Rise in Plasma Lactate Concentrations with Psychosocial Stress: A Possible Sign of Cerebral Energy Demand

Abstract

Objective: It is known that exogenous lactate given as an i.v. energy infusion is able to counteract a neuroglycopenic state that developed during psychosocial stress. It is unknown, however, whether the brain under stressful conditions can induce a rise in plasma lactate to satisfy its increased needs during stress. Since lactate is i) an alternative cerebral energy substrate to glucose and ii) its plasmatic concentration is influenced by the sympathetic nervous system, the present study aimed at investigating whether plasma lactate concentrations increase with psychosocial stress in humans. Methods: 30 healthy young men participated in two sessions (stress induced by the Trier Social Stress Test and a non-stress control session). Blood samples were frequently taken to assess plasma lactate concentrations and stress hormone profiles. Results: Plasma lactate increased 47% during psychosocial stress (from 0.9 ± 0.05 to 1.4 ± 0.1 mmol/l; interaction time × stress intervention: F = 19.7, p < 0.001). This increase in lactate concentrations during stress was associated with an increase in epinephrine (R² = 0.221, p = 0.02) and ACTH concentrations (R² = 0.460, p < 0.001). Conclusion: Plasma lactate concentrations increase during acute psychosocial stress in humans. This finding suggests the existence of a demand mechanism that functions to allocate an additional source of energy from the body towards the brain, which we refer to as ‘cerebral lactate demand’.

The distances covered by basketball referees in a match increase throughout the competition phases, with no change in physiological demand

“…These results were likely as a result of stress, anxiety, pressure, and responsibility of referees in the development of the game. It is known that [lac] is influenced by the sympathetic nervous system, and it has been verified that psychosocial stress can increase [lac] by up to 47%, which is attributed to increases in epinephrine and drenocorticotropic hormone 19. Krustrup and Bangsbo12 found higher [lac] concentrations in soccer referees than those found in our study (4.8 ± 0.4 mM in halftime and 5.0 ± 0.5 mM at the end of the match), but the distance covered by the referees was greater (10.07 ± 0.13 km), as was the game duration (90 minutes).…”

Mitochondrial Gene Expression Profiles Are Associated with Maternal Psychosocial Stress in Pregnancy and Infant Temperament

“…In the brain, psychosocial stress increases energy demand by a mechanism referred to as "cerebral insulin suppression". This mechanism limits glucose flux into peripheral tissue to enhance cerebral glucose supply thus affecting the metabolism of many other organs as, particularly, those with high metabolic rates [ 14 , 15 , 16 , 17 ].…”

Multiscattering-enhanced optical biosensor: multiplexed, non-invasive and continuous measurements of cellular processes

“…In particular, the detection of glucose is interesting in the context of the biochemical cycle of energy harvesting, diabetes pathology, as well as fermentation control in food industry [7][8][9][10][11]. Lactate, in addition, acts as a cerebral energy substrate and as a product in anaerobic metabolism during muscle contraction, malnutrition and hypoxia [12][13][14][15][16][17]. Thus, a sensitive method for the continuous and simultaneous detection of several such metabolites will broaden our understanding of cell biochemistry and have a significant impact on medical diagnostics.…”