Changes in the concentration of high-affinity oestradiol receptors in rat uterine supernatant preparations during the oestrous cycle, pseudopregnancy, pregnancy, maturation and after ovariectomy

A quantitative method was used to determine the concentration of high-affinity oestradiol-receptor sites in rat uterine supernatant preparations under various physiological conditions. Cyclic changes in concentration were observed during the oestrous cycle, with a maximum occurring in late dioestrus. The changes followed a similar pattern in endometrium and myometrium, although concentrations were higher in the former. In pseudopregnancy the concentration was initially low, rising to a maximum on the tenth day. In early pregnancy a high concentration of receptor was found to be associated with the developing placenta, but this declined in later stages of pregnancy. After ovariectomy or combined ovariectomy and adrenalectomy the receptor concentration remained at a constant low value that could be increased by treatment with oestradiol. The receptor concentration was considerably higher in immature than in adult uteri.

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THE MEASUREMENT OF HIGH-AFFINITY OESTRADIOL RECEPTORS IN HUMAN UTERINE ENDOMETRIUM AND MYOMETRIUM

Acta Endocrinologica ◽

10.1530/acta.0.0680534 ◽

1971 ◽

Vol 68 (3) ◽

pp. 534-542 ◽

Cited By ~ 22

Author(s):

D. M. Robertson ◽

J. Mešter ◽

J. Beilby ◽

S. J. Steele ◽

A. E. Kellie

Keyword(s):

Menstrual Cycle ◽

Normal Range ◽

Biopsy Material ◽

Uterine Endometrium ◽

High Affinity ◽

Biopsy Tissue ◽

Receptor Sites ◽

Receptor Concentration ◽

Human Uterine Endometrium

ABSTRACT The concentration of unoccupied high-affinity oestradiol receptors in the cytosol of human uterine endometrial curettings and biopsy tissue has been determined. In normal specimens, where the day of the menstrual cycle could be assessed histologically, a variation of tissue receptor concentration throughout the cycle was observed showing a maximum at mid-cycle and minima at the beginning and end of the cycle. The distribution of oestradiol receptor sites in the endometrium and myometrium along the length of the uterus has also been studied. Highest concentrations in the endometrium were found in the fundus and these levels fell progressively to negligible concentrations in the isthmus and cervix. In general, the concentration of receptor sites in biopsy material was lower than in curettings and this observation has been related on the region of the uterus from which the samples were obtained. The concentration of receptor sites in abnormal uterine specimens lay within the normal range.

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Parametric Images of the Extrastriatal D2 Receptor Density Obtained Using a High-Affinity Ligand (FLB 457) and a Double-Saturation Method

Journal of Cerebral Blood Flow & Metabolism ◽

10.1097/00004647-200112000-00014 ◽

2001 ◽

Vol 21 (12) ◽

pp. 1493-1503 ◽

Cited By ~ 9

Author(s):

Jacques Delforge ◽

Michel Bottlaender ◽

Christian Loc'h ◽

Frédéric Dolle ◽

André Syrota

Keyword(s):

Dopamine Receptors ◽

Quantitative Estimation ◽

Temporal Cortex ◽

D2 Receptor ◽

Experimental Protocol ◽

D2 Dopamine Receptors ◽

High Affinity ◽

Receptor Sites ◽

Receptor Concentration ◽

Saturation Method

The potential of positron emission tomography for the quantitative estimation of receptor concentration in extrastriatal regions has been limited in the past because of the low density of the D2 receptor sites in these regions and the insufficient affinity of the most widely used radioligands for dopamine receptors. The new method described in this paper permits the estimate of the D2 receptor concentration in the extrastriatal regions using a two-injection protocol and FLB 457, a ligand with a high affinity (20 pmol/L in vitro) with D2 dopamine receptors. This approach is not valid for the striatal regions because some hypotheses cannot be verified (because of the high receptor concentration in these regions). The experimental protocol includes two injections with ligand doses designed to significantly occupy the extrastriatal receptor sites (≈ 90%), while leaving less than 60% of the receptor sites occupied by the ligand in the striatal regions. The results obtained using this double-saturation method are in line with the concentration estimates previously obtained using the multiinjection approach. The receptor concentration is 2.9 ± 0.5 pmol/mL in the thalamus, 1.0 ± 0.2 pmol/mL in the temporal cortex, and 0.35 ± 0.13 pmol/mL in the occipital cortex. This study provides new arguments supporting the presence of a small receptor-site concentration in the cerebellum, estimated at 0.35 ± 0.16 pmol/mL The simplicity of the calculation used to estimate the receptor concentration lends itself easily to parametric imaging. The receptor concentration is estimated pixel by pixel, without filtering. This method permits estimation of the extrastriatal D2 receptor concentration using an experimental protocol that can easily be used in patient studies (i.e., single experiment, no blood sampling, short experiment duration).

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Determination of high-affinity oestrogen-receptor sites in uterine supernatant preparations

Biochemical Journal ◽

10.1042/bj1200831 ◽

1970 ◽

Vol 120 (4) ◽

pp. 831-836 ◽

Cited By ~ 85

Author(s):

J. Méšter ◽

D. M. Robertson ◽

Patricia Feherty ◽

A. E. Kellie

Keyword(s):

Dissociation Constant ◽

Oestrogen Receptor ◽

Scatchard Plot ◽

Assay Method ◽

Physiological Conditions ◽

High Affinity ◽

Receptor Sites ◽

Assay Procedure ◽

Order Of Magnitude

An assay method was developed for the determination of high-affinity oestradiol receptors in uterine supernatant preparations. When only high-affinity sites are present in such preparations, or when they predominate, the analysis of the equilibrium between oestradiol and receptor sites based on the Scatchard (1949) plot may be used to determine the dissociation constant of the equilibrium and the molar concentration of the high-affinity sites. When both high-affinity and low-affinity sites are present the Scatchard plot is no longer linear and cannot be used directly to determine high-affinity sites. Determination of the reverse velocity constants of the reaction between high-affinity (k−1) and low-affinity (k−2) receptor sites and [3H]oestradiol has shown that these constants differ by at least one order of magnitude. Advantage has been taken of this difference to introduce an additional step into the assay procedure that eliminates oestradiol bound to low-affinity sites and permits the determination of high-affinity sites in different species and under a variety of physiological conditions.

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The unoccupied nuclear oestradiol receptor in the rat uterus and hypothalamus during the oestrous cycle

Biochemical Journal ◽

10.1042/bj1940667 ◽

1981 ◽

Vol 194 (3) ◽

pp. 667-671 ◽

Cited By ~ 3

Author(s):

S Thrower ◽

C Neethling ◽

J O White ◽

L Lim

Keyword(s):

Nuclear Receptor ◽

Oestrogen Receptor ◽

Oestrous Cycle ◽

Oestrogen Receptors ◽

Rat Uterus ◽

Immature Rat ◽

High Affinity ◽

Receptor Component ◽

Cyclic Changes

The nuclear oestrogen receptor population in the rat uterus contained an unoccupied receptor component that bound oestradiol with the high affinity (Kd congruent to 0.5 nM) characteristic of oestrogen receptors. This unoccupied receptor was present at all phases of the oestrous cycle. Its content changed in parallel with that of the total nuclear receptor during the cycle. Oestradiol administration to the immature rat resulted in increases in the uterine content of long-term nuclear receptors (i.e., those still present 8 h after administration); these increases were due to occupied oestrogen receptors, since the content of unoccupied receptor was unchanged. Our previous experiments [White & Lim (1980) Biochem. J. 190, 833-837] have shown in contrast, that oestradiol administration results in an increase in the content of unoccupied nuclear receptor in the hypothalamus. However, as in the uterus, similar cyclic changes in the content of unoccupied nuclear receptor occurred in parallel with those of the total nuclear receptor population in the hypothalamus. Differences and similarities between the unoccupied nuclear receptor of the uterus and hypothalamus are briefly discussed.

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Nucleo-cytoplasmic relationships of oestrogen receptors in rat liver during the oestrous cycle and in response to administered natural and synthetic oestrogen

Biochemical Journal ◽

10.1042/bj1900017 ◽

1980 ◽

Vol 190 (1) ◽

pp. 17-25 ◽

Cited By ~ 34

Author(s):

W Marr ◽

J O White ◽

M G Elder ◽

L Lim

Keyword(s):

Nuclear Receptors ◽

Nuclear Receptor ◽

Rat Liver ◽

Fold Increase ◽

Oestrous Cycle ◽

Physiological Changes ◽

Oestrogen Receptors ◽

High Affinity ◽

Cyclic Changes ◽

Similar Affinity

Oestrogen receptors were measured in the cytosolic and purified nuclear fractions of rat liver. Both cytosolic and nuclear receptors bind oestrogen with high affinity (Kd = 1.47 and 2.28 nM respectively) and specificity similar to that of receptors in order oestrogen-target tissues such as the uterus. During the 4-day oestrous cycle the receptor content and distribution between cytosol and nucleus did not vary; in particular, the content of nuclear receptor did not appear to fluctuate in concert with known cyclic changes in the concentration of plasma oestrogen. Injection of 50 micrograms of oestradiol-17 beta or 10 micrograms of ethynyloestradiol resulted in a 4–6-fold increase in the nuclear receptor content, with a concomitant decrease in the unoccupied-receptor content of cytosol 1 h after injection. The nuclear receptors present after injection bind oestrogens with similar affinity (Kd = 2.78 nM) and specificity to receptors present in uninjected animals. The administration of lower doses of either oestrogen was less effective in producing increases in nuclear receptor content. Hence there is apparently substantial translocation of receptor to the nucleus in response to hyperphysiological doses of oestrogen, but not to the physiological changes in plasma oestrogen concentrations during the oestrous cycle. The response to exogenous oestrogens is discussed in relation to the clinical use of synthetic oestrogens and progestogens.

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Abiotic reduction of 2,4-dinitrotoluene in the presence of sulfide minerals under anoxic conditions

Water Science & Technology ◽

10.2166/wst.1996.0235 ◽

1996 ◽

Vol 34 (10) ◽

pp. 25-33 ◽

Cited By ~ 3

Author(s):

Cheng Jiayang ◽

Makram T. Suidan ◽

Albert D. Venosa

Keyword(s):

Electron Donor ◽

Chemical Reduction ◽

Sulfide Minerals ◽

Sulfide Concentration ◽

Magnesium Ions ◽

High Concentration ◽

Anoxic Conditions ◽

High Affinity ◽

Iron Nickel ◽

Abiotic Reduction

Abiotic reduction of 2,4-dinitrotoluene (DNT) in the presence of sulfide minerals has been investigated under anoxic conditions at 35°C. 2,4-DNT was abiotically reduced to 4-amino-2-nitrotoluene (4-A-2-NT) and 2-amino-4-nitrotoluene (2-A-4-NT) in the presence of high concentration of sulfide (0.84 mM). No abiotic reduction of 2,4-DNT was observed in the presence of low sulfide concentration (0.42 mM). The rate and the extent of the abiotic reduction of 2,4-DNT were increased with an increase in sulfide concentration. Sulfide served as an electron donor for the reduction of 2,4-DNT. The 2-nitro group was preferentially reduced, making the 2-A-4-NT:4-A-2-NT ratio in the final products 2:1. The addition of iron, nickel, and cobalt minerals significantly enhanced the abiotic reduction. The FeS, NiS, and CoS solids formed in the serum bottles catalyzed the reduction of 2,4-DNT preferentially to 4-A-2-NT. MnS and CuS solids also catalyzed the reduction of 2,4-DNT to 4-A-2-NT, but did not change the overall reduction of 2,4-DNT. However, the presence of calcium, zinc, and magnesium minerals impeded 2,4-DNT reduction. The calcium, zinc, and magnesium ions have a high affinity to sulfide, inactivating sulfide as an electron donor for the chemical reduction of 2,4-DNT.

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