Human Chorionic Somatomammotrophin Research Articles

Potentiation of the somatogenic and lactogenic activity of human growth hormone with monoclonal antibodies

Monoclonal antibodies of certain epitope specificity have been shown to produce a marked dose-dependent enhancement of the somatogenic and lactogenic activity of human GH (hGH). Two antibodies (EB1 and EB2), binding to distinct antigenic determinants and expressed on both hGH and human chorionic somato-mammotrophin (hCS), significantly enhanced the hGH-stimulated uptake of 35S-labelled sulphate into cartilage. Similarly, these antibodies enhanced the lactogenic activity of both hGH and hCS in the pigeon crop sac test. Two hGH specific monoclonal antibodies (QA68 and NA71), defining a further two epitopes, exhibited only modest enhancing or inhibitory activity in these assays, whereas the binding of certain combinations of monoclonal antibodies resulted in either reversal of enhancement or inhibition of hormone activity. Univalent antibody fragments derived from EB1 were as enhancing as the intact antibody indicating that bivalency dependent mechanisms were not involved in the phenomenon. Enhancing monoclonal antibodies were relatively poor inhibitors of 125I-labelled hGH binding to liver microsomal receptors, which is in contrast with their previously described property of potent suppression of hGH interaction with lymphoid cell receptors. It is tentatively concluded that 'restriction' of hormone binding to particular hGH receptors, relevant to somatic growth or lactogenic activity, may play a role in the enhancement phenomenon of hGH in vivo.

An 18-month follow-up study of growth-retarded neonates. Relation to biochemical tests of placental function in late pregnancy and neurobehavioural condition in the newborn period

Serial estimations of maternal urinary oestriol, serum cystine aminopeptidase (S-CAP), and human chorionic somatomammotrophin (S-HCS) were studied prospectively in 29 pregnancies complicated by intrauterine growth retardation. The newborn growth-retarded infants were examined by neurological and behavioural techniques. Growth variables and neurological and developmental findings were compared with those in 18 healthy controls at 5, 10 and 18 months of age. The growth-retarded infants caught up with regard to body size from 5 months of age, although the severely retarded infants (birth weight ⩽ −2 SD) differed from the controls with regard to weight and head circumference at 18 months of age. Abnormal maternal oestriol excretions were negatively correlated to weight and length during the follow-up period. Infants who had been severely growth-retarded at birth were neurologically below optimal level at 10 months of age, compared to the controls. There were no significant differences between the growth-retarded infants and the controls with regard to psychomotor development, as assessed by a screening test and by Griffiths' method. Significant correlations were found between abnormal biochemical placental tests (especially urinary oestriol and S-CAP) and psychomotor development. Significant correlations also appeared between neonatal orientation and motor behaviour and some Griffiths' scales at 18 months of age. No relationship was found between the neurological condition in the neonatal period and the neurological findings and development at follow-up.

Neurology and behaviour of growth-retarded neonates. Relation to biochemical placental function tests in late pregnancy

Serial estimations of maternal urinary oestriol, serum cystine aminopeptidase (S-CAP), and human chorionic somatomammotrophin (S-HCS) were done in a prospective study on 29 pregnancies in which intrauterine growth retardation was diagnosed in the third trimester by the gravidogram method and/or serial ultrasound measurements of the fetal biparietal diameter. The series was divided into 2 growth-retarded groups: (i) severe growth retardation with birth weight less than -2 SD from the mean for gestational age (N = 14); (ii) moderate growth retardation with birth weight between −1 and −2 SD from the mean for gestational age (N = 15). These were compared with a control group of 18 normal pregnancies and infants. A modified Prechtl neurological examination and the Brazelton Neonatal Behavioural Assessment Scale (NBAS) were done in the neonatal period at full-term age. Both categories of growth-retarded infants showed lower muscle tonus than the controls. The severely growth-retarded infants showed fewer optimal items in the neurological examination; they also showed poorer capacity for orientation to external stimuli, inferior motor function, and less physiological stability in NBAS than the controls. The abnormal biochemical placental tests were significantly correlated to low Apgar scores (urinary oestriol), to low excitability (S-CAP) and to poor motor function (S-HCS). The neurological and behavioural condition of the neonate seemed to be more closely associated to the extent of growth retardation than to the occurrence of abnormal biochemical placental tests.

THE IMMUNODEPRESSIVE EFFECT OF HUMAN GLUCOPROTEINS AND THEIR POSSIBLE ROLE IN THE NONREJECTION PROCESS DURING PREGNANCY

Human chorionic gonadotrophin (HCG) and human chorionic somatomammotrophin (HCS) were shown to suppress the proliferative T and B cell response induced by different mitogens in human and mouse lymphocytes. Thyroid stimulating hormone (TSH), sharing the alpha-chain subunit with HCG was devoid of effect suggesting that the immunosuppressive entity is localized within the beta-chain subunit. Human growth hormone (HGH) which is partly biologically cross-reactive with HCS did not impair mitogen responsiveness. HCG was also able to inhibit the differentiation of cells since the induction of antibody-formation was depressed. Expression of plaque forming cells was also reduced by addition of HCG directly in the PFC assay possibly reflecting the anti-complementary effect of this hormone, since cell mediated lysis of target cells by Con A activated lymphocytes, which is not complement-dependent, was unaffected by adding HCG in the assay system.

Performance of various mathematical methods for computer-aided processing of radioimmunoassay results

Interpolation and regression methods are available for computer aided determination of radioimmunological end results. We compared the performance of 6 algorithms (weighted and unweighted linear logit log regression; quadratic logit log regression, smoothing spline interpolation with a large and small smoothing factor, respectively, and polygonal interpolation and the manual curve fitting on the basis of three radioimmunoassays with different reference curve characteristics (digoxin, estriol, human chorionic somatomammotrophin (HCS)). Great store was set by the accuracy of the approximation at the intermediate points on the curve i.e. those points that lie midway between two standard concentrations. These concentrations were obtained by weighing and inserted as unknown samples. In the case of digoxin and estriol the polygonal interpolation provided the best results, while the weighted logit log regression proved superior in the case of HCS.

Specific binding of purified Human Chorionic Somatomammotrophin antibody to polyribosomes from term human placenta

Specific binding of purified Human Chorionic Somatomammotrophin antibody to polyribosomes from term human placenta

Biological actions of human somatotrophin and its derivatives on mouse mammary gland and teleost urinary bladder.

These studies are concerned with the structural and functional evolution of the ancestrally related pituitary prolactins and somatotrophins. Prolactin-like biological activities of human somatotrophin (hGH) and its peptide fragments were bioassayed in vitro on the mouse mammary gland and the teleost urinary bladder. Plasmin modified-hGH was as active as hGH in both bioassays. The NH2-terminal 134-residue fragment possessed about 10% of the lactogenic and urinary bladder potency of hGH, whereas the CO2H-terminal 51-residue fragment was inactive at the concentrations observed. These results suggest that the same regions of primary structure are responsible for the prolactin-like actions of hGH on the target organs of lower and higher vertebrates. Alteration of the tertiary structure of hGH, human chorionic somatomammotrophin, and ovine prolactin by performic acid oxidation destroys the mammary gland activities of these hormones.

IMMUNOREACTIVE ACTH, IMMUNOREACTIVE HUMAN CHORIONIC SOMATOMAMMOTROPHIN (HCS) AND 11-OH STEROIDS PLASMA LEVELS IN NORMAL AND PATHOLOGICAL PREGNANCIES

Plasma immunoreactive ACTH (I.R.ACTH), immunoreactive human chorionic somatomammotrophin (I.R.HCS) and 11-OH steroids levels were measured during normal and pathological pregnancies. Plasma I.R.ACTH levels were found to be above normal during pregnancy, with a slight decrease near term. This observation correlates well with the recent description of human chorionic corticotrophin (HCC), i.e. a factor of placental origin possessing a high biological adrenocorticotrophic activity and presenting partial immunological cross-reaction with human ACTH. The 11-OH steroids levels, as measured by a fluorimetric method, increased regularly during pregnancy but, unlike ACTH, reached their highest value near term, I.R.HCS increased progressively until term when a slight decrease was observed. In pathological pregnancies, I.R.ACTH levels behaved like other placental hormones. On the contrary, 11-OH steroids levels remained generally unmodified. Treatment with high doses of prednisolone caused no inhibition of the plasma I.R.ACTH and of plasma 11-OH steroids levels. These data suggest placental autonomy of the secretion of HCC and low adrenal responsiveness to endogenous ACTH variations throughout pregnancy.

SPECIFIC RECEPTORS FOR PROLACTIN IN THE OVARY

A role of prolactin (PRL) in ovarian function has been suggested in several species, but not unequivocally established except in the rat. We, therefore, examined the presence of specific receptor for PRL in ovaries of rat, cow, and human. Human PRL (hPRL) labelled with 125I by the lactoperoxidase method was shown to be capable of specific binding to rat mammary tissue homogenate. Human, cow, and rat ovarian homogenates and/or partially purified plasma membranes were also shown to specifically bind 125I-hPRL. Binding was a saturable phenomenon and was dependent on receptor protein concentration. Optimal binding was observed at pH 7.0 and 37 degrees C. Binding was reversibly inhibited by exposure of membranes to pH 10.0 and irreversibly destroyed by exposure to pH 3.0. Bound 125I-hPRL was displaceable by unlabelled human, ovine, and bovine PRL but not by FSH or LH. However, human chorionic somatomammotrophin (hCS) and hGH showed some competition with 125I-hPRL. Number of binding sites/mg protein was lowest (0.8 x 10(-12)M) during metoestrus and increased during dioestrus (11 x 10(-12)M) reaching the maximum number at pro-oestrus (24.6 x 10(-12)M). These results demonstrate that presence of specific PRL receptor in the ovaries and are consistent with a role of PRL at the ovarian level.

The existence during gestation of an immunological buffer zone at the interface between maternal and foetal tissues

In mammalian pregnancy the trophoblast normally constitutes an uninterrupted boundary of foetal tissue in immediate contact with maternal tissue, including blood in some species, and is the decisive immunological barrier to rejection of the foetus as an allograft. The ability of the trophoblast to function as a barrier evidently results from its capacity to resist immunological attack by either alloantibody or alloimmune cells and to prevent immunocompetent cells from reaching and damaging the foetus but, as yet, there is no general agreement regarding the means by which it exercises these functions. In view of the dramatic hormonal changes that occur during pregnancy and the undisputed involvement of trophoblast in these endocrine events, the possibility exists of an interaction between the hormones of pregnancy and the immunological phenomena. The present account furnishes evidence that endocrine activity at the maternal surface of the trophoblast, the presumptive site of the immunological frontier between foetus and mother, may be a factor in its local survival at implantation. The placental hormones so far known that are capable of blocking the antigen receptor sites of the mother's lymphocytes and thus preventing the latter from reacting with the foetal antigens are the glycoprotein, human chorionic gonadotrophin (HCG) and the polypeptide hormone, human chorionic somatomammotrophin (HCS) or human placental lactogen (HPL), both of which are specific to the human placenta. The origin of these hormones, their spatial distribution and their probable interaction with placental steroid hormones are discussed. It is argued that the place of highest concentration of these hormones is on the surface of the syncytial microvilli and the adjacent caviolae of the apical plasma membrane, as well as on the surfaces of the persisting cytotrophoblastic cells of the basal plate (cytotrophoblastic shell), the cell islands and the septa-precisely where the immunological challenge of the foetal allograft to the maternal host occurs. An explanation is offered for the continuing production of the voluminous quantities of these hormones during human pregnancy.

HORMONE AND ENZYME ASSAYS IN PREGNANCY

ABSTRACT A comparative study of human chorionic somatomammotrophin (HCS), placental cystine-aminopeptidase (P-CAP), progesterone and total urinary oestrogens (Oe) in pregnancies complicated with essential hypertension, mild or severe pre-eclampsia was performed. No significant reduction in the 4 parameters could be demonstrated in cases complicated with essential hypertension. In cases complicated with mild pre-eclampsia, however, a significant reduction was found in the HCS (P < 0.001) and P-CAP (0.01 <P < 0.02) but not in the urinary oestrogen values (0.1 < P < 0.2). A tendency to increased progesterone values could be demonstrated. Furthermore, in those cases of mild pre-eclampsia associated with a birth weight below the 10 percentile, the HCS and P-CAP assays proved to be more sensitive than the urinary oestrogen assay. No influence upon the progesterone levels was observed in these cases. On the other hand, in pregnancies complicated with severe pre-eclampsia the HCS, P-CAP and urinary oestrogen values were significantly reduced (P < 0.001) but not the progesterone values (P > 0.5). Again, when severe pre-eclampsia was associated with low birth weight, HCS and P-CAP were the most reliable tests. Based upon the HCS, P-CAP and the urinary oestrogen readings placental and foeto-placental scores were introduced. The placental score provided valuable information concerning the viability of the infants but no additional information was obtained by the foetoplacental score. The results indicated that simultaneous measurements of HCS and P-CAP as a placental function test and total urinary oestrogens as a foeto-placental test contribute reliable information in pregnancies complicated with pre-eclampsia. The measurement of progesterone could not be recommended as a test for the placental function.

Hormonal Effects on Mammary Cytology

This reviews cytological studies of hormonal effects on the mammary gland. Normal lobuloalveolar growth in the intact animal requires the stimulation of estrogen and progesterone. Exogenous estrogen alone brings about limited growth in ovariectomized mice but a combination of exogenous estrogen and progesterone brings about growth similar to early pregnancy. Proliferation of mammary epithelium is under the direct influence of estrogen and progesterone. Alveolar and terminal duct epithelia undergo a marked morphological change during lactogenesis. Ultrastructural differentiation of the epithelium occurs immediately before and after parturition. The need for pituitary and adrenal hormones in addition to ovarian steroids for the progression of lactogenesis has been shown by endocrine ablation studies. Midpregnancy mouse mammary tissue exposed in vitro to the lactogenic hormone combination of glucocorticoid insulin and prolactin develops alveolar cells displaying all the accepted ultrastructural correlates of lactogenesis and lactation. This emphasizes the primary action of these 3 hormones on mammary epithelial structure. Human chorionic somatomammotrophin will substitute for pituitary prolactin in initiating secondary development of mouse and rabbit mammary tissue in vitro. Growth hormone is not needed in culture for lactogenesis unless insulin cortocoid and prolactin are in minimal amounts. Nonsecretory midpregnancy mouse mammary cells treated with insulin divided in vitro into cells ultrastructurally identical to parent cells. These daughter cells when treated with hydrocortisone developed a granular endoplasm reticulum but not milk protein or lactose synthesis. They divide only once and cannot be maintained long in a secretory state. Cytomorphological studies of induced lactogenesis in pseudopregnant rabbits showed that mammary cells do not develop to full synthesizing capacity until 72 hours after prolactin treatment and some hours after organelle development. Steroid hormones may inhibit lactogenesis either alone or in concert with lactogenic hormones. The observation that dairy cows yield significant milk prepartum shows that mammary growth and development are not absolutely parallel with elevated hormones at partuition. Also a gland-specific lactogenic inhibitor mechanism independent of hormones has been shown in cows.

275. Progesterone, estriol, human chorionic somatomammotrophin and human chorionic gonadotrophin in normal and pathological pregnancy during the first half of gestation

275. Progesterone, estriol, human chorionic somatomammotrophin and human chorionic gonadotrophin in normal and pathological pregnancy during the first half of gestation

HORMONE AND ENZYME ASSAYS IN PREGNANCY

ABSTRACT Simultaneous measurements of plasma human chorionic somatomammotrophin (HCS)1), progesterone and placental cystine-aminopeptidase (P-CAP) was performed during normal human pregnancies from about day 70 to term. By using Phadebas® HCS Test (Pharmacia) the HCS levels showed a gradual increase from detectable values at about day 70 to 5.6 μg/ml (mean level) at term. Both a wide range in the plasma levels and daily variations up to 1.5 μg/ml were observed. The lower limit during the last 2 months was 4.0–4.5 μg/ml. The gradually increasing plasma levels of progesterone showed considerable variations between and in each individual, especially during the last trimester. Individual variations up to 100 ng/ml from one day to another were observed. The lower limit of progesterone during the last trimester was about 30 ng/ml. These great variations make the progesterone assay of limited value as an index of the placental function. The P-CAP showed a gradual increase toward term, but the variations were minor compared with the HCS and progesterone levels. No systematic relationship between the HCS, progesterone and P-CAP values were found. In evaluation of the placental function, simultaneous measurements of hormones with a short half-life and enzymes with a long half-life would be benificial.

Studies on follicle-stimulating hormone in serum and urine during pregnancy

Human follicle-stimulating hormone (FSH) in urine and serum was determined during various stages of pregnancy by a double-antibody radioimmunoassay method. Out of 241 samples of urine analyzed from 156 women in their third trimester of pregnancy, all except 14 samples showed values that could be measured with reasonable accuracy. The mean ± S.D. values of urinary FSH in pregnancy were found to be 5.04 ± 4.55 U IRP-HMG/24 h. These compare well with FSH values of 5.8 ± 3.1 and 6.11 ± 3.34 U IRP-HMG/24 h found in the follicular and luteal phases, respectively, of the menstrual cycle of non-pregnant healthy women of reproductive age. Serum FSH in pregnancy was found to be very low and out of 223 samples from 103 normal pregnant women only 39 samples showed detectable amounts of FSH. A small positive correlation was found between urinary FSH and total oestrogens but no correlation was found between serum FSH and human chorionic somatomammotrophin (HCS). Implications of these findings are discussed.

In vitro synthesis of an ACTH-like hormone and human chorionic somatomammotrophin by placental and amniotic cells.

La synthèse de la somatomammotrophine (HCS) et d'un facteur présentant une réaction immunologique croisée avec l'ACTH a été démontrée dans des cultures de fragments de placenta et de membrane amniotique. Ce facteur est comparable à la corticotrophine chorionique humaine précédemment décrite dans le plasma de femme enceinte et les extraits placentaires.

Prolactin receptors: characteristics of the particulate fraction binding activity.

SUMMARY Ovine 125I-labelled prolactin was incubated with a membrane-rich particulate fraction of mouse mammary gland and bound hormone was separated by centrifugation and washing. The experiments identified two types of binding activity: total binding and specific binding, the fraction of the total which could be displaced competitively by native prolactin but not by a number of other polypeptides. Two other lactogenic hormones, human chorionic somato-mammotrophin and human growth hormone, displaced 125I-labelled prolactin in proportion to their known intrinsic lactogenic activities. Binding of 125I-labelled prolactin was complete within 20 min at 4 or 37 °C. Scatchard analysis of the binding indicated an apparent dissociation constant (Kd) of approximately 9 × 10−9 mol/l and a concentration of binding sites of 15·5 × 10−13 mol/mg particulate protein. The greatest rate of specific displacement of bound 125I-labelled prolactin was observed at concentrations of prolactin between 50 and 250 ng/ml, a concentration range near the mid-point of the dose—response curve of casein induction in intact mammary cells. The saturating concentration of prolactin for specific binding to mammary particles was similar to that for casein induction in intact cells. The prolactin binding activity was sensitive to treatment with trypsin or heating at 70 °C, indicating its protein nature. These properties of the mammary prolactin binding activity are those required of a receptor for prolactin or other lactogens. Prolactin-specific binding activity was also found in particles from mouse liver, kidney, and midbrain and from the ovary, adrenal, and seminal vesicle of the rat. These results suggest a fairly widespread tissue distribution of the prolactin receptor, and potentially implicate prolactin in the hormonal regulation of these organs.

Effect of prolactin on isolated rabbit myometrium.

Reports in recent years that normal levels of human chorionic somato-mammotrophin (HCS) in cases of threatened abortion are associated with continuation of pregnancy (Genazzani, Aubert, Casoli, Fioretti & Felber, 1969; Singer, Desjardins & Friesen, 1970; Niven, Landon & Chard, 1972) have led to the suggestion that lactogenic hormones may play a role in the maintenance of pregnancy. Sheep prolactin at a concentration of 10 μg/ml has been shown to exert a marked inhibitory effect on myometrial activity in pregnant guinea-pigs (Manku & Horrobin, 1973), rats primed with oestrogen and progesterone (Horrobin, Lipton, Muiruri, Manku, Bramley & Burstyn, 1973), as well as in non-pregnant human myometrium (Mugambi, Mati, Thairu & Muriuki, 1973). In the present study we show that sheep pituitary prolactin at a dose of 40 μg/ml exerts a less inhibitory effect on pregnant rabbit myometrium than in the species quoted above. Two parallel myometrial strips were obtained from the

Effect of human chorionic somatomammotrophin and human chorionic gonadotrophin on phytohaemagglutinin-induced lymphocyte transformation.

Effect of Human Chorionic Somatomammotrophin and Human Chorionic Gonadotropin on Phyto-haemagglutinin-induced Lymphocyte Transformation

Determination of plasma human chorionic somatomammotrophin and urinary oestriol in diabetic pregnancies.

Abstract. Human chorionic somatomammotrophin (HCS) in plasma and oestriol excretion in urine were serially determined in 45 diabetic and 15 normal pregnancies. In the diabetic group there were three perinatal deaths. Mean HCS and oestriol values were not significantly influenced by factors such as maternal age, age at onset of diabetes, duration of diabetes or presence of retinopathy. Group mean HCS and oestriol values were not significantly different between diabetics and controls. Six diabetics had one or more HCS values below 4 μg/ml. Four of them delivered small for date infants with one intra‐uterine and one neonatal death. In the former case death was preceded by a pronounced drop in oestriol and in the latter case oestriol values were low and fluctuating. Among Ihe remaining women with low HCS values, three had normal and one had increasing oestriol values within the lower normal range. All women with HCS values above 4 μg/ml had normal oestriol values and normal outcomes with one exception; this woman had low oestriol values and delivered a small for date infant with congenital rubella, who died as a result of hyaline membranes disease. It is concluded that determination of HCS in addition to determination of oestriol in pregnancies at risk could be of practical clinical value.