Elsevier

Neuroscience

Volume 81, Issue 3, 26 September 1997, Pages 593-597
Neuroscience

Letter to Neuroscience
Estradiol reduction of α2-adrenoceptor binding in female rat cortex is correlated with decreases in α2A/D-adrenoceptor messenger RNA

https://doi.org/10.1016/S0306-4522(97)00359-XGet rights and content

Abstract

We developed a quantitative RNAse protection assay for α2A/D-adrenoceptor messenger RNA in rats to test the hypothesis that decreases in cortical α2-adrenoceptor binding observed following estrogen treatment of ovariectomized rats correlate with reduced levels of messenger RNA encoding the predominant α2-adrenoceptor subtype expressed in cortex. Estradiol treatment for 48 h reduced cortical α2A/D-adrenoceptor messenger RNA by approximately 50% when compared to ovariectomized, oil-treated control animals. Estradiol down-regulation of α2A/D-adrenoceptor messenger RNA was accompanied by a significant decrease in cortical α2-adrenoceptor density, as measured by 3H-RX821002 binding. Estrogen treatment did not alter α2A/D-adrenoceptor messenger RNA or α2-adrenoceptor binding in female rat hypothalamus–preoptic area.

This study provides the first evidence that estradiol regulates expression of postsynaptic α2-adrenoceptors in female rat frontal cortex, suggesting a possible molecular substrate for hormonal modulation of cognitive function.

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Acknowledgements

This work was supported by Grants HD29856, MH41414 and RSDA MH00636 to AME, by American Diabetes Association and Goldsmith Foundation Grant to GBK and by the Department of Neuroscience, Albert Einstein College of Medicine. The authors acknowledge the generous contribution of RG20 cDNA by Dr Stephen M. Lanier. We also express our thanks to Dr Margaret J. Lin for sequencing the RG20 PCR product.

References (28)

  • A.F.T Arnsten et al.

    α2-Adrenergic mechanisms in prefrontal cortex associated with cognitive decline in aged nonhuman primates

    Science

    (1985)
  • D.B Bylund

    Subtypes of α1- and α2-adrenergic receptors

    Fedn Proc. Fedn Am. Socs exp. Biol.

    (1992)
  • Corcoran M. E. and Weiss G. K. (1990) Noradrenaline and kindling revisited. In Kindling 4 (ed. Wada J. A.), pp....
  • J.T Coull

    Pharmacological manipulations of the alpha 2-noradrenergic system. Effects on cognition

    Drugs Aging

    (1994)
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