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)

The purpose of our study was to investigate the effect of hypermagnesemia on spinal metabolic rate. The 2-[14C]deoxyglucose technique was used to measure regional glucose utilization in the lumbar spinal cord of paralyzed, mechanically ventilated rats receiving 70% nitrous oxide and an intravenous infusion of either saline (n = 5) or magnesium sulfate (n = 5). Plasma magnesium concentrations were 6.75 +/- 0.5 and 0.9 +/- 0.5 mM (p less than 0.01) in hypermagnesemic and control rats, respectively. Hypermagnesemic rats were hypotensive (88 +/- 1 vs. 130 +/- 4 mm Hg, p less than 0.01) but blood pressure remained within the autoregulatory range. Glucose utilization was reduced 26-45% in spinal gray matter and 53-63% in spinal white matter during hypermagnesemia. We conclude that magnesium is a potent spinal metabolic depressant and that this action, which is unusually prominent in spinal white matter, is a plausible explanation for the recently reported beneficial effect of magnesium therapy during spinal cord ischemia.
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PMID:Effect of profound hypermagnesemia on spinal cord glucose utilization in rats. 337 67

We tested the hypothesis that acute, intravenous (i.v.) magnesium (Mg2+) supplementation would protect against myocardial stunning in an in situ swine model of regional ischemia and reperfusion and that a concomitant inhibitory effect on platelet aggregation would be elicited. An open-chest model was used, with transient occlusion of the left anterior descending coronary artery (LAD) for 8 min. Regional contractile function was assessed by measuring wall thickening fraction with epicardial Doppler crystals. One control group (n = 6) and two treatment groups were studied: group I (n = 6) received 750 mg MgSO4 before occlusion; group II (n = 6) received 1 g MgSO4 after the occlusion. Both protocols produced significant hypermagnesemia. In group I, platelet aggregation was measured before and after Mg2+ treatment using platelet-rich plasma (PRP) and various agonists (ADP 5 and 10 mM and collagen 1 mg/ml). As compared with controls, both treatment groups experienced significantly less postischemic dysfunction, with systolic function returning more quickly to baseline. Furthermore, platelet aggregation was significantly decreased immediately after Mg2+ infusion. Inhibition of platelet aggregation induced by Mg2+ treatment occurs concomitantly with significant amelioration of postischemic myocardial dysfunction.
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PMID:Effects of magnesium supplementation in a porcine model of myocardial ischemia and reperfusion. 752 43

Magnesium is a potential neuroprotective agent in the treatment of head injury and ischemia whose efficacy is likely determined by increases in brain extracellular fluid (ECF) magnesium, which in turn depends on its concentration in plasma. The objectives of this study were to: 1) examine the effects of increasing plasma magnesium concentration ([Mg]plasma) to 4-6 mM on brain ECF magnesium concentration ([Mg]ECF) and 2) determine whether maturational changes occur in the transfer of magnesium into brain ECF for newborn and more mature (approximately 1 month old) miniswine. Increases in [Mg]plasma by systemic administration of MgSO4 resulted in similar maximal elevations in brain [Mg]ECF for both age groups (193+/-76% versus 253+/-106% of control for newborn and 1-month-old miniswine, respectively). Calculations of half-lives (t1/2) for the increase and decrease in magnesium concentration (t1/2 uptake and t1/2 clearance) were used to characterize magnesium kinetics in plasma and brain ECF. Plasma magnesium uptake was shorter in 1-month-old (t1/2 = 11.1+/-0.9 min) compared with newborns (12.9+/-1.7 min, p < 0.05). The faster increase in [Mg]plasma probably contributed to a faster uptake of brain [Mg]ECF in 1-month-old compared with newborn swine (t1/2 uptake = 27.9+/-12.8 versus 46.0+/-20.9 min, respectively, p < 0.05). Although plasma magnesium clearance was shorter in 1-month-old swine compared with newborn (t1/2 = 34.3+/-7.0 versus 74.7+/-33.7 min, respectively, p < 0.05), the clearance of magnesium from the brain ECF was similar for each age group. Reductions in blood pressure and heart rate occurred during hypermagnesemia and were similar in each age group. This study shows that acute elevations in [Mg]plasma to 4-6 mM result in similar relative increases in brain [Mg]ECF for both newborn and 1-month-old miniswine. However, there are maturational differences, as demonstrated by the faster rate of magnesium uptake into the ECF observed in the older miniswine.
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PMID:Age-dependent differences in the relationship between plasma and brain extracellular fluid concentrations of magnesium after MgSO4 infusions in miniswine. 1047 42

Magnesium (Mg) , one of the fundamental minerals acting the co-factor of about 300 kinds of enzymes and natural Ca channel blocker, plays an important role of cardiovascular, neurological, and metabolic functions in physiological, and pathophysiological conditions. Common abnormal Mg metabolism is an absolute or relative deficiency of Mg due to an attenuated Mg intake and an enhanced urinary Mg excretion, particularly in the metabolic syndrome (MetS) , type 2 diabetes (DM) , chronic heart failure (CHF) and hemodialysis (HD) patients with diabetes. It has been reported the Mg deficiency relating to enhanced risk of MetS and type 2 DM, and to fatal cardiac events in CHF and an atherosclerotic, vascular calcification in HD patients. On the otherhand, severe and fatal hypermagnesemia is very rare, except for the condition associated with high dose administration of Mg, renal failure and an abnormally enhanced Mg absorption from damaged intestine in the mesenteric ischemia/infarction, severe constipation or ileus. In this paper, we conduct to review and discuss the pathophysiological and pathogenetical role of the abnormal Mg metabolism focused on Mg deficiency, and the protective and therapeutic significance of Mg administration in the MetS, type 2 DM, CHF and diabetic HD patients.
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PMID:[Abnormalities of magnesium (Mg) metabolism and therapeutic significance of Mg administration in patients with metabolic syndrome, type 2 diabetes, heart failure and chronic hemodialysis]. 2284 58