Ageing and thymus-induced differential regulation of beta 1 and beta 2 adrenoceptors of mouse brain cortex.
Two questions have been addressed by the present paper, that is, the differential influence of age on beta 1 and beta 2 receptors and the thymus-induced recovery of such changes in receptor density and affinity have been assayed in brain cortex of Balb/c-nu mice of different ages. Results have shown a progressive decrease of beta 1 receptor density with advancing age, while no statistically significant changes were observed in beta 2 receptor density. Receptor affinity did not show any changes among the various groups examined. The influence of the thymus on receptor characteristics has been studied comparing young, old and thymus-grafted old mice. Total receptor density, which is decreased in old animals, can be up-regulated by thymus graft in old recipients. Interestingly, such a corrective effect is exerted only on the beta 1 population, the beta 2 receptor not being significantly affected. Thymic graft, therefore, acts just on the population which is found altered during ageing.
Viticchi
C
C
Department of Gerontologic Research, INRCA, Ancona, Italy.
Gentile
S
S
Piantanelli
L
L
D000375:Aging / Q000502:physiology*; D000818:Animals; D002540:Cerebral Cortex / Q000032:analysis*; D051379:Mice; D008807:Mice, Inbred BALB C; D011943:Receptors, Adrenergic, beta / Q000032:analysis / Q000502:physiology*; D013950:Thymus Gland / Q000378:metabolism / Q000502:physiology* / Q000637:transplantation
D011943:Receptors, Adrenergic, beta