Initial investigations into adrenaline accumulation and adrenergic responsiveness in cultured neonatal rat heart cells.

1 Accumulation of tritiated adrenaline (and/or its products) has been studied by a variety of techniques in viable, attached and free-floating myoblasts cultured from neonatal rat heart cells. 2 Accumulation increased with the number of cells used, the culture age of cells, incubation time and the concentration of adrenaline in the incubation mixture. 3 Accumulation-concentration data were not linearly correlated with dose-response data. 4 Accumulation did not correlate well with beta-adrenoceptor responsiveness in a number of situations of varying responsiveness. 5 Accumulation was not blocked by a variety of uptake blocking agents or alpha- and beta-adrenoceptor antagonists. 6 A much smaller accumulation process was observed in fibroblasts which respond to adrenaline with reversible morphological changes.