Demonstration of a catecholaminergic innervation in human perirenal brown adipose tissue at various ages in the adult.

From light and electron microscopic studies on perirenal fat from human donors 27, 39 and 47 years old, unequivocal evidence is found for the presence of islands of multilocular adipocytes. After glyoxylic acid condensation for visualisation of biogenic amines, catecholaminergic nerve plexuses were demonstrated around the arteries of supply to these islands and within the intercellular spaces between their constituent adipocytes. Transmission electron microscopy revealed the cytology of these adipocytes to be similar to that of brown adipocytes in rodents. These findings are viewed in the light of a possible energetic potential for brown adipose tissue in the human adult.