RESUMEN
The importance of the opioid receptor system in substance dependence is increasingly recognised. We used PET with the non-selective tracer [11C]diprenorphine to examine opioid receptor binding in early abstinence from alcohol dependence and the relationship to craving. We recruited 11 alcohol dependent patients and 13 controls. Subjects underwent one [11C]diprenorphine PET scan in early abstinence from dependent alcohol use (approximately 2 weeks) and 2 months later if continuously abstinent. Global and regional [11C]diprenorphine volumes of distribution (VD) were increased in alcohol dependent patients compared with controls but did not reach significance. We demonstrated a correlation between global and regional [11C]diprenorphine VD and craving in alcohol dependent patients which persisted in the anterior cingulate cortex into extended abstinence. This confirms previous work showing increased opioid receptor availability in early abstinence from substances of abuse and correlation with craving suggesting that the opioid system plays a fundamental role in this phase of addiction.
Asunto(s)
Alcoholismo/metabolismo , Conducta Adictiva/metabolismo , Encéfalo/metabolismo , Diprenorfina/análisis , Tomografía de Emisión de Positrones/métodos , Receptores Opioides/metabolismo , Adulto , Alcoholismo/diagnóstico por imagen , Alcoholismo/psicología , Conducta Adictiva/diagnóstico por imagen , Encéfalo/diagnóstico por imagen , Isótopos de Carbono/análisis , Estudios de Casos y Controles , Humanos , Masculino , Persona de Mediana Edad , Antagonistas de Narcóticos/análisis , Ensayo de Unión Radioligante/métodos , Síndrome de Abstinencia a Sustancias/metabolismoRESUMEN
An autoradiographic technique is reported for the in vivo localization in the Syrian hamster of small doses of the opiate antagonist, 3H-diprenorphine. The regional distribution in the hamster brain was similar to that reported in the rat. The adrenal medulla showed a high degree of localization providing supportive evidence for the presence of opiate receptors in the medulla and a possible paracrine function for opioid peptides in this site. Other peripheral sites showed selective uptake of 3H-diprenorphine which was not apparently related to the vascularity of the tissue.
Asunto(s)
Médula Suprarrenal/análisis , Química Encefálica , Diprenorfina/análisis , Morfinanos/análisis , Corteza Suprarrenal/análisis , Animales , Autorradiografía , Cricetinae , Mesocricetus , Páncreas/análisis , Ratas , Receptores Opioides/fisiología , Glándula Submandibular/análisisRESUMEN
It is possible to localize opiate receptors by histochemical methods. They appear in high densities in anatomical areas associated with physiologic functions altered by opiates. They appear to mediate inhibitory responses; some of them, in certain regions could be involved in axo-axonic synapses. The immunohistochemical studies as well as the electrophysiologic results are compatible with the view that the enkephalins are the endogenous substrates for the opiate receptors.