TY - JOUR
T1 - Mechanism of estrogen action studies in the human
AU - Siiteri, P. K.
AU - Ashby, R.
AU - Schwarz, B.
AU - MacDonald, P. C.
N1 - Funding Information:
The authorsw ish to thankM r. B. Athey for his expertt echnicala ssistance. These studies were supportedb y the Robert A. Welch Foundation, Houston, Texas, and the American Cancer Society.
PY - 1972/4
Y1 - 1972/4
N2 - The interaction of both estradiol and estrone with human endometrial tissue obtained during the proliferative phase of the menstrual cycle has been examined by in vivo and in vitro techniques. Infusions of the tritium-labeled steroids resulted in tissue: plasma concentration gradients for both steroids, although the tissue levels of estrone were generally lower than those of estradiol. Little if any conversion of estrone to estradiol within the tissue was observed. Sucrose density gradient ultracentrifugal analysis of cytoplasmic and nuclear extracts following incubations with [3H]-estradiol revealed the presence of 8S and 4-5S receptors, respectively. While cytoplasmic binding of estrone was observed, transfer to the nucleus, although possible, was not proven. The human estrogen receptor system was found to be more labile than that of other species. Finally, evidence has been obtained which suggests that intranuclear conversion of estradiol to estrone may constitute a "release" mechanism for estradiol turnover in target cells.
AB - The interaction of both estradiol and estrone with human endometrial tissue obtained during the proliferative phase of the menstrual cycle has been examined by in vivo and in vitro techniques. Infusions of the tritium-labeled steroids resulted in tissue: plasma concentration gradients for both steroids, although the tissue levels of estrone were generally lower than those of estradiol. Little if any conversion of estrone to estradiol within the tissue was observed. Sucrose density gradient ultracentrifugal analysis of cytoplasmic and nuclear extracts following incubations with [3H]-estradiol revealed the presence of 8S and 4-5S receptors, respectively. While cytoplasmic binding of estrone was observed, transfer to the nucleus, although possible, was not proven. The human estrogen receptor system was found to be more labile than that of other species. Finally, evidence has been obtained which suggests that intranuclear conversion of estradiol to estrone may constitute a "release" mechanism for estradiol turnover in target cells.
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U2 - 10.1016/0022-4731(72)90092-1
DO - 10.1016/0022-4731(72)90092-1
M3 - Article
C2 - 4343487
AN - SCOPUS:0015330182
SN - 0022-4731
VL - 3
SP - 459
EP - 470
JO - Journal of Steroid Biochemistry
JF - Journal of Steroid Biochemistry
IS - 3
ER -