Desipramine treatment differently down-regulates beta-adrenoceptors of freshly isolated neurons and astrocytes.

R Sapena, D Morin, R Zini, C Morin, J P Tillement

Département de Pharmacologie, Faculté de Médecine de Paris XII, Créteil, France.

European journal of pharmacology 1996 Apr 4

filter terms:

Eight days' desipramine administration (16 mg/kg per day i.p.) to rats resulted in a significant decrease in the density of beta-adrenoceptors in neuronal and astroglial cells from rat forebrain and cerebellum without modification of their corresponding affinity. beta-Adrenoceptor subtypes, beta 1 and beta 2, which coexist in neurons and astrocytes, are differently distributed in the brain and differently modified by desipramine administration which down-regulates beta 1-adrenoceptor in forebrain neurons and astrocytes and beta 2-adrenoceptor in cerebellum neurons. This down-regulation affects the predominant subtype, beta 1 or beta 2, of the relevant structure. Astroglial and neuronal beta-adrenoceptors are differently coupled to G-proteins. Only neuronal cells contain the high-affinity conformational state of the beta-adrenoceptors which is sensitive to GTP. The percentage of neuronal receptors in the high-affinity state differs according to brain area. Desipramine treatment decreases the neuronal density of both cerebellar high- and low-affinity sites and only the forebrain high-affinity site. The desipramine effects are thus subtype-dependent and differ between the two brain areas selected.

Citation

R Sapena, D Morin, R Zini, C Morin, J P Tillement. Desipramine treatment differently down-regulates beta-adrenoceptors of freshly isolated neurons and astrocytes. European journal of pharmacology. 1996 Apr 4;300(1-2):159-62