Estradiol Regulation ofα1b-Adrenoceptor mRNA in Female Rat Hypothalamus-Preoptic Area
| Autor: | George B. Karkanias, Michael A. Ansonoff, Anne M. Etgen |
|---|---|
| Rok vydání: | 1996 |
| Předmět: |
medicine.medical_specialty
medicine.drug_class Ovariectomy Endocrinology Diabetes and Metabolism Hypothalamus Estrogen receptor Alpha (ethology) Biology Polymerase Chain Reaction Rats Sprague-Dawley Cellular and Molecular Neuroscience chemistry.chemical_compound Endocrinology Internal medicine medicine Animals RNA Messenger Receptor DNA Primers Estradiol Endocrine and Autonomic Systems RNA-Directed DNA Polymerase Receptors Adrenergic alpha Preoptic Area Rats Preoptic area Gene Expression Regulation chemistry Estrogen Estradiol benzoate Ovariectomized rat Female hormones hormone substitutes and hormone antagonists |
| Zdroj: | Journal of Neuroendocrinology. 8:449-455 |
| ISSN: | 0953-8194 |
| DOI: | 10.1046/j.1365-2826.1996.04716.x |
| Popis: | Estradiol treatment for 48 h increases the density of alpha 1B-adrenoceptors in the hypothalamus-preoptic area of ovariectomized female rats by five- to six-fold. Present studies tested the hypothesis that estradiol elevation of hypothalamus-preoptic area alpha 1B-adrenoceptor density is correlated with increased levels of mRNA for this receptor. We developed a semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) protocol for measuring brain alpha 1b-adrenoceptor mRNA. The primers chosen yielded the predicted 409 base pair PCR product when used to amplify authentic alpha 1b-adrenoceptor cDNA. The identity of the RT-PCR products from rat brain was confirmed by restriction digest analysis and sequencing. Moreover, there was a good correlation between the levels of alpha 1b-adrenoceptor mRNA measured by RT-PCR in liver, whole brain and cerebellum with previous measurements using Northern blots and RNAse protection assays. We then performed RT-PCR on total RNA from hypothalamic-preoptic area tissue taken from ovariectomized control rats and from ovariectomized rats injected once or twice with 2 micrograms of estradiol benzoate at 24 or 24 and 48 h before sacrifice. Exposure to estradiol for either 24 or 48 h significantly increased levels of alpha 1b-adrenoceptor mRNA by 86-110% in the hypothalamus-preoptic area of ovariectomized female rats when compared to oil-treated controls. We also examined whether estradiol regulates alpha 1b-adrenoceptor mRNA in the cortex. Cortical alpha 1b-adrenoceptor mRNA levels were reduced to approximately 20% of control levels when measured 24 h after hormone injection. A similar decrease in cortical alpha 1b-adrenoceptor mRNA was observed 48 h after estrogen administration. In summary, estradiol treatment significantly increases the level of alpha 1b-adrenoceptor mRNA in the hypothalamus-preoptic area, a brain region involved in the control of reproductive function. In the cortex, a brain region with relatively few estrogen receptors, the same estrogen treatment reduces alpha 1b-adrenoceptor mRNA levels. |
| Databáze: | OpenAIRE |
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