We have recently demonstrated the presence of two classes of neurohypophysial hormone receptors in the vagina, myometrium, and oviduct of rabbit: an oxytocin (OT) site and a V1 arginine vasopressin (AVP) site. We now report binding and in vitro contractility studies on human myometrial specimens obtained at cesarean section from women at the end of pregnancy. The program Ligand was used to analyze self- and cross-displacement curves for labeled OT, AVP or its V1 antagonist d(CH2)5TyrMeAVP, the corresponding unlabeled peptides, and selective analogs. Our results clearly indicate the presence of heterogeneity of binding sites in human uterus. Blocking experiments were performed to evaluate the density of OT and V1 AVP receptors in individual uterine specimens. The contractile response of the same samples to OT, AVP, and analogs was also evaluated. Our results indicate that V1 AVP receptors are present in all of the uterine specimens investigated, with virtually equal density from 32 weeks to term. AVP and the V1-selective agonist [Phe2,Ile3,Orn8]VP stimulate contractility of uterine strips, an effect blocked by nanomolar concentration of the V1 antagonist d(CH2)5TyrMeAVP. Uterine OT receptors increase during late pregnancy, peaking in early labor. A significant correlation between the density of OT receptors and the frequency of uterine contractions (external tocography) was found in pregnant women before surgery. OT stimulated in vitro contractility of uterine strips only when the density of receptors was more than 150 fmol/mg protein. In conclusion, we identified biologically active V1 AVP receptors in human uterus at the end of gestation and confirmed the primary relevance of OT receptors in human parturition.

Objective: Leptin, a protein secreted by white adipocytes, plays a relevant role in the regulation of body weight and food intake. A possible role for sex hormones in the regulation of leptin secretion has been suggested; however, the effect of variations in oestrogen concentration on serum leptin levels has not been described so far. Methods: In study 1, serum leptin concentrations were measured on days 3, 10, 17 and 24 of the menstrual cycle in 18 healthy, lean, regularly menstruating women, aged 18-35 years. Serum oestradiol, progesterone, testosterone, D 4 -androstenedione, dehydroepiandrosterone sulphate (DHEAS), LH and FSH concentrations were also determined. In study 2, serum leptin and oestradiol levels were measured on the 5th and 7th day of ovarian stimulation with human FSH (225 IU daily) during an in vitro fertilisation programme for infertility in 20 women aged 25-45 years. Results:The results from study 1 show a physiological fluctuation of leptin levels during the menstrual cycle, which has not been described previously. Leptin levels are significantly lower in the early follicular phase. The results of study 2 show a parallel increase in serum oestrogen and leptin concentrations during FSH administration. Conclusions:The fluctuation in leptin levels during the menstrual cycle observed in study 1 is compatible with the hypothesis of a stimulatory effect of oestrogen on leptin secretion. The results of study 2 support the hypothesis of a relevant role for oestrogen in the regulation of leptin secretion. Leptin fluctuations during the menstrual cycle are consistent with reported perimenstrual variations in food craving and consumption.

In patients with endometrial carcinoma who did not receive radiotherapy or chemotherapy before surgery, the presence of decreased levels of pRb2/p130 in tumor cells is associated with a significantly increased risk of recurrence and death of disease, independent of tumor stage and ploidy status.

One hundred twenty-four patients with invasive carcinoma of the cervix were examined with transrectal ultrasound (TRUS) before treatment. Since surgery preceded any other kind of therapy, sonographic findings could be compared with the surgical pathologic stage. The accuracy of staging with TRUS was 83%, compared with an accuracy of 78% for clinical staging performed according to the criteria of the International Federation of Gynecology and Obstetrics (FIGO). For extent of parametrial involvement, the sensitivity of TRUS evaluation was 78%, with a specificity of 89% and a diagnostic accuracy of 87%. The same reliability parameters for clinical evaluation were 52%, 92%, and 84%, respectively. From these data and from analysis of the cases--in which a discrepancy between clinical and TRUS staging was observed--it can be concluded that TRUS could be usefully applied to routine pretreatment evaluation of patients with cervical carcinoma.

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