During a complex data registration period comprising the continuous recording of muscle sympathetic nerve activity (MSNA) and respiration and of various other measurements at Visit 1, placebo and 50 μg of salmeterol via Diskus™ inhaler will be administered in a sequential design. Following Visit 1, the subjects will be treated with salmeterol 50 μg twice daily via Diskus inhaler for 4 weeks. At the Final Visit (Visit 2) the data registration period of Visit 1 will be repeated with the only difference that no placebo will be administered.