Glucocorticoids Flashcards
what are GCs?
Synthesised in the adrenal gland
steroid hormone- chemical messengers secreted into the blood
e.g. the effects of catecholamines on vascular tone
* Important in homeostasis e.g. conditioning the body’s
response to stress
where are GCs made?
secreted by the adrenal gland
what do GCs do?
mediate essential metabolic functions in target tissues
what is the effect of GCs?
- raise/lower mood state
- stimulate gluconeogenesis
- digestion is slowed
- permanently increased dosage = increase Osteoporosis and muscle weakness
- production of cortisol via the hypothalamus and the pituitary gland
- increase blood sugar levels
- reduces allergic reactions/anti-inflammatorys
what are the 3 main functions of GCs? and how does this occur?
- increase glucose mobilisation
- augment gluconeogenesis
- amino acid generation
- increased lipolysis - maintenance of circulation
- vascular tone
- salt and water balance - immunomodulation
- dampens/suppresses the immune system
DURING STRESS
what is cortisol also known as ?
hydrocortisone
what family are GCs apart of?
cholesterol family
what else are within the cholesterol family?
steroid hormones
- GCs
- mineralocorticoids
- vitamin D
- androgens (sex hormone)
- oestrogens
- progesterone
what structural properties are within GCs?
lipophilic = cross membranes
bind to cytosolic receptors
how do GCs mediate their effects
alter gene transcription
GC bind to GC receptors that act as TF that determine gene expression applying its effects to distant tissues
what the classifications of steroids?
- corticoids
- androgens
- oestrogens
what determines GC synthesis and secretion?
- diurnal rhythm (highest serum cortisol levels in the morning)
- hypothalamus regulation
how can GC cause morning sickness?
high conc of GC’s in the morning = inducing sickness
how does the hypothalamus control GC synthesis?
hypothalamus detects the stress/stimuli
then alerts pituitary gland
pituitary gland releases hormones to endocrine glands
what stimuli is detected by the hypothalamus?
- diurnal rhythm (e.g. daylight)
- stress (physical trauma/emotional)
- inflammation (pro-inflammatory cytokines)
what hormone is released by the pituitary gland?
adrenocorticotropic hormone (ACTH)
anterior
what does ACTH do?
regulate GC synthesis