Question

Which of the following adenohypophyseal hormones does not affect their target cells via a cyclic AMP second messenger?

1) GH
2) ACTH
3) TSH
4) FSH

Answer 1

Growth Hormone (GH) does not use cyclic AMP as a second messenger for its effects on target cells, unlike other adenohypophyseal hormones mentioned.

Step-by-step explanation:

The question pertains to which of the four adenohypophyseal hormones does not use cyclic AMP as a second messenger in their action on target cells. The hormones in question are Growth Hormone (GH), Adrenocorticotropic Hormone (ACTH), Thyroid-Stimulating Hormone (TSH), and Follicle-Stimulating Hormone (FSH). Of these, GH does not act via a cyclic AMP second messenger system. Growth hormone’s actions are indirectly mediated by insulin-like growth factors (IGFs) which do not involve the cyclic AMP secondary messenger pathway.