Endomorphin peptides: pharmacological and functional implications of these opioid peptides in the brain of mammals. Part one. - Gelman, Philippe Leff; Herrera, Norma Estela González; Ortega, Maura Epifanía Matus; Romero, Lenin Pavón; Santillán, Carlos Téllez; Juárez, Alberto Salazar; Palma, Benito Antón (Salud Mental, 2010)