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
paracrine

Explanation:

• Permissive effect: One hormone is needed for another hormone to exert its full effect. In this case, thyroid hormone allows epinephrine to have a more substantial release of fatty acids (its full effect).
• Antagonistic: Hormones would oppose each other's actions. But here, thyroid hormone enhances epinephrine's action, so not antagonistic.
• Synergistic: Two hormones would have an additive effect (e.g., \(1 + 1=2\)). But here it's about one enabling the other's full action (not just adding up), so not synergistic.
• Direct: Not a standard term for this hormonal interaction context.
• Paracrine: Refers to cell - to - cell communication within a local area (like a tissue), not relevant to this hormonal interaction between two hormones.

Answer:

Permissive