Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P01189 (beta-endorphin)
 21,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The intracerebroventricular (i.c.v.) injection to mice of a polyclonal antibody raised against the peptide sequence 208-216 (TKYRQGSID) of cloned rat mu opioid receptor, reduced the analgesic potency of DAMGO, morphine and beta-endorphin-(1-31) when studied 48 h later in the tail-flick test. Antinociception elicited by delta agonists, DPDPE and [D-Ala2]-Deltorphin II, and by the kappa agonist U-50488H, was fully expressed in mice undergoing this treatment. The specific binding displayed by 0.6 nM [3H]-DAMGO was reduced in membranes preincubated with the antiserum, whereas no change could be detected for 3 nM [3H]-DPDPE or 2 nM [3H]-U-69593 labelling delta and kappa opioid receptors respectively. Naloxonazine, irreversible antagonist of the pharmacologically defined mu 1 opioid receptor, and beta-funaltrexamine (beta-FNA), that also displays irreversible antagonism at mu 1/2 receptors, when injected i.c.v. 24 h before the opioids significantly reduced the activity of DAMGO and morphine. In mice treated with naloxonazine, but not with beta-FNA, the antibody further reduced the remaining analgesic effect of DAMGO and morphine. Thus, both the antibody and beta-FNA blocked a wider population of mu opioid receptors than that tagged by naloxonazine.
 ...
PMID:In vivo injection of antibodies directed against the cloned mu opioid receptor blocked supraspinal analgesia induced by mu-agonists in mice. 747 89

Deep layers of the superior colliculus (DLSC), the dorsal and ventral periaqueductal gray matter (PAG), and inferior colliculus (IC) are midbrain structures involved in the generation of defensive behavior. beta-Endorphin and Leu-enkephalin are some neurotransmitters that may modulate such behavior in mammals. Light microscopy immunocytochemistry with streptavidin method was used for the localization of the putative cells of defensive behavior with antibodies for endogenous opioids in rat brainstem. Midbrain structures showed positive neurons to beta-endorphin and Leu-enkephalin in similar distributions in the experimental animals, but we also noted the presence of varicose fibers positive to endogenous opioids in the PAG. Neuroanatomical techniques showed varicose fibers from the central nucleus of the inferior colliculus to ventral aspects of the PAG, at more caudal levels. Naloxonazine and nor-binaltorphimine, competitive antagonists that block mu(1)- and kappa-opioid receptors, were then used in the present work to investigate the involvement of opioid peptide neural system in the control of the fear-induced reactions evoked by electrical stimulation of the neural substrates of the inferior colliculus. The fear-like responses were measured by electrical stimulation of the central nucleus of the inferior colliculus, eliciting the escape behavior, which is characterized by vigorous running and jumping. Central administration of opioid antagonists (2.5 microg/0.2 microl and 5.0 microg/0.2 microl) was performed in non-anesthetized animals (Rattus norvegicus), and the behavioral manifestations of fear were registered after 10 min, 2 h, and 24 h of the pretreatment. Naloxonazine caused an increase of the defensive threshold, as compared to control, suggesting an antiaversive effect of the antagonism on mu(1)-opioid receptor. This finding was corroborated with central administration of nor-binaltorphimine, which also induced a decrease of the fear-like responses evoked by electrical stimulation of the inferior colliculus, since the threshold of the escape behavior was increased 2 and 24 h after the blockade of kappa-opioid receptor. These results indicate that endogenous opioids may be involved in the modulation of fear in the central nucleus of the inferior colliculus. Although the acute treatment (after 10 min) of both naloxonazine and nor-binaltorphimine causes nonspecific effect on opioid receptors, we must consider the involvement of mu(1)- and kappa-opioid receptors in the antiaversive influence of the opioidergic interneurons in the dorsal mesencephalon, at caudal level, after chronic (2-24 h) treatment of these opioid antagonists. The neuroanatomical study of the connections between the central nucleus of the inferior colliculus and the periaqueductal gray matter showed neuronal fibers with varicosities and with terminal bottons, both in the pericentral nucleus of the inferior colliculus and in ventral and dorsal parts of caudal aspects of the periaqueductal gray matter.
 ...
PMID:Neuroanatomical and neuropharmacological study of opioid pathways in the mesencephalic tectum: effect of mu(1)- and kappa-opioid receptor blockade on escape behavior induced by electrical stimulation of the inferior colliculus. 1462 57