1. Multiple opiate receptors. Enkephalins and morphine bind to receptors of different specificity.
2. CHANG, K.J., MULTIPLE OPIATE RECEPTORS - DIFFERENT REGIONAL DISTRIBUTION IN THE BRAIN AND DIFFERENTIAL BINDING OF OPIATES AND OPIOID PEPTIDES, MOLECULAR PHARMACOLOGY 16: 91 (1979).
3. CHAPMAN, D, PHASE-TRANSITIONS AND FLUIDITY CHARACTERISTICS OF LIPIDS AND CELL-MEMBRANES, QUARTERLY REVIEWS OF BIOPHYSICS 8: 185 (1975).
4. CHIN, J.H., EFFECTS OF LOW CONCENTRATIONS OF ETHANOL ON FLUIDITY OF SPIN-LABELED ERYTHROCYTE AND BRAIN MEMBRANES, MOLECULAR PHARMACOLOGY 13: 435 (1977).
5. GILBERT, P.E., EFFECTS OF MORPHINE-LIKE AND NALORPHINE-LIKE DRUGS IN NONDEPENDENT, MORPHINE-DEPENDENT AND CYCLAZOCINE-DEPENDENT CHRONIC SPINAL DOG, JOURNAL OF PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS 198: 66 (1976).