Final answer:
Angiotensin, specifically angiotensin II, primarily raises blood pressure by inducing vasoconstriction and stimulating aldosterone release, which leads to sodium and water retention in the kidneys.
Step-by-step explanation:
One of the primary effects of angiotensin in a healthy animal is to increase blood pressure. Angiotensin II, in particular, acts as a potent vasoconstrictor, which narrows the blood vessels and leads to an increase in blood pressure. Additionally, angiotensin II stimulates the release of aldosterone from the adrenal cortex, which causes the kidneys to retain sodium (Na+). This retention of sodium subsequently leads to water retention, which further increases blood volume and pressure.