Aims: The purpose of the current study was to evaluate the significance of the endothelin system in
catecholamine release and synthesis in the adrenal gland. Main Methods: Primary cultures of isolated bovine adrenal medullary cells were prepared. Gene expression,
intracellular calcium changes, epinephrine release, and other factors were investigated. Key findings: Expression of endothelin receptors in the rat adrenal gland was confirmed. Intravenous infusion of endothelin-1 (1.0 nmol) increased blood pressure (systolic and diastolic). Endothelin-1 stimulated intracellular calcium changes, resulting in increased nuclear factor of T cell (NFAT) activity and epinephrine release from cultured adrenal medullary cells. Furthermore, endothelin-1 increased catecholamine synthesis and caused hypertrophic changes in the cell size. Significance: Our findings indicate involvement of the endothelin system in the sympathetic regulation of the adrenal medulla.