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

Effect of ischemia, resulted from ligation of the abdominal part of the aorta, on the rate of anterograde and retrograde transport in the nervous pathways of the posterior roots has been studied in the canine spinal nerves. The anterograde transport rate is studied after injection of labelled 14C-leucine into spinal ganglia. An increased rate from 365 mm/day to 487 mm/day is revealed. The retrograde transport rate, that is estimated by means of horseradish peroxidase injected into the spinal cord, increases after the ischemia from 141 mm/day to 200 mm/day. A suggestion is made that the increase in the rate is caused by certain changes in ionic balance and osmosis produced by ischemia.
 ...
PMID:[Changes in axonal transport induced by ischemia]. 242 11

Rats with a portacaval anastomosis and ligation of the hepatic artery 2 days later were infused for 6 hr with a 10% glucose solution (group I) or the same solution combined with 0.24 M/liter branched-chain amino acids (BCAA, group II). Control animals with portacaval anastomosis and sham-operation (group III) or two sham-operations (group IV) were infused with a 10% glucose solution. The rats were killed by decapitation and indoleamines and amino acids were determined in the brain. Rats with liver ischemia were stuporous at the end of the experiment irrespective of treatment. The concentrations in the cortex of lysine, methionine, phenylalanine, threonine, alanine, glutamine, glycine, histidine, and tyrosine were significantly increased in group I compared to group IV. Infusion of BCAA to rats with liver-ischemia (group II) resulted in significantly lower concentrations of lysine, methionine, phenylalanine, threonine, histidine and tyrosine and increased concentrations of isoleucine, leucine, valine, and arginine compared to group I. The content of serotonin in the cortex and brain stem was significantly increased in group I compared with the BCAA-treated animals (group II) and the control groups III and IV. The concentrations of 5-hydroxyindoleacetic acid (5-HIAA) in the cortex and brain stem were higher in group I than in group IV. Infusion of BCAA to rats with liver ischemia normalized the concentrations of 5-HIAA in the cortex and brain stem.
 ...
PMID:Amino acids and indoleamines in the brain after infusion of branched-chain amino acids to rats with liver ischemia. 242 87

The purpose of this study is to investigate whether isolated hearts perfused with cardioplegic solution release inflammatory mediators such as neutrophil chemotactic factors (NCF). Three conditions were tested, including: (1) perfusion of rabbit hearts with crystalloid cardioplegic solution (4 degree C) saturated with air (95% oxygen) and containing dextrose (i.e. complete system), (2) perfusion of rabbit hearts with non-oxygenated cardioplegic solution, containing dextrose (i.e. minus oxygen system), and (3) perfusion of hearts with cold cardioplegic solution saturated with air in the absence of dextrose (i.e. minus dextrose system). At various time intervals (5 min, 1, 2, 3 and 4 h) samples of circulated perfusate were removed and assayed for the presence of NCF using modified Boyden chambers. Rabbit peritoneal neutrophils were the indicator cells. The standard chemoattractant, f-Met-Leu-Phe (f-MLP) was the positive control. High levels of neutrophil chemotactic activity were detected in perfusate of all above described hearts perfused for 4 h (i.e. 194 +/- 22% of f-MLP control--complete system, 126 +/- 13%--minus oxygen and 136 +/- 10%-minus dextrose). Histological evaluation of these hearts showed evidence of global ischemia. We also detected significant levels of NCF in effluent of hearts perfused for 5 min, 1, 2 and 3 h. Similar to perfused hearts, isolated rabbit hearts incubated for 4 h with non-oxygenated cardioplegic solution (in presence and absence of dextrose) released high levels of NCF (132 +/- 18%-intact heart; and 100 +/- 6% myocardial segments). Standard checkerboard analysis revealed that the observed activity released from these hearts is chemotactic.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Cardiac derived neutrophil chemotactic factors; preliminary biochemical characterization. 267 54

To study the effects of glucagon-insulin (G-I) infusion on protein synthesis and DNA synthesis in a condition with partial hepatic ischemia, G-I or saline was infused via portal vein for 40 minutes before and after a period of partial hepatic ischemia or following a period of partial hepatic ischemia. Protein synthesis was measured by 14C-leucine incorporation into proteins in incubated liver slices and DNA synthesis by 3H-thymidine incorporation into DNA. Protein synthesis in the postischemic liver was significantly recovered faster and more completely in G-I treated rats. G-I infusion enhanced the DNA synthesis of postischemic liver significantly, peaking 48 hours after the period of partial hepatic ischemia. However, the dosage of G-I infused in this investigation couldn't increase the hepatic tissue blood flow measured by hydrogen gas clearance method. On the histological examination, mitotic index was significantly higher in G-I treated group than in control. These results suggest that G-I infusion could be beneficial effects on the liver in situation with partial ischemic injury and that G-I infusion could remarkably augment hepatic tissue repair following ischemic damage.
 ...
PMID:[Beneficial effects of glucagon-insulin infusion on hepatic protein synthesis and DNA synthesis in partial hepatic ischemia]. 267 61

The threshold of the relation between regional cerebral blood flow and regional cerebral protein synthesis was investigated in gerbils submitted to a 1-hour occlusion of the left common carotid artery. Blood flow was measured with [131I]iodoantipyrine and protein synthesis with [14C]leucine using double-tracer autoradiography and trichloroacetic acid wash-incubation for removal of nonincorporated tracer radioactivity. Specific activity of blood and brain leucine and [14C]leucine incorporation into brain proteins was also measured by conventional high-performance liquid chromatography to validate the autoradiographic approach. In control gerbils, gray matter blood flow ranged between 180 and 220 ml/100 g/min and fractional amino acid incorporation was approximately 80%. Unilateral carotid artery occlusion resulted in graded ischemia with blood flow between 10 and 100 ml/100 g/min. Regional cerebral protein synthesis gradually declined at blood flows of less than 100 ml/100 g/min and approached 0 at a blood flow of 40 ml/100 g/min. This threshold for complete suppression of protein synthesis is much higher than that for maintenance of tissue energy state and suggests that the size of an infarct after focal ischemia is determined by the suppression of protein synthesis rather than by the breakdown of energy metabolism.
 ...
PMID:Ischemic threshold of brain protein synthesis after unilateral carotid artery occlusion in gerbils. 271 2

Although endogenous opioids have been implicated in the pathophysiology of spinal cord injury and brain ischemia, the role of specific opioid peptides and opiate receptors in the pathophysiology of traumatic brain injury remains unexplored. This study examined regional changes in brain opioid immunoreactivity and cerebral blood flow (CBF) after fluid-percussion brain injury in the cat and compared the effect of an opiate antagonist (Win 44,441-3 [Win-(-)]) with its dextroisomer Win 44,441-2 [Win-(+)] (which is inactive at opiate receptors) in the treatment of brain injury. Dynorphin A immunoreactivity (Dyn A-IR) but not leucine-enkephalin-like immunoreactivity accumulated in injury regions after traumatic injury; Dyn-IR increases also occurred predominantly in those areas showing significant decreases in regional CBF. Administration of Win-(-) but not Win-(+) or saline at 15 min after injury significantly improved mean arterial pressure, electroencephalographic amplitude, and regional CBF and reduced the severity and incidence of hemorrhage. Win-(-) also significantly improved survival after brain injury. Taken together, these findings suggest that dynorphin, through actions at opiate receptors, may contribute to the pathophysiology of secondary brain injury after head trauma and indicate that selective opiate-receptor antagonists may be useful in treatment of traumatic brain injury.
 ...
PMID:Endogenous opioids may mediate secondary damage after experimental brain injury. 289 3

Isolated and perfused rat hearts can be maintained for up to 2.5 h with minimal synthesis of a stress protein with a relative mass (Mr) of 71 kilodaltons (SP71). Isolated hearts, subjected to 17 h of cold (4 degrees C) ischemia, upon perfusion (37 degrees C) synthesize a large amount of SP71. In the present study, the effect of in vivo hyperthermia on protein synthesis in isolated and perfused hearts was examined. Hearts were excised from rats subjected to a 15-min episode of hyperthermia (42 degrees C), either immediately (no recovery) or after 24 h of recovery. The excised hearts were perfused either immediately or after 17 h of cold ischemia. Hyperthermia (no recovery) increased [3H]leucine incorporation into SP71, while hyperthermia with a 24-h recovery did not increase incorporation into SP71 during perfusion (no ischemia). Hyperthermia (no recovery) increased the incorporation of [3H]leucine into SP71 seen after cold ischemia. Hyperthermia with a 24-h recovery decreased the incorporation of [3H]leucine into SP71 seen after cold ischemia. This reduction in synthesis of SP71 after 24-h recovery from hyperthermia could be caused by the accumulation of SP71 suppressing its own synthesis or a measure of protection (tolerance) induced by the hyperthermia.
 ...
PMID:Protein synthesis in perfused rat hearts after in vivo hyperthermia and in vitro cold ischemia. 337 Jan 40

The authors studied ultrastructural and biochemical changes in spinal ganglia neurons of dogs after ischemia. Partial spinal cord ischemia was induced by occlusion of the abdominal aorta just below the renal arteries and the arterial blood pressure was registered above and below the occlusion. - In the course of 2-4 hours' ischemia the amount of free ribosomes increased. In some cases the formation of filamentous material or tubular structures inside the cisterns of endoplasmic reticulum was apparent. The proteosynthesis declined. Incorporation of 14C - leucine into the spinal ganglion was 50% as compared to the control animals. The morphological and biochemical changes were more pronounced after 4 h ischemia.
 ...
PMID:The arrangement of endoplasmic reticulum and proteosynthesis in spinal ganglia neurons of dog after ischemia. 359 Dec 43

Isolated and perfused rat hearts were examined by 2-dimensional gel electrophoresis and liquid scintillation counting to determine the effect of ischemia or perfusion temperature on protein synthesis. Isolated hearts were subjected to ischemia at either 4 degrees, 20 degrees, or 30 degrees C and then perfused at 37 degrees C and radio-labeled with [3H]-leucine from 0.5 to 2.5 h of perfusion. Following 0.5 h of 4 degrees C or 0.2 h of 20 degrees C ischemia, minimal or no effect was seen by fluorography on the patterns of protein synthesis and there was no apparent synthesis of the stress-induced (heat shock) protein with Mr = 71,000 (SP71). After 4.0 h of 4 degrees C or 0.5 h of 20 degrees C ischemia, SP71 was detectable on fluorograms. After 17 h of 4 degrees C or 1 h of 20 degrees C or 30 degrees C ischemia, SP71 was a prominent spot on fluorograms; the percentage incorporation of precursor into SP71 was significantly increased and overall incorporation of precursor into protein appeared depressed. Following 17 h at 4 degrees C, during which time the buffer was continuously oxygenated, percentage incorporation of precursor into SP71 was only moderately increased, suggesting that hypoxia was responsible for the high level of SP71 synthesis. The effect of perfusion temperature was initially examined using a perfusion method which results in a moderate synthesis of SP71 at 37 degrees C between 2.5 and 4.5 h of perfusion. Fluorograms revealed synthesis of some normal proteins at all temperatures, with little or no synthesis of SP71 at 31 degrees and 34 degrees C, moderate synthesis at 37 degrees C, and intense synthesis at 40 degrees C. The percentage incorporation of precursor into SP71 and total incorporation of precursor appeared depressed at 31 degrees C and 34 degrees C, from that at 37 degrees C, while at 40 degrees C, percentage incorporation of precursor into SP71 was significantly increased but overall incorporation of precursor into protein appeared depressed. When SP71 synthesis was induced by 17 h of 4 degrees C ischemia, hearts were sensitive to a lower perfusion temperature (34 degrees C); the percent incorporation of precursor into SP71 was significantly reduced from that seen at 37 degrees C. Interestingly, the effect of prolonged ischemia on protein synthesis (increased synthesis of SP71; suppression of overall synthesis) is the same as the heat shock response seen after perfusion at 40 degrees C.
 ...
PMID:Effects of ischemia and perfusion temperature on the synthesis of stress-induced (heat shock) proteins in isolated and perfused rat hearts. 369 80

Regional patterns of protein synthesis were examined in rat cortex made ischemic by the occlusion of the right common carotid and middle cerebral arteries. At 2 h of ischemia, proteins were pulse labeled with intracortical injections of a mixture of [3H]leucine, [3H]isoleucine, and [3H]proline. Newly synthesized proteins were analyzed by two-dimensional gel fluorography, and the results correlated with local CBF, measured with [14C]iodoantipyrine as tracer. Small blood flow reductions (CBF = 50-80 ml 100 g-1 min-1) were accompanied by a modest inhibition in synthesis of many proteins and a marked increase in one protein (Mr 27,000). With further reduction in blood flow (CBF = 40 ml 100 g-1 min-1), synthesis became limited to a small group of proteins (Mr 27,000, 34,000, 73,000, 79,000, and actin) including two new polypeptides (Mr 55,000 and 70,000). Severe ischemia (CBF = 15-25 ml 100 g-1 min-1) caused the isoelectric modification of several proteins (Mr 44,000, 55,000, and 70,000) and induced synthesis of another protein (Mr 40,000). Two polypeptides (Mr 27,000 and 70,000) dominated residual protein synthesis in severe ischemia. The changes in protein synthesis induced by different grades of ischemia most likely comprise a variation of the so-called "heat shock" or "stress" response found in all eukaryotic cells subjected to adverse conditions. Since heat shock genes are known to confer partial protection against anoxia and a variety of other noxious insults, their induction may be a factor in limiting the extent of ischemic tissue damage.
 ...
PMID:Selective gene expression in focal cerebral ischemia. 371 Nov 55


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>