Stress response hormones

Noradrenaline

) a catecholamine with roles as a hormone (where it is synthesised by the adrenal medulla as a stress hormone) and a neurotransmitter (acting on the central and sympathetic nervous system).

Renin

angiotensinogenase, participates in the Renin-angiotensin-aldosterone (RAA) pathway. Stimuli such as dehydration, Na+ deficiency or haemorrhage cause a decrease in blood volume, therefore decrease in BP. This lowered BP stimulates certain cells in the kidneys (juxtaglomerular cells) to secrete the enzyme rennin, which acts on plasma protein angiotensinogen (produced by the liver) converting it to angiotensin I.

Adrenaline

central role in short-term stress reaction acting on both types of adrenoreceptors, α and β receptors. β2 receptors are found primarily in skeletal muscle blood vessels where they trigger vasodilation. α-adrenergic receptors are found in most smooth muscles and splanchnic vessels and adrenaline triggers vasoconstriction in those vessels.

Cortisol

hormone produced by the adrenal gland. Cortisol is often referred to as the stress hormone as it is involved in responses to stress. It increases blood sugar, blood pressure and decreases immune responses.

Antidiuretic hormone (vasopressin)

is released from the posterior pituitary but synthesised in the hypothalamus. The purpose of this peptide hormone is to regulate water reabsorption by altering the permeability of principal cells in the last part of the distal convoluted tubule and throughout the collecting duct.

Corticotropic releasing hormone

low blood level of glucocorticoids (mainly cortisol) stimulate hypothalamus to secrete CRH. Both low levels and CRH secretion promote the release of ACTH. The negative feedback of cortisol control levels of CRH secretion.

Growth Hormone

peptide hormone stimulating (generally anabolic reactions) growth and cell reproduction. Stimulates IGF-1 production (liver is principle).

ACTH (Adrenocorticotropic hormone)

produced and secreted in the anterior lobe of the pituitary gland in response to the CRH released from the hypothalamus, which then stimulates the cortex of the adrenal gland and increases the synthesis of corticosteroids. Important molecule in the hypothalamic-pituitary-adrenal axis.

Endorphin

produced by the pituitary gland and hypothalamus during strenuous exercise, excitement and orgasm which gives painkiller effects. This is done by inhibiting substance P releasing.