Estrogens normalize the hypothalamic-pituitary-adrenal axis response to stress and increase glucocorticoid receptor immunoreactivity in hippocampus of aging male rats
Aging is associated with a disturbance in the regulation of the hypothalamic-pituitary-adrenal axis (HPA) and reduced levels of glucocorticoid receptors (GR) in the hippocampus. To compensate for these effects, we have investigated whether estrogen therapy normalized the HPA response to stress and G...
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1999
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00283835_v69_n2_p129_Ferrini http://hdl.handle.net/20.500.12110/paper_00283835_v69_n2_p129_Ferrini |
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paper:paper_00283835_v69_n2_p129_Ferrini2023-06-08T14:55:03Z Estrogens normalize the hypothalamic-pituitary-adrenal axis response to stress and increase glucocorticoid receptor immunoreactivity in hippocampus of aging male rats Adrenal steroid receptors Adrenal steroids Aging Corticotropin Gonadal steroids Hippocampus Stress corticosterone estrogen glucocorticoid receptor aging Alzheimer disease animal experiment animal tissue article controlled study corticosterone blood level estrogen therapy feedback system hippocampus hypothalamus hypophysis adrenal system immunoreactivity male nonhuman priority journal rat stress subiculum Adrenal Glands Aging Animals Corticosterone Estradiol Ether, Ethyl Hippocampus Hypothalamus Kinetics Male Organ Size Pituitary Gland Rats Rats, Sprague-Dawley Receptors, Glucocorticoid Stress Aging is associated with a disturbance in the regulation of the hypothalamic-pituitary-adrenal axis (HPA) and reduced levels of glucocorticoid receptors (GR) in the hippocampus. To compensate for these effects, we have investigated whether estrogen therapy normalized the HPA response to stress and GR in hippocampus and paraventricular (PVN) nucleus. Young (3-4 months) and old (20 months) male Sprague-Dawley rats were bled by tail cut in the basal state and following ether stress. While basal and ether-stimulated levels of plasma corticosterone (CORT) were similar in the two groups, old animals presented a delayed termination of the response to ether stress. A dexamethasone inhibition test carried out in old animals, showed a failure to completely block plasma CORT after ether stimulation. Furthermore, in old rats GR-immunoreactive levels were reduced in CA1-CA2 hippocampal subfields and subiculum, while normal levels were obtained in CA3-CA4 and PVN. We observed that prolonged estrogen treatment (6 weeks) of old rats normalized the termination of the stress response, restored dexamethasone inhibition of plasma CORT, and increased GR immunoreactivity in CA1 and CA2 hippocampal subfields and subiculum. The results suggest that estrogen treatment enhanced the glucocorticoid feedback signal by increasing GR in hippocampus, and corrected the disturbances in HPA axis regulation. These animal experiments may be important to elucidate the effects of estrogenic on the hippocampal and HPA dysfunction associated with aging and Alzheimer's disease in humans. 1999 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00283835_v69_n2_p129_Ferrini http://hdl.handle.net/20.500.12110/paper_00283835_v69_n2_p129_Ferrini |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Adrenal steroid receptors Adrenal steroids Aging Corticotropin Gonadal steroids Hippocampus Stress corticosterone estrogen glucocorticoid receptor aging Alzheimer disease animal experiment animal tissue article controlled study corticosterone blood level estrogen therapy feedback system hippocampus hypothalamus hypophysis adrenal system immunoreactivity male nonhuman priority journal rat stress subiculum Adrenal Glands Aging Animals Corticosterone Estradiol Ether, Ethyl Hippocampus Hypothalamus Kinetics Male Organ Size Pituitary Gland Rats Rats, Sprague-Dawley Receptors, Glucocorticoid Stress |
| spellingShingle |
Adrenal steroid receptors Adrenal steroids Aging Corticotropin Gonadal steroids Hippocampus Stress corticosterone estrogen glucocorticoid receptor aging Alzheimer disease animal experiment animal tissue article controlled study corticosterone blood level estrogen therapy feedback system hippocampus hypothalamus hypophysis adrenal system immunoreactivity male nonhuman priority journal rat stress subiculum Adrenal Glands Aging Animals Corticosterone Estradiol Ether, Ethyl Hippocampus Hypothalamus Kinetics Male Organ Size Pituitary Gland Rats Rats, Sprague-Dawley Receptors, Glucocorticoid Stress Estrogens normalize the hypothalamic-pituitary-adrenal axis response to stress and increase glucocorticoid receptor immunoreactivity in hippocampus of aging male rats |
| topic_facet |
Adrenal steroid receptors Adrenal steroids Aging Corticotropin Gonadal steroids Hippocampus Stress corticosterone estrogen glucocorticoid receptor aging Alzheimer disease animal experiment animal tissue article controlled study corticosterone blood level estrogen therapy feedback system hippocampus hypothalamus hypophysis adrenal system immunoreactivity male nonhuman priority journal rat stress subiculum Adrenal Glands Aging Animals Corticosterone Estradiol Ether, Ethyl Hippocampus Hypothalamus Kinetics Male Organ Size Pituitary Gland Rats Rats, Sprague-Dawley Receptors, Glucocorticoid Stress |
| description |
Aging is associated with a disturbance in the regulation of the hypothalamic-pituitary-adrenal axis (HPA) and reduced levels of glucocorticoid receptors (GR) in the hippocampus. To compensate for these effects, we have investigated whether estrogen therapy normalized the HPA response to stress and GR in hippocampus and paraventricular (PVN) nucleus. Young (3-4 months) and old (20 months) male Sprague-Dawley rats were bled by tail cut in the basal state and following ether stress. While basal and ether-stimulated levels of plasma corticosterone (CORT) were similar in the two groups, old animals presented a delayed termination of the response to ether stress. A dexamethasone inhibition test carried out in old animals, showed a failure to completely block plasma CORT after ether stimulation. Furthermore, in old rats GR-immunoreactive levels were reduced in CA1-CA2 hippocampal subfields and subiculum, while normal levels were obtained in CA3-CA4 and PVN. We observed that prolonged estrogen treatment (6 weeks) of old rats normalized the termination of the stress response, restored dexamethasone inhibition of plasma CORT, and increased GR immunoreactivity in CA1 and CA2 hippocampal subfields and subiculum. The results suggest that estrogen treatment enhanced the glucocorticoid feedback signal by increasing GR in hippocampus, and corrected the disturbances in HPA axis regulation. These animal experiments may be important to elucidate the effects of estrogenic on the hippocampal and HPA dysfunction associated with aging and Alzheimer's disease in humans. |
| title |
Estrogens normalize the hypothalamic-pituitary-adrenal axis response to stress and increase glucocorticoid receptor immunoreactivity in hippocampus of aging male rats |
| title_short |
Estrogens normalize the hypothalamic-pituitary-adrenal axis response to stress and increase glucocorticoid receptor immunoreactivity in hippocampus of aging male rats |
| title_full |
Estrogens normalize the hypothalamic-pituitary-adrenal axis response to stress and increase glucocorticoid receptor immunoreactivity in hippocampus of aging male rats |
| title_fullStr |
Estrogens normalize the hypothalamic-pituitary-adrenal axis response to stress and increase glucocorticoid receptor immunoreactivity in hippocampus of aging male rats |
| title_full_unstemmed |
Estrogens normalize the hypothalamic-pituitary-adrenal axis response to stress and increase glucocorticoid receptor immunoreactivity in hippocampus of aging male rats |
| title_sort |
estrogens normalize the hypothalamic-pituitary-adrenal axis response to stress and increase glucocorticoid receptor immunoreactivity in hippocampus of aging male rats |
| publishDate |
1999 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00283835_v69_n2_p129_Ferrini http://hdl.handle.net/20.500.12110/paper_00283835_v69_n2_p129_Ferrini |
| _version_ |
1768544261600444416 |