Molecular signalling Flashcards
What is the need for hormone system
Communication to coordinate growth, development, metabolism & reproduction
What is the 2 components of a hormone
- Ligand that can be hydrophilic (bind to carrier & diffuse into cell) or hydrophilic that needs to enter cell w/ a receptor
- Receptor GCPR, ligand gated ion channels or receptor tyrosine kinase
What is the 2 classifications of hormone
- Structure: modified AA, peptide or steroids
- Signaling: autocrine, paracrine & endocrine
What is autocrine signaling
Cell signals self
What is paracrine signaling
Cell signals nearby cell of different cell type
What is endocrine signaling
Cells signals distal cells
What is the 5 characteristics of hormones
- Tissue specific
- Multi step cascade
- Intracellular secondary messenger
- Co-ordinate/counter regulation of opposing pathways
- Augmentation/opposition by other hormones
What is steroids composed of
Cholesterol
What is 5 examples of steroids
Estrogen, progesterone, testosterone, glucocorticoid & mineralocorticoid
What is the 6 steps of action of testosterone
- Testosterone is bound to SHBG in the plasma & diffuse into the androgen cell
- Testosterone gets converted to DHT via 5-alpha reductase & binds to androgen receptor
- HSP/chaperons are proteins that binds & inhibits the AR
- AR is dimerisation & activated once testosterone binds & HSP dissociate
- Dimirized complex pass into nucleus & binds to promoter regions of genes causing transcription of target genes
- Results in increase growth, survival & PSA
Where is DHT formed
Hair follicles, prostate & adrenal glands
What differs between DHT & testosterone
DHT has higher affinity for AR
How does testosterone act in prostate
Endocrine manner
How does DHT act
Autocrine manner on prostate cells & paracrine manner at adjacent cells
What hormone is responsible for proliferation of prostate
DHT
