Kelatorphan is primarily used in research settings to study the role of enkephalin-degrading enzymes in various physiological processes. It acts as a potent inhibitor of these enzymes, which helps in understanding the regulation of enkephalins, naturally occurring opioid peptides in the body. By preventing the breakdown of enkephalins, Kelatorphan can be used to explore their effects on pain modulation, mood regulation, and other neurological functions. This makes it a valuable tool in neuroscience and pharmacology research, particularly in studies related to pain management and the development of potential therapeutic agents targeting the opioid system.