During shock, prognosis of a patient depends largely on intestinal barrier function. The potency of gut epithelium to represent an obstacle to toxins is determined by the blood supply. All established methods of mucosal function determination necessitate the functional involvement of bloodstream. Microdialysis allows monitoring of extracellular substances in the gut submucosa, but its potential use for gut barrier integrity assessment is unknown. Twelve rats underwent perfusion of the descending colon either with 20 % ethanol or control medium (vehicle). Both media contained equal amounts of a radioactive tracer substance (51Cr-EDTA). Mucosal permeability for 51Cr-EDTA was assessed by microdialysate to luminal perfusate activity ratios. Sampling was performed using the colon submucosal microdialysis technique. The group subjected to ethanol treatment had profound macro- and microscopical alterations in perfused colonic segment associated with a significant increase in tracer permeability during ethanol exposure (2.354±0.298 % for ethanol as opposed to 0.209±0.102 % for control group, p<0.01), which remained elevated for 60 min after cessation of ethanol administration (3.352±0.188 % for ethanol compared to 0.140± 0.0838 % for the control group, p<0.001). Submucosal microdialysis with radioactive tracer substance can be considered a feasible and advantageous alternative of gut barrier function estimation. Parallel monitoring of local tissue chemistry with this method remains a challenge in the future., N. Cibiček, H. Živná, Z. Zadák, J. Kulíř, E. Čermáková, V. Palička., and Obsahuje bibliografii a bibliografické odkazy
Hypothermia was shown to attenuate ventilator-induced lung injury due to large tidal volumes. It is unclear if the protective effect of hypothermia is maintained under less injurious mechanical ventilation in animals without previous lung injury. Tracheostomized rats were randomly allocated to non-ventilated group (group C) or ventilated grou ps of normothermia (group N) and mild hypothermia (group H). After two hours of mechanical ventilation with inspiratory fraction of oxygen 1.0, respiratory rate 60 min-1 , tidal volume 10 ml·kg-1 , positive end-expiratory pressure (PEEP) 2 cm H 2 O or immediately after tracheostomy in non-ventilated animals inspiratory pressures were recorded, rats were sacrificed, pressure-volume (PV) curve of respiratory system constructed, bronchoalveolar lavage (BAL) fluid and aortic blood samples obtained. Group N animals exhibited a higher rise in peak inspiratory pressures in comparison to group H animals. Shift of the PV curve to right, higher total protein and interleukin- 6 levels in BAL fluid were observed in normothermia animals in comparison with hypothermia animals and non-ventilated controls. Tumor necrosis factor- α was lower in the hypothermia group in comparison with normothermia and non-ventilated groups. Mild hypothermia attenuated changes in respiratory system mechanics and modified cytokine concentration in bronchoalveolar lavage fluid during low lung volume ventilation in animals without previous lung injury., P. Dostál, M. Šenkeřík, R. Pařízková, D. Bareš, P. Živný, H. Živná, V. Černý., and Obsahuje bibliografii