RESUMEN
To investigate the significance of endogenous, neuroleptic-like gamma-type endorphins and their putative receptors, polyclonal and monoclonal antibodies against gamma-type endorphins, which may bio-inactivate the ligands for the receptors, and monoclonal anti-idiotype antibodies, which presumably bind to the receptors, were injected into the nucleus accumbens of the rat brain. The desenkephalin-gamma-endorphin-induced antagonism of the hypomotility response elicited by challenge with apomorphine injected into the nucleus accumbens was used as test system. Both the anti-desenkephalin-gamma-endorphin antibodies and anti-idiotype antibodies blocked the action of exogenous desenkephalin-gamma-endorphin. Thus, the anti-idiotype antibodies may serve as receptor antagonists. Chronic treatment (injection into the nucleus accumbens) with the anti-idiotype antibodies induced sustained hypermotility, decreased habituation and impaired passive avoidance behavior. In such treated animals local treatment with apomorphine did not elicit hypomotility. It is suggested that gamma-type endorphins influence the setpoint for feedback regulation in dopaminergic neurons equipped with gamma-type endorphin receptor systems.
Asunto(s)
Anticuerpos Monoclonales/farmacología , Conducta Animal/efectos de los fármacos , Receptores Opioides/efectos de los fármacos , gamma-Endorfina/inmunología , Animales , Apomorfina/farmacología , Reacción de Prevención/efectos de los fármacos , Agonistas de Dopamina/farmacología , Retroalimentación/fisiología , Habituación Psicofisiológica/efectos de los fármacos , Masculino , Actividad Motora/efectos de los fármacos , Oxitocina/inmunología , Ratas , Ratas Wistar , Receptores Dopaminérgicos/efectos de los fármacos , Receptores Opioides/inmunologíaRESUMEN
An in vitro autoradiographic study was performed to characterize specific rat brain binding sites for non-opioid neuroleptic-like gamma-type endorphins, using [35S]Met-des-enkephalin-gamma-endorphin ([35S]Met-DE gamma E; [35]S-beta-endorphins(5-17)) with high specific activity as radioligand. The binding sites appeared to be confined to rat forebrain regions, e.g., orbital cortex, frontal cortex, cingulate cortex, piriform cortex, nucleus accumbens, amygdala, mediodorsal nucleus of the thalamus and arcuate and periventricular nuclei of the hypothalamus. These regions are part of the mesocorticolimbic feedback circuit. Densitometric analysis of the autoradiographs revealed that the density of the binding sites was highest in the mediodorsal nucleus of the thalamus and the amygdala. Concentration-dependent displacement of [35S]Met-DE gamma E (500 pM) with DE gamma E yielded an IC50 of 0.6 nM whereas DE alpha E (beta-endorphin(6-16)) had an IC50 of 210 nM. Various endorphins, sharing the gamma-endorphin C terminus, displaced [35S]Met-DE gamma E to the same extent as non-labelled DE gamma E (at 10(-6) M) whereas non-endorphin peptides did not show displacing capacity. Possible relationships of the binding sites with opioid receptors were investigated. DAMGO (mu) and DPDPE (delta) displaced [35S]Met-DE gamma E to some extent at 10(-6) M whereas U69,593 (kappa) was inactive, suggesting that the binding sites for gamma-type endorphins may resemble mu- and delta-opioid receptors in some aspects. Similarly, relationships with dopamine receptors were investigated. Haloperidol partially displaced [35S]Met-DE gamma E whereas sulpiride, SKF38,393 and 3-PPP at 10(-6) M did not induce significant displacement. Thus, binding sites are distinct from dopamine receptors.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Encéfalo/metabolismo , Endorfinas/metabolismo , Receptores Opioides/metabolismo , betaendorfina , Amígdala del Cerebelo/metabolismo , Animales , Anticuerpos Monoclonales , Autorradiografía , Unión Competitiva , Cromatografía Líquida de Alta Presión , Densitometría , Masculino , Ratas , Ratas Wistar , Receptores Dopaminérgicos/metabolismo , Relación Estructura-Actividad , Radioisótopos de Azufre , betaendorfina/inmunologíaRESUMEN
The transferrin receptor is encoded by a diallelic locus which had been described as the T-cell antigenic system TCA. Using a human lymphoblastoid T-cell line (HSB) which reportedly carries a transferrin receptor and which we showed to be TCA-2 positive by serology, it appeared that only a TCA-2 but not a TCA-1 specific alloantiserum had the capacity to precipitate a protein with a molecular weight of 94,000, which comigrated exactly with the Mr 94,000 protein precipitated by the rabbit anti-HSB and rabbit anti-SB antisera, as well as the transferrin receptor which was precipitated by a transferrin-antitransferrin complex. The positive sera and the latter complex were shown to cross-react in a binding assay. Conversely, a monospecific TCA-1 alloantiserum was shown to react with the Mr 94,000 protein of TCA-1-positive leukocyte suspensions. The allelomorphism of the transferrin receptor may be relevant for the eventual regulatory mechanism controlling cell proliferation, which would be essential at least for those cells that are supposed to play an immunological role like the TCA-positive cells which are described as T-cells probably involved in the process of immunosuppression. In addition, we found increasing amounts of autoantibodies with TCA-1 specificity in serum from a healthy individual (referred to as "donor" in this paper), whose brother at the same time suffered a chronic myeloid leukemia, probably associated with a retrovirus, and whose blood in contrast was shown to contain cytotoxic anti-TCB, from a diallelic locus expressed on theophylline-insensitive T-cells, and anti-B-cell activity.
Asunto(s)
Antígenos de Neoplasias/análisis , Enfermedades en Gemelos , Isoantígenos/análisis , Leucemia Mieloide/inmunología , Receptores de Superficie Celular/análisis , Linfocitos T/inmunología , Transferrina/análisis , Gemelos Monocigóticos , Gemelos , Adulto , Citotoxicidad Celular Dependiente de Anticuerpos , Trasplante de Médula Ósea , Línea Celular , Femenino , Antígenos HLA/análisis , Humanos , Células Asesinas Naturales/inmunología , Leucemia Linfoide/inmunología , Masculino , Peso Molecular , Embarazo , Receptores de TransferrinaRESUMEN
We studied a patient with a Philadelphia chromosome-positive chronic myeloid leukemia, who died in relapse after multiple transfusions and grafting with bone marrow from his monozygotic twin brother (referred to as "donor" in this paper). We present data indicating that this patient may have had a retro-virus infection that this virus is related to the group of exogenous primate type C retroviruses. Antibodies to simian sarcoma virus (SSV) M.W. 30,000 protein (p30) but not endogenous feline virus RD-114 could be found in patient but not donor serum. Patient but not donor cells were able to actively synthesize a p30 protein that could be precipitated with patient serum and rabbit anti-SSV p30 but not with donor serum or rabbit anti-RD 114 p30. Patient p30 resembles SSV p30 but not RD-114 p30 in peptide mapping by limited proteolysis and subsequent slab gel electrophoresis. Patient but not donor cells were able to actively synthesize a M.W. 78,000 protein that could be precipitated with goat anti-SSV. An enzyme with properties of reverse transcriptase was increased 30-fold ion patient cells when compared with donor and other control cells. Related to the presence of widespread infectious agents may be the finding that, in the course of the patient's disease, donor serum showed increasing amounts of possibly immunoregulatory (Cancer Research, submitted for publication) antibodies, reactive with autologous and, more effectively, with patient-derived cell membrane M. W. 80,000 protein (a possible idiotypic receptor structure) and M.W. 94,000 protein (a T-cell alloantigen).