Obésité humaine et système nerveux sympathique

Abstract

The sympathetic nervous system (SNS) is an important element of the autonomic nervous system which has an essential role in the maintenance of body homeostasis. SNS activation involves norepinephrine release by noradrenergic fibres and epinephrine secretion by adrenal medulla. SNS controls a number of physiological events including metabolic processes, cardiac and vascular activities, gastrointestinal functions and endocrine secretions. The SNS has a major role in the control of adipose tissue function through a direct effect on adipocytes and adipose tissue vessels, and by an indirect effect on pancreatic hormones secretion. Various alterations of SNS effects on metabolism have been implicated in the development and the maintenance of obesity. This review provides an overview of physiological aspects of the SNS involvement in normal and obese subjects. Physiological and pathological changes in SNS activity are summarized. Modifications occurring in adipose tissue function and fat cell responsiveness to norepinephrine and epinephrine are also considered.

Keywords

• sympathetic nervous system
• norepinephrine
• epinephrine
• obesity
• adipocytes
• adrenergic receptors
• lipolysis
• energy expenditure
• physical exercise