TY - JOUR
T1 - Differential effects of aging on estrogen receptor dynamics in hypothalamus, pituitary and uterus of the C57BL/6J mouse
AU - Bergman, Mark D.
AU - Karelus, Katarzyna
AU - Felicio, Lêda S.
AU - Nelson, James F.
N1 - Funding Information:
*This work was supported by the Quebec Fonds Pour la Formation de Chercheurs et L’Aide a la Recherche (FCAR), and the Medical Research Council (MRC) of Canada. Preliminary reports of this work were presented at the 38th and 40th Annual Meetings of the Gerontolog-ical Society, New Orleans, Louisiana, November 1985; and Washington DC., November, 1987. tAddress correspondence to: Dr James F. Nelson, Depart-ment of OblGvn. Room F336. Roval Victoria Hospital. 687 Pine Ave-West, Montreal, Quebec, Canada H3A 1Al.
Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 1989/12
Y1 - 1989/12
N2 - Estrogen receptor (ER) dynamics and content were measured in the hypothalamus (HYPO), pituitary (PIT) and uterus (UT) of aging mice because of their potential importance to age-related changes in sensitivity to estrogen. Young (3-6 months), and old (22-24 months) C57BL/6J mice were injected with a dose of E2 (0.05 μg/10g body wt) sufficient to achieve maximal levels of nuclear ER (ERn) in all tissues, and the rise and fall of ERn and the depletion and replenishment of cytosolic ER (ERc) were measured 0, 1, 2, 4, 8, 12 and 24h later. Integrated areas under the ERn profiles in old HYPO, PIT and UT were reduced 34, 28 and 19%, respectively. These reductions were due to (1) lower levels of ERn throughout the profiles, (2) delays in attainment of peak ERn in UT and PIT, and (3) accelerated loss of peak ERn in HYPO. ERc levels were also reduced in old mice, and replenishment of ERc was delayed in old HYPO and PIT, but not in UT. Reductions in total ER (ERn + ERc) were sufficient to account for all reductions and altered dynamics of ERn, except for the delayed attainment of peak ERn in UT. These results indicate that levels and dynamics of nuclear ER are altered during aging, and that most of these changes are secondary to alterations in ER content and turnover rather than a reduced ability of ER to bind to nuclear sites.
AB - Estrogen receptor (ER) dynamics and content were measured in the hypothalamus (HYPO), pituitary (PIT) and uterus (UT) of aging mice because of their potential importance to age-related changes in sensitivity to estrogen. Young (3-6 months), and old (22-24 months) C57BL/6J mice were injected with a dose of E2 (0.05 μg/10g body wt) sufficient to achieve maximal levels of nuclear ER (ERn) in all tissues, and the rise and fall of ERn and the depletion and replenishment of cytosolic ER (ERc) were measured 0, 1, 2, 4, 8, 12 and 24h later. Integrated areas under the ERn profiles in old HYPO, PIT and UT were reduced 34, 28 and 19%, respectively. These reductions were due to (1) lower levels of ERn throughout the profiles, (2) delays in attainment of peak ERn in UT and PIT, and (3) accelerated loss of peak ERn in HYPO. ERc levels were also reduced in old mice, and replenishment of ERc was delayed in old HYPO and PIT, but not in UT. Reductions in total ER (ERn + ERc) were sufficient to account for all reductions and altered dynamics of ERn, except for the delayed attainment of peak ERn in UT. These results indicate that levels and dynamics of nuclear ER are altered during aging, and that most of these changes are secondary to alterations in ER content and turnover rather than a reduced ability of ER to bind to nuclear sites.
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U2 - 10.1016/0022-4731(89)90405-6
DO - 10.1016/0022-4731(89)90405-6
M3 - Article
C2 - 2615349
AN - SCOPUS:0024786917
SN - 0022-4731
VL - 33
SP - 1027
EP - 1033
JO - Journal of Steroid Biochemistry
JF - Journal of Steroid Biochemistry
IS - 6
ER -