Recent studies demonstrated remote effects of renal ischemia/reperfusion (I/R) injury on some organs such as brain, liver, and lungs. We investigated the effects of renal I-R injury on function, histology and oxidative stress state of pancreas. Twenty -four male adult Sprague-Dawley rats were divided equally into 2 groups; sham group: rats underwent midline laparotomy and dissection of renal pedicles without renal ischemia, and ischemic group: rats underwent bilateral renal ischemia for 45 min. Renal functions (serum creatinine and BUN), pancreatic functions (serum amylase, lipase and insulin) and fasting blood glucose were measured at 2 h, 1 day, 3 days and 7 days after ischemia. Also, pancreatic histology and malondialdehyde (MDA), catalase and reduced glutathione (GSH) were examined at 2 h and 7 days after ischemia. The ischemic rats showed significant increase in serum creatinine and BUN with significant increase in serum amylase and lipase at 2 h, 1 day and 3 days after ischemia. Blood glucose and fasting insulin showed no significant change apart from significant increase in insulin in sham group at 1 day after ischemia. Pancreas isolated from ischemic rats showed significant increase in histopathological damage score and significant increase in MDA and catalase enzyme with decrease in GSH. In conclusion, bilateral renal ischemia for 45 min caused significant impairment of pancreatic functions and histology. This might be due to deficiency of antioxidant and increased lipid peroxidations in pancreatic tissues., A. M. Hussein ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
The pathological potential of glial cells was recognized already by Rudolf Virchow, Santiago Ramon y Cajal and Pio Del Rio-Ortega. Many functions and roles performed by astroglia in the healthy brain determine their involvement in brain diseases; as indeed any kind of brain in sult does affect astrocytes, and their performance in pathological conditions, to a very large extent, determines the survival of the brain parenchyma, the degree of damage and neurological defect. Astrocytes being in general responsible for overall brain homeostasis are involved in virtually every form of brain pathology. Here we provide an overview of recent developments in identifying the role and mechanisms of the pathological potential of astroglia., A. Chvátal, M. Anděrová, H. Neprašová, I. Prajerová, L. Benešová, O. Butenko, A. Verkhratsky., and Obsahuje bibliografii a bibliografické odkazy
Microparticles are small fragments of the plasma membrane released by activated and/or apoptotic cells. In theory, all type of cells can shed microparticles representing a physiological process in the cell life. Mainly, microparticles generation has been studied in different cardiovascular pathologies due to the facility to obtain blood samples from individuals. Although microparticles have been considered as simply markers of several diseases, in the last decade, several studies support the hypothesis that they participate in the regulation of the cardiovascular system function by carrying biological messages between cells. Among the effects of microparticles, recent data show that they can be implicated in the modulation of neovascularization, an essential function of cells from cardiovascular system during either ischemic diseases or cancer development. Whereas during pathologies associated with ischemia an increase of neovascularization may have beneficial effects, anti-angiogenic strategies represent new approaches for manipulation of tumor development. Here, we give an overview of the mechanisms and factors involved in neovascularization, and finally, we look at the role and the consequences of the modulation of this process by microparticles in pathological situations., H. A. Mostefai, R. Andriantsitohaina, M. C. Martínez., and Obsahuje bibliografii a bibliografické odkazy
This study was designed to determine the gastroprotective properties of quercetin in ischemia/reperfusion-induced gastric mucosal injury and the involvement of endogenous prostaglandins in this process. Oral pretreatment of rats with quercetin (100 mg.kg-1) 30 min before surgery significantly decreased the length of gastric mucosal lesions. However, lower doses of quercetin (25 and 50 mg.kg-1) only slightly decreased the gastric mucosal injury. Intraperitoneal application of indomethacin (5 mg.kg-1) had no effect in control (sham-operated) animals, but significantly worsened gastric injury in non-treated animals after ischemia/reperfusion. Furthermore, indomethacin only slightly reversed protective effect of quercetin. Non-treated animals showed a marked decrease in adherent mucus after ischemia/reperfusion. On the other hand, application of quercetin prevented this significant decrease even in animals pretreated with indomethacin. It can be concluded that antioxidant properties of quercetin and its mucus protective effect might be the main factors responsible for its protective effect against ischemia/reperfusion-induced gastric mucosal injury., J. Mojžiš, K. Hviščová, D. Germanová, D. Bukovičová, L. Mirossay., and Obsahuje bibliografii
Remifentanil is a commonly used opioid in anesthesia with cardioprotective effect in ischemia-reperfused (I/R) heart. We evaluated the influence of remifentanil on myocardial infarct size and expressions of proteins involved in apoptosis in I/R rat heart following various time protocols of remifentanil administration. Artificially ventilated anesthetized Sprague-Dawley rats were subjected to a 30 min of left anterior descending coronary artery occlusion followed by 2 h of reperfusion. Rats were randomly assigned to one of five groups; Sham, I/R only, remifentanil preconditioning, postconditioning and continuous infusion group. Myocardial infarct size, the phosphorylation of ERK1/2, Bcl2, Bax and cytochrome c and the expression of genes influencing Ca2+ homeostasis were assessed. In remifentanil-administered rat hearts, regardless of the timing and duration of administration, infarct size was consistently reduced compared to I/R only rats. Remifentanil improved expression of ERK 1/2 and anti-apoptotic protein Bcl2, and expression of sarcoplasmic reticulum genes which were significantly reduced in the I/R rats only. Remifentanil reduced expression of pro-apoptotic protein, Bax and cytochrome c. These suggested that remifentanil produced cardioprotective effect by preserving the expression of proteins involved in anti-apoptotic pathways, and the expression of sarcoplasmic reticulum genes in I/R rat heart, regardless of the timing of administration., H. S. Kim ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Remote ischemic preconditioning (RIP)-induced protection of myocardial energetics was well documented on the level of tissue, but data concerning the involvement of mitochondria were missing. We aimed at the identification of changes in membrane properties and respiratory functions induced in rat heart mitochondria by RIP. Experiments were performed on 46 male Wistar rats divided into control and RIP-treated groups of 21 animals each. Blood flow in the occluded area was recorded by MRI angiography in four animals. RIP protocol comprised of three successive 5-min occlusions each followed by 5-min reperfusions of descending branches of the right hind limb femoral artery. The efficacy of RIP was evaluated as the extent of RIP-induced protection against damage to the functions of mitochondria isolated by differential centrifugation after 30-min global ischemia followed by 40-min reperfusion of the hearts in Langendorff mode. Assessments: mitochondrial membrane fluidity with a fluorescent probe DPH, CoQ9 and CoQ10 with HPLC, mitochondrial respiration with the Oxygraph-2k (Oroboros). Results revealed that RIP was affecting the mitochondria. The immediate protection conferred by RIP involves beneficial and prognostically significant effects: a total elimination of ischemia/reperfusion-induced depression of mitochondrial membrane fluidity and a trend for better preservation of mitochondrial state 3 respiration., M. Ferko, I. Kancirová, M. Jašová, S. Čarnická, M. Muráriková, I. Waczulíková, Z. Sumbalová, J. Kucharská, O. uličná, T. Ravingerová, A. Ziegelhöffer., and Obsahuje bibliografii
Remote ischemic preconditioning (RIPC) is a novel strategy of protection against ischemia-reperfusion (IR) injury in the heart (and/or other organs) by brief episodes of non-lethal IR in a distant organ/tissue. Importantly, RIPC can be induced noninvasively by limitation of blood flow in the extremity implying the applicability of this method in clinical situations. RIPC (and its delayed phase) is a form of relatively short-term adaptation to ischemia, similar to ischemic PC, and likely they both share triggering mechanisms, whereas mediators and end-effectors may differ. It is hypothesized that communication between the signals triggered in the remote organs and protection in the target organ may be mediated through substances released from the preconditioned organ and transported via the circulation (humoral pathways), by neural pathways and/or via systemic anti-inflammatory and antiapoptotic response to short ischemic bouts. Identification of molecules involved in RIPC cascades may have therapeutic and diagnostic implications in the management of myocardial ischemia. Elucidation of the mechanisms of endogenous cardioprotection triggered in the remote organ could lead to the development of diverse pharmacological RIPC mimetics. In the present article, the authors provide a short overview of RIPC-induced protection, proposed underlying mechanisms and factors modulating RIPC as a promising cardioprotective strategy., T. Ravingerova, V. Farkasova, L. Griecsova, S. Carnicka, M. Murarikova, E. Barlaka, F. Kolar, M. Bartekova, L. Lonek, J. Slezak, A. Lazou., and Obsahuje bibliografii
Gastric mucus plays an important role in gastric mucosal protection. Apart from its “barrier” function, it has been demonstrated that mucus protects gastric epithelial cells against toxic oxygen metabolites derived from the xanthine/xanthine oxidase system. In this study, we investigated the effect of malotilate and sucralfate (mucus production stimulators) and N-acetylcysteine (mucolytic agent) on ischemia/reperfusion-induced gastric mucosal injury. Gastric ischemia was induced by 30 min clamping of the coeliac artery followed by 30 min of reperfusion. The mucus content was determined by the Alcian blue method. Sucralfate (100 mg/kg), malotilate (100 mg/kg), and N-acetylcysteine (100 mg/kg) were given orally 30 min before surgery. Both sucralfate and malotilate increased the mucus production in control rats. On the other hand, N-acetylcysteine significantly decreased mucus content in control (sham) group. A significant decrease of mucus content was found in the control and the N-acetylcysteine pretreated group during the period of ischemia. On the other hand, sucralfate and malotilate prevented the decrease the content of mucus during ischemia. A similar result can be seen after ischemia/reperfusion. In the control group and N-acetylcysteine pretreated group a significant decrease of adherent mucus content was found. However, sucralfate and malotilate increased mucus production (sucralfate significantly). Sucralfate and malotilate also significantly protected the gastric mucosa against ischemia/reperfusion-induced injury. However, N-acetylcysteine significantly increased gastric mucosal injury after ischemia/reperfusion. These results suggest that gastric mucus may be involved in the protection of gastric mucosa after ischemia/reperfusion., J. Mojžiš, R. Hegedüšová, L. Mirossay., and Obsahuje bibliografii
Given the potential clinical benefit of inhibiting Na+/Ca2+ exchanger (NCX) activity dur ing myocardial ischemia reperfusion (I/R), pharmacological approaches have been pursued to both inhibit and clarify the importance of this exchanger. SEA0400 was reported to have a potent NCX selectivity. Thus, we examined the effect of SEA0400 on NCX currents and I/R induced intracellular Ca2+ overload in mouse ventricular myocytes using patch clamp techniques and fluorescence measurements. Ischemia significantly inhibited inward and outward NCX current (from -0.04±0.01nA to 0 nA at -100 mV; from 0.23±0.08 nA to 0.11±0.03 nA at +50 mV, n=7). Subsequent reperfusion not only restored the current rapidly but enhanced the current amplitude obviously, especially the outward currents (from 0.23±0.08 nA to 0.49±0.12 nA at +50 mV, n=7). [Ca2+]i, expressed as the ratio of Fura-2 fluorescence intensity, increased to 138±7 % (P<0.01) during ischemia and to 210±11 % (P<0.01) after reperfusion. The change of NCX current and the increase of [Ca 2+]i during I/R can be blocked by SEA0400 in a dose-dependent manner with an EC50 value of 31 nM and 28 nM for the inward and outward NCX current, respectively. The results suggested that SEA0400 is a potent NCX inhibitor, which can protect mouse cardiac myocytes from Ca2+ overload during I/R injuries., J. Wang, Z. Zhang, Y. Hu, X. Hou, Q. Cui, Y. Zang, C. Wang., and Obsahuje bibliografii a bibliografické odkazy
The aim of our study was to characterize resistance to ischemia/reperfusion (I/R) injury in Langendorff-perfused rat hearts and effectivity of ischemic preconditioning (PC) under condition of simulated acute hyperglycemia (SAHG) by perfusion of the hearts with Krebs-Henseleit (KH) solution with elevated glucose concentration (22 mmol/l). I/R injury was induced by 30- min coronary occlusion followed by 120-min reperfusion and PC by two cycles of 5-min occlusion/5-min reperfusion, prior to I/R. The severity of I/R injury was characterized by determination of the size of infarction (IS, expressed in % of area at risk size) and the amount of heart-type fatty acid binding protein (h-FABP, a marker of cell injury) released from the hearts to the effluent. Significantly smaller IS (8.8±1 %) and lower total amount of released h-FABP (1808±660 pmol) in PC group compared with IS 17.1±1.2 % (p<0.01) and amount of h-FABP (8803±2415 pmol, p<0.05) in the non-PC control hearts perfused with standard KH solution (glucose 11 mmol/l) confirmed protective effects of PC. In contrast, in SAHG groups, PC enhanced IS (21.4±2.2 vs. 14.3±1.3 %, p<0.05) and increased total amount of h-FABP (5541±229 vs. 3458±283 pmol, p<0.05) compared with respective non-PC controls. Results suggest that PC has negative effect on resistance of the hearts to I/R injury under conditions of elevated glucose in vitro., M. Zálešák, P. Blažíček, D. Pancza, V. Ledvényiová, M. Barteková, M. Nemčeková, S. Čarnická, A. Ziegelhöffer, T. Ravingerová., and Obsahuje bibliografii