Which hormone(s) cause the release of ADH?

The release of antidiuretic hormone (ADH), also known as vasopressin, is primarily influenced by Angiotensin II. Angiotensin II is a peptide hormone that plays a critical role in regulating blood pressure and fluid balance. When blood volume is low or when there is decreased renal perfusion, the renin-angiotensin system is activated, leading to the formation of Angiotensin II. This hormone stimulates the posterior pituitary gland to release ADH, which then acts on the kidneys to promote water reabsorption. This mechanism helps to increase blood volume and restore blood pressure to normal levels.

In contrast, the other options do not have a significant direct role in stimulating the release of ADH. While ephedrine is a sympathomimetic agent and can indirectly influence fluid balance, it does not directly stimulate ADH release. Serotonin is primarily involved in mood regulation and has no direct relation to the secretion of ADH. Insulin plays a role in glucose metabolism and does not have a direct influence on ADH release either. Thus, Angiotensin II is the key hormone responsible for promoting the release of ADH in response to low blood volume or blood pressure.