ABSTRACT
Nerve endings in the surgical region continue to be sensitized by prostaglandins and stimulated by the autocoids. Separate nerve fibers, unmyelinated C fibers, carry this ‘‘slow pain’’ message. The C fibers are also responsible for transmitting visceral pain stimulation. Importantly, the neurotransmitter mediating synaptic activity in C fibers is SP, the presynaptic release of which can be inhibited by endogenous enkephalins.
