Down regulation of dihydroalprenolol and imipramine binding sites in brain of rats repeatedly treated with imipramine.
In rats receiving repeated injections of imipramine, there is a reduction in the number of high affinity binding sites for [3H]imipramine and [3H]dihydroalprenolol present in crude synaptic membrane preparations from various brain structures. The location of the sites that become subsensitive to the two ligands did not coincide; the binding sites to [3H]imipramine became subsensitive in the hippocampus but not in cortex or cerebellum. In contrast the binding sites to [3H]dihydroalprenolol became subsensitive in cortex and cerebellum but not in hippocampus. It can be suggested that in rats repeatedly treated with imipramine the down regulation of beta-adrenergic receptors may not coincide with the down regulation of the high affinity binding sites for imipramine. Such a dissociation is supported further by experiments with rats treated with iprinidol.
D000526:Alprenolol / Q000031:analogs & derivatives*; D000818:Animals; D001665:Binding Sites; D001921:Brain / Q000378:metabolism*; D004082:Dihydroalprenolol / Q000378:metabolism*; D007099:Imipramine / Q000378:metabolism / Q000494:pharmacology*; D066298:In Vitro Techniques; D007488:Iprindole / Q000494:pharmacology; D051381:Rats; D011941:Receptors, Adrenergic / Q000187:drug effects*; D011943:Receptors, Adrenergic, beta / Q000187:drug effects*
D011941:Receptors, Adrenergic; D011943:Receptors, Adrenergic, beta; D004082:Dihydroalprenolol; D007488:Iprindole; D000526:Alprenolol; D007099:Imipramine