The regulation of adipose cell metabolism.

The adipose cell maintains a central role in the regulation of lipid metabolism (Galton, 1971). It contains the largest store of triglyceride and cholesterol in the body; it is the only source of plasma fatty acids, a major oxidative fuel, particularly in the fasting state, and it is the major site of clearance of chylomicrons and very-low-density lipoprotein (VLDL) in the fed state. The importance of the tissue for fuel metabolism is observed in conditions of generalized lipodystrophy (total atrophy of adipose tissue) where a severe hyperlipidaemia develops often with glucose intolerance (Schwartz et al. 1960). The metabolic pathways of the cell are regulated by a variety of agents including hormones, apolipoproteins and metabolites (Fig. I). It is convenient to consider this in terms of the regulation of substrate utilization by the cell, then to consider the substrate output from the cell.