Which statement about beta-endorphin is most accurate?
A. It is exclusively located in the spinal cord
B. Enzymes for its synthesis are located in nerve endings C. It selectively activates delta opioid receptors
D. Its actions are mainly inhibitory
Ans. D. Its actions
are mainly inhibitory
The
opioid peptides are widely distributed in the CNS at all levels of the neuraxis
and are synthesized in the cell bodies.
They
activate several receptor subtypes and cause inhibition. No mechanism has been
described for termination of the synaptic actions of endogenous peptides
