Summary
Prazosin is know to block postsynaptic α-adrenoceptors. In this study 3H-prazosin has been used to label biochemically central α-adrenoceptors. In rat brain membranes 3H-prazosin bound specifically in a rapid, reversible and saturable manner to a single class of high affinity sites. The relative order of potencies for inhibition of 3H-prazosin binding was WB4101 > ARC 239 > phentolamine ≫ piperoxane > yohimbine which is a characteristic of the α1 type of adrenoceptors. In contrast, the relative order of potencies for inhibition of 3H-clonidine binding was yohimbine > piperoxane > WB4101 > ARC239 > prazosin which is a characteristic of the peripheral ‘α1’-and ‘α1’-adrenoceptors.
These results indicate that 3H-prazosin binds to central ‘α1’ and 3H-clonidine to ‘α’2-receptor and confirm the presence of two classes of α-adrenoceptors in rat brain membranes.
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Miach, P.J., Dausse, JP., Cardot, A. et al. 3H-prazosin binds specifically to ‘α1’-Adrenoceptors in rat brain. Naunyn-Schmiedeberg's Arch. Pharmacol. 312, 23–26 (1980). https://doi.org/10.1007/BF00502569
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DOI: https://doi.org/10.1007/BF00502569