Re: Is the stress hormone adrenalin involved in the HPA axis?

Hi Michael,

        Indeed, the adrenaline (or it's other name, epinepherine) is under control of the HPA axis. Cortisol will cause the upregulation of the enzymes that make adrenaline, notably the enyzmes tyrosine hydroxylase and dopamine-beta-hydroxylase. Release of adrenaline is also under control of the sympathetic nervous system .

        Adrenaline also acts on the HPA axis. Adrenaline will stimulate the production of ACTH in the pituitary. This positive feedback will then will increase the release of cortisol from adrenal glands, which leads to more adrenaline... And so on.

        But generally speaking, while adrenaline definitely regulates the HPA axis, it is not considered a core component of the HPA axis; the adrenal cortex (which makes cortisol) and the adrenal medulla (which makes adrenaline) are distinct structures.

        I hope that helps!
- Alex