Biomaterial Database

Effects of glucose infusion on hormone secretion and hepatic glucose production during heavy exercise. 1993

M M Wiersma, and J Vissing, and A B Steffens, and H Galbo

Department of Medical Physiology, Panum Institute, University of Copenhagen, Hellerup, Denmark.

Blood-borne metabolic feedback vs. neural feedforward regulation of glucose homeostasis during exercise was investigated by infusion glucose and [3H]glucose for glucose appearance determination intravenously in rats running for 20 min at 28 m/min [approximately 85% of maximal O2 consumption (VO2max)]. Infused glucose corresponded to the exercise-induced increase in hepatic glucose production (HGP) found in saline-infused rats. Saline- and glucose-infused resting rats were also studied. Arterial blood was sampled for analyses of hormones and metabolites. Plasma epinephrine, norepinephrine, and insulin were always similar and HGP was initially similar in the two exercising groups, although glucose infusion resulted in higher plasma glucose compared with control (P < 0.05). Late during exercise, high plasma glucose (11.3 +/- 0.4 vs. 9.6 +/- 0.3 mM) and low glucagon (16 +/- 2 vs. 27 +/- 3 pM) in glucose- vs. saline-infused rats caused an inhibition of HGP in glucose-infused rats, although never below preexercise levels. In resting rats, glucose infusion resulted in elevated plasma glucose and insulin and, in turn, inhibition of HGP but had no effect on catecholamines, corticosterone, or glucagon. The findings indicate that during heavy exercise, glucose homeostasis is regulated primarily by neural feedforward mechanisms and that blood-borne metabolic feedback mechanisms play a regulatory role if metabolic error signals are pronounced.

UI	MeSH Term	Description	Entries
D007773	Lactates	Salts or esters of LACTIC ACID containing the general formula CH3CHOHCOOR.
D008099	Liver	A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.	Livers
D008297	Male		Males
D009132	Muscles	Contractile tissue that produces movement in animals.	Muscle Tissue,Muscle,Muscle Tissues,Tissue, Muscle,Tissues, Muscle
D005082	Physical Exertion	Expenditure of energy during PHYSICAL ACTIVITY. Intensity of exertion may be measured by rate of OXYGEN CONSUMPTION; HEAT produced, or HEART RATE. Perceived exertion, a psychological measure of exertion, is included.	Physical Effort,Effort, Physical,Efforts, Physical,Exertion, Physical,Exertions, Physical,Physical Efforts,Physical Exertions
D005947	Glucose	A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement.	Dextrose,Anhydrous Dextrose,D-Glucose,Glucose Monohydrate,Glucose, (DL)-Isomer,Glucose, (alpha-D)-Isomer,Glucose, (beta-D)-Isomer,D Glucose,Dextrose, Anhydrous,Monohydrate, Glucose
D005990	Glycerol	A trihydroxy sugar alcohol that is an intermediate in carbohydrate and lipid metabolism. It is used as a solvent, emollient, pharmaceutical agent, or sweetening agent.	1,2,3-Propanetriol,Glycerin,1,2,3-Trihydroxypropane,Glycerine
D006003	Glycogen
D006728	Hormones	Chemical substances having a specific regulatory effect on the activity of a certain organ or organs. The term was originally applied to substances secreted by various ENDOCRINE GLANDS and transported in the bloodstream to the target organs. It is sometimes extended to include those substances that are not produced by the endocrine glands but that have similar effects.	Hormone,Hormone Receptor Agonists,Agonists, Hormone Receptor,Receptor Agonists, Hormone
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia