What is the Origin of Body Fat Mobilization?

The concept is foundational to the study of human metabolism and energy balance, a field that developed significantly in the mid-20th century with the characterization of fat as a dynamic energy store. The term synthesizes the anatomical location "body fat" with "mobilization," which is derived from the Latin mobilis, meaning movable, indicating the release of stored energy for use.

What is the Mechanism of Body Fat Mobilization?

The process is initiated by the binding of lipolytic hormones, such as catecholamines, glucagon, and growth hormone, to their respective receptors on the adipocyte membrane. This binding activates adenylyl cyclase, which increases the concentration of intracellular cyclic AMP (cAMP), a crucial second messenger. Elevated cAMP then activates Protein Kinase A (PKA), which in turn phosphorylates and activates Hormone-Sensitive Lipase (HSL) and Perilipin. HSL subsequently hydrolyzes the stored triglycerides, releasing glycerol and NEFAs, which are then transported to other tissues for beta-oxidation and ATP production.

Body Fat Mobilization ∞ Area

Body Fat Mobilization

Meaning

Body Fat Mobilization is the fundamental physiological process involving the breakdown of stored triglycerides within adipose tissue into glycerol and non-esterified fatty acids (NEFAs), which are then released into the systemic circulation. This catabolic process serves as a primary mechanism for supplying energy substrates to peripheral tissues when metabolic demand exceeds the immediate availability of glucose. Efficient fat mobilization is a hallmark of metabolic flexibility and is crucial for maintaining energy homeostasis, especially during fasting or prolonged exercise. This process is under tight regulatory control by various endocrine signals.