Late luteal phase progestogen-dependent endometrial protein levels in women with in-phase biopsies--can low levels predict a subfertile group?

A group of infertile women who had luteal phase defects (LPD), but in whom follicular maturation was deemed normal, were treated with progesterone until the endometrial biopsy was corrected. At the time the corrected biopsy was obtained, serum was taken and the progestogen-dependent endometrial protein (PEP) concentration was determined. Serum PEP concentration in patients who successfully conceived was 102.5 +/- 62.6% units/mL, while PEP concentrations in patients who failed to conceive were 57.9 +/- 34.4% (P = .003). In patients whose PEP value was more than two standard deviations below the corresponding mean control PEP, pregnancy was achieved in 6/17 (35.3%). The conception rate was significantly greater (25/35, 71.4%) in patients with values higher than this. Thus, the PEP concentration in serum may identify a group of patients with persistent LPD despite apparent normalization of the morphology of late secretory phase endometrium, which might explain some cases of cryptic, unexplained infertility.

Serum and peritoneal fluid proteins in women with and without endometriosis.

We examined the proteins in serum and peritoneal fluid of women with endometriosis (and of healthy controls) for evidence of an autoimmune response that might account for their impaired fertility. No antibodies against endometrial glycoproteins or against "progestin dependent endometrial protein" (PEP) were found in any serum or peritoneal fluid sample. Levels of PEP were not different in serum from women with moderate to severe endometriosis (n = 6), with mild endometriosis (n = 21), or from disease-free cycling controls (n = 19). PEP levels in peritoneal fluid from mild endometriosis and from controls did not differ but were elevated ten times in fluid obtained in the secretory phase from women with moderate to severe disease. This suggests that PEP levels in peritoneal fluid reflect the extent of ectopic endometrial growth. The salient finding was a heretofore undescribed protein (mol wt 70,000) in secretory phase peritoneal fluid samples (18/20) and its absence during the proliferative phase (0/35).

Luteal phase concentrations of a progestagen-associated endometrial protein (PEP) in the serum of cycling women with adequate or inadequate endometrium.

We previously demonstrated that the human endometrium synthesizes and secretes a specific protein designated "Progestagen-associated Endometrial Protein" or PEP. This work was undertaken to determine luteal phase levels of PEP in serum of cycling women with histologic evidence of adequate endometrium (endometrium in phase) or inadequate endometrium (endometrium out of phase by 3-4 days). The results provide a normative curve with 95% confidence limits for serum PEP concentrations vs normalized cycle day in women with adequate endometrium (judged by histologic endometrial dating), and indicate that the PEP concentration increases exponentially after day 22, with a mean doubling time of 2.95 +/- 1.60 (mean +/- SD) days (based on serial data from 13 women). More importantly, the proportion of serum PEP values falling outside of the 95% confidence limits was significantly greater (p less than 0.001) in women with inadequate endometrium (83%) than in women with adequate endometrium (16%). Therefore, determination of PEP in serum, rather than the more invasive endometrial biopsy examination, may serve as a method of choice for evaluating endometrial adequacy in infertile women.

Placental protein 14 and progestagen-dependent endometrial protein are immunologically indistinguishable.

Placental protein 14 isolated from the human placenta and its adjacent membranes, and progestagen-dependent endometrial protein (PEP) isolated from the endometrium have been described independently by two groups. We report results of the radioimmunological and immunodiffusion tests which show that the proteins are immunologically indistinguishable from each other.

Evidence for the presence of specific prolactin binding protein in rat seminal vesicle fluid.

The presence of a specific prolactin binding in rat seminal vesicle fluid has been demonstrated. The binding phenomenon was saturable and pH dependent, the optimum pH being 7.2. The prolactin binding protein (PBP, 1800 x g supernatant) was characterized by a single order affinity binding sites with an association constant (Ka) 1.52 x 10(7) mol-1. The specificity of the prolactin binding was demonstrated by the fact that other proteohormones such as rFSH, rLH, rTSH and hTSH failed to inhibit the binding of labelled hormone to PBP, while unlabelled oPRL gave a dose-response inhibition curve. Among the rats in the age group 45 to 180 days, PBP obtained from animals of 90 day old showed a maximum binding of radioiodinated rPRL. Following castration for five days the percent binding of 125I-rPRL to PBP decreased markedly. The treatment of castrated rats with testosterone propionate for five days returned the 125I-rPRL binding to near intact values. Following a centrifugation of 1800 x g supernatant at 360 000 x g for 3 h, prolactin binding activity still remained in the supernatant thus implicating that the binding protein is in a soluble state.