On the source of uterine 'luminal fluid' proteins in the mouse

Self Cite

The hydrostatic pressures generated during controlled flushing of the mouse uterus increased at implantation and under conditions of uterine closure. These pressures may be responsible for inducing tissue damage during flushing. The possibility that samples collected by flushing might be contaminated with interstitial fluid or plasma was studied using intravenously administered 51Cr-labelled EDTA and 125I-labelled human serum albumin as markers. The presence of both tracers was detected in all flushings and was greatest in flushings from uteri with luminal closure and early implantation sites. These observations raise serious doubts about the validity of the flushing technique for analysing uterine luminal constituents in mice.

Section: Discussionmentioning

confidence: 70%

Section: Introductionmentioning

confidence: 99%

The resistance of the mouse uterine lumen to flushing and possible contamination of samples by plasma and interstitial fluid

Milligan¹,

Martin²

1984

Self Cite

“…These compounds, which are already synthesized in the progesterone-treated epithelium, as shown in our work, might be secreted into the uterine lumen only after treatment with 'nidatory' oestrogen. Since flushing has been shown to disrupt the endometrial lining it is also possible that more intracellular proteins are liberated as a consequence of increased damage which occurs when tight closure of the uterine lumen has been completed through luteal oestrogen action (Martin, 1984;Milligan & Martin, 1984).…”

Section: Discussionmentioning

confidence: 99%

Patterns of protein synthesis in endometrial tissues from ovariectomized rats treated with oestradiol and progesterone

Lejeune¹,

Lamy²,

Lecocq³

et al. 1985

Groups of ovariectomized rats were taken as controls or given hormonal treatment mimicking the successive steps in the sequence of ovarian secretions leading to implantation. Total endometrium or separated epithelium and stroma were incubated in vitro with [35S]methionine. Dissolved proteins were submitted to two-dimensional polyacrylamide gel electrophoresis (pH range 5-7), followed by autoradiography. Priming with oestradiol (2 days) and subsequent treatment with progesterone (3 days) enhanced the synthesis of 12 and 14 polypeptides, respectively, which are specific for each of these treatments. Progesterone also suppressed the production of 10 oestrogen-dependent proteins both in the epithelium and the stroma. When an oestrogen-progesterone-oestrogen treatment was given, synthesis of all but 4 of the progesterone-induced polypeptides in the epithelium was inhibited while 5 of the proteins abolished by progesterone in this tissue compartment reappeared. These results are compatible with a mechanism of implantation acting at the epithelial level by lifting of intrauterine inhibition and stimulation by embryotrophic substances.

“…Damage to the uterine luminal epithelium caused by flushing of the uterine luminal and consequent contamination of uterine luminal flushes by plasma and interstitial fluid has been de¬ scribed in mice (Martin, 1984;Milligan and Martin, 1984). It is not known whether the presumed contamination of uterine luminal flushes contributed to the observed alterations in the electrolyte composition in the present study.…”

Section: Discussionmentioning

confidence: 73%

Role for insulin-like growth factor I in the regulation of electrolyte composition of uterine luminal fluid

Katagiri¹,

Ma²,

Yuen³

et al. 1997

A potential role for insulin-like growth factor I (IGF-I) in the regulation of the uterine electrolyte environment was studied in conjunction with hyperoestrogenaemia caused by superovulation. Uterine luminal fluid from immature rats treated with 4 (control), 10, 20 and 40 i.u. (superovulation) pregnant mares' serum gonadotrophin (PMSG, day -2) and the electrolyte composition was determined on day 3 of pregnancy. Superovulation increased total cation content in uterine flushes by more than twofold, suggesting a comparable increase in the uterine luminal fluid volume. Percentages of K+ and HCO-3 content to total cations or anions increased by 27% and 16%, respectively, and those of Na+ and Cl- decreased by 26% and 15%, respectively, after superovulation. Daily injections with 1.0 micrograms or more oestradiol, from day 0 to day 2, in the 4 i.u. PMSG-primed immature rats caused similar changes in total cation content and electrolyte composition of uterine luminal fluid. Anti-IGF-I antibody infusion in the superovulated or oestradiol-treated immature rats restored the alterations in cation composition but had no effect on anion composition and total cation content. IGF-I was infused into adult rats to achieve increased IGF-I action observed after superovulation. IGF-I infusion altered electrolyte composition, as is observed after superovulation or oestradiol treatment, but had no effect on total cation content. In conclusion, hyperoestrogenaemia caused by superovulation may alter the uterine electrolyte environment for preimplantation embryonic development. IGF-I appears to play a central role in mediating this action of oestrogen.