Final answer:
Atrial Natriuretic Peptide (ANP) suppresses the secretion of renin, aldosterone, and Antidiuretic Hormone (ADH), leading to reduced reabsorption of Na+ and water in the kidneys, causing decreased blood volume and pressure.
Step-by-step explanation:
The hormone Atrial Natriuretic Peptide (ANP) is released by the atrial cells of the heart in response to high blood volume. ANP plays a crucial role in reducing blood volume and blood pressure primarily through its effects on the kidneys. One significant action of ANP is to suppress the secretion of the hormones renin, aldosterone, and Antidiuretic Hormone (ADH).
By inhibiting these hormones, ANP decreases the reabsorption of Na+ by the nephrons which leads to a reduction in water reabsorption, further promoting the excretion of Na+ and water in the urine. This diuretic effect essentially results in a decreased blood volume and pressure. Additionally, ANP's antagonistic action to the angiotensin pathway includes suppression of the angiotensin-converting enzyme, which is responsible for the conversion of angiotensin I to angiotensin II, a potent vasoconstrictor. Thus, ANP also contributes to vasodilation, further aiding in the decrease of blood pressure.