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)

Ethane and pentane are alkanes that are excreted through the lungs to a small degree in healthy subjects. These gasses are produced from the peroxidation of unsaturated fats which are found both in body tissues and in foods. These gasses are excreted in larger amounts by patients with increased production of reactive oxygen metabolites, including those with inflammation or ischemia. Thus, detection of these gasses in excessive quantities is considered evidence for lipid peroxidation. However, the effects of dietary factors on these measurements have not been defined. To define the effects of eating on the pulmonary excretion of these alkanes, 29 healthy subjects were fed a standardized liquid diet (1060 kcal, 12.9 g linoleic acid and 385 mg linolenic acid) after an overnight fast. Breath alkanes were measured at 0, 1, 3, and 6 hours. All subjects had normal vitamin E (1.11 + 0.26 mg/dl), retinol (64 +/- 14 micrograms/dl), beta carotene (27 +/- 21 micrograms/dl), lycopene (23 +/- 12 micrograms/dl) and zinc (81.9 +/- 13.5 micrograms/dl) levels. No statistically significant changes in either alkane were noted relative to the fasting level. We conclude that oral diet does not alter pulmonary ethane or pentane excretion in healthy subjects.
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PMID:Oral diet does not alter pulmonary pentane or ethane excretion in healthy subjects. 161 88

After renal ischemia, oxygen free radicals are formed and produce tissue injury, in large part, through peroxidation of polyunsaturated fatty acids. We used an in vivo method to monitor lipid peroxidation after renal ischemia, the measurement of ethane in expired gas, to determine the time course of lipid peroxidation and the effect of several agents to limit lipid peroxidation after renal ischemia. In anesthetized rats there was no significant increase in ethane production during 60 min of renal ischemia. During the first 10 min of renal reperfusion, there was a prompt increase in ethane production from 2.9 +/- 1.3 to 6.3 +/- 1.9 pmol/min (P less than 0.05). Ethane production was significantly increased during the first 50 min of reperfusion and then rapidly tapered to base-line levels. Preischemic administration of allopurinol to prevent superoxide radical generation or the superoxide radical scavenger superoxide dismutase prevented the increase in ethane production during postischemic reperfusion. These studies confirm that there is increase lipid peroxidation following renal ischemia that can be prevented by agents which limit the formation or accumulation of oxygen free radicals. This in vivo method for measuring lipid peroxidation could also be employed to study the effects of ischemia on lipid peroxidation in other organs, as well as to monitor lipid peroxidation in other forms of injury.
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PMID:Ethane production as a measure of lipid peroxidation after renal ischemia. 377 80

The goals of this study were to (1) determine the utility of quantification of ethane as a marker of ischemia-reperfusion during human cardiopulmonary bypass (CPB); and (2) determine, using an animal model for this surgical procedure, whether the mode of surgical approach produced increases the quantity of exhaled ethane. Human CPB was initiated following standard anesthetic and monitoring regimens. Samples of gas were collected at baseline and at multiple defined time points throughout the studies. Ethane was determined using cryogenic concentration and gas chromatography. Sternotomy increased exhaled ethane compared to baseline (p < .007; 5.8 +/- 1.7 vs. 3.0 +/- 0.7 nmol/m2 x min); ethane returned to baseline levels prior to the initiation of CPB. Aortic unclamping produced ethane elevation (p < .05; 2.3 +/- 0.8 vs. 1.5 +/- 0.4 nmol/m2 x min) with the levels being related to a lower cardiac index and a higher systemic vascular resistance post aortic unclamping. Termination of CPB significantly increased ethane levels compared to baseline (p < .002; 4.8 +/- 1.7 vs. 3.0 +/- 0.7 nmol/m2 x min). Independent variables that correlated with increased ethane measurements included a higher arterial blood pH on bypass and the change in hemoglobin pre- and post-CPB. Electrocautery, but not scalpel, incision of the porcine abdominal wall increased ethane levels significantly (p < .02). These results indicate that exhaled ethane may be a valuable marker of lipid peroxidation during and following CPB.
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PMID:Ethane: a marker of lipid peroxidation during cardiopulmonary bypass in humans. 989 36