HARMONES

HARMONES

What are harmones ?

•Extracellular chemical messengers

•Often produced in very small amounts
Isolation of TRH required 20 tons of hypothalami from nearly 2 million sheep
(Andrew Schally’s group)

•Often long range effects (endocrine effects)
Some messengers have also short range effects.

Example: Epinephrine is as a neurotransmitter & a hormone

•Bind to receptor molecules

•Trigger a change in the target cell