Adrenal steroid-secreting cells express endothelin-1

Endothelin-1 (ET-1) is involved in adrenal steroid secretion but its cell o rigin remains unclear. We showed, using RT-PCR the expression of the mRNAs for preproET-1 and ECE-1 in primary cultures of human adrenal cells enriche d in glomerulosa cells. Since these expressions could be due to contaminati on of steroid secreting cells by other cells, we also used the human adreno cortical cell line H295R, which was shown to produce steroids. This cell li ne also expressed preproET-1-RNA and released mature ET. Functional ET rece ptors were shown on H295R and cultured human adrenocortical cells. These fi ndings indicate that adrenal steroid-secreting cells synthesize and release ET-1, raising the possibility for an autocrine-paracrine effect of ET-1 on adrenocortical functions.