Search Results
You are looking at 1 - 10 of 14 items for
- Author: B. G. MILLER x
- Refine by access: All content x
Search for other papers by B. G. MILLER in
Google Scholar
PubMed
SUMMARY
Estimates were obtained of the half-lives of ribosomal RNA (rRNA) and transfer RNA (tRNA) in the uteri of ovariectomized mice receiving daily doses of 6 or 25 ng oestradiol, or no oestrogen injections. Apparent half-lives were calculated from data for the loss of radioactivity from rRNA and tRNA fractions after a single intravenous injection of [methyl-3H]l-methionine. The half-life of rRNA in mice which received no oestradiol injections was about 7 days and decreased to about 4 days in mice that received either 6 or 25 ng oestradiol daily. The half-life of tRNA after all treatments was about 3 days.
Search for other papers by B. G. MILLER in
Google Scholar
PubMed
SUMMARY
Changes in the metabolism of pyrimidine 5′-nucleotides and RNA in the mouse uterus during the oil-induced decidual cell reaction were investigated. During the first 20 h after the intraluminal injection of 10 μl sesame oil the amounts of HClO4-soluble nucleotides and uridine 5′-nucleotides in the treated horn increased by 55% and 115%, respectively. During the same interval RNA increased by 101%, while the increase in protein was much smaller, and the amount of DNA remained almost unchanged.
Doses of [2-14C]uridine, [5-3H]cytidine and [5-3H]orotic acid were administered to mice 20 min before killing. After [2-14C]uridine injection the specific activity of the uridine 5′-nucleotide fraction 20 h after the oil stimulus had not changed, while the specific activity of RNA increased by 43% during the 20-h interval. Similar results were obtained when [5-3H]-cytidine was injected. In contrast, after an injection of [5-3H]orotic acid the specific activities of both the uridine 5′-nucleotide and RNA fractions decreased with increasing time after the intraluminal injection of oil. When approximate rates of RNA synthesis were calculated independently from the data for [2-14C]uridine and [5-3H]orotic acid incorporation in these two fractions, the results agreed well, and indicated that the rate of synthesis of RNA in the decidualizing uterus increased by 64% and 163% at 8 and 20 h respectively after the intraluminal administration of sesame oil.
Search for other papers by B. G. MILLER in
Google Scholar
PubMed
SUMMARY
The effects on RNA and protein metabolism in the oviduct and endometrium at pro-oestrus of oestradiol and progesterone secreted during the oestrous cycle were examined, using the ovariectomized, hormone-treated ewe as a model system. Thirty ewes received hormone injections during a period of 13 days, according to schedules designed to simulate endogenous ovarian secretion of oestradiol and progesterone during the oestrous cycle. Hormone effects on RNA:DNA ratios and on rates of synthesis of protein and methylated RNA in vitro, as well as effects on oviducal and uterine weight, were examined.
The results obtained suggest that endogenous ovarian hormones have the following effects in the intact ewe. The secretion of oestradiol at pro-oestrus rapidly increases rates of synthesis of protein and methylated RNA, and mean cell content of RNA in both the endometrium and oviduct. Oestradiol secreted during the previous luteal phase of the oestrous cycle markedly increases mean cell content of RNA and amounts of protein and methylated RNA synthesis occurring in both tissues at pro-oestrus. In the endometrium, progesterone secreted during the luteal phase increases the RNA: DNA ratio, and probably also the amounts of protein and methylated RNA synthesized at pro-cestrus, but there are no significant interactions between the effects of oestradiol and progesterone. Progesterone had no effect on either the amounts or rates of synthesis of protein or methylated RNA in the oviduct. The results are discussed in relation to the hormonal regulation of physiological functions of the oviduct and endometrium during the first few days after the onset of oestrus.
Search for other papers by B. G. MILLER in
Google Scholar
PubMed
SUMMARY
The effects of oestriol, oestradiol and oestrone on the uterus and vagina of the mouse have been investigated, by measuring changes in the incorporation of tritiated uridine into RNA, and in wet and dry organ weight. The time course of the uridine response to a single injection of oestriol differs markedly from that seen with single injections of oestradiol and oestrone. Oestriol has only a weak uterotrophic action in tests employing daily oestrogen injections, but when administered every 4 hr. in small doses it elicits as much growth in both organs as does oestradiol. The relative capacities of oestriol and oestradiol to sensitize the uterus to the induction of deciduomata by peanut oil are contrasted.
Search for other papers by B. G. MILLER in
Google Scholar
PubMed
Search for other papers by C. W. EMMENS in
Google Scholar
PubMed
SUMMARY
The uptake of uridine in vivo into uterine and vaginal RNA after intravenous administration provides a sensitive measure of early oestrogenic effects in the ovariectomized mouse. The response of the uterus to a dose of 0·05 μg. of oestradiol increases rapidly to about tenfold at 8–16 hr., and returns to control levels by 32 hr. In the vagina the response develops more slowly, being maximal at 16–24 hr. The relative potencies of oestradiol, oestrone, oestriol, diethylstilboestrol and meso-hexoestrol tested by this criterion at 4 hr. were similar to those obtained in the 6-hr. water imbibition test.
Search for other papers by B. G. MILLER in
Google Scholar
PubMed
Search for other papers by C. W. EMMENS in
Google Scholar
PubMed
SUMMARY
The pattern of changes in levels of uridine incorporation into uterine and vaginal RNA at different times after the commencement of daily injections of several dose combinations of oestradiol and progesterone has been determined. Progesterone does not antagonize the response to oestradiol in the uterus and vagina at 16 hr., but in the uterus augments the effects of lower doses of oestradiol. At 48 hr., progesterone eliminates the response to oestradiol in the vagina. The interaction in the uterus is more complex. At 47 hr., or later, relatively high levels of uridine incorporation into uterine RNA are maintained by the administration of either oestradiol alone, at doses of 27 ng. or more; or by oestradiol and progesterone together, at doses of about 6 ng. and 0·33 mg. respectively. In mice receiving intraluminal peanut oil as a decidual stimulus the sensitivity of the uterus to deciduoma formation is not well correlated with its ability to incorporate uridine into RNA.
Search for other papers by B. G. MILLER in
Google Scholar
PubMed
Search for other papers by C. W. EMMENS in
Google Scholar
PubMed
SUMMARY
The effects of oestradiol, diethylstilboestrol, α,α′-dimethylstilbene-4,4′-diol (DMS), α-ethyl-α′-methylstilbene-4,4′-diol (MES), meso-hexoestrol, dl-hexoestrol, meso-butoestrol, dl-butoestroland erythro-α-ethyl-α′-methyl-4,4′-dihydroxybibenzyl (erythro-MEA) on the incorporation of tritiated uridine into uterine RNA were investigated. At 2 hr., valid relative potency estimates with oestradiol were obtained with all substances, and MES, erythro-MEA and meso-butoestrol were almost as potent as diethylstilboestrol and meso-hexoestrol. The time-course of the uridine response to the different substances varied markedly. Injections every 16 hr. of DMS, MES, dl-hexoestrol, meso-butoestrol and erythro-MEA elicited little uterine or vaginal growth, but small doses of these substances given every 4 hr. elicited considerable growth in both organs. It was concluded that the compounds tested were oestrogens and not pro-oestrogens.
Search for other papers by B. G. MILLER in
Google Scholar
PubMed
Search for other papers by LEIGH MURPHY in
Google Scholar
PubMed
Search for other papers by G. M. STONE in
Google Scholar
PubMed
SUMMARY
The concentrations of soluble oestradiol and progesterone receptor proteins and several metabolic activities were measured in the genital tracts of ewes killed on Days 0 (oestrus), 2, 5, 10 or 14 of the oestrous cycle. In caruncular endometrium and in whole uterus the concentrations of oestradiol receptor (pmol steroid bound/mg tissue DNA) were highest at oestrus and declined steadily thereafter to minimal values at Day 14. The concentrations of progesterone receptor were highest on Days 0–5, then declined to low levels on Days 10–14. There was little metabolism of either [3H]oestradiol or [3H]progesterone in minces of whole uterus and with either steroid the pattern of metabolism did not change at any stage of the cycle. The in-vivo rates of synthesis of protein in caruncular endometrium and in isthmic oviduct were highest at or shortly after oestrus (Days 0–2), then declined to low levels on Days 10–14. RNA:DNA ratios in these two tissues were also greatest at oestrus and subsequently fell to minimal values by Day 14. The results are discussed in relation to ovarian secretion of oestradiol and progesterone during the oestrous cycle of the ewe.
Search for other papers by B. G. Miller in
Google Scholar
PubMed
Search for other papers by R. Tassell in
Google Scholar
PubMed
Search for other papers by G. M. Stone in
Google Scholar
PubMed
The time-course of cell hypertrophy and changes in in-vitro rates of secretion and synthesis of protein in intercaruncular and caruncular endometrium and maternal and fetal cotyledonary placenta have been examined during days 0–112 of pregnancy in the ewe. The concentrations of high-affinity receptors for oestradiol and progesterone in nuclear and cytosol fractions from these tissues were also determined.
Protein secretion by intercaruncular endometrium increased 25-fold between days 0 and 84. On day 84 10−5 m-colchicine blocked 75% of total secretion. Protein secretion did not increase in the other tissues. Protein synthesis and RNA: DNA ratio in intercaruncular endometrium increased steadily between days 0 and 112, whereas they did not change in caruncular endometrium between days 0 and 28 and declined in cotyledon between days 56 and 112. The levels of cytosol receptor for oestradiol and progesterone and of nuclear receptor for oestradiol in all tissues during days 56–112 were very low in relation to the corresponding levels in caruncular endometrium on day 0. The level of nuclear progesterone receptor in caruncular endometrium increased threefold between oestrus and day 28. The level of this receptor in cotyledon remained low on days 56–112, but in intercaruncular endometrium it increased to high values on days 84–112.
The results demonstrated a major surge in secretory activity by the intercaruncular endometrium at around mid-gestation, which was associated with a marked increase in nuclear progesterone receptor levels but only a low level of nuclear oestradiol receptor. The observations do not suggest any important role for oestradiol or progesterone in the growth of fetal and maternal cotyledon.
Search for other papers by B. G. MILLER in
Google Scholar
PubMed
Search for other papers by W. H. OWEN in
Google Scholar
PubMed
Search for other papers by C. W. EMMENS in
Google Scholar
PubMed
SUMMARY
In the uterus of pregnant mice an increase in uptake of tritiated uridine occurs between days 2 and 3 of pregnancy, followed by a further increase from day 4 onwards. Uridine uptake changes in the same manner in pseudopregnant mice up to day 4, but thereafter declines to a minimum at day 6. The non-pregnant horn of the unilaterally pregnant mouse shows the same changes as the uterus of the pseudopregnant mouse. The results suggest that implantation occurs during a period of declining ovarian stimulation of the uterus and that the increased uptake of uridine in pregnant mice is stimulated locally by implantation.
