A spider derived peptide, PnPP-19, induces central antinociception mediated by opioid and cannabinoid systems Daniela da Fonseca Pacheco, Ana Cristina Nogueira Freitas, Adriano Monteiro C. Pimenta, Igor Dimitri Gama Duarte and Maria Elena de Lima Journal of Venomous Animals and Toxins including Tropical Diseases, 2016, 22, 34, Doi : 10.1186/s40409-016-0091-6   Abstract Background : Some peptides purified from the venom of the spider Phoneutria nigriventer have been identified as potential sources of drugs for pain treatment. In this study, we characterized the antinociceptive effect of the peptide PnPP-19 on the central nervous system and investigated the possible involvement of opioid and cannabinoid systems in its action [...]