The regulation of ovine placental steroid 17 alpha-hydroxylase and aromatase by glucocorticoid.

Parturition in the pregnant sheep is preceded by an abrupt alteration in placental steroid metabolism causing a shift from progesterone to estrogen production. This change is believed to be a consequence of the prepartum rise in cortisol in the fetal circulation and involves increases in activities of the enzymes steroid 17 alpha-hydroxylase (cytochrome P-450(17)alpha), steroid C-17,20-lyase, and possibly aromatase. We have investigated the activity levels of aromatase and 17 alpha-hydroxylase in placental microsomes in late pregnancy and dexamethasone-induced labor. Over the gestational period of 118-140 days basal levels of placental aromatase were relatively constant [mean value (+/- SD) of 5.6 +/- 1.6 pmol min-1 mg microsomal protein-1 (n = 10)]. Steroid 17 alpha-hydroxylase activity was undetectable [less than 0.5 pmol min-1 mg microsomal protein-1 (n = 7)]. In six animals in labor induced with infusion of dexamethasone into the fetus, placental aromatase activity had a mean value of 14.0 +/- 2.5 pmol min-1 mg protein-1; placental steroid 17 alpha-hydroxylase, measured in four of the animals, had a mean (+/- SD) activity of 319 +/- 58 pmol min-1 mg microsomal protein-1. Immunoblotting of placental microsomal preparations with specific antibodies to cytochrome P-450(17)alpha and NADPH-cytochrome P-450-reductase indicated that the glucocorticoid-induced activity of 17 alpha-hydroxylase was associated with increased content of cytochrome P-450(17)alpha. Northern blotting with a cDNA probe for cytochrome P-450(17)alpha showed that glucocorticoid increased the levels of mRNA for the enzyme.(ABSTRACT TRUNCATED AT 250 WORDS)

Determinants of total body and regional bone mineral density in normal postmenopausal women--a key role for fat mass.

In order to determine which clinical, anthropometric, dietary, and biochemical variables are independent predictors of total and regional bone mineral density (BMD) in normal postmenopausal women, a cross-sectional study of 140 normal postmenopausal women has been carried out. Subjects were white, aged 45-71 yr (mean 58 yr), and had no history of disorders or medication use likely to influence bone or calcium metabolism. Multiple regression analysis was used to derive models for total and regional BMD in terms of the other variables measured. The analysis indicated that total body BMD was positively related to fat mass (P less than 0.0001), serum estrone (P = 0.0095) and age at menopause (P = 0.0165), and negatively related to age (P less than 0.0001), 24-h urine calcium (P = 0.0002), sex hormone-binding globulin (P = 0.0003), and serum alkaline phosphatase activity (P = 0.0029) (R2 = 0.61). Similar relationships were found in the subregions of the total body scans and in the lumbar spine and proximal femur, with insulin-like growth factor-1, parity, and age at menarche also being related to BMD at at least two of these sites. Lean body mass was not an independent correlate of BMD at any site once fat mass was taken into account. Muscle strength, physical activity, alcohol intake, and dietary intakes of calcium, sodium and protein did not emerge as significant predictors of BMD in this homogeneous group of postmenopausal women. We conclude that total body fat is the most significant predictor of BMD throughout the skeleton and this relationship is not explicable in terms of either estrone production in fat tissue or the dependence of skeletal load-bearing on fat mass. The mechanism underlying this relationship is an important question to be addressed in bone biology.

Ovine placental steroid 17 alpha-hydroxylase/C-17,20-lyase, aromatase and sulphatase in dexamethasone-induced and natural parturition.

Parturition in the sheep is preceded by an abrupt alteration in placental steroid metabolism causing a shift from progesterone to oestrogen production. This change is believed to be a consequence of the preparatum rise in cortisol in the fetal circulation and involves increases in activities of the enzymes steroid 17 alpha-hydroxylase (cytochrome P-450(17) alpha), steroid C-17,20-lyase, and possibly aromatase and steroid sulphatase. The activity levels have been determined of steroid 17 alpha-hydroxylase, aromatase and steroid sulphatase in placental microsomes in late pregnancy, dexamethasone-induced labour and in natural labour at term. Over the gestational period of 118-140 days, basal levels of placental aromatase were relatively constant (mean value (+/- S.E.M.) of 5.6 +/- 0.5 pmol/min per mg microsomal protein (n = 10]. Pregnenolone and progesterone 17 alpha-hydroxylase activities were undetectable (less than 0.5 pmol/min per mg microsomal protein (n = 7]. In six animals in labour induced with infusion of dexamethasone into the fetus, placental aromatase activity increased to a value of 14.0 +/- 1.0 pmol/min per mg protein; placental pregnenolone 17 alpha-hydroxylase, measured in four of the animals, also increased to 453 +/- 77 pmol/min per mg microsomal protein. In five animals in natural spontaneous labour with vaginal delivery, aromatase activity was 26.7 +/- 5.2 pmol/min per mg microsomal protein and pregnenolone 17 alpha-hydroxylase activity was 141 +/- 14 pmol/min per mg microsomal protein. Steroid sulphatase activity was barely detectable (less than 1.5 pmol/min per mg microsomal protein) during late pregnancy, dexamethasone-induced labour or natural parturition.(ABSTRACT TRUNCATED AT 250 WORDS)

Activin-A stimulates, while transforming growth factor beta 1 inhibits, chorionic gonadotrophin production and aromatase activity in cultured human placental trophoblasts.

Transforming growth factor-beta (TGF-beta) and activin-A, two members of a ubiquitous family of regulators of growth, differentiation and hormonogenesis, are produced by the human placenta. Their effects on placental hCG, inhibin, and oestrogen production in vitro, either alone or in combination, were investigated using cultured Percoll-purified placental trophoblasts. Inhibin and hCG were measured by immunoassay, while aromatase activity (i.e. oestrogen production) was measured using the tritiated water method. Aromatase activity and production of hCG, but not inhibin, were inhibited (up to approximately 30 per cent) in a dose-dependent fashion by 48 h treatment with TGF-beta. The effects were significant at all doses tested, from 0.1-10 ng/ml. In contrast, activin stimulated hCG production and aromatase activity over the doses tested (0.25-25 ng/ml). The maximum effect (approximately 50 per cent stimulation above control) was seen at the 2.5 ng/ml dose, with lesser effects seen at the lower and higher doses. This characteristic bell-shaped dose-response curve was maintained in the presence of TGF-beta (10 ng/ml) or a maximally-effective dose of forskolin (6.7 microM). This suggests that the actions of activin were independent of those of TGF-beta, and were not mediated by the protein kinase-A pathway. Activin had a weak stimulatory effect on inhibin production. The results indicate that in the placenta activin and TGF-beta have opposing actions on hormonogenesis. Both factors may play a role in regulating placental function and the timing and progression of labour.

Comparative regulation of inhibin, activin and human chorionic gonadotropin production by placental trophoblast cells in culture.

In the present study, we investigated the roles of cyclic adenosine monophosphate (cAMP), intracellular calcium, glucocorticoids, protein kinase-C and gonadotrophin-releasing hormone (GnRH) in regulating human chorionic gonadotrophin (hCG), inhibin and activin production in cultured human term placental trophoblast cells. Inhibin and hCG were measured in conditioned media by radioimmunoassay, while putative forms of inhibin and activin were characterized by western blotting using affinity-purified antisera directed against the inhibin alpha- and beta A-subunits. Inhibin and hCG secretion were stimulated by dexamethasone (0.2 microM), GnRH (5-25 microM), calcium ionophore A23187 (0.2-1 microM), phorbol-12-myristate-13-acetate (22 nM) and epinephrine (1 microM), with increasing response over successive 24-h treatment periods. Two molecules Mr approximately 30 and 32 kDa appeared to be the predominant dimeric forms of inhibin secreted by the cells, while 26 kDa activin was present in excess over inhibin. Large amounts of 40-44 kDa protein were detected by the alpha-directed antisera only, which may be a form of the inhibin alpha-subunit precursor protein. Secretion of activin was responsive to phorbol ester-mediated stimulation but not to the presence of GnRH or elevated cAMP concentrations. The divergence in maternal serum inhibin and hCG concentrations during late pregnancy remains unexplained by these findings.

A prospective study of the preselection of the sex of offspring by timing intercourse relative to ovulation.

The relationship between the sex of offspring and the time interval between coitus and ovulation/fertilization has been prospectively investigated in 33 pregnancies using the rise in luteinizing hormone in the early morning urine, the peak cervical mucus symptom, and the shift in basal body temperature as indicators for ovulation. Reference to the peak cervical mucus symptom showed a significant association of conception of a male child with longer intervals (greater than 2 days) between coitus and fertilization (P less than 0.03). However, while a similar trend for male conceptions was evident when the duration of sperm survival was determined by reference to each of the other two indicators of ovulation, the relationship was not significant. The results clearly refute the theory that intercourse close to ovulation favors male conceptions. While the findings are consistent with the contrary theory, it may be premature to conclude that a male child is more likely to be conceived if coitus takes place several days before ovulation.

Dominance and testosterone in women.

Fifty-two young women completed the Simple Adjective Test (a questionnaire designed to measure dominance) and at the same time provided 5 ml blood for testosterone assay. Higher dominance scores were associated with higher serum testosterone levels (t-test P<0.008).

The development of a programme for in vitro fertilisation in New Zealand.

The first seven months experience of a programme for in vitro fertilisation at National Women's Hospital in Auckland is described. Following a five month period of technique development, 36 women with tubal infertility were admitted to the programme from July 1983 to February 1984. A clinical pregnancy rate of 15% (6/41 laparoscopies) was achieved during this period.

An evaluation of the performance of laboratories in the assays of oestriol and creatinine in pregnancy urine: the national pregnancy urine survey.

The performance of clinical chemistry laboratories in New Zealand in the assays of oestriol and creatinine in pregnancy urine has been investigated. The quality of oestriol determinations in general was poor. Only seven of 20 laboratories achieved an inter-assay precision of better than 12 percent consistently through the range of oestriol levels represented by three control urines. The precision of laboratories in assaying urinary creatinine was, however, of a higher standard. Only three of 18 laboratories had precision values that could be regarded overall as unsatisfactory.

The development of fertility assay kits: an overview.

This paper analyzes the importance of developing fertility assays kits, specially in order to shorten the estimate of the fertile period in NFP users. It presents the criteria that an assay kit needs to meet. Urinary hormones, metabolites of progesterone, estrogens, and luteinizing hormones are analyzed as fertile-period markers. Progesterone and estradiol in saliva, as well as other constituents of saliva, the volumetric vaginal aspirator, and the change in the electrical conductivity of the vaginal fluid are also analyzed with the same purposes.

Overview of the biological aspects of the fertile period.

The fertile period of the human menstrual cycle consists of those days on which sexual intercourse can result in a pregnancy. Its duration is determined by the functional life span of the gametes within the female reproductive tract. Various mechanisms control gamete transport and survival in the reproductive tract of the human female. The ovarian hormones estradiol and progesterone have an important role in regulating these mechanisms. The nature of cervical mucus and its governing influences on sperm transport and survival following coitus are of prime importance in defining the fertile days of the menstrual cycle. Man's early concepts of the fertile period were often based on erroneous theories of the female reproductive cycle. It is only since the late 1920's that a true understanding of ovulation and the menstrual cycle has evolved. Current approaches in natural family planning to recognizing the fertile and infertile days of the menstrual cycle are discussed and evaluated.

The ovulation method of family planning.

PIP: The ovulation method of family planning relies on self-recognition of physiological changes occuring around time of ovulation rather than a calendar to enable a couple to avoid sexual intercourse during the fertile period. The most practical signs are elevated basal body temperature, changes in the amount and physicochemical properties of cervical mucus, and ovulation pain. The basal body temperature rises about .3 degrees C following ovulation. The problem with this method is that it is retrospective. The mucus symptoms, as described by Billings and associates in Melbourne, Australia, are: 1) a variable number of days with no vaginal discharge following menstrual bleeding; 2) onset of mucus symptoms characterized by increasing quantities of ''cloudy'' or ''sticky'' secretion; 3) a clear, slippery lubricative mucus having the characteristics of raw white of egg (spinnbarkeit), which is an immediate forwarning of ovulation; 4) a variable period of thick, opaque, diminished volume discharge followed by dry days. The clear ''peak symptom'' mucus lasts 1-2 days; in a study of 22 women followed for 27 cycles this symptom occurred .9 days +3 or -2 days before ovulation. The problem is that 2 of the 22 cycles reported in detail had ovulation 3 days after the peak symptom and 1 had ovulation 4 days after. Intercourse on the 4th day, therefore, would have had a significant risk of pregnancy. Weissman and associates collected data on 282 women on the Pacific island of Tonga who used the mucus symptoms alone to control conception. In the 2503 cycles there were 53 unplanned pregnancies, 25.4 per 100 woman-years using the Pearl formula. 50 resulted from the couples ''taking a chance,'' 2 misunderstood the method, 28 abandoned the method because they wanted more children, and 1 woman became pregnant even though she thought she understood the method. Field trials with groups who are more motivated than those in the Tongan trial are needed.^ieng

Maternal plasma and urinary hormone levels during and after a successful abdominal pregnancy.

In a successful abdominal pregnancy, urinary oestriol levels were about the fifth centile, but other hormone concentrations suggested that placental function was normal until 32 weeks gestation. After that, plasma oestrogen concentrations levelled off and plasma placental lactogen concentrations declined. Pre-eclampsia developed at 34 weeks and necessitated the delivery at 36 weeks and 2 days of a live normal female infant by laparotomy. The placenta was not removed. All hormone levels fell rapidly during the first weeks of the puerperium and then more slowly during the next six weeks to non-pregnancy levels. Plasma progesterone, urinary pregnanediol, and plasma oestradiol were the slowest to return to non-pregnant levels.

Studies of the biochemical basis of steroid sulphatase deficiency--III. Phospholipid composition of microsomes from normal and steroid sulphatase deficient placentas.

The phospholipid composition has been determined for placental microsomes from 11 normal and eight pregnancies complicated by steroid sulphatase deficiency. Phosphatidylcholine, phosphatidylethanolamine and sphingomyelin were found to be the major phospholipids of normal placental microsomes, comprising respectively 41.6 +/- 4.6% (mean +/- SD). 30 +/- 5.7% and 22.5 +/- 4.9% of the total phospholipid content. There was no correlation between the steroid sulphatase activity of the microsomes and the content of any of the three phospholipids. Though their contents were significantly decreased. (P less than 0.001) phosphatidylcholine, phosphatidylethanolamine and sphingomyelin similarly constituted the major portion of the total phospholipids in sulphatase deficient microsomes, representing 36 +/- 4.2%, 34 +/- 6.1% and 22.4 +/- 6.7% respectively. Only the percentage of phosphatidylcholine was significantly different (P less than 0.02) from normal microsomes. The results show that the decreased phospholipid content of steroid sulphatase deficient placental microsomes reflects a lower content of all major classes of phospholipids, particularly phosphatidylcholine.

Alkaline phosphatase, arylsulfatase and beta-glucuronidase in saliva of cyclic women.

Levels of the enzymes alkaline phosphatase, arylsulfatase, and beta-glucuronidase have been measured in whole unstimulated saliva samples collected daily during normal menstrual cycles. The cellular content of the saliva has been shown to be a major source of the three enzymes. The enzymes were found to have peak maximum levels of activity during the periovulatory -hase of the cycle. This observation can be attributed to the presence of increased numbers of exfoliated cells from the oral mucosa resulting from the pre-ovulatory estrogen stimulus to cell proliferation.

PIP: It is known that the composition and character of human saliva alters during the menstrual cycle, presumably in response to changes in the level of ovarian hormones. A clinical study was undertaken to determine cyclic variations in salivary enzymes. Saliva from 4 healthy women aged 20-31 with a history of normal menstrual cycles were studied. The laboratory procedures performed on the saliva samples--from 6 menstrual cycles--are described and the results are graphed. Exfoliated cells from the oral mucosa were the main source of these enzymes. In all the cycles, alkaline phosphatase activity peaked sharply at mid-cycle, close to the expected time of ovulation; in 5 of the cycles, the peak occurred before the postovulation rise in body temperature. The levels of arylsulfatase and beta-glucuronidase, studied in 2 consecutive cycles of 1 woman, peaked in the periovulatory phase. All 3 enzymes were elevated during the luteal phase of the cycle as well. Increased cellular content of the saliva is attributed to the elevated circulating blood estrogen levels in the immediate preovulatory and midluteal phases of the cycles. There is great variability among subjects, however. Before a simple test for ovulation by home measurement of salivary enzymes can be developed, an ajustment of the test sensitivity would be necessary for adaptation to the individual woman.

An alternative fluorescence enhancement solution for use in lanthanide-based time-resolved fluoroimmunoassays.

Time-resolved fluoroimmunoassays that make use of lanthanide chelates as labels require the addition of an enhancement solution to elicit the formation of a fluorescent lanthanide complex. All solutions previously described are based on 2-naphthoyltrifluoroacetone (NTA), a beta-diketone. Currently, this compound is not commercially available. We report here the properties and performance of an enhancement solution prepared with a commercially available beta-diketone, thenoyltrifluoroacetone. Use of this solution in a commercial time-resolved fluoroimmunoassay gave results essentially identical to those obtained with the NTA-based solution, although fluorescence emission was approximately 27% lower. The lower fluorescence yield did not, however, significantly reduce assay sensitivity. We conclude that this solution represents a viable and highly economical alternative to the preparation currently in use, particularly for laboratories wishing to develop their own assays based on lanthanide fluorescence.