Transfer of morphine along the olfactory pathway to the central nervous system after nasal administration to rodents
2005 (English)In: European Journal of Pharmaceutical Sciences, ISSN 0928-0987, E-ISSN 1879-0720, Vol. 24, no 5, 565-573 p.Article in journal (Refereed) Published
The aim of this study was to investigate whether morphine can be transferred along the olfactory pathway to the CNS, thereby circumventingthe blood–brain barrier, after nasal administration to rodents. Radiolabelled and unlabelled morphine were administered via the right nostrilto mice and rats. Olfactory bulbs, brain tissue and blood samples were collected. Morphine-derived radioactivity was measured using liquidscintillation (LS) and the concentrations of morphine and its metabolite morphine-3-glucuronide (M3G) were also assessed with highperformanceliquid chromatography. The location of morphine-derived radioactivity in the rat brain was visualised by autoradiography.Overall, the levels of morphine in the right olfactory bulbs (ROBs) significantly exceeded those in the left olfactory bulbs (LOBs) and braintissue samples 15, 60 and 240 min after right-sided nasal administration. Fifteen minutes after intravenous administration, there were nosignificant differences between olfactory bulbs and the other brain areas. Five minutes after nasal administration, autoradiography revealedradioactivity surrounding the ROB and reaching one of the ventricles in the brain. After 60 min, radioactivity had reached the peripheral partsof the ROB. All the techniques used in this study demonstrate that morphine was transferred along the olfactory pathway to the CNS afternasal administration to rodents.
Place, publisher, year, edition, pages
2005. Vol. 24, no 5, 565-573 p.
Olfactory pathway, Nasal drug delivery, Autoradiography, Morphine, Rats
IdentifiersURN: urn:nbn:se:uu:diva-95787DOI: 10.1016/j.ejps.2005.01.009ISI: 000228318300017PubMedID: 15784346OAI: oai:DiVA.org:uu-95787DiVA: diva2:170127