In the context of hypothalamic-pituitary regulation, acute alcohol consumption most directly inhibits the release of which hormone from the posterior pituitary?

• A. Thyroid-stimulating hormone (TSH)
• B. Growth hormone (GH)
• C. Oxytocin
• D. Antidiuretic hormone (ADH, vasopressin)

Answer: (D)

Verified step by step guidance

1. Understand the roles of the hormones listed: TSH regulates thyroid function, GH influences growth and metabolism, oxytocin is involved in childbirth and lactation, and ADH (vasopressin) controls water balance by regulating kidney function.
2. Recall that the posterior pituitary releases two main hormones: oxytocin and ADH (vasopressin). The anterior pituitary releases TSH and GH.
3. Recognize that acute alcohol consumption primarily affects water balance by inhibiting the release of ADH from the posterior pituitary, leading to increased urine production.
4. Note that alcohol does not directly inhibit the release of TSH or GH, as these are secreted by the anterior pituitary, nor does it primarily inhibit oxytocin release in the context of acute consumption.
5. Conclude that the hormone most directly inhibited by acute alcohol consumption from the posterior pituitary is ADH (vasopressin).