Adrenergic control of plasma magnesium in man

Whyte, K.; Addis, G. J.; Whitesmith, R.; Reid, John L.

doi:10.1042/cs0720135

Cited by 80 publications

(27 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, we could not find a close relationship between the fluctuation in Mg and the Ca-PTH relation. In addition, we could not prove whether the Ca-PTH relation was involved in the regulation of [ Clinical and experimental studies have demonstrated that increased circulating catecholamine causes hypomagnesemia, as the influx of magnesium into the intracellular compartment is under the influence ofadrenergic activity [4,[20][21][22]. Therefore, both endogenous catecholamines released by surgical nociception and exogenous catecholamines given after the end of CPB may have partly contributed to the hypomagnesemia in our study.…”

Section: Resultscontrasting

confidence: 63%

Changes in plasma total and ionized magnesium concentrations and factors affecting magnesium concentrations during cardiac surgery

et al. 2004

View full text Add to dashboard Cite

The purpose of this study was to measure blood total and ionized magnesium concentrations ([TMg] and [Mg(2+)], respectively) and to investigate factors that might be affecting their changes during cardiac surgery using hypothermic cardiopulmonary bypass. Eight patients were examined. All the patients received diuretics and predeposited autologous blood during surgery. No drugs containing Mg(2+) were administered. Nine blood samples and eight urine samples were collected from the pre-induction period to the end of surgery. Hematocrit, [TMg], [Mg(2+)], plasma concentrations of calcium ([Ca(2+)]), creatinine, parathyroid hormone (PTH), urinary concentrations of TMg, and creatinine were measured, and the fractional excretion of Mg (FEMg) was calculated. Both [TMg] and [Mg(2+)] decreased significantly in the prebypass period and remained significantly depressed thereafter. The ionized fraction of magnesium ([Mg(2+)]/[TMg]) was decreased during the postbypass period. Hematocrit decreased significantly from the prebypass period, and FEMg increased significantly after aortic cross-clamping. In conclusion, hemodilution and renal loss were main causes of hypomagnesemia, and citrate in predeposited autologous blood may contribute to the decrease in [Mg(2+)]/[TMg] in the postbypass period. These results suggest that magnesium supplementation under close monitoring of [Mg(2+)] should be required during cardiac surgery.

show abstract

Section: Resultscontrasting

confidence: 63%

Changes in plasma total and ionized magnesium concentrations and factors affecting magnesium concentrations during cardiac surgery

et al. 2004

View full text Add to dashboard Cite

show abstract

“…Hypomagnesemia occurs in patients with elevated blood catecholamines: in AMI, cardiac surgery and insulininduced hypoglycemia stress tests [17]. Epinephrine in fused into healthy volunteers, with and without prior treat ment with Ca-blocking agents, lowered both serum Mg and potassium (K) [18].…”

Section: Stress Reactions As Affected By Magnesium and Calciummentioning

confidence: 99%

Consequences of magnesium deficiency on the enhancement of stress reactions; preventive and therapeutic implications (a review).

Seelig

1994

Journal of the American College of Nutrition

139

View full text Add to dashboard Cite

Stress intensifies release of catecholamines and corticosteroids that increase survival of normal animals when their lives are threatened. When magnesium (Mg) deficiency exists, stress paradoxically increases risk of cardiovascular damage including hypertension, cerebrovascular and coronary constriction and occlusion, arrhythmias and sudden cardiac death (SCD). In affluent societies, severe dietary Mg deficiency is uncommon, but dietary imbalances such as high intakes of fat and/or calcium (Ca) can intensify Mg inadequacy, especially under conditions of stress. Adrenergic stimulation of lipolysis can intensify its deficiency by complexing Mg with liberated fatty acids (FA), A low Mg/Ca ratio increases release of catecholamines, which lowers tissue (i.e. myocardial) Mg levels. It also favors excess release or formation of factors (derived both from FA metabolism and the endothelium), that are vasoconstrictive and platelet aggregating; a high Ca/Mg ratio also directly favors blood coagulation, which is also favored by excess fat and its mobilization during adrenergic lipolysis. Auto-oxidation of catecholamines yields free radicals, which explains the enhancement of the protective effect of Mg by anti-oxidant nutrients against cardiac damage caused by beta-catecholamines. Thus, stress, whether physical (i.e. exertion, heat, cold, trauma--accidental or surgical, burns), or emotional (i.e. pain, anxiety, excitement or depression) and dyspnea as in asthma increases need for Mg. Genetic differences in Mg utilization may account for differences in vulnerability to Mg deficiency and differences in body responses to stress.

show abstract

“…Another alternative is suggested by data obtained from adults indicating strong adrenergic control of plasma Mg. Specifically, infusions of adrenaline in healthy adult humans resulted in a 10 -15% reduction in plasma TMg concentration (25)(26)(27). Experiments performed on adult ewes demonstrated that the adrenaline induced by hypomagnesemia was abolished by ␤-adrenoreceptor blockade with propranolol (28).…”

Section: Discussionmentioning

confidence: 99%

Total and Ionized Plasma Magnesium Concentrations in Children after Traumatic Brain Injury

et al. 2005

View full text Add to dashboard Cite

This study examined 1) whether plasma total Mg (TMg) and ionized Mg (IMg) concentrations in children are reduced by traumatic brain injury (TBI) and 2) whether the extent of reduction correlates with severity of trauma assessed by the Glasgow Coma Scale (GSC) score. This was a prospective cohort study of 98 pediatric patients who had TBI and were admitted through the emergency department. A GCS score was assigned and blood was obtained upon presentation and 24 h later. Plasma was analyzed for TMg and IMg. Patients were grouped into three categories-GCS scores 13-15, 8 -12, and Ͻ8 -to designate mild (n ϭ 21), moderate (n ϭ 37), and severe (n ϭ 40) TBI, respectively. Blood was obtained from 50 healthy children before elective surgery as controls. Control subjects had a TMg and an IMg of 0.94 Ϯ 0.08 and 0.550 Ϯ 0.06 mM. TBI patients had an initial TMg and IMg of 0.83 Ϯ 0.09 and 0.520 Ϯ 0.05 mM, respectively. Initial TMg for mild, moderate, and severe TBI subgroups (0.87 Ϯ 0.16, 0.81 Ϯ 0.15, and 0.83 Ϯ 0.14 mM, respectively) was reduced from control subjects (p Ͻ 0.01). IMg was reduced only in the severe TBI subgroup (0.516 Ϯ 0.07 mM; p ϭ 0.016). Twenty-four hours later, TMg remained lower than in control subjects for all subgroups of TBI; however, IMg normalized. TBI in children is associated with a reduction in TMg, whereas IMg decreased only with severe TBI. Traumatic brain injury (TBI) remains an important health problem in children. Hospitalizations are frequent after TBI (180/100,000 children) (1), mortality is substantial (10/100,000 children) (1), and up to 17,000 children per year are left with permanent developmental disabilities (2,3). TBI represents the most common cause of acquired disability in childhood (3,4). The pathogenesis of tissue injury after TBI remains complex, reflecting mechanical tissue destruction and multiple secondary processes such as energy failure, excitotoxin release, lipid peroxidation, osmodysregulation, apoptosis, and other pathways (5-8). Over the past 15 y, there has been growing interest in altered Mg homeostasis after TBI and a potential neuroprotective role for exogenous Mg administration. The proposed link between TBI and Mg is based primarily on work in an experimental model of TBI in rodents in which a fluid percussion model was used to induce damage. In this TBI model, both brain total and intracellular Mg (measured with P-31 magnetic resonance spectroscopy) (9 -11) were reduced, and the extent of injury correlated with the decrease in total and intracellular Mg (12). Supplemental parenteral Mg administered as prophylaxis minimized the decrease in brain Mg and improved neurobehavioral scores (12)(13)(14)(15). In addition, Mg that was given to rodents that sustained TBI attenuated histologic brain damage (16).Instruments to measure ionized Mg (IMg) using ionselective electrodes are now commercially available. This has prompted studies in adult rodents to determine whether Mg concentrations (either total or ionized) are altered after TBI in body fluids, such as blood or pl...

show abstract

Adrenergic control of plasma magnesium in man

Cited by 80 publications

References 0 publications

Changes in plasma total and ionized magnesium concentrations and factors affecting magnesium concentrations during cardiac surgery

Changes in plasma total and ionized magnesium concentrations and factors affecting magnesium concentrations during cardiac surgery

Consequences of magnesium deficiency on the enhancement of stress reactions; preventive and therapeutic implications (a review).

Total and Ionized Plasma Magnesium Concentrations in Children after Traumatic Brain Injury

Contact Info

Product

Resources

About