cytokines can be classified as
proteins
peptides
or glycoproteins
cytokines
small cell-signaling protein molecules
2 popular cytokines
the immunomodulating agents
INTERLEUKINS & INTERFERONS
growth hormone is secreted where?
by somatotroph cells within the anterior pituitary gland
growth hormone main 3 roles
growth of all tissues
promotes size & number
protein synthesis
metabolic effects of growth hormone
1. increases protein synthesis by ribosomes
2. lipolytic effect : burning off fat to give energy
3.on carbohydrates it has diabetogenic effect
where is somatostatin produced?
hypothalamus and delta cell of islets of langerhans of pancreas
somatostatin ______ of GH, insulin and glucagon
INHIBITS SECRETION
IGF
produced by liver, it is the mediator of growth hormone induced groth. it decreases GH secretion by direct inhibition of pituitary and increases somatostatin
Ghrelin
secreted by STOMACH. it increases GH and increases appetite
somatostatin inhibits all ____ signaling
peptide
what 4 stimuli can increase GH secretion?
1. hypoglycemia
2. decrease level of cell protein
3. deep sleep
4. exercise, emotions, stress
3 inhibitors of GH secretion
1. somatostatin from the PVN
2. circulating concentrations of GH and IGF-1 ( negative feedback)
3. dihydrotestosterone
IGF stands for
insulin like growth factors
GH hormone causes liver to form...
IGFs
IGFs and bone?
strongly increase all aspects of bone growth; stimulation of osteoblasts increased protein deposition by osteogenic cells;
acromegaly
chronic endocrine disease caused by GH secreting pituitary adenoma
growth hormone exerts its growth effects through...
IGF
____ is diabetogenic and lipolytic
GH
prolactin is secreted by
the anterior pituitary
what is the function of prolactin?
milk secretion by mammary gland and stimulation of synthesis of fat and lactose in the mammary gland
what is the constitutive repressor of prolactin secretion?
dopamine
negative feedback for prolactin?
PIH from hypothalamus
increased secretion of prolactin in...
exercise
stress
suckling
sleep
prolactin effects? label 3
1. regulating lactation
2.stimulating proliferation of oligodendrocyte precursors
3. high PRL increases proinflammatory immune responses
Janus Kinase 2
activated when prolactin binds to a prolactin receptor. it is a tyrosine kinase that intiates the JAK-STAT pathway
IRF-1 role?
important role in maturation and differentiation of both B and T lymphocytes
STATs importance?
lead to increased transcriptional initiation