PROBLEM TO BE SOLVED: To provide treatment strategies on hypertension and hypotension.SOLUTION: A complex of DOPA receptor OA1 and α 1adrenergic receptor is used to screen an effective agent as a blood-pressure controller. A DOPA receptor OA1 and α 1adrenergic receptor coexpressing cell is characterized by forcibly expressing DOPA receptor OA1 and/or α 1adrenergic receptor. A blood-pressure controlling agent targets a complex of DOPA receptor OA1 and α1B adrenergic receptor.SELECTED DRAWING: Figure 4