Question

acting alone, epinephrine and thyroid hormone each stimulates release of only a small amount of fatty acids from adipose cells. in the presence of thyroid hormone, epinephrine causes a much more substantial release of fatty acids from the cells. what is the term describing the effect of thyroid hormone on epinephrines actions?

multiple choice

antagonistic

agonistic

permissive

direct

Explanation:

• Permissive effect: One hormone is needed for another hormone to exert its full effect. Here, thyroid hormone allows epinephrine to have a more substantial release of fatty acids (its full effect).
• Antagonistic effect: Hormones have opposing actions. This is not the case here as they are not opposing.
• Synergistic effect: Hormones have an additive effect (e.g., \(1 + 1=2\) or more). But the key here is that one is enabling the other (not just adding up).

Answer:

Permissive