ABSTRACT
In the present study we explored glutathione S-transferase (GST) polymorphisms in selected patients who experienced accelerated myocardial injury following open heart surgery and compared these to a control group of patients without postoperative complications. 758 Patients were enrolled from which 132 patients were selected to genotype analysis according to exclusion criteria. Patients were divided into the following groups: Group I: control patients (n = 78) without and Group II.: study patients (n = 54) with evidence of perioperative myocardial infarction. Genotyping for GSTP1 A (Ile105Ile/Ala113Ala), B (Ile105Val/Ala113Ala) and C (Ile105Val/Ala113Val) alleles was performed by using real-time-PCR. The heterozygous AC allele was nearly three times elevated (18.5 vs. 7.7 %) in the patients who suffered postoperative myocardial infarction compared to controls. Contrary, we found allele frequency of 14.1 % for homozygous BB allele in the control group whereas no such allele combination was present in the study group. These preliminary results may suggest the protective role for the B and C alleles during myocardial oxidative stress whereas the A allele may represent predisposing risk for cellular injury in patients undergoing cardiac surgery.
Subject(s)
Glutathione Transferase/genetics , Myocardial Infarction/genetics , Polymorphism, Genetic/genetics , Alleles , Cardiac Surgical Procedures/methods , Case-Control Studies , Female , Gene Frequency/genetics , Genotype , Humans , Male , Middle Aged , Myocardial Infarction/surgery , Risk FactorsABSTRACT
BACKGROUND: Recently several alternative forms of the original clopidogrel hydrogensulfate (CHS) were spread worldwide. A large amount of such drugs turned out to be clopidogrel besylate (CB). Only three studies, involving healthy volunteers, investigated the antiplatelet effect of CB, whereas its attribute remained unexplored in the case of patients with cardiovascular diseases. This retrospective study aimed to evaluate the difference between the antiplatelet effects of two clopidogrel formulas, CHS and CB, on patients with coronary artery diseases. METHODS: Data of 150 patients with previous CHS treatment were investigated. According to the documentations, the CHS therapy was shifted to CB. 94 patients of the selected population received dual antiplatelet therapy, clopidogrel and aspirin. The antiplatelet effects of CHS and CB were compared by ADP induced platelet aggregation measurements using light transmission aggregometry. RESULTS: Irrespective of the therapeutic combinations the performed statistical investigations failed to show significant difference (p=0.30) between the effect of CB (AGGmax(CB): 27.6±13.7%) or CHS (AGGmax(CHS): 29.0±15.3%) on the ADP induced platelet aggregation. Insignificant deviations were found in both forms of clopidogrel salts, either in the lack (AGGmax(CB) : 32.5±14,2%; AGGmax(CHS): 34,0±16,1%; p=0,29) or in the presence of aspirin (AGGmax(CB): 24.7±12,5%; AGGmax(CHS): 26,0±14,1%; p=0,31). CONCLUSION: Our results indicated that both CB and CHS had an identical inhibitory effect on ADP induced platelet aggregation in patients with cardiovascular diseases. Moreover their efficiency showed no overall significant difference in the case of dual antiplatelet therapy with aspirin as well. However there might be an inter- and intraindividual variability between the two clopidogrel formulas.
Subject(s)
Coronary Artery Disease/blood , Coronary Artery Disease/drug therapy , Platelet Aggregation Inhibitors/therapeutic use , Platelet Aggregation/drug effects , Ticlopidine/analogs & derivatives , Clopidogrel , Female , Humans , Male , Middle Aged , Platelet Aggregation Inhibitors/adverse effects , Retrospective Studies , Ticlopidine/adverse effects , Ticlopidine/therapeutic useABSTRACT
A PMMA (polymethyl-methacrylate)-sorbitol-based capsule system was recently developed, and the permeability of 16 types of capsules with different wall thicknesses and sorbitol contents tested. By optimizing these two parameters, we showed that capsule permeability could be controlled. Promising preliminary data obtained using BPB (Bromophenol Blue) as diffusion marker prompted us to further investigate the antibiotic release of capsules showing the most appropriate release characteristics. PMMA-sorbitol capsules were prepared with wall thickness of 0.5 or 0.6 mm and 60 or 70 w/w% (weight percent) of sorbitol content. In vitro gentamicin, amikacin, tobramycin releases were determined by using a microbiological agar plate diffusion assay. Capsules released 70-100% of their gentamicin load, substantially superior to Septopal, and showed preferable, extended release profiles when compared with the beads. The release kinetics of amikacin and tobramycin closely resembled those of gentamicin. PMMA-sorbitol capsules have been developed and tested, which make them promising devices for local antibiotic delivery.
Subject(s)
Anti-Bacterial Agents/administration & dosage , Capsules/chemistry , Polymethyl Methacrylate/chemistry , Sorbitol/chemistry , Amikacin/administration & dosage , Amikacin/chemistry , Amikacin/pharmacology , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Diffusion , Drug Carriers/chemistry , Gentamicins/administration & dosage , Gentamicins/chemistry , Gentamicins/pharmacology , Kinetics , Microbial Sensitivity Tests , Tobramycin/administration & dosage , Tobramycin/chemistry , Tobramycin/pharmacologyABSTRACT
Pre- and postconditioning are powerful endogenous adaptive phenomenon of the organism whereby different stimuli enhance the tolerance against various types of stress. Urocortin (Ucn), member of the corticotropin-releasing factor (CRF) family has potent effects on the cardiovascular system. The aim of this article was to investigate the action of Ucn on cultured cardiomyocytes in the process of pre- and postconditioning. Isolated neonatal rat ventricular myocytes were preconditioned with adenosine, simulated ischemia, and Ucn (10-min treatment followed by 10-min reperfusion/recovery). For detecting the effect of alternative types of preconditioning, necrosis enzyme (lactate dehydrogenase [LDH]) release, vital staining (trypan blue), and ratio of apoptosis/necrosis were examined after cardiac cells were exposed to 3-h sustained ischemia and 2-h reperfusion. Same parameters were measured in the postconditioned groups (30- or 60-min ischemia followed by postconditioning with 10-min ischemic stimulus or Ucn and 2-h reperfusion). Cells exposed to 3-h ischemia followed by 2-h reperfusion were shown as control. Our results show that LDH release a number of trypan blue-stained dead cells and the ratio of apoptotized and necrotized cells was decreased in all preconditioned groups compared with control group. In postconditioned groups LDH content of culture medium, trypan blue-positive cardiomyocytes, and the rate of apoptotic/necrotic cells was reduced contrasted with non-postconditioned group. We can conclude that preconditioning with Ucn induced such a powerful cell protective effect as adenosine and ischemia. Furthermore, postconditioning with Ucn after 60-min ischemia was more cardioprotective than ischemic postconditioning.
Subject(s)
Cardiotonic Agents/pharmacology , Corticotropin-Releasing Hormone/physiology , Heart/physiology , Ischemic Preconditioning, Myocardial , Myocardium/metabolism , Reperfusion Injury/prevention & control , Animals , Animals, Newborn , Cells, Cultured , Heart/drug effects , Myocardium/cytology , Pilot Projects , Rats , Rats, Wistar , UrocortinsABSTRACT
In the study the authors aimed to demonstrate the expression and protective effect of heme oxygenase-1 (HO-1) in the delayed preconditioning (PC) on cultured myocardiac cells. Neonatal rat cardiac myocytes were exposed to ischemic (ischemic medium [IM] for 20 min) and pharmacological (adenosine, epinephrine, opioid) PC. Twenty-four hours later cells were subjected to a simulated ischemia (SI)--culturing for 3 h in IM, followed by 2-h reperfusion in normal medium--and then lactate dehydrogenase (LDH), live/death ratio, and apoptosis were measured. For demonstrating the protective role of HO-1, its enzymatic activity was competitively inhibited by administration of zinc protoporphyrin IX (ZnPPIX), and HO-1 synthesis was blocked with HO-1 siRNA. Cells in control group were cultured under normoxic conditions. In SI group, cells underwent only an SI without PC. HO-1 expression in all of the groups was demonstrated with immunostaining. Our results showed a significant decrease of LDH release, apoptosis, and cell death in PC groups versus SI group, which has been risen in ZnPPIX- and HO-1 siRNA-treated groups. HO-1 immunostaining showed an appreciable HO-1 expression in PC groups, which was abolished with HO-1 siRNA administration, but not in ZnPPIX group. The results therefore suggest that HO-1 expression increases in both ischemic and pharmacological PC, and HO-1 has cellular protective effect against cell death and apoptosis in ischemia-reperfusion-induced oxidative injury.
Subject(s)
Heme Oxygenase-1/biosynthesis , Ischemic Preconditioning, Myocardial , Myocardium/enzymology , Animals , Animals, Newborn , Cells, Cultured , Heme Oxygenase-1/genetics , Heme Oxygenase-1/physiology , Myocardium/cytology , Rats , Rats, WistarABSTRACT
Articular chondrocytes have a well-developed osmoregulatory system that enables cells to survive in a constantly changing osmotic environment. However, osmotic loading exceeding that occurring under physiological conditions severely compromises chondrocyte function and leads to degenerative changes. The aim of the present study was to investigate the form of cell death and changes in apoptotic signaling pathways under hyperosmotic stress using a primary chondrocyte culture. Cell viability and apoptosis assays performed with annexin V and propidium iodide staining showed that a highly hyperosmotic medium (600 mOsm) severely reduced chondrocyte viability and led mainly to apoptotic cell death, while elevating osmotic pressure within the physiological range caused no changes compared to isosmotic conditions. Western blot analysis revealed that a 600 mOsm hyperosmotic environment induced the activation of proapoptotic members of the mitogen-activated protein kinase family such as c-Jun N-terminal kinase (JNK) and p38, and led to an increased level of extracellular signal regulated kinase (ERK1/2). Hyperosmotic stress also induced the activation of caspase-3. In summary, our results show that hyperosmotic stress leads to mainly apoptotic cell death via the involvement of proapoptotic signaling pathways in a primary chondrocyte culture.
Subject(s)
Apoptosis/physiology , Chondrocytes/physiology , Signal Transduction/physiology , Animals , Annexin A5/pharmacology , Cartilage, Articular/cytology , Caspase 3/metabolism , Cell Survival , Cells, Cultured , Enzyme Activation , Enzyme Inhibitors/pharmacology , Ethidium/metabolism , Female , Flow Cytometry , Fluoresceins/metabolism , Fluorescent Dyes/metabolism , Formazans/metabolism , JNK Mitogen-Activated Protein Kinases/metabolism , Mitogen-Activated Protein Kinase 1/metabolism , Mitogen-Activated Protein Kinase 3/metabolism , Osmolar Concentration , Osmotic Pressure , Oxidative Stress/physiology , Swine , p38 Mitogen-Activated Protein Kinases/metabolismABSTRACT
Pituitary adenylate cyclase activating polypeptide (PACAP) and its receptors are present in the retina and exert several distinct functions. PACAP has well-known neuroprotective effects in neuronal cultures in vitro and against different insults in vivo. Recently we have shown that PACAP is neuroprotective against monosodium glutamate (MSG)-induced retinal degeneration. In the present study we investigated the possible signal transduction pathways involved in the protective effect of intravitreal PACAP administration against apoptotic retinal degeneration induced by neonatal MSG treatment. MSG induced activation of proapoptotic signaling proteins and reduced the levels of antiapoptotic molecules in neonatal retinas. Co-treatment with PACAP attenuated the MSG-induced activation of caspase-3 and JNK, inhibited the MSG-induced cytosolic translocation of apoptosis inducing factor (AIF) and cytochrome c, and increased the level of phospho-Bad. Furthermore, PACAP treatment alone decreased cytosolic AIF and cytochrome c levels, while PACAP6-38 increased cytochrome c release, caspase-3 and JNK activity and decreased phospho-Bad activity. In summary, our results show that PACAP treatment attenuated the MSG-induced changes in apoptotic signaling molecules in vivo and suggest that also endogenously present PACAP has neuroprotective effects. These results may have further clinical implications in reducing glutamate-induced excitotoxicity in several ophthalmic diseases.
Subject(s)
Apoptosis/drug effects , Neuroprotective Agents/pharmacology , Pituitary Adenylate Cyclase-Activating Polypeptide/pharmacology , Retinal Diseases/chemically induced , Signal Transduction/drug effects , Sodium Glutamate/toxicity , Animals , Rats , Rats, WistarABSTRACT
The present article investigated the effect of pituitary adenylate cyclase-activating polypeptide (PACAP) on oxidative stress-induced apoptosis in neonatal rat cardiomyocytes. Our results show that PACAP decreased the ratio of apoptotic cells following H2O2 treatment. PACAP also diminished the activity of apoptosis signal-regulating kinase. These effects of PACAP were counteracted by the PACAP antagonist PACAP6-38. In summary, our results show that PACAP is able to attenuate oxidative stress-induced cardiomyocyte apoptosis and suggest that its cardioprotective effect is mediated through inhibition of the MAP kinase-dependent apoptotic pathway.
Subject(s)
Apoptosis/drug effects , MAP Kinase Kinase Kinase 5/metabolism , Myocytes, Cardiac/cytology , Myocytes, Cardiac/drug effects , Oxidative Stress , Pituitary Adenylate Cyclase-Activating Polypeptide/pharmacology , Animals , Cells, Cultured , Enzyme Activation/drug effects , Myocytes, Cardiac/enzymology , Rats , Rats, WistarABSTRACT
Pituitary adenylate cyclase-activating polypeptide (PACAP) has well-documented neuroprotective actions, which have also been shown in retinal degeneration induced by monosodium glutamate (MSG) in neonatal rats. The aim of this article was to investigate the activation of extracellular signal-regulated kinase (ERK1/2) and cyclic adenosine 3',5'-phosphate (cAMP)-responsive element binding protein (CREB) signaling pathways by Western blot analysis in retinal degeneration induced by MSG. We found that intravitreal administration of PACAP preceding the MSG treatments induced significant increases in the phosphorylation, that is, the activation of ERK1/2 and its downstream target, CREB, 12 h after the treatment compared to the contralateral untreated eye during the first two treatments, with no further elevations 24 h after treatments. These results demonstrate that the degenerative effect of MSG and the protective effect of PACAP involve complex kinase signaling pathways and are related to cAMP/ERK/CREB activation.
Subject(s)
Cyclic AMP Response Element-Binding Protein/metabolism , Extracellular Signal-Regulated MAP Kinases/metabolism , Pituitary Adenylate Cyclase-Activating Polypeptide/pharmacology , Retina/drug effects , Retina/metabolism , Signal Transduction/drug effects , Sodium Glutamate/pharmacology , Animals , Phosphorylation/drug effects , Rats , Rats, WistarABSTRACT
The study aims at elucidating the leukocyte activation in the joint fluid of patients with acute traumatic hemarthrosis. Paired samples of peripheral blood and articular effusions after an acute hemorrhage were obtained from 22 patients. Leukocytes were separated and stained with fluorescein isothiocyanate (FITC)-conjugated mouse anti-human CD11a, CD18, and CD97 monoclonal antibodies for flow cytometry. The reactive oxygen species (ROS) production of leukocytes in corresponding samples of peripheral blood and joint effusion was measured via luminol dependent whole blood chemiluminometry. Significant decrease of CD11a density on monocytes, but markedly enhanced expression of CD97 and CD18 on polymorphonuclear neutrophil granulocytes (PMN), and significantly increased proportion of CD97 positive lymphocytes were found in the joint fluids as compared to the corresponding peripheral blood samples. Moreover, significantly decreased lag time and elevated rate of ROS production were revealed by chemiluminometry in case of joint derived leukocytes. Our results provide good evidence for intraarticular leukocyte activation during acute hemarthrosis. Since the activation precedes synovial inflammation, it is suggested that the leukocytes play an important role as an initiator in the pathogenesis of acute hemarthrosis.
Subject(s)
Hemarthrosis/immunology , Lymphocyte Activation , Monocytes/physiology , Neutrophil Activation , Acute Disease , Adolescent , Adult , Aged , Antigens, CD/analysis , CD11a Antigen/analysis , Female , Flow Cytometry , Humans , Male , Membrane Glycoproteins/analysis , Middle Aged , Reactive Oxygen Species/metabolism , Receptors, G-Protein-CoupledABSTRACT
Nuclear factor-kappaB (NF-kappaB) plays an essential role in the intracellular signal transduction of the second window of protection (SWOP). Acetylsalicylic acid (ASA) blocks NF-kappaB-dependent gene activation in leukocytes and endothelial cells through preventing phosphorylation and subsequent degradation of the inhibitor IkappaB-alpha. This study investigated the effect of ASA on the late phase of ischemic preconditioning (PC) against myocardial infarction and on the activation of NF-kappaB in the preconditioned myocardium. Conscious rabbits were subjected to 4 cycles of 5 minutes of coronary occlusion and 5 minutes of reperfusion together with 3 different doses of ASA (5 mg/kg; 25 mg/kg; 130 mg/kg). After 30 minutes of reperfusion we determined the activation of NF-kappaB with an electrophoretic mobility shift assay (EMSA). Twenty-four hours later, after 30 minutes of test ischemia, we performed infarct size analysis using triphenyltetrazolium-chloride (TTC) staining. Neither 5 mg/kg (antithrombotic dose) nor 25 mg/kg (analgesic/antipyretic dose) of ASA interfered with the NF-kappaB activation and the protective effect of late preconditioning against myocardial infarction. In contrast, NF-kB activation and late PC effect were completely abrogated by 130 mg/kg of ASA. Our results suggest that nonselective doses of NSAIDs should be used with caution in patients with atherosclerotic cardiovascular disease because they may deprive the heart of its innate defensive response.
Subject(s)
Aspirin/pharmacology , Cyclooxygenase Inhibitors/pharmacology , Ischemic Preconditioning, Myocardial , Myocardial Infarction/prevention & control , NF-kappa B/metabolism , Animals , Arrhythmias, Cardiac/physiopathology , Biotransformation/drug effects , Electrophoretic Mobility Shift Assay , Myocardial Infarction/pathology , Myocardium/pathology , Rabbits , Signal Transduction/drug effects , Time FactorsABSTRACT
Pituitary adenylate cyclase activating polypeptide (PACAP) exerts neuroprotective effects in various in vitro and in vivo models of cerebral pathologies. It has been shown that PACAP protects neurons in rat models of both global and focal ischemia. In the present study, we investigated factors that may play a role in the neuroprotective effects of PACAP. PACAP strongly reduced the anisomycin-induced apoptosis of PC12 cells, which was abolished in a PKA-deficient PC12 cell line (A126). This effect was also observed in vivo, in permanent occlusion of the middle cerebral artery, where the number of TUNEL-positive neurons was significantly reduced in the ischemic core of PACAP-treated animals. Our results show that PACAP has a minor antioxidant effect in a non-cellular in vitro system, and has considerable antioxidant effects in an in vitro red blood cell filtration model. PACAP had no effect on platelet aggregation induced by collagen, ADP or epinephrine. Our results demonstrate that the effects of PACAP on delayed neuronal death may play a significant role in the reduction of the infarct size in vivo, but the antioxidant effect could only be observed at concentrations higher than that used in the model of focal ischemia.
Subject(s)
Nerve Growth Factors/pharmacology , Neurons/drug effects , Neuropeptides/pharmacology , Neurotransmitter Agents/pharmacology , Platelet Aggregation/drug effects , Animals , Antioxidants/pharmacology , Apoptosis/drug effects , Brain Ischemia/metabolism , Brain Ischemia/pathology , Brain Ischemia/prevention & control , Erythrocyte Deformability/drug effects , Humans , In Vitro Techniques , Leukocytes/drug effects , Leukocytes/metabolism , Male , Neurons/cytology , Neurons/metabolism , Neuroprotective Agents/pharmacology , PC12 Cells , Pituitary Adenylate Cyclase-Activating Polypeptide , Rats , Reactive Oxygen Species/metabolismABSTRACT
Using an in vitro model, based on primary cultured chondrocytes, we examined possible oxidative injury caused by activated polymorphonuclear neutrophil granulocytes (PMNs), which are thought to be part of the pathomechanism of hemarthrosis. Chondrocytes were isolated from swine knee joints and divided into three groups. Pure chondrocytes acted as the control population (group I). PMNs from the systemic circulation, and hydrogen peroxide (as an artificial source of reactive oxygen species (ROS)) were added to groups II and III, respectively. All cultures were incubated for 6 hours. After the experiment, lipid membrane degradation by ROS was assessed by monitoring changes in the levels of malondialdehyde (MDA) and 4-hydroxyalkenal contents of the chondrocyte specimens. Changes in the endogenous scavenger status of the chondrocytes were characterized by measuring of reductions in glutathione (GSH) concentration and superoxide dismutase (SOD) activity. Significant increases in MDA/4-hydroxyalkenal levels and SOD activity as well as an expressive reduction in intracellular GSH content were highlighted by comparing the control to the PMN- or H2O2-treated cell populations. These findings confirm previous suggestions that PMN-derived ROS contribute to degradation of cartilage in hemarthrosis.
Subject(s)
Cartilage, Articular/cytology , Chondrocytes/metabolism , Hemarthrosis/physiopathology , Neutrophil Activation/physiology , Oxidative Stress , Aldehydes/metabolism , Animals , Cartilage, Articular/metabolism , Cartilage, Articular/pathology , Cells, Cultured , Chondrocytes/drug effects , Chondrocytes/pathology , Free Radical Scavengers/metabolism , Glutathione/metabolism , Hemarthrosis/pathology , Hydrogen Peroxide/pharmacology , Knee Joint , Lipid Peroxidation , Malondialdehyde/metabolism , Oxidants/pharmacology , Superoxide Dismutase/metabolism , SwineABSTRACT
One determining factor in intestinal transplantation is the bowel's extreme sensitivity to ischemia-reperfusion injury. This study was meant to investigate the effect of ischemic preconditioning prior to autotransplantation. Total orthotopic intestinal autotransplantation was performed in 40 mongrel dogs. Four groups (GI-GIV) were established. In GI and GII grafts were stored in 4 degrees C Euro Collins and University of Wisconsin solutions. In GIII and GIV before preservation IPC was induced by 4 cycles (5-min ischemia + 10-min reperfusion). Three hours of preservation was followed by 1 hour of reperfusion. We determined oxidative stress markers in bowel tissue [reduced glutathione (GSH), superoxide dismutase (SOD)], oxygen free radicals (OFRs) (confocal microscopy), NF-kappa B (gel electrophoretic mobility shift assay), DNA damage (TUNEL). Cold preservation could not prevented against oxidative stress and resulted decrease of SOD activity significantly during reperfusion. In the preconditioned groups the elevated GSH and better preserved SOD activity indicated development of protection. Production of OFRs increased during reperfusion in non-preconditioned groups. Activation of NF-kappa beta was peaking by 1-3 hours following preconditioning. We detected more cells suffered DNA strand breaks in preconditioned groups. Our findings confirm that ischemic preconditioning prior to preservation can moderate the severity of oxidative stress and activate the endogenous celluar adaptation in bowel tissue.
Subject(s)
Intestine, Small/transplantation , Ischemic Preconditioning , Oxidative Stress , Reperfusion Injury/prevention & control , Animals , DNA Damage , Dogs , Glutathione/metabolism , Microscopy, Confocal , NF-kappa B/metabolism , Neutrophils/metabolism , Reactive Oxygen Species/metabolism , Superoxide Dismutase/metabolism , Transplantation, AutologousABSTRACT
BACKGROUND: One determining factor in intestinal transplantation is the extreme sensitivity of the small bowel to ischemia-reperfusion injury. This study investigated the effect of ischemic preconditioning prior to autotransplantation. METHODS: Total orthotopic intestinal autotransplantation was performed in 40 mongrel dogs. In 4 groups (GI-GIV), grafts were stored for 3 hours in cold Euro Collins (GI,GIII) and University of Wisconsin (GII,GIV) solutions. In GIII and GIV, before preservation, preconditioning was induced by 4 cycles (5-min ischemia + 10-min reperfusion). Bowel samples were collected after laparotomy (control), at the end of preservation and reperfusion periods. We determined oxidative stress markers (reduced glutathione [GSH], superoxide dismutase [SOD]), production of oxygen free radicals, activity of nuclear factor-kappaB (NF-kappaB), and DNA damage. RESULTS: In the non-preconditioned groups, GSH concentration increased slightly, while SOD activity decreased significantly during reperfusion. In the preconditioned groups, GSH increased markedly, and better preservation of SOD was observed. The number of oxygen free radicals increased during reperfusion mainly in non-preconditioned groups. Activation of NF-kappaB peaked by 1 hour, and decreased 3 hours after preconditioning. We observed DNA-damaged cells in all groups. CONCLUSIONS: Our findings confirm that preconditioning prior to preservation can moderate the severity of oxidative stress and activate the endogenous cellular adaptation in bowel tissue.
Subject(s)
Intestine, Small/physiopathology , Intestine, Small/transplantation , Ischemic Preconditioning , Oxidative Stress , Animals , DNA Damage , Dogs , Female , Hemodynamics , In Situ Nick-End Labeling , Intestine, Small/blood supply , Male , NF-kappa B/physiology , Neutrophils/metabolism , Reactive Oxygen Species/metabolism , Splanchnic Circulation , Transplantation, AutologousABSTRACT
OBJECTIVES: Pituitary adenylate cyclase activating polypeptide (PACAP) and vasoactive intestinal polypeptide (VIP) belong to the same peptide family, and both neuropeptides have been shown to exert in vitro and in vivo neurotrophic and neuroprotective effects. The aim of the present study was to investigate and compare the protective effects of PACAP and VIP in permanent focal cerebral ischemia in rats. The effect on the progression of the cerebral infarct was also studied. METHOD: Male rats were injected 450 pmol PACAP or VIP dissolved in physiological saline intracerebroventricularly, preceding the occlusion of the middle cerebral artery. Control animals received vehicle treatment. Permanent focal ischemia was induced by the intraluminal filament occlusion of the middle cerebral artery. Animals were sacrificed 12 or 24 hours after the onset of ischemia, and infarcted brain areas were determined by staining bran sections with triphenyl-tetrazolium chloride. RESULTS: Twelve hours after ischemia, the infarcted brain volume resulted to be 14.8% in the control group, 15.3% in the VIP-treated group and 5.8% in the PACAP-treated animals. Twenty-four hours after middle cerebral artery occlusion, the infarcted brain volumes were 21.5%, 20.7% and 14.3% in the control, VIP and PACAP-treated animals, respectively. CONCLUSION: Our results provide further evidence for the neuroprotective effects of PACAP38 as given in form of a preischemic bolus. It slows down the progression of the evolution of the infarct and reduces the final infarct size. In contrast, a related peptide, VIP, does not have neuroprotective effects under the same experimental conditions.