Final answer:
Angiotensin II is the peptide hormone that causes blood vessel constriction, sodium and water retention, and stimulates thirst and a salt appetite, thereby increasing blood pressure.
Step-by-step explanation:
The peptide hormone that constricts blood vessels, causes the retention of sodium and water, and produces thirst and a salt appetite is Angiotensin II. This hormone functions as a powerful vasoconstrictor, which significantly increases blood pressure. It also prompts the release of aldosterone from the adrenal cortex, which leads to the reabsorption of sodium and consequently water by the kidneys, increasing blood volume and pressure. Additionally, Angiotensin II stimulates the thirst center in the hypothalamus, causing an increased intake of fluids, further affecting blood volume and pressure.