[Characteristics of opiate receptors in the brain and spinal cord of morphine tolerant mice].

The in vitro studies of 3H-morphine binding to synaptosomal brain and spinal cord membranes and the in vivo detection of pA2 values were carried out in mice. Both morphine-tolerant and intact animals were used. Morphine-tolerant mice showed no changes in specific binding and naloxone pA2 values. Desensitization of neural tissue is most likely to result from variation in translation from opiate receptors to subreceptor effector systems.