Ontogenic development of alpha-adrenergic receptors and responsiveness in white adipocytes

The influence of age on adipocyte alpha-adrenergic receptors was studied by using the binding of [3H]dihydroergocryptine to crude adipocyte membranes from hamsters of different ages (1-10 months). The number of alpha-receptor sites was found to increase with increasing age, but in contrast, their binding affinity remained unchanged. These changes in receptor concentrations, which were not related to cell-size differences, were also accompanied by parallel variations of the alpha-adrenergic responsiveness of the fat-cells.