Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Five minutes of oxygen and glucose deprivation (termed "in vitro ischemia") causes long-term synaptic transmission failure (LTF) in the CA1 region of the rat hippocampal slice. Dependence of LTF on cell calcium was tested by generating graded reductions in cell Ca. There was a strong correlation between the average level of exchangeable cell Ca in CA1 during ischemia, and the extent of LTF. In standard buffer, exchangeable cell Ca in CA1 increased by 35% after 3 min of ischemia and remained elevated for the entire 5 min of ischemia. Unidirectional Ca influx increased by 35% during the first 2.5 min of ischemia and remained at that level for the next 2.5 min. There were no changes in unidirectional Ca efflux during this period. Thus, the accumulation results from increased influx of Ca. Ca influx during the first 2.5 min of ischemia depended entirely on NMDA channels; it was completely blocked by the noncompetitive NMDA receptor antagonist MK-801. However MK-801 had no effect during the second 2.5 min. This inactivation of NMDA-mediated influx during ischemia appears to result from dephosphorylation. Okadaic acid increased Ca influx during the second 2.5 min of ischemia and this increase was blocked by MK-801. The ischemia-induced Ca influx during the second 2.5 min of ischemia was attenuated 25% by nifedipine (50 microM) and an additional 35% by the Na/Ca exchange inhibitor benzamil (100 microM). The AMPA/kainate antagonist DNQX had no effect on the Ca influx. Antagonists were used to relate Ca influx to LTF. Blockade of enhanced Ca entry during ischemia in standard buffer (2.4 mM Ca) had no effect on LTF, consistent with total cell Ca prior to ischemia being adequate to cause complete LTF. However, MK-801 strongly protected against LTF when the buffer contained 1.2 mM Ca, a more physiological level. MK-801 combined with DNQX prevented transmission damage in standard buffer. Thus, AMPA/kainate receptor activation contributes to ischemic damage, although not by enhancing Ca entry.
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PMID:Intracellular calcium levels and calcium fluxes in the CA1 region of the rat hippocampal slice during in vitro ischemia: relationship to electrophysiological cell damage. 822 2

A comparative analysis of intraneuronal relationship between Purkinje cells and granule cells zones of the cerebellar cortex molecular layer with different extent of expression of destructive and compensatory-adaptive processes was performed in rats in the dynamics of postischemic period. The ischemia was modelled by the 10 minutes long compression of the heart vascular bundle under the ethereal narcosis, Dependence between type and extent of the synaptic profile and functional state of the synapse was shown. Dynamics of changes of the synapse numerical density was demonstrated so as the regularities of the axo-spinous synapses structural organization changes during their dysfunction, destruction and interneuronal contact repair within and outside the nidi of interneuronal interrelations during 30 days of postischemic period.
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PMID:[The patterns of focal reorganization of the synaptic pool at the molecular level of the cerebellar cortex in the ischemic period]. 876 56

The effects of growth hormone (GH) deficiency on cardiac function were studied in young male rats administered an anti-GH-releasing hormone (GHRH) serum from postnatal day 20 to 40. Dependence of heart abnormalities on GH deficiency was ascertained by giving a group of anti-GHRH serum-treated rats GH replacement therapy. Heart preparations from anti-GHRH serum-treated rats, undergoing low-flow ischemia, showed a progressive increase in left ventricular end-diastolic pressure with poor recovery of mechanical activity and increased coronary perfusion pressure upon reperfusion. Hearts from anti-GHRH serum + GH-treated rats, undergoing global reduction to the flow, showed only a minimal increase of left ventricular end-diastolic pressure and, upon reperfusion, cardiac mechanical activity recovered almost completely. Similar findings were also observed in heart preparations from control (normal rabbit serum-treated) rats. Infusion of acetylcholine (10(-6) M) into heart preparations in the preischemic period increased coronary perfusion pressure values more markedly in hearts from normal rabbit serum- and anti-GHRH serum + GH-treated rats than in those from anti-GHRH serum-treated rats. These results indicate that selective GH deficiency in young male rats renders the heart more sensitive to ischemic damage and leads to an impairment of cardiac muscarinic receptor function.
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PMID:Worsening of ischemic damage in hearts from rats with selective growth hormone deficiency. 895 55

The impact of brain imaging on the assessment of tissue status is likely to increase with the advent of treatment methods for acute cerebral ischemia. Multimodal magnetic resonance imaging (MRI) demonstrates potential for selecting stroke therapy patients by identifying the presence of acute ischemia, delineating the perfusion defect, and excluding hemorrhage. Yet, the identification of tissue subject to reversible or irreversible ischemia has proven to be difficult. Here, the authors show that T1 relaxation time in the rotating frame, so-called T1rho, serves as a sensitive MRI indicator of cerebral ischemia in the rat. The T1rho prolongs within minutes after a drop in the CBF of less than 22 mL 100 g(-1) min(-1). Dependence of T1rho on spin-lock amplitude, termed as T1rho dispersion, increases by approximately 20% on middle cerebral artery (MCA) occlusion, comparable with the magnitude of diffusion reduction. The T1rho dispersion change dynamically increases to be 38% +/- 10% by the first 60 minutes of ischemia in the brain region destined to develop infarction. Following reperfusion after 45 minutes of MCA occlusion, the tissue with elevated T1rho dispersion (yet normal diffusion) develops severe histologically verified neuronal damage; thus, the former parameter unveils an irreversible condition earlier than currently available MRI methods. The T1rho dispersion as a novel MRI index of cerebral ischemia may be useful in determination of the therapeutic window for acute ischemic stroke.
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PMID:Early detection of irreversible cerebral ischemia in the rat using dispersion of the magnetic resonance imaging relaxation time, T1rho. 1104 8

The composition of circulating immune complexes with cryo-properties (cryo-IC) were determined in 70 patients on days 1, 2, 3, 7, 14 and 21 after ischemic carotid stroke. The quantitative and qualitative assessments of cryo-IC content were conducted on a spectrophotometer and on a vertical electrophoresis, respectively. Concentrations of immunoglobulins (Ig) M, A and C, fibronectin, percentage of IgM with rheumatoid factor activity, IgG isotypes (IgG1, IgG2, IgG3, IgG4) were measured with ELISA. The control group included 15 healthy age- and sex-matched people. Compared to the controls, the cryo-IC content was higher in 100% of patients studied, it was higher in atherothrombotic variant than in cardioembolic one. The cryo-IC level was directly correlated with the clinical state severity (p < 0.01). IgG, IgM and fibronectin were observed in 100%, IgA--in 11% and IgM with rheumatoid factor activity--in 6% of patients. The percentage of IgG1 and IgG2 was not less than 90% of the total amount, with the IgG1 percentage about 50%. Cryo-IC changing in the time in dependence on ischemic variant were formed on different stages of development of acute brain ischemia. Dependence of concentrations of fibronectin and IgG, IgA, IgM on the time of observation was similar for both variants of ischemic stroke, but with a time axis shift, running faster and with a smaller range of changes of parameters studied in cardioembolic than in atherothrombotic stroke.
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PMID:[Cryoglobulins in patients with ischemic stroke]. 2146 38

Participants consisted of 184 patients (160 males, 24 females) with positive angiograms or prior myocardial infarctions who displayed at least 1 mm of ST segment depression on a standardized treadmill test. Mean scores on the Reward Dependence subscale of the Tridimensional Personality Questionnaire were higher in patients displaying ischemia during mental stress. Patients who reported higher levels of irritability/anger in response to the Speech stressor were also more likely to display ischemia. However, this result was primarily a result of the females in the sample whose ratings of interest and irritability were associated with ischemia during the Speech task. Psychometric measures previously found in prospective studies to predict acute cardiac events were unrelated to mental stress-induced ischemia in the laboratory.
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PMID:Psychological Correlates of Mental Stress-induced Ischemia in the Laboratory: The Psychophysiological Investigation of Myocardial Ischemia (PIMI) Study. 2204 26