TUMOUR-DERIVED HUMAN ADRENOCORTICAL CELLS EXPRESS β-ADRENERGIC RECEPTORS: STEROIDOGENIC EFFECTS OF β-ADRENERGIC INPUT

Abstract

It is well established that catecholamines have potent actions on adrenocortical function and steroidogenesis in different species. The effect of these substances on steroid production of the human adrenal cell line H295R is the subject of this study. H295R cells were cultured in the presence of the synthetic catecholamine, isoproterenol for four hours. Aldosterone, cortisol, and DHEA secretion was measured using direct radioimmunoassays. Administration of 10⁻¹¹–10⁻⁷ mol/L isoproterenol produced a dose-dependent increase in secretion of aldosterone, cortisol, and DHEA by H295R cells resulting in 3-fold, 2.5-fold, and 2-fold stimulation respectively, relative to basal values. Analysis of mRNA using nested PCR revealed the presence of all three types of β-adrenergic receptors namely β1, β2, and β3 in H295R cells. Isoproterenol had no effect on the proliferation rate of H295R cells as determined by ³H-incorporation assay and the colorimetric WST-1 cell proliferation assay.