A review of the microcirculation of adipose tissue: anatomic, metabolic, and angiogenic perspectives.

Adipose tissue microcirculation is unique within the vascular system because of a capacity for this tissue to grow throughout most of adult life. A review of the microcirculation of adipose tissue has included a historical review of the early studies, which served as a foundation for later investigations on this topic, including basic hemodynamic measurements in mammalian adipose tissue. The various methods for measuring blood flow in white and brown adipose tissue are discussed with respect to studies of transport of substrates involved in adipose tissue metabolism. The role of innervation and vascular adrenergic receptors and the effects of diet and exercise on adipose tissue blood flow are also included. An in-depth analysis of the development of adipose tissue microvasculature indicates that angiogenesis often precedes adipogenesis. The clinical effects of hemodynamic adaptations to adipose tissue expansion are discussed in view of an epidemic increase in the prevalence of obesity and its co-morbidities. The recent discovery of sites of nuclear regulation of adipocyte differentiation, together with the identification of growth factors in adipose tissue, is an indication of the progress that is being made in the further understanding of molecular and cellular events that affect adipose tissue growth and, ultimately, adipose tissue microcirculation.