No abstract

To determine the influence of ovarian relaxin on the secretion of pituitary GH and PRL in vivo, we evaluated circulating serum hormone levels in 17 pregnant patients with functional corpora lutea (group I) and compared them to levels in 10 patients with premature ovarian failure (POF; group II) who became pregnant with egg donation and did not have corpora lutea. Group II patients had exogenous hormonal support. Serum relaxin (RLX), GH, PRL, estradiol (E2), and progesterone levels were measured weekly by RIA from weeks 4-8 of pregnancy. Analysis of variance and covariance were used to determine hormonal relationships. Serum RLX was present in the natural pregnancy group, with a mean of 1.94 micrograms/L over the study period. Serum RLX was undetectable in the POF patients (less than 0.16 micrograms/L). No significant difference in PRL or progesterone levels between the two groups was noted. E2 levels showed an upward trend in both groups with time and were significantly higher in patients of the POF group than in group I women (P = 0.001). GH levels were significantly higher in the natural cycle patients (P = 0.02) despite lower E2 levels. These data provide additional support for the concept that RLX production in early pregnancy originates from the corpus luteum. They suggest that a luteal product, probably RLX, stimulates GH secretion in early pregnancy. This is a previously undescribed role for RLX in pituitary physiology during human pregnancy.

In order to determine the effects of endothelin (ET) and relaxin on uterine contractility, immature female rats were treated with estrogen (E, 1 microgram s.c., Days 1-3) or estrogen and progesterone (2 mg s.c. [E + P], Days 2 and 3), and killed; the uterine horns were removed and suspended in muscle baths. Initially, we determined the contractile response to varying doses of ET and how this response was altered by pretreatment with progesterone. Uterine strips from animals treated with E + P (n = 10) were less sensitive to the stimulatory effects of ET than were strips from E-treated animals (n = 10). This difference was significant at ET doses above 2.5 nM. After completion of the dose-response studies, contractile patterns in response to ET and relaxin were then studied in animals treated with E (n = 10) or E + P (n = 9). ET (5 nM) significantly increased uterine contractility, mostly through an effect on the frequency of contractions (p less than 0.01). Relaxin (25 ng/ml) decreased contractility, affecting all contractile parameters measured (p less than 0.01). ET stimulated contractility in uterine horn segments previously inhibited by relaxin (p less than 0.01), and relaxin reduced the increased contractility produced by earlier exposure to ET (p less than 0.01). These data indicate that ET and relaxin can interact reversibly to control contractility in uterine horn segments in vitro, and that progesterone pretreatment can diminish the contractile response to the stimulatory effects of ET.

To determine the effects of prolonged hCG treatment in vitro upon granulosa cells from follicles of various sizes previously exposed to clomiphene citrate and hCG in vivo, progesterone and relaxin concentrations of spent media were correlated with light microscopic and ultrastructural characteristics. Intact, freshly dispersed cells were characterized by numerous lipid droplets, elliptical mitochondria with tubular or lamellar cristae, moderate rough-surfaced endoplasmic reticulum (RER), sparse smooth-surfaced endoplasmic reticulum (SER), and few Golgi. After 10-24 days in culture, 2 morphologically distinct cell types, 'granulosa-type' and 'luteal-type', were noted at the light microscopic level. Ultrastructurally, lipid droplets decreased in number, mitochondria became pleomorphic, RER became more prominent and dilated, and Golgi became more widely dispersed. Tubular SER became abundant and annular nexuses became more numerous after hCG treatment in vitro. Granulosa cells generated from all follicles responded to hCG treatment with significantly increased progesterone secretion after 4 days in culture. Relaxin was not detectable in any sample of medium. This study shows that human granulosa cells from 15-25-mm follicles retain their differentiated function of progesterone secretion in long-term culture and recover responsiveness to hCG in vitro, as demonstrated by enhanced progesterone secretion and development of prominent SER and increased annular nexuses.

This paper reports the case of a patient undergoing IVF and polar body analysis for aneuploidy screening because of advanced maternal age. A total of nine fertilized oocytes were obtained from the patient's third treatment cycle. Three supernumerary pronuclear stage oocytes were identified as suitable after aneuploidy screening for five chromosomes and vitrified. Because the fresh cycle did not result in a pregnancy, vitrified pronuclear stage oocytes were warmed for transfer in an artificial cycle. All three zygotes survived warming and were transferred to the patient's uterus 2 days later as 4-, 5- and 6-cell stage embryos. After 2 weeks, a positive pregnancy test indicated successful implantation. The gestation is developing normally and is presently (end of September 2007) in the 22nd week.