Maximal densities of mu, delta, and kappa receptors are differentially altered by focal cerebral ischaemia in the mouse.
Though opioids are known to have neuroprotective properties, little information is available on the functional state of opioidergic receptors following focal cerebral ischaemia. The present study investigated the evolution of the Bmax and Kd for [3H]DAMGO, [3H]DADLE, and [3H]U69,593, respectively, for the mu, delta, and kappa opioidergic receptors after permanent focal cerebral ischaemia in mice. While the various Kd were unchanged, mu and delta Bmax values were precociously decreased in frontoparietal cortices, earlier than kappa receptors, reflecting infarct extension with time. The Bmax values for mu and delta receptors were also altered in non-infarcted tissues, such as tissues at risk (e.g., temporal auditory cortex) and exofocal (e.g., contralateral and non-infarcted) cortices. These results suggest that, in non-infarcted areas, the observed changes reflect functional modifications to focal ischaemia.
Boutin
H
H
Université de Caen, CNRS UMR 6551, Boulevard H. Becquerel, BP 5229, 14074 Caen Cedex, France. boutin@cyceron.fr
Jauzac
P
P
MacKenzie
E T
ET
Dauphin
F
F
D000818:Animals; D001345:Autoradiography; D001923:Brain Chemistry / Q000502:physiology*; D002545:Brain Ischemia / Q000378:metabolism*; D002536:Cerebral Arteries / Q000502:physiology; D002540:Cerebral Cortex / Q000378:metabolism; D002544:Cerebral Infarction / Q000378:metabolism; D007700:Kinetics; D051379:Mice; D008815:Mice, Inbred Strains; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism*; D017473:Receptors, Opioid, kappa / Q000378:metabolism*; D017450:Receptors, Opioid, mu / Q000378:metabolism*; D017480:Receptors, sigma / Q000378:metabolism*; D013238:Stereotaxic Techniques
D016760:Proto-Oncogene Proteins c-fos; D017473:Receptors, Opioid, kappa; D017450:Receptors, Opioid, mu; D017480:Receptors, sigma