scholarly journals Changes in the patterns of synthesis of ribonucleic acid species in immature rat uterus in response to oestradiol-17β

1969 ◽  
Vol 112 (5) ◽  
pp. 563-569 ◽  
Author(s):  
R J Billing ◽  
B Barbiroli ◽  
R. M. S. Smellie
Keyword(s):  
Ribosomal Rna ◽  
Hormone Treatment ◽  
Transfer Rna ◽  
Time Intervals ◽  
Rat Uterus ◽  
Immature Rat ◽  
Oestradiol Treatment ◽  
Wet Weight ◽  
Major Increase ◽  
Rna And Dna

1. After treatment of immature rats with diethylstilboestrol, the wet weight and RNA content of uterine tissue increased rapidly, reaching a peak at 40hr. After an initial lag of a few hours, the acid-soluble ribose and protein contents also rose to maxima at 40hr. No increase in DNA content occurred until at least 24hr. after treatment. 2. The RNA from immature rat uterus isolated at various times up to 6hr. after administration of oestradiol-17β was labelled by injecting [3H]uridine and [3H]guanosine intraperitoneally 30min. before the animals were killed. It was fractionated on columns of kieselguhr coated with methylated serum albumin and the radioactivity in fractions corresponding to transfer RNA, 7s RNA, ribosomal RNA, Q1-RNA, Q2-RNA and DNA-like RNA was determined. 3. The radioactivity of the whole RNA increased steadily for 6hr. after hormone treatment. The earliest changes occurred in the Q1-RNA (ribosomal RNA precursor), whereas at longer time-intervals the radioactivity of the ribosomal RNA, 7s RNA and transfer RNA increased by four- to five-fold. The radioactivity of the DNA-like RNA increased by about 50%, but only at the longer time-intervals. 4. It is concluded that one of the earliest changes in response to oestradiol treatment is a major increase in synthesis of ribosomal RNA followed later by a similar increase in synthesis of transfer RNA and by a much smaller increase in synthesis of DNA-like RNA. The change in synthesis of ribosomal RNA in immature rat uterus may represent one of the most important responses to oestradiol treatment.

Estrogen–androgeri interaction: selective inhibition of estrogen-induced uterine peroxidase by testosterone and 5α-dihydrotestosterone

1983 ◽  
Vol 61 (7) ◽  
pp. 779-783 ◽  
Author(s):  
Peter H. Jellinck ◽  
Andrew Affleck ◽  
Anne-Marie Newcombe
Keyword(s):  
Estrogen Receptor ◽  
Low Dose ◽  
Combined Treatment ◽  
Selective Inhibition ◽  
Time Intervals ◽  
Rat Uterus ◽  
Immature Rat ◽  
Uterine Growth ◽  
Nuclear Estrogen Receptor ◽  
Glucose 6 Phosphate Dehydrogenase

The effect of testosterone (T) and dihydrotestosterone (DHT) on the induction of peroxidase and glucose-6-phosphate dehydrogenase (G6PDH) in the immature rat uterus by estradiol (E2) was investigated. T (0.5–12.5 mg/rat) given on 3 successive days produced a large increase in uterine weight but, in contrast to E2, did not induce peroxidase or significantly augment uterine G6PDH. However, this androgen, even at a very low dose (50 μg/rat three times), inhibited the induction of peroxidase without a corresponding effect on G6PDH when given concurrently with E2 and was more effective than DHT. Inhibition by androgen was also observed when diethylstilbestrol was used to stimulate uterine growth. Combined treatment with E2 (3 μg/rat) and T (3 mg/rat) produced a cytosolic and nuclear estrogen receptor pattern in the uterus similar to that observed with E2 alone after various time intervals. The results speak against a direct inhibitory action or T on E2-induced uterine peroxidase via the estrogen receptor and confirm the lack of aromatization of T to E2 in the immature rat. Possible mechanisms for modifying the action of estrogens by androgens are discussed, particularly in the light of E2-induced eosinophilia. It is proposed that steroid hormones can interact in several ways and that uterine peroxidase provides a useful indicator to study steroid hormone action.

scholarly journals The synthesis of ribonucleic acid in immature rat uterus responding to oestradiol-17β

1971 ◽  
Vol 125 (2) ◽  
pp. 605-614 ◽  
Author(s):  
J. T. Knowler ◽  
R. M. S. Smellie
Keyword(s):  
Rna Synthesis ◽  
Actinomycin D ◽  
Soluble Fraction ◽  
Rat Uterus ◽  
Immature Rat ◽  
Radioactive Precursor ◽  
Major Increase ◽  
Very High ◽  
Time Of Administration ◽  
Stimulation Of

Stimulation of incorporation of labelled precursors into the RNA of immature rat uterus is an early result of oestradiol-17β action. However, the extent of the increased incorporation varies with the mode of administration of the labelled precursors and with the weight of the rat. At the age and weight range normally used response is maximal at ten times control incorporation, 4h after the administration of 0.3μg or more of oestradiol-17β. Under these conditions the stimulation of incorporation into the acid-soluble fraction is only 2–2.5-fold. When the purified RNA is separated on polyacrylamide gels the major increase in incorporation of radioactive precursor is found in rRNA and 4S RNA; the formation of the former has been followed from the 45S precursor. Preceding these events by at least 30min, however, is an increase in the incorporation of precursor into RNA species of very high molecular weight, which remained in the first few slices of the gel. The possible significance of these findings is discussed. The increased synthesis of rRNA in response to oestradiol-17β is more strongly inhibited by actinomycin D than the synthesis of other RNA species. Cycloheximide, depending on time of administration and dosage, inhibits either RNA synthesis or the maturation of rRNA.

EFFECT OF EQUOL ON OESTROGEN RECEPTORS AND ON SYNTHESIS OF DNA AND PROTEIN IN THE IMMATURE RAT UTERUS

1980 ◽  
Vol 85 (2) ◽  
pp. 291-297 ◽  
Author(s):  
B. Y. TANG ◽  
N. R. ADAMS
Keyword(s):  
Subcutaneous Injection ◽  
Female Rats ◽  
Receptor Complex ◽  
Oestrogen Receptors ◽  
Rat Uterus ◽  
Immature Rat ◽  
Nuclear Binding ◽  
Uterine Growth ◽  
Wet Weight

In immature, 3-week-old female rats, 5 mg equol given by subcutaneous injection increased uterine wet weight 24 h later to the same degree as did 5 μg oestradiol-17β. At this dose there was more receptor complex binding to the nucleus in the equol-injected rats than in the rats injected with oestradiol-17β even after 6 h. However, the equol–receptor complex that bound to the nucleus was more extractable with 0·3 m-KC1. In the equol-injected rats the duration of uterine growth was shorter and there was less receptor replenishment and synthesis of protein and DNA than in the rats injected with oestradiol-17β 30 h after either injection. It was concluded that equol is a weakly oestrogenic compound which is antagonistic to oestradiol-17β by competing with oestradiol–receptor complex for nuclear binding and yet fails to initiate the replenishment of oestrogen receptors effectively in the cytoplasm.

STUDIES ON GONADOTROPHIN-INDUCED OVULATION IN THE IMMATURE RAT

1968 ◽  
Vol 41 (2) ◽  
pp. 171-177 ◽  
Author(s):  
E. T. BELL ◽  
S. F. LUNN
Keyword(s):  
Marked Effect ◽  
Cell Mass ◽  
Hormone Treatment ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Maximum Increase ◽  
Immature Rat ◽  
Immature Rats ◽  
Wet Weight ◽  
Pregnant Mare Serum Gonadotrophin

SUMMARY The effect of the administration of 25 i.u. human chorionic gonadotrophin (HCG) on the induction of ovulation in intact immature rats treated with 50 i.u. pregnant mare serum gonadotrophin (PMSG) has been studied. After the administration of HCG a marked increase in ovarian wet weight was observed. The maximum increase, which occurred 10 hr. after hormone treatment, was noted 2 hr. before ova were found in the oviducts. The alteration in ovarian wet weight was associated with a fall in percentage solids. However, it appears likely that an increase both in follicular fluid and in cell mass occurred before ovulation. Possible reasons for the absence of any marked effect on uterine wet weight or percentage solids are discussed.

scholarly journals The effect of oestradiol on the acid-soluble nucleotides of rat uterus

1970 ◽  
Vol 119 (2) ◽  
pp. 187-191 ◽  
Author(s):  
Janet M. Oliver ◽  
A. E. Kellie
Keyword(s):  
Fine Powder ◽  
Hormone Treatment ◽  
Two Dimensional ◽  
Purine Nucleotides ◽  
Rat Uterus ◽  
Pyrimidine Nucleotides ◽  
Immature Rat ◽  
Short Columns ◽  
Layer Chromatography

1. Techniques have been developed to measure the concentrations of the ribonucleotides of the immature rat uterus in vivo. Tissue was frozen rapidly in liquid nitrogen, ground to a fine powder, dispersed in frozen perchloric acid and thawed slowly. Nucleotides were separated from other acid-soluble constituents on short columns of polyethyleneimine-cellulose and the mixture was resolved into individual nucleotides by two-dimensional thin-layer chromatography on polyethyl-eneimine-cellulose plates. 2. The nucleotides of immature rat uterus consisted of approximately 75% of ATP–ADP, 10–12% each of GTP–GDP and UTP–UDP and less than 2% of CTP. 3. Injection of oestradiol (5μg) promoted a linear decrease in the amounts of purine nucleotides to approximately 60% of control values in 4–5h, followed by a return to greater than control values in 8–10h. Concentrations of the pyrimidine nucleotides remained constant for 4–6h and then increased to 200% of control at 12h after hormone treatment.

scholarly journals INFLUENCE OF ESTROGEN ON THE ELECTROLYTE PATTERN OF THE IMMATURE RAT UTERUS

1940 ◽  
Vol 132 (1) ◽  
pp. 1-9 ◽  
Author(s):  
N.B. Talbot ◽  
Oliver H. Lowry ◽  
E.B. Astwood
Keyword(s):  
Rat Uterus ◽  
Immature Rat

scholarly journals Oestradiol inhibits collagen breakdown in the involuting rat uterus

1972 ◽  
Vol 127 (4) ◽  
pp. 705-713 ◽  
Author(s):  
Janet N. Ryan ◽  
J. Frederick Woessner
Keyword(s):  
Cathepsin D ◽  
Density Gradient Centrifugation ◽  
Post Partum ◽  
Gradient Centrifugation ◽  
Specific Radioactivity ◽  
Rat Uterus ◽  
Oestradiol Treatment ◽  
Cathepsin D Activity ◽  
Stimulation Of

1. The earlier observation (Woessner, 1969) of oestradiol inhibition of collagen breakdown is confirmed and extended. Administration of 100μg of oestradiol-17β/day to parturient rats strongly inhibits the loss of collagen from the involuting uterus. Three experiments show that this effect is due to an inhibition of collagen degradation rather than to a stimulation of collagen synthesis. 2. Uterine collagen was labelled with hydroxy[14C]-proline by the administration of [14C]proline near the end of pregnancy. By 3 days post partum, control uteri lost 83% of their collagen and 90% of their hydroxy[14C]proline. Uteri from oestradiol-treated rats lost only 50% of both total and labelled hydroxyproline, with no decrease in the specific radioactivity of the hydroxyproline. 3. Incorporation of [14C]proline into uterine collagen hydroxyproline in vivo was not affected by oestradiol treatment. 4. Urinary excretion of hydroxyproline was increased in post-partum control rats and decreased in oestradiol-treated rats. 5. An enzyme capable of cleaving 4-phenylazobenzyloxycarbonyl-l-prolyl-l-leucylglycyl- l-prolyl-d-arginine (a substrate for clostridial collagenase) increased in activity in the post-partum uterus and was unaffected by oestradiol treatment. 6. Uterine homogenates digested uterine collagen extensively at pH3.2. This digestion was unaffected by the oestradiol treatment. 7. Lysosomal fractions prepared by density-gradient centrifugation of uterine homogenates contained coincident peaks of cathepsin D activity and peptide-bound hydroxyproline. The cathepsin D and hydroxyproline contents of this peak were unaffected by oestradiol treatment.

Effects of estrogen and progesterone on thymidine kinase activity in the immature rat uterus

1983 ◽  
Vol 145 (6) ◽  
pp. 711-715 ◽  
Author(s):  
Shinobu Sakamoto ◽  
Akio Abe ◽  
Hideki Kudo ◽  
Noriko Yamada ◽  
Keiko Seki ◽  
...  
Keyword(s):  
Thymidine Kinase ◽  
Kinase Activity ◽  
Thymidine Kinase Activity ◽  
Rat Uterus ◽  
Immature Rat
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