Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020672 (hypothermia)
 17,327 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The level of glutathione and the activity of its exchange enzymes (glutathione reductase, glutathione-S-transferase, glutathione peroxidase), the content of malonic dialdehyde were studied in the red blood levels of 70 patients operated on under hypothermal perfusion for correction of acquired cardiac diseases. The plasma concentrations of myoglobin were also measured. There was a relationship of the time course of changes in the parameters in question to the depth of the body's cooling during surgical interventions. Shallow hypothermia (30-34 degrees C) caused a compensatory increase in the activity of glutathione peroxidase (by more than 30%) and in the concentration of glutathione (by more than 60%) at the cooling stage. Moderate hypothermia (26-29 degrees C) produced no impact on the level of glutathione and the activity of its exchange enzymes while deeper hypothermia (25 degrees C or below) induced decreases in the levels of glutathione (by more than 30 degrees C) and suppressed the activity of all the tested enzymes of its exchange. At the same time there are elevated concentrations of malonic dialdehyde at the warming-up stage and during early postperfusion. Myoglobin washing into plasma occurs under all temperature conditions of perfusion at the warming-up stages and in the early postperfusion period, but it is most profound in deeper hypothermia, which is caused by the toxic effect of oxygen whose plasma solubility increases with lowered temperatures.
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PMID:[Effect of various perfusion temperature regimens in heart surgery with extracorporeal circulation on glutathione levels and activity of enzymes of glutathione metabolism in erythrocytes]. 915 86

Release of myoglobin (Mg) into the plasma and increase of its concentration during perfusion are a result of muscle cell injury during artificial circulation. High values of oxygen tension and hypothermia during cardiosurgery are sources of active oxygen forms damaging the biomembranes. We investigated release of Mg into the blood and relationship of this parameter with oxygen tension and depth of cooling. 95 patients were tested during open-heart surgery and operations on the main vessels: 25 perfusions at 30-32 degrees C, 41 at 26-29 degrees C, and 20 at 12-14 degrees C. The patients were divided into subgroups depending on arterial blood oxygen pressure. Myoglobin release into the blood was minimum under mild hypothermia and moderate PaO2. The degree of myoglobinemia increased with elevation in PaO2. As body temperature decreased, the concentration of Mg increased and differences between the groups with different PaO2 leveled. Critical myoglobinemia (30-fold vs. the initial value) was observed in the group with the deepest hypothermia (14 degrees C). Since the myocardium contains high amounts of Mg, it is clear that loss of this heme-containing protein impairs the feeding of the myocardium and, hence, decreases its contractility.
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PMID:[Causes of myoglobinemia in surgery with artificial circulation]. 1122 Sep 41

Myoglobin (Mb) gene expression, Citrate Synthase (CS) and Succinate Dehydrogenase (SDH) activities of Soleus (S) and Extensorum Digitalis Longus (EDL) muscles were studied in intact, thyroidectomized and T3-treated (25 microg/100g, BW, ip, 15 days) rats. The fiber type composition of S muscle was also evaluated and used as control of the T3-induced effects. In the S muscle, the T3 treatment increased the Mb mRNA and protein expression, as well as the CS and SDH activity. These changes occurred parallel to the expected increase in type II (fast) and decrease in type I (slow)-fibers in S muscle. In the hypothyroid state, the Mb mRNA was decreased, while the Mb expression and CS activity tended to decrease. In contrast the SDH activity was increased, probably due to the enhanced motor activity that occurs as a short-term response to the hypothermia induced by hypothyroidism. In the EDL, the alterations were milder than those in S muscle in both thyroid states. These findings show that Mb gene expression is induced by T3. This is concomitant with the enhancement of Krebs Cycle enzyme activities and provides additional evidence that thyroid hormone increases the aerobic potential of skeletal muscles, as well as the speed of muscle contraction.
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PMID:Thyroid hormone stimulates myoglobin expression in soleus and extensorum digitalis longus muscles of rats: concomitant alterations in the activities of Krebs cycle oxidative enzymes. 1144 1