Elsevier

Brain Research

Volume 569, Issue 2, 13 January 1992, Pages 323-329
Brain Research

Age-related changes in the turnover rates of D1-dopamine receptors in the retina and in distinct areas of the rat brain

https://doi.org/10.1016/0006-8993(92)90646-QGet rights and content

Abstract

The steady-state density and the turnover rates of D1-dopamine receptors were investigated in the striatum, nucleus accumbens, substantia nigra, and retina of adult (3-month-old) and aged (23-month-old) rats. The turnover rates were measured by monitoring the repopulation kinetics of D1-dopamine receptors labeled with [3H]-SCH 23390 after the irreversible inactivation induced by a single dose of N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ, 10 mg/kg, s.c.). In all the neural tissues examined, the repopulation of D1 dopamine receptors could be adequately described by a theoretical model that assumes a constant rate of receptor production (i.e. zero order) and a rate of degradation that is dependent on the receptor density at any time (i.e. first order). The results obtained indicate that the reduction in the density of D1-dopamine receptors in the striatum, nucleus accumbens and substantia nigra of aged rats is the result of a larger decrease in the receptor production rate (−44 to −60%) than in the receptor degradation rate (−21 to −46%). By contrast, the production rate of D1-dopamine receptors in the retina of aged rats remains unchanged, whilst the degradation rate is reduced by 25%. This results in an age-related increase in the density of D1-dopamine receptors in the rat retina.

References (40)

Cited by (20)

  • Variations of dopamine, serotonin, and amino acid concentrations in Noda epileptic rat (NER) retina

    2006, Brain Research
    Citation Excerpt :

    In another hand, in controls as well in NERs, an increase in DA and DA metabolite levels was observed with age suggesting neither increased sensitivity nor particular vulnerability of NER due to the impact of aging itself. Available data of little studies about age-related changes in rat retina dopaminergic system describe an increase in D1-dopamine receptors density in aged rats (Giorgi et al., 1992; Riccardi et al., 1981) rather than DA metabolism. Furthermore, a functional deficit in the endogenous DA activity was described in the senile retina from 24 months old pigmented rats (Hankins, 2000).

View all citing articles on Scopus
View full text