Chapter 7 - Plasma membrane properties and receptors in white adipose tissue

Abstract

This chapter reviews the fat cell plasma membrane components, which are involved in the control of the internal milieu of the cells or are responsible for the recognition of hormonal or neurotransmitter signals. It further discusses the concepts concerning the peptide hormone and neurotransmitter receptors of the plasma membrane and the links with their transducing systems. Plasma membrane has a key role in the preservation of the internal milieu of a cell by controlling water, ion, and nutrient movements. It also has a major role in intercellular communication and in the recognition of hormonal or immunological messages. Protein diffusion within plasma membrane is a major process in numerous receptor-mediated events—for example, insulin action or adenylate cyclase activation—and can be regulated by the membrane lipid viscosity. The degree of saturation of phospholipid fatty acids affects the responses by inducing modifications into the membrane lipid fluidity. Thus, an increase in membrane lipid fluidity facilitates the lateral diffusion of membrane receptor proteins and effector enzymes and can be analyzed by fluorescence polarization measurements. Although a more precise physiological role for numerous fat cell membrane-located events remains to be defined in vivo , the fat cell offers an invaluable model for basic research on adrenergic and peptide hormone receptors and other plasma membrane properties.