Receptors for clonidine in brain: insights into therapeutic actions.
Clonidine acts at specific receptor sites in the brain. These sites, i.e. adrenergic receptors, can be localized in the brain at the light-microscopic level by utilizing autoradiographic techniques. Autoradiographic studies revealed a striking differential distribution throughout the brain. These results provide an anatomical basis for understanding the actions of clonidine in the CNS. For example, the finding of high densities of alpha-2-receptors in the nucleus tractus solitarius and in the dorsal motor nucleus of the vagus is very likely related to its antihypertensive action. Also, the striking codistribution of alpha-2 receptors with opiate receptors in some areas could provide an explanation for the observation that alpha-2 drugs block opiate withdrawal.
D000818:Animals; D001345:Autoradiography; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D003000:Clonidine / Q000378:metabolism / Q000627:therapeutic use*; D006801:Humans; D007031:Hypothalamus / Q000378:metabolism; D054755:Imidazoline Receptors; D008526:Medulla Oblongata / Q000378:metabolism; D009434:Neural Pathways / Q000378:metabolism; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects / Q000378:metabolism; D018341:Receptors, Adrenergic, alpha-2
D054755:Imidazoline Receptors; D011942:Receptors, Adrenergic, alpha; D018341:Receptors, Adrenergic, alpha-2; D003000:Clonidine