Abstract
High affinity [ 3H]ryanodine binding sites were characterized in P1 (crude nuclear), P2 (mitochondrial/synaptosomal) and P3 (microsomal) subcellular fractions of rat brain. Binding in each of the fractions was highest at 37°C and pH 8–9, optimal in the presence of 100 μM Ca 2+, 550 μM ATP and 1.0 M KCl, and increased linearly as a function of protein. Saturation analyses revealed a single class of binding sites with mean K D values (nM) of 8.9, 1.6 and 5.7 and B max values (fmol/mg protein) of 122, 69 and 106 for the P1, P2 and P3 fractions, respectively. The levels of [ 3H]ryanodine binding in P1 and P2 fractions of 4 brain regions were fairly uniform while those in P3 fractions were 5-fold greater in cerebral cortex than in the other areas examined. By autoradiography, a high concentration of [ 3H]ryanodine binding sites was seen in the dentate gyrus and CA3 subregions of the hippocampus. The results suggest that [ 3H]ryanodine binding sites, perhaps similar to [ 3H]ryanodine receptors in muscle, are associated with various subcellular structures and are heterogeneously distributed in the CNS.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
