Abstract
Crotalphine, a 14-mer peptide, isolated from the venom of C. d. terrificus snake, present long lasting antinociceptive activity (3-5 days) when administered by p.o., i.v. or s.c. routes. The antinociceptive effect is mediated by activation of peripheral kappa opioid receptor (acute pain models), or kappa and delta opioid receptors (chronic pain). Preliminary results obtained in binding as…