Answering to the question "Does cortisol down regulate adrenaline and noradrenaline?"

Let me try to answer.

In our body, there is a pair of glands located above the kidney called adrenal glands. Adrenal glands consist of two main parts. The first one is called the adrenal cortex, while the second one is called the medulla.

Cortisol is one type of hormones produced by the adrenal cortex while Epinephrine is a hormone produced by adrenal medula.

Cortisol, as well as other adrenal cortex hormones, is primarily regulated by what we know as HPA axis (Hipothalamus-Pituitary-Adrenal axis). Hipothalamus produces hormone called CRH (Corticotropin-Releasing Hormone) which then affect Pituitary to release ACTH (Adrenocorticotropic releasing hormone). ACTH would eventually affect the adrenal cortex. Some of which is increasing the cortisol production by adrenal cortex.

Cortisol is known as “stress hormone” in which its level would increase during stress condition. Cortisol itself has several effects in our body. Those are

1. increasing blood pressure (by upregulating beta-1 adrenergic receptors in the heart)
2. increasing glucose level
3. increasing catabolism

The increase of cortisol in our body would then gives negative feedback to the pituitary and hypothalamus so that the release of CRH and ACTH be lowered.

Epinephrine is hormone released during “fight and flight” time. Fight and flight is a condition described for life threatening situation. During this life threatening situation, our body would react as increasing symphatetic nervous activity (worked through the help of norepinephrine as neurotransmitter, chemical substance for communicating between neurons). The increase of symphatetic nervous system would then affect the adrenal gland production of epinephrine.

Epinephrine itself has several functions depending on where it binds the receptor. If it is bound to alpha-1 adrenergic receptor, it will constrict the blood vessel and the following result will be increasing in blood pressure. If it is bound to beta-1 adrenergic receptor, it will increase the heart beat which then will increase blood pressure. If it is bound to beta-2 adrenergic receptor, it will widen the airway. Norepihrine itself also has this ability, the difference is only that norepinephrine doesn’t bind to beta-2 adrenergic receptor.

The red string that I see in your question is that cortisol will “upregulate” beta-1 adrenergic receptors in the heart. This increase in numbers of beta-1 receptors would then made the chance of both epinephrine and norepinephrine binding with beta-1 receptor higher. This will lead to increase in blood pressure.

Other than that epinephrine is released during fight and flight (relatively short period of time). Cortisol level is higher during chronic stress (longer period of time). It means that when a person is suffering from chronic stress, the cortisol level in his/her blood would expected to be above normal range but the epinephrine level in his/her blood would expected to be normal. As far as I know, there is no direct upregulating or downregulating mechanism involving both cortisol and epinephrine.