January 2018; Revised submission: 26 March 2018; Accepted: 10 April 2018. doi: 10.17392/946-18 Aim To investigate the lipid membranes of rat enterocytes in chro­ nic carrageenan-induced gastroenterocolitis accompanied by the activation of apoptotic processes. Methods Steady-state fluorescence spectroscopy: a study by flu­ orescent probes - by ortho-hydroxy derivatives of 2,5-diaryl-1,3- oxazole. Activity of apoptosis signal-regulating kinase 1 and p o ly (A D P -ribose) p o lym era se in small intestinal homogenates, blood serum levels of matrix metalloproteinase-2 and caspase-3 and the level of DNA fragmentation in small intestinal homogenates were determined. Results Biochemical analysis revealed that an activation of apop­ totic processes occurred in the intestinal epithelium of rats during chronic carrageenan-induced gastroenterocolitis. The fluorescence probes showed that activation of apoptotic processes in carragee­ nan-induced gastroenterocolitis was accompanied by changes in polar regions of rat enterocyte membranes, while no changes were revealed in more hydrophobic regions of the membranes. Conclusion The increase in hydration of membranes was attributed to the activation of the apoptosis of enterocytes. It has been shown that a fluorescent probe (2-(2'-hydroxyphenyl)-5-phenyl-l,3-oxa- zole) can be used for the detection of apoptosis of enterocytes. Key words: apoptosis, caspases, food additives, rats, inflamma­ tion Med Glas (Zenica) 2018; 15(2):87-92 87 mailto:antontkachenko555@gmail.com http://www.orcid.org/0000-0002-1029-1636 http://www.orcid.org/0000-0002-1029-1636 Medicinski Glasnik, Volume 15, Number 2, August 2018 INTRODUCTION MATERIALS AND METHODS Carrageenan is a high molecular weight anionic polymer, which is obtained by extraction from red seaweeds (1). Carrageenan acts as a natural gelling agent and a thickener in dairy, confectionery and meat products. Food carrageenan (food additive E407) has an average molecular weight of over 100 kDa with a small percentage of smaller fra­ gments. It has been reported that carrageenans are widely used to induce inflammation such as peri­ tonitis, pleurisy, arthritis and carrageenan-induced paw edema (2,3). There is evidence that carrage­ enans also contribute to tumour development (4). Moreover, the oral intake of carrageenans by labo­ ratory animals may lead to intestinal inflammati­ on. It has been reported that carrageenan is able to induce colitis in mice (5). In this connection, the question about the safety of carrageenan as a food additive arises (6). The clinical study of the impact of the systematic use of carrageenan on the body is problematic, so there is an urgent need to study the impact of carrageenan on metabolic parameters in experi­ mental models (2). A model of moderate chronic carrageenan-induced gastroenterocolitis without necrotizing process was designed through the use of lower doses of this food additive on the base of the model of necrotizing carrageenan-induced gastroenterocolitis (7). In our previous publications (6-8) we have shown that the development of chronic carrage­ enan-induced gastroenterocolitis in rats leads to activation of apoptotic processes. This was con- finned by the activation of apoptosis signal-re­ gulating kinase 1 (ASK-1) (8,9), inactivation of p o ly (A D P -ribose) po lym era se (PART) (6, 8) and an increase in DNA fragmentation level (8,9) in small intestinal homogenates; activation of me­ talloproteinase-2 (MMP-2) (10) and activation of caspase-3 (10) in blood serum. However, the study of changes in the membranes of enterocytes during activation of apoptotic pro­ cesses in chronic carrageenan-induced gastroen­ terocolitis has not been conducted. Study design The experiment was carried out on 20 adult fe­ male WAG rats, which were kept under standard vivarium conditions. Laboratory animals were di­ vided into 2 groups: group 1 consisted of animals with experimental chronic carrageenan-induced gastroenterocolitis, and group 2 was the control and consisted of intact animals. Chronic carrage­ enan-induced gastroenterocolitis was evoked by free access of animals to the 1% carrageenan so­ lution in drinking water. The following biochemical parameters after carrageenan intake were measured: apoptosis signal-regulating kinase 1 (ASK-1), p o ly (AD P- ribose) p o lym era se (PARP) and DNA fragmen­ tation in small intestinal homogenates, as well as matrix metalloproteinase-2 (MMP-2) and caspa- se-3 in blood serum (Table 1). Table 1. Parameters of apoptosis in chronic carrageenan-in­ duced gastroenterocolitis in blood serum and small intestinal homogenates Parameter Median (interquartile 25%; 75%) Control Gastroente­ rocolitis P Apoptosis signal-regulating ki­ nase 1 (ASK-1) activity in small 1.79 4.45 intestinal homogenate (units/ (1.72;1.80) (4.27; 4.59) P 1 min. mg of protein) Level of matrix metallopro­ teinase-2 (MMP-2) in blood serum (ng/mL) 7.29 11.31 (6.87;7.72)(10.73;12.37) p<0.01 Poly (ADP-ribose) polymerase (PARP) activity in small intesti- 1.39 0.47 nal homogenate (mmol/mg of (1.30; 1.42) (0.42; 0.50) P< protein) Concentrations of caspase-3 in 0.93 34.66 Mood serum (ng/mL) (0.65;1.14)(30.40;38.20)P< ‘ DNA fragmentation in small 15.5 23.8 intestinal homogenate (%) (15.0;16.7) (23.0; 24.7) P< All experimental procedures were performed in accordance with the provisions of the European Convection for the Protection of Vertebrate Ani­ mals used for Experimental and other Scientific Purposes (11). The aim of this research was to study the lipid membranes of rat enterocytes in chronic carrage­ enan-induced gastroenterocolitis accompanied by the activation of apoptotic processes. Methods A month after the beginning of carrageenan inta­ ke the animals were derived from the experiment by decapitation. The intestine was removed in the cold immediately after the decapitation of rats. 88 T kachenko et al. Enterocyte m embranes and apoptosis activation Perfusion of intestine was performed using chilled physiological solution. The epithelial cells were detached from the internal surface of the intestine by scraping with anatomical knife. A suspension of epithelial cells in Tris-HCl buffer (pH 7.4) was prepared. The cell suspension, corresponding to 56-57%, was used for the study. To investigate the lipid membranes of rat en- terocytes, we used fluorescent probes - ortho- hydroxy derivatives of oxazole, whose molecules non-co'valently bind to the membranes of cells and respond to changes in the microenvironment (12-14): 2-(2 ’ -hydroxyphenyl)-5 -phenyl-1,3- oxazole (probe 1) and 2-(2’-hydroxyphenyl)phe- nanthrene (10,11)-1,3-oxazole (probe 2). The choice of fluorescent probes 1 and 2 (ortho­ hydroxy derivatives of 2,5-diaryl-1,3-oxazole) for the studies of rat enterocyte membranes is due to the fact that the fluorescence characteri- » sties of these fluorescent probes depend on the physicochemical properties of their microenvi­ ronment: on proton-donor ability, polarity and viscosity of the medium (15-18). Fluorescence of the probes was measured in physiological solutions, containing: the entero- cytes of rats with chronic carrageenan-induced gastroenterocolitis (experimental group) and the enterocytes of intact healthy animals (control). For all the fluorescence measurements, the cells were fluorescentiy labelled using the same pro­ cedure. Since the solubility of the probes is li­ mited in water, the 0.2 mM stock solution of the probes in acetonitrile was used. An aliquot of 0.2 mM stock solution of the probe in acetonitrile was added to physiological solution with entero­ cytes (i.e. acetonitrile final concentration was < 0.5% vol.) to achieve final probe concentration of 1 juM (such concentration of the probe corres­ ponded to lipid-to-probe molar ratio 1000:1). The cell suspension was then incubated with the probes in a dark at room temperature for 1 hour before fluorescence measurements. Fluorescence spectra were recorded on a Hitac­ hi F850 steady-state fluorescence spectrome­ ter at room temperature. The slits on excitation and emission monochromators were 5 nm. The measurements were made in a 10 mmxlQ mm cuvette. An excitation wavelength was 330 nm. Emission was recorded in the range of 340 - 600 nm, with an increment of 1 nm. Data were collec­ ted with a 1 s interval. The accuracy of the fluorescence intensity mea­ surements of the samples was 5%. Statistical analysis Mann-Whitney U test was used to compare the numerical values of two groups. Differences between groups were considered statistically si­ gnificant at p<0.05. RESULTS Biochemical parameters whose changes were observed after carrageenan intake were ASK-1, PART and DNA fragmentation in small intestinal homogenates and MMP-2, caspase-3 in blood se­ rum. Activation of apoptotic processes in the in­ testinal epithelium of rats during chronic carrage­ enan-induced gastroenterocolitis was judged by the activation of apoptosis signal-regulating ki­ nase 1 (ASK-1): the activation from 1.79 [1.72; 1.80] (control) to 4.45 [4.27; 4.59] units/min. mg of protein (gastroenterocolitis); inactivation of p o ly (A D P -ribose) p o lym era se (PARP): from 1.39 [1.30; 1.42] (control) to 0.47 [0.42; 0.50] pmol/mg of protein (gastroenterocolitis); activa­ tion of caspase-3 from 0.93 [0.65; 1.14] (control) to 34.66 [30.40; 38.20] ng/mL (gastroenterocoli­ tis); increase in the level of DNA fragmentation: from 15.5 [15.0; 16.7] % (control) to 23.8 [23.0; 24.7] % (gastroenterocolitis) (Table 1). A marked decrease in the intensity of the long-wa­ velength fluorescence band (470 nm) arid a slight increase in the intensity of the short-wavelength fluorescence band (390 nm) of probe 1 were ob­ served in the case of enterocytes from the animals with carrageenan-induced gastroenterocolitis in condition of activation of apoptotic processes (Ta­ ble 2, Figure 1). Thus, the fluorescence intensity ratio I470/I390 of probe 1 was reduced in case of ac­ tivation of apoptotic processes (Table 2). Table 2. Fluorescence intensity of probes 1 and 2 in enterocyte membranes of rats Fluorescence intensity* Probe 1 Probe 2 Sample 390 nm 470nm *47q/ j 90 425 nm 485 nm ^ ________ _______________________3 2 5 ____ Control (n=10) 3.7±0.2 21.0±1.1 5.7±0.3 56i3 112±6 2.0i0.1 Gastroenteroco­ litis (n=lG) 4.0±0.2 14.1i0.7 3.5±0.2 54i3 114±6 2.1 ±0.1 * arbitrary units At the same time, no significant changes in the flu­ orescence parameters of probe 2 were observed in the case of the enterocyte membranes of rats with 89 Medicinski Glasnik, Volume 15. Number 2. August 2018 carrageenan-induced gastroenterocolitis in condi­ tion of activation of apoptotic processes (Table 2, Figure 1). Figure 1. Ffyoresoence spectrum of probes 1 (pane! A) and 2 (panel B) were recorded for: (f) the probes bound to enterocyte membranes from the control group of rats (solid line); (if) the probes bound to enteroeyfe membranes of animals with carra­ geenan-induced gastroenterocolitis in condition of activation of apoptotic processes (dashed line) DISCUSSION It is well-known that during apoptotic processes some biochemical parameters are changed (19). Biochemical parameters whose changes were observed after carrageenan intake in the present study were ASK-1, PARP and DNA fragmentati­ on in small intestinal homogenates and MMP-2, caspase-3 in blood serum (8-10). Our results are consistent with numerous researches that confirm the activation of apoptosis in inflammatory inte­ stinal diseases, e.g. inflammatory bowel disease (20). In particular, there is strong evidence that inflammatory bowel disease is associated with the activation of apoptosis in the intestinal muco­ sa of patients (21). Probes 1 and 2 are capable of isomerization in the excited state (Figure 2), forming normal (N*) and phototautomer (T*) species (12-16). This reacti­ on is known as an excited state intramolecular proton transfer (ESIPT) (15,16). N * Excited state J * N Ground state ”f Figure 2. Scheme of excited state intramolecular proton trans­ fer (ESIPT) in 2-(2 '“hydroxyptteny!) -5-ph@ny!-1s3~oxazoie (probe 1). The upwards arrow shows the electronic excitation and the downwards arrow represents the emission of light (fluorescence). Corresponding maximum of absorption and the ranges of emission are measured in nanometres The presence of dual fluorescence allows us to perform ratiometric measurements, i.e. to use the ratio of fluorescence intensities of the phototau­ tomer form (IT*) and of the normal form (IN*) as a parameter to investigate the physicochemical properties of the microenvironment (12-14). Usage of ratiometric fluorescent probes elimina­ tes not only the measurement error caused by the deviation of the fluorescent probe concentration (e.g., uneven content of fluorescent probe in vario­ us membranes), but also the measurement errors due to deviation in configuration and adjustment of equipment for measurements of fluorescence (e.g. deviation in the intensity of the source of excitation light, changes in focusing, changes in the sensitivity of the photodetector, etc.) (17). The fluorescent probes (i.e. probes 1 and 2), which differ in iipophilicity (12-14), were chosen for the present study. It is expected that the regions of location of the selected probes in the membrane are different and correspond to Iipophilicity of the pro­ bes (Figure 3). The expected location and orientati­ on of probes 1 and 2 are based on their fluorescence properties in lipid membranes (12-14) and on their structural similarity to the fluorescent probes with known location in lipid membranes (17): probe 1 located in the area of glycerol residues of the phos­ pholipids (closer to the centre of the lipid bilayer), in the area of carbonyl groups of the phospholipids and in the area of fatty acid chains of the phospho- 90 Tkachenko et al. Enterocyte membranes and apoptosis activation lipids (closer to the carbonyl groups); probe 2 - in the area of fatty acid chains of the phospholipids (near the centre of the bilayer) and in the centre of membrane lipid bilayer (Figure 3). According to some authors (18,19,22), apoptosis is accompani­ ed by the following changes in the cell membrane: (a) lost of lipid asymmetry (18,19). Charged lipids (phosphatidylserine (PS), phosph ati dv 1 eth an o 1 am i - ne (PE)) appear in the outer layer of the membrane (18,19); (b) the negative charge on the external li­ pid layer of the membrane is increased (18,19), the lipid ordering is reduced (18,19), the activation of the oxidation of lipids is observed (22). All such changes should lead to an increase in polarity and to increase in hydration of the membrane (23). Figure 3. Expected location and orientation of fluorescent probes 1 and 2. Two molecules of phosphatidylcholine from the outer monolayer are shown to denote the location of the probes Based on the properties of the probes 1 and 2 (12- lb), one can expect that the growth in polarity and in hydration of the membrane will result in: an increase in the relative fluorescence intensity of the normal form N*; a decrease of the relative fluorescence intensity of phototautomer form T*; a decrease of the ratio of fluorescence intensities of the phototautomer and normal forms (IT*/ IN*). As it was expected, the decrease in fluorescence intensity of the band of phototautomer form (IT j and the increase in the ratio IT*/IN* were observed for probe 1 in case of the disease. The mentioned changes in the fluorescent parameters of probe 1 indicate an increase in polarity and proton-donor ability of the microenvironment of the probe (14) in enterocyte membranes of rats with carrageenan- induced gastroenterocolitis during activation of apoptotic processes. Such an increase in polarity and proton-donor ability of the microenvironment of probe 1 indicates an increase in hydration of the probe microenvironment (14) in the enterocyte membranes of the experimental group of animals. The observed increase in hydration of the area of location of probe 1, (i.e. the polar regions of the membrane) indicates that apoptosis is activated (18) in enterocytes during the course of chronic carrageenan-induced gastroenterocolitis. The absence of changes in the area where probe 2 is located (i.e. in more hydrophobic regions of the lipid bilayer), is explained by the fact that, apparently, no significant changes in hydration occur in hydrophobic regions of the lipid bilayer during the activation of apoptosis of enterocytes. Thus, in condition of activation of apoptotic pro­ cesses in the course of chronic carrageenan-indu­ ced gastroenterocolitis, an increase in hydration of rat enterocyte membrane is observed in the area where probe 1 is located, i.e. in rather polar regi­ ons of the membrane - presumably in the area of glycerol residues of phospholipids (closer to the centre of the lipid bilayer), and in the area of the carbonyl groups of phospholipids and fatty acid chains of the phospholipids (closer to the area of the carbonyl groups). The observed changes in the hydration of the polar regions of the membra­ ne are attributed to the activation of apoptosis of enterocytes in the course of chronic gastroentero­ colitis. At the same time, in condition of activati­ on of apoptotic processes, no changes are noticed in the area, where probe 2 is located, i.e. in more hydrophobic regions of enterocyte membrane: presumably in the area of fatty acid chains of the phospholipids (near the center of the bilayer) and in the centre of membrane lipid bilayer. In conclusion, an increase in hydration of the po­ lar regions of enterocyte membranes occurs in rats with chronic carrageenan-induced gastroenteroco- iitis. The increase in hydration has been attributed to the activation of the apoptosis of enterocytes. A fluorescent probe (2-(2'-hydroxyphenyl)- 5-phenyl-l,3-oxazole) could be used for the detec­ tion of apoptosis of enterocytes. ACKNOWLEDGEMENT Authors are grateful to Prof. A.O. Doroshenko for gifting us with ortho-hydroxy derivatives of 2,5-diaryl-1,3-oxazole. 91 Medicinski Glas FUNDING TRANSPARENCY DECLARATION No specific funding was received for this study. 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