Maintained cerebral metabolic ratio during exercise in patients with β‐adrenergic blockade

Gam, Christiane Marie Bourgin Folke; Rasmussen, Peter; Secher, Niels H.; Seifert, Thomas; Larsen, Fin Stolze; Nielsen, Henning Bay

doi:10.1111/j.1475-097x.2009.00889.x

Cited by 13 publications

(15 citation statements)

References 39 publications

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“…Part of the reduction in CMR O2 /CMR glc ratio during brain activation may also reflect retention of some glucose in tissue by (i) an increase in lactate, (ii) use of glucose for glycogen synthesis, and (iii) increased pyruvate carboxylation (Öz et al, 2004) leading to enhanced glutamate formation (Gibbs et al, 2007; Mangia et al, 2012). The reduced CMR O2 /CMR glc ratio during exercise is also inhibited by propranolol (Quistorff et al, 2008; Gam et al, 2009). …”

Section: Influence Of Noradrenaline On Lactate Traffickingmentioning

confidence: 99%

Fluxes of lactate into, from, and among gap junction-coupled astrocytes and their interaction with noradrenaline

2014

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Lactate is a versatile metabolite with important roles in modulation of brain glucose utilization rate (CMRglc), diagnosis of brain-injured patients, redox- and receptor-mediated signaling, memory, and alteration of gene transcription. Neurons and astrocytes release and accumulate lactate using equilibrative monocarboxylate transporters that carry out net transmembrane transport of lactate only until intra- and extracellular levels reach equilibrium. Astrocytes have much faster lactate uptake than neurons and shuttle more lactate among gap junction-coupled astrocytes than to nearby neurons. Lactate diffusion within syncytia can provide precursors for oxidative metabolism and glutamate synthesis and facilitate its release from endfeet to perivascular space to stimulate blood flow. Lactate efflux from brain during activation underlies the large underestimation of CMRglc with labeled glucose and fall in CMRO2/CMRglc ratio. Receptor-mediated effects of lactate on locus coeruleus neurons include noradrenaline release in cerebral cortex and c-AMP-mediated stimulation of astrocytic gap junctional coupling, thereby enhancing its dispersal and release from brain. Lactate transport is essential for its multifunctional roles.

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Section: Influence Of Noradrenaline On Lactate Traffickingmentioning

confidence: 99%

Fluxes of lactate into, from, and among gap junction-coupled astrocytes and their interaction with noradrenaline

2014

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“…For the sake of consistency, only data collected using the same experimental methods and only publications where data were presented comprehensively, i.e., in a table, were included. Of those, 8 were patients with cirrhosis (23), while the remaining 88 were young, healthy volunteers. The included publications are presented in Table 1.…”

Section: Data Acquisitionmentioning

confidence: 99%

“…Brachial arterial (4,8,9,13,(23)(24)(25), or radial arterial (22), and jugular venous blood gases and metabolite concentrations were determined on a Radiometer ABL 700 series (Radiometer Medical, Brønshøj, Denmark) in all studies. A measure of global CBF was derived from changes in transcra- nial ultrasound Doppler flow velocity.…”

Section: Data Acquisitionmentioning

confidence: 99%

Cerebral glucose and lactate consumption during cerebral activation by physical activity in humans

2011

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At rest, the brain takes up oxygen and carbohydrate at an ~6:1 ratio. Exercise increases systemic lactate availability reducing this to as little as 1.7:1 despite a ~20% increase in cerebral metabolic rate for oxygen (CMRo₂), thus indicating a disproportionate increase of carbohydrate metabolism. Underlining mechanisms and metabolic fate for the augmented lactate uptake are unknown. This meta-analysis examines whether adrenergic activation explains the increased lactate uptake, cerebral lactate release following cerebral activation compensates for the extra carbohydrate uptake during exercise, and cerebral lactate uptake spares glucose as fuel. Ten studies (n=96) measuring arteriovenous differences for lactate, glucose, and oxygen and cerebral blood flow were included. Cerebral lactate uptake increased during brain activation by whole-body exercise compared to the resting state. Unlike glucose, lactate uptake is proportional to its arterial concentration but is unaffected by sympathetic activity. Following exercise, significant cerebral lactate released as arterial lactate levels decreased, which may balance the surplus lactate uptake in the brain during physical activity in the long term. Finally, cerebral glucose uptake was reduced by ~25% in relation to CMRo₂ when cerebral lactate uptake increased, suggesting, in part, preferential lactate consumption during activation. This meta-analysis favors the notion that cerebral lactate uptake is mainly passively governed by its availability, but when lactate is available, lactate supplements glucose and supports an increase in cerebral energy metabolism in an activity-dependent manner.

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“…Thus, the incidence of POCD with nitroglycerine is higher than that with nicardipine. In this study, the incidences of POCD were the same in Groups A and B, while those in Groups C and D showed no significant difference, thereby suggesting that esmolol may produce no effect on cerebral metabolism 20,21 . In addition, although the use of nicardipine entails the risk of intracranial hemorrhage by dilating cerebrovascular blood vessels to increase baseline rCBF, none of the patients in this study developed intracranial hemorrhage.…”

Section: 5±324 ----------------------mentioning

confidence: 63%

“…Li et al 19 found that treatment with calcium channel antagonists may protect against neuronal damage, improve cognitive function, and delay cognitive dysfunction. Calcium channel antagonists have been found to influence cerebral metabolism, and beta-receptor blockers have been shown to have no effect on OCI 16,20,21 . Several studies have shown that the uptake of lactate and glucose reduces OCI 22,23 .…”

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confidence: 99%

Effects of vasodilator and esmolol-induced hemodynamic stability on early post-operative cognitive dysfunction in elderly patients: a randomized trial

Sun¹,

Yang²,

Sun³

et al. 2017

Afr H. Sci.

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Objective: To investigate the effect of continuous intravenous injection of nicardipine and/or nitroglycerin with or without esmolol on the occurrence of early post-operative cognitive dysfunction (POCD) in elderly patients. Methods: Elderly patients (n=340) who underwent radiofrequency ablation for atrial fibrillation were randomized into five groups: A, nicardipine; B nicardipine+esmolol; C, (nitroglycerin) group; D nitroglycerin+esmolol; E (control) groups. The hemodynamic parameters were recorded, and Mini Mental State Examination was used to assess cognitive function. Results: At 30 min and 60 minutes after anesthesia and at the conclusion of surgery, the rate pressure product value was significantly lower in Groups B (10621.1±321.7, 10544.2±321.8, and 10701.3±325.5, respectively) and D (10807.4±351.1, 10784.3±360.3, and 10771.7±345.7, respectively) than in Group E (13217.1±377.6, 13203.5±357.3, and 13119.2±379.5, respectively). The heart rate was significantly higher in Groups A (104.1±10.3, 104.9±11.1, and 103.9±11.8, respectively) and C (103.7±11.3, 105.5±10.5, and 107.7±11.7, respectively) than in Group E (89.3±12.0, 88.5±11.5, and 85.5±11.6, respectively). The incidence of POCD was significantly lower in Groups A and B than in Groups C, D, and E. Univariate regression analysis showed that regimens in Groups A, B, and E and doses of propofol and fentanyl were risk factors for POCD. Multivariate logistic regression analysis revealed significant associations between the incidence of POCD and interventions in Groups A and B. Conclusion: Maintenance of stable intraoperative hemodynamics using nicardipine and nitroglycerin or their combinations with esmolol, especially nicardipine with esmolol, reduced the incidence of POCD in the elderly with potential cardiovascular diseases. Afri Health Sci2016;16(4): 1056-1066

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Maintained cerebral metabolic ratio during exercise in patients with β‐adrenergic blockade

Abstract: During exhaustive exercise in cirrhotic patients the CMR is maintained and a significant cerebral uptake of lactate is demonstrated. The data suggest that oral treatment with a non-selective beta-adrenergic receptor antagonist attenuates cerebral non-oxidative metabolism.

Cited by 13 publications

References 39 publications

Fluxes of lactate into, from, and among gap junction-coupled astrocytes and their interaction with noradrenaline

Fluxes of lactate into, from, and among gap junction-coupled astrocytes and their interaction with noradrenaline

Cerebral glucose and lactate consumption during cerebral activation by physical activity in humans

Effects of vasodilator and esmolol-induced hemodynamic stability on early post-operative cognitive dysfunction in elderly patients: a randomized trial

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