SEX-BASED COMPARISION OF THE ADRENERGIC REGULATION OF SUBSTRATE METABOLISM

这个子项目是众多研究子项目之一

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Men and women differ in the way their bodies prioritize the use of fat and carbohydrate as fuel sources. This is seen particularly in response to situations where there is an increase in the body s energy requirements, and/or glucose requirements. An example of this is during exercise. How these sex-based differences in the pattern of fuel utilization are achieved is not known. Two important hormones that are involved in mobilizing fat and carbohydrate from the bodies stores are epinephrine and norepinephrine (called catecholamines). Once mobilized, the fat or carbohydrate can be used as a fuel. Women appear to be better able to mobilize fat in response to these hormones compared to men. This study will, therefore, look in more detail at how exactly one of these lipid mobilizing hormones increase fat release more in women than men. This will require a low level infusion of the hormone, and/or hormone-like compounds that either mimic or stop some of the effects of the lipid-mobilizing hormone, into an arm vein. To look at how much fat versus how much glucose is mobilized in response to these hormone/hormone-like compounds, infusions will be made into the same arm vein of naturally occurring tracers of fat and glucose. Blood samples will be taken from a hand vein to look at the levels of these tracers in the blood as well as levels of hormones and fat and glucose metabolites. To draw blood samples, the hand is heated in a warm box. Breath samples will also be collected throughout the study to look at how much of the fat and carbohydrate that is mobilized is used as a fuel. Results from this study will help us to gain a better understanding of how fuel use is controlled differently in men and women. Thus, important information will be gained to better help us understand conditions such as obesity and diabetes where there can be abnormalities in glucose and lipid utilization.