Abstract
Affinity of drugs and peptides for U-69,593-sensitive and -insensitive kappa opiate binding sites: the U-69,593-insensitive site appears to be the beta endorphin-specific epsilon receptor.
B Nock, A L Giordano, T J Cicero and L H O'Connor
Journal of Pharmacology and Experimental Therapeutics August 1990, 254 (2) 412-419;