Four grams of glucose

Abstract

Four grams of glucose circulates in the blood of a person weighing 70 kg. This glucose is critical for normal function in many cell types. In accordance with the importance of these 4 g of glucose, a sophisticated control system is in place to maintain blood glucose constant. Our focus has been on the mechanisms by which the flux of glucose from liver to blood and from blood to skeletal muscle is regulated. The body has a remarkable capacity to satisfy the nutritional need for glucose, while still maintaining blood glucose homeostasis. The essential role of glucagon and insulin and the importance of distributed control of glucose fluxes are highlighted in this review. With regard to the latter, studies are presented that show how regulation of muscle glucose uptake is regulated by glucose delivery to muscle, glucose transport into muscle, and glucose phosphorylation within muscle.

Limited Acute Influences of Electrical Baroreceptor Activation on Insulin Sensitivity and Glucose Delivery: A Randomized, Double-Blind, Crossover Clinical Study

“…Muscular insulin sensitivity is determined by vascular glucose and insulin delivery to the muscular interstitial space, insulin-mediated cellular glucose uptake, and intracellular glucose metabolism (20). According to earlier studies (4,5), we expected to observe decreased muscular glucose delivery and insulin-mediated glucose disposition and metabolism when electrical carotid sinus stimulation was acutely interrupted.…”

Evolution of glucose utilization: Glucokinase and glucokinase regulator protein

“…In mammals, several tissues, such as the brain, depend upon glucose for the generation of ATP for cellular functions (Wasserman, 2009;Thorens, 2011). To supply these tissues, glucose is distributed by the blood stream, and complex systems have evolved to maintain appropriate blood glucose levels in the face of changes due to the availability of food and the expenditures of energy (Suh et al, 2007;Wasserman, 2009;Polakof et al, 2011;Thorens, 2011). The diet is the ultimate source of glucose in mammals, where it is either directly absorbed from the digested food in the intestine or is generated by gluconeogenesis (generally from amino acids) from precursors obtained from the diet.…”

“…Counter-regulatory hormone systems have evolved to maintain blood glucose within a narrow range. Insulin promotes glucose uptake from the blood by diverse tissues when blood glucose levels are high; e.g., after feeding, while glucagon induces gluconeogenesis by the liver to release glucose and prevent hypoglycemia (Bansal and Wang, 2008;Wasserman, 2009). Additional physiological systems, including other hormones and the central nervous system, contribute to the regulation of blood glucose levels (Polakoff et al, 2011;Thorens, 2011;Grayson et al, 2013).…”

Suplementação com carboidratos durante treinamento intensivo aumenta as concentrações de lipídios intramiocelulares e reduz os marcadores de lesão tecidual em corredores competitivos: interação hormonal e metabólica

“…Os estoques de glicogênio no músculo esquelético atingem cerca de 500g e representam 82% do CHO endógeno. Aproximadamente 100g estão armazenados no fígado (14% do total de CHO endógeno) e o restante, compreende a glicose presente no plasma (4% do total de CHO endógeno), podendo essas concentrações variarem em consequência do estado de treinamento e do estado nutricional do atleta (Wasserman, 2009;. Segundo , quanto mais condicionado estiver o atleta, maior a sua capacidade de estocar glicogênio, podendo atingir 900g no músculo esquelético.…”

“…Segundo , no estado pós-absortivo, o organismo humano armazena ~100g de glicogênio no fígado e ~400g no músculo (Wasserman, 2009).…”