Question

beta- 1 receptor
heart cell
adh decreases its expression.
parathyroid hormone decreases its expression.
t3 and t4 (thyroid hormones) increase its expression.
aldosterone increases its expression.

Explanation:

To solve this, we analyze each hormone's effect on Beta - 1 receptor expression:

1. ADH (Antidiuretic Hormone): Its main role is in water balance and blood pressure regulation, not related to Beta - 1 receptor expression on heart cells. So it does not decrease the expression.
2. Parathyroid Hormone: It is involved in calcium homeostasis, has no direct relation to Beta - 1 receptor expression in heart cells. So it does not decrease the expression.
3. T3 and T4 (Thyroid Hormones): Thyroid hormones have a positive inotropic and chronotropic effect on the heart, and they increase the expression of Beta - 1 receptors on heart cells. This is a known physiological relationship.
4. Aldosterone: It is mainly involved in sodium and potassium balance and blood pressure regulation through the renin - angiotensin - aldosterone system, and it does not increase Beta - 1 receptor expression.

Answer:

T3 and T4 (thyroid hormones) increase it's expression.