Thymus-induced recovery of age-related decrease of brain cortex alpha- and beta-adrenoceptors.
It has previously been demonstrated that thymus exerts a regulatory influence on beta-adrenergic system during aging. In particular, it has been shown that thymus can correct the beta-adrenoceptor density decrease in old mice. In the present paper results of experiments are reported dealing with the influence of the thymus on alpha-adrenoceptors of mouse brain cortex. Both subtypes of alpha-adrenoceptors are studied separately, using different labelled ligands. Results show that alpha 1-adrenoceptor density decreases in old animals, while alpha 2-adrenoceptor density does not change significantly. A neonatal thymus grafted into old recipients is capable of correcting the alteration observed in old mice. The differential impairment of alpha-adrenoceptors resembles that one previously observed on beta-adrenoceptors, where beta 1-type decreases in number during aging with a parallel decrease of adenylyl-cyclase activity, while beta 2-type remains unchanged.
Rossolini
G
G
Centre of Biochemistry, Gerontol. Res. Department INRCA, Ancona, Italy.
Viticchi
C
C
Basso
A
A
Zaia
A
A
Piantanelli
L
L
D000262:Adenylyl Cyclases / Q000378:metabolism; D000375:Aging / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn / Q000502:physiology; D002540:Cerebral Cortex / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D003000:Clonidine; D004082:Dihydroalprenolol; D066298:In Vitro Techniques; D007700:Kinetics; D008566:Membranes / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D011217:Practolol; D011224:Prazosin; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects*; D011943:Receptors, Adrenergic, beta / Q000187:drug effects*; D013950:Thymus Gland / Q000637:transplantation*
D011942:Receptors, Adrenergic, alpha; D011943:Receptors, Adrenergic, beta; D004082:Dihydroalprenolol; D000262:Adenylyl Cyclases; D003000:Clonidine; D011217:Practolol; D011224:Prazosin