Physiopathology of Sodium Retention in Acromegaly

Acromegaly is a disease due to an excess of growth hormone that abnormally occurs in adulthood. It is due to a benign (non cancerous) tumor located in a particular part of the brain that secretes several hormones, the hypophysis. The excess of growth hormones in adults induces an increase in bone (resulting in large enlargement of extremities), and organs. The disease is complicated by the apparition of cardiovascular events including retention of water, salt in the tissues and increase in blood pressure, that altogether might major the mortality of the patients. The investigators recently got experimental data suggesting that the retention of water and salt is mainly due to the activation by the growth hormone of a renal transporter of sodium. Because this transporter is highly sensitive to amiloride, a well know diuretic, the investigators hypothesize that this drug will be very efficient in treating the hypertension in patients, as compared to another diuretic, furosemide.