bluuebunny/crossref_metadata_2025_split huggingface dataset:
STUDIES ON OXYTOCIN IN THE BABOON DURING PREGNANCY AND DELIVERY
Authors: Dawood M. Yusoff , Lauersen Niels H. , Trivedi Devendra , Ylikorkala Olavi , Fuchs Fritz 
Published: December 2008

ABSTRACT
Oxytocin was determined by radioimmunoassay in pregnant baboons throughout gestation, in the foetus at caesarean section, and after oxytocin infusion into the mother and foetus. Serial maternal plasma oxytocin in 6 baboons during pregnancy showed a significant correlation between the gestational age and maternal plasma oxytocin concentrations with a correlation coefficient of r = 0.3185 and P < 0.005. Seventy-one out of 75 plasma samples (94.7 %) during pregnancy had detectable levels of oxytocin. Uterine vein plasma had higher oxytocin concentrations than maternal plasma and amniotic fluid (18.6 ± 4.6 pg/ml; mean ± se) but lower than umbilical, jugular vein and cardiac blood from the foetus. Foetal pituitary gland contained 5.4–26.1 μg oxytocin/g. Regular uterine contractions were established with iv oxytocin of 4–20 mU/min and the plasma oxytocin measured showed a significant correlation with the uterine activity achieved (r = 0.64, P < 0.001). The disappearance of plasma oxytocin at 179 days gestation gave an apparent half-life of 1.1 and 1.7 min in 2 baboons with a late half-life of 9.9 and 17.3 min, respectively. In one baboon at 171 days gestation, the apparent half-life of oxytocin was 9.9 min. The metabolic clearance rates were calculated to be 3.1, 3.2 and 11.7 ml/kg/min, respectively. The production rates were 97, 74, 390 pg/kg/min, respectively. Oxytocin injected into the umbilical vessel near term showed an increase in oxytocin concentration in maternal and uterine vein plasma and amniotic fluid, suggesting that oxytocin can cross the placenta from the foetal to the maternal side. Our findings indicate that in the baboon (1) oxytocin is present throughout pregnancy, (2) uterine activity can be correlated with plasma oxytocin during oxytocin infusion, (3) foetal circulation has higher oxytocin concentration than maternal blood and (4) oxytocin probably can cross the placenta from the foetus to the mother.
LH AND TESTOSTERONE RELEASE IN DEVELOPING BULLS FOLLOWING LH-RH TREATMENT. EFFECT OF GONADECTOMY AND CHRONIC TESTOSTERONE PROPIONATE PRE-TREATMENT.
Authors: Lacroix A. , Pelletier J. 
Published: December 2008

ABSTRACT
LH and testosterone release after LH-RH treatment was studied in male calves from 1 week to 8 months of age. Total LH release, LH peak values and duration of the discharge increased from 1 week to 4 months of age by 406, 453 and 110 %, respectively. Significant decreases of 54, 48 and 24 % were observed at 6 months of age compared to 4 months of age. This was followed by steep increases in those variables of 344, 129 and 69 % at 8 months compared to 4 months. A testosterone response following an LH increase was first seen at 4 months of age when a weak discharge occurred in 2 out of 5 calves. In older calves strong and LH-correlated testosterone responses were always observed.
In a second experiment the LH response to LH-RH was studied in 6 months old calves castrated 2 months previously. The total LH response was 61 % greater than in intact controls. When animals were castrated and pre-treated briefly with testosterone propionate the response was increased by 183 % and the time to reach the LH peak was increased by 360 % From these and other results a synthesis of endocrine events during the first year of life is proposed. In particular it seems that the period between 4 and 8 months of age is crucial since interactions between steroid feedback and pituitary sensitivity to LH-RH change and eventually reach an equilibrium.
INHIBITORY EFFECT OF DIBUTYRYL CYCLIC AMP ON THE RELEASE OF CALCIUM, INORGANIC PHOSPHATE AND LYSOSOMAL ENZYMES FROM CALVARIAL BONES CULTURED FOR 24 HOURS
Authors: Lerner U. , Gustafson G. T. 
Published: December 2008

ABSTRACT
The effect of N6,O2′-dibutyryl adenosine 3′,5′-cyclic-monophosphate (dbcAMP) on the mobilization of calcium (Ca2 +), inorganic phosphate (Pi) and lysosomal enzymes was studied in a bone culture system for 24 h using half calvaria from 6–7 day-old mice. DbcAMP inhibited spontaneous as well as parathyroid hormone-stimulated mineral mobilization. DbcAMP in a concentration of 5 × 10−4m also reduced the activities of β-glucuronidase, β-galactosidase and acid phosphatase found in the media while the activities of lactate dehydrogenase, aspartate aminotransferase and alanine aminotransferase were not affected. It is concluded that cAMP is not a stimulator but an inhibitor of bone resorption within the culture period studied (24 h) and that the cyclic nucleotide might interfere with release processes involved in bone resorption.
COMPARISON OF AVIDIN INDUCTION IN THE DIFFERENTIATED AND UNDIFFERENTIATED CHICK OVIDUCT BY PROGESTERONE, ACTINOMYCIN D AND OVIDUCTAL INJURY
Authors: Elo Heikki A. 
Published: December 2008

ABSTRACT
Various oestrogen (diethylstilboestrol, DES) pre-treatments were carried out on chicks and the production of avidin in the oviduct was induced by progesterone, actinomycin D or oviductal injury.
Avidin induction was dose-dependent at doses between 5 mg and 40 mg progesterone/kg or 50 μg and 300 μg actinomycin D/kg respectively. The induction by oviductal injury correlated with the magnitude of tissue injury. First signs of avidin induction were seen at 4 h after oviductal injury, 12 h after progesterone or 12–16 h after actinomycin D administration. Actinomycin D (200 μg/kg), when administered after progesterone injection, did not increase avidin induction by progesterone, this indicating that avidin induction by actinomycin D is not a "superinduction" effect.
Evidence is presented here that the mechanism of avidin induction by oviductal injury and actinomycin D differs from that by progesterone. The differentiation of the oviduct caused by DES treatment was necessary for the induction by progesterone, whereas actinomycin D and oviductal injury also induced avidin in the undifferentiated or poorly differentiated oviduct. Simultaneous DES stimulation potentiated induction by progesterone but not by actinomycin D or oviductal injury. Furthermore, single prior DES stimulation increased avidin induction in the differentiated oviduct of DES-withdrawn chicks caused by progesterone but not that by actinomycin D or oviductal injury.
A POSSIBLE ROLE OF CORPORA LUTEA WITH REGARD TO OESTROGEN-INDUCED CHANGES IN PITUITARY RESPONSIVENESS TO LH-RH
Authors: Schuiling G. A. , Pols-Valkhof N. , Koiter T. R. 
Published: December 2008

ABSTRACT
The effect of oestradiol benzoate (OeB; 3 μg sc) on LH-RH-induced LH-secretory responses was investigated in: (1) long-term ovariectomized (OVX) rats; (2) intact (i.e. sham-OVX) and 24 h-OVX persistent oestrous (PO) rats (intact PO rats do not possess corpora lutea); (3) intact and 24 h-OVX cyclic (dioestrous) rats (intact cyclic rats possess "not-activated" corpora lutea), and (4) intact and 24 h-OVX phase-2-pseudo-pregnant (phase-2-PSP) rats (phase 2 of PSP lasts from day 2 to day 10. Experiments were performed on days 7-8. Intact phase-2-PSP rats possess "activated" corpora lutea).
A "positive" effect of OeB was observed in: (1) long-term OVX rats; (2) intact and 24 h-OVX PO rats; (3) 24 h-OVX cyclic rats and (4) 24 h-OVX phase-2-PSP rats. In intact cyclic and phase-2-PSP rats OeB was completely ineffective.
From these observations it is concluded that only in the absence of corpora lutea OeB can exert a "positive" effect on LH-RH-induced LH-secretory responses. Ovariectomy alone, however, may have a negative impact on LH-RH-induced LH-secretory responses. This holds for PO- and phase-3-PSP rats (phase 3 of PSP begins once the corpora lutea come to lysis, i.e. on or shortly before day 10, and lasts until the end of PSP), but not for phase-2-PSP rats. In cyclic rats, on the other hand, ovariectomy performed on dioestrus-1 "only" interferes with the normal development of pituitary responsiveness to LH-RH and this can be nullified by OeB.
Our observations suggest that (1) relatively long-acting products of corpora lutea "stabilize" (phase-2-PSP rats), c.q. limit the (almost certainly oestrogen-dependent) development of pituitary responsiveness to LH-RH (cyclic and phase-3-PSP rats); (2) in ovariectomized rats the influence of these products vanishes and that (3) this results in a situation in which OeB can become effective. It is also suggested that in the course of the ovulatory cycle and phase 3 of PSP a similar disappearance of corpora luteal products occurs "spontaneously" as a result of the process of luteolysis with as a consequence that the pituitary responsiveness to LH-RH, under the influence of endogenous oestrogens, develops continuously until, on pro-oestrus, an LH-surge occurs.
Evidence is presented that the corpora luteal products, postulated in this paper, are not identical to progesterone.
TWENTY-FOUR HOUR SLEEP-WAKE PATTERN OF PLASMA LH IN PATIENTS WITH ANOREXIA NERVOSA
Authors: Pirke Karl M. , Fichter Manfred M. , Lund Raimar , Doerr Peter 
Published: December 2008

ABSTRACT
The 24-h sleep-wake pattern of plasma LH was studied in 18 patients with severe weight loss. Sixteen patients had anorexia nervosa, one suffered from schizophrenia and one had a gastric ulcer. The age of the patients ranged from 13 to 31 years. Seventeen women and one boy participated in the study. Their weight ranged from 51 to 73 % of the ideal body weight (IBW) at the first 24-h study which was at one week after admission to the hospital. Blood was taken through an indwelling venous catheter every 30 min. The patients' weight increased under behavioural therapy and they were re-studied when they had gained approximately 10 % IBW and again prior to release from the psychiatric ward. The LH patterns were classified as infantile, pubertal or adult. All patients except for two had an iniantile pattern at the first study. Except for the two patients who had no anorexia nervosa, all developed a pubertal and/or an adult pattern. All patients whose weight was below 69 % IBW had an infantile LH pattern. Adult patterns were only seen when the body weight was greater than 80 % IBW. The increase of the average 24-h LH values was slower the older the patients were and the longer they had been anorectic.
TIAPRIDE-INDUCED CHRONIC HYPERPROLACTINAEMIA: INTERFERENCE WITH THE HUMAN MENSTRUAL CYCLE
Authors: L'Hermite M. , Michaux-Duchêne A. , Robyn C. 
Published: December 2008

ABSTRACT
Four regularly menstruating volunteers were submitted to an oral treatment, for 3 consecutive cycles and starting on the first day of a cycle, with tiapride at daily doses ranging from 1 × 100 mg to 2 × 100 mg. The first and the last cycle under treatment, as well as a prior control cycle, were thoroughly studied by means of daily measurements of blood concentrations of LH, FSH, prolactin (PRL), oestradiol and progesterone. Tiapride, a benzamide derivative with dopaminergic blocking activity at the level of the lactotrophes, increased mean PRL secretion in each subject but a permanent hyperprolactinaemia above 700 μU/ml was attained only in one subject.
Despite these widely fluctuating PRL levels in most subjects, the resulting overall hyperprolactinaemia induced in all cases a progressive deterioration of the function of the corpus luteum: 5 cycles showed luteal phases reduced by 2–5 days, one cycle was characterized by some slight luteinisation but questionable ovulation and the 2 remaining cycles were anovulatory. The interruption of drug intake one week after the onset of menses led thereafter to a cycle with a likely inadequate luteal phase but of normal length. It is concluded that even a non-permanent hyperprolactinaemia can impair the normal function of the hypothalamo-pituitaryovarian axis, as well as exhibit some effects in a cycle consecutive to the normalization of PRL.
With the exception of the impaired luteal progesterone secretion, the pooled hormonal data from the short luteal phase cycles under tiaprideinduced hyperprolactinaemia exhibit very little significant differences, as compared to the corresponding values in the control cycles. Some delay in the onset of follicular maturation, however, should be assumed since the follicular phase had been lengthened by 1 to 31 days in 5 of the 6 cycles with luteinisation during treatment.
The present results are compatible with a double impact – both at the ovarian and the hypothalamo-pituitary levels – of hyperprolactinaemia in its mechanisms of impaired function of the hypothalamo-pituitary ovarian axis.
INTERACTION OF [125I]LH-RH AND OTHER OLIGOPEPTIDES WITH PLASMA MEMBRANES OF RAT ANTERIOR PITUITARIES
Authors: Baumann Rudolf , Kuhl Herbert 
Published: December 2008

ABSTRACT
The specific binding of [125I]LH-RH to isolated plasma membranes of rat pituitaries was investigated. The binding process was found to be highly specific, temperature-dependent and saturable. The dissociation constant as calculated by three different methods was approximately 1.3 · 10−8 m, indicating a single type of binding sites. Maximal binding capacity was 1 · 10−12 moles/mg protein (=2 ng LH-RH/pituitary gland), and the number of binding sites was calculated to be 6 · 1011 per mg membrane protein (= 1 · 1010 binding sites/pituitary gland). When diluted with icecold buffer the dissociation of specifically bound LH-RH occurred very rapidly (half-life 3.17 min) with a rate constant of 0.219 min−1. The dissociation process followed first-order kinetics.
Specificity of binding was demonstrated by dose-dependent competition of unlabelled LH-RH, the highly potent analogue D-glutamine-(cyclohexyl)6-LH-RH-nonapeptide-ethylamide and the fragment of an analogue (6-D-Ser(TBu))-LH-RH-(3-9)-heptapeptide-ethylamide with the binding [125I]LH-RH, while angiotensin I, II, oxytocin and bacitracin did not compete. The affinities of LH-RH and the analogue to the binding sites of the pituitary plasma membranes were not consistent with the respective biological activities.
EFFECT OF EXERCISE ON THYROID PARAMETERS AND ON METABOLIC CLEARANCE RATE OF ANTIPYRINE IN MAN
Authors: Theilade Peter , Hansen Jens Mølholm , Skovsted Lis , Kampmann Jens P. 
Published: December 2008

ABSTRACT
Serum concentrations of thyroxine, triiodothyronine, free-thyroxine-index, free-triiodothyronine-index and reverse-triiodothyronine (r-T3) were followed in nine normal men, aged 18 to 22 years, during a nights rest and during nine hours march (4.6 km/h). In addition antipyrine elimination was measured in the same periods after iv injection of 1 gram of antipyrine. No significant differences were found in any of the thyroid parameters during exercise except for a small increase in serum r-T3 after 3 hours. During rest a small but significant decrease was found in serum r-T3. Otherwise no significant differences were found except for a significant increase in free-T3-index after 3 hours rest.
The mean value of total body clearance of antipyrine was identical at rest and during exercise.
In conclusion: Prolonged exercise does not change the metabolic clearance rate of antipyrine and does not elicit any major change in the serum concentrations of the thyroid hormones.
INHIBITORY EFFECT OF CERTAIN DRUGS ON THYROID HORMONE BINDING BY HUMAN LIVER CYTOSOL
Authors: Hamada Satoshi , Nishimoto Miyuki 
Published: December 2008

ABSTRACT
Effects of dinitrophenol (DNP), salicylate, diphenylhydantoin (DPH) and heparin on thyroid-hormone binding by human liver cytosol were studied using Pevikon thin-layer electrophoresis. Thyroxine (T4) binding by the major cytosol T4-binding protein, hT4-2, was significantly depressed with these drugs, and the displaced T4 was bound by another cytosol binding protein, hT4-1. Triiodothyronine (T3) binding by the major cytosol T3-binding protein, hT3-2, was significantly decreased with DPH and heparin, but not with DNP and salicylate. Comparative studies using human serum indicated that T4 binding by serum Ti-binding prealbumin (TBPA) was inhibited with DNP and salicylate, and that binding of T4 and T3 by serum T4-binding globulin (TBG) was decreased only with DPH. The results obtained indicate that these drugs inhibit thyroid-hormone binding by the liver cytosol binding proteins for T4 and T3, and that the displaced hormones may be responsible for changes in free hormone levels in serum, and within the cells, and for the accelerated turnover of hormones.
IODOAMINO ACID SYNTHESIS IN THYROID LOBES IN VITRO WITH EXCELLENT YIELD OF IODOTHYRONINES
Authors: Okamura Ken , Inoue Kenjiro , Nakashima Toshiro , Shiroozu Akiyo , Yoshinari Mototaka 
Published: December 2008

ABSTRACT
Thyroid lobes of male Sprague-Dawley rats on an iodine-sufficient diet were incubated in our improved in vitro system with 0.01 μm 127I and 5 mU/ml of bovine TSH. Thyroidal 131I-uptake and the relative incorporation of iodine into iodothyronines increased with time. The average yield of each iodoamino acid after 8 h of incubation was: monoiodotyrosine 28.0 %, diiodotyrosine 46.5 %, triiodothyronine 1.9 % and thyroxine 13.9 %, which showed a striking resemblance to the values obtained in vivo. The yields of iodotyrosines and iodothyronines, the latter in particular, were strikingly high, and this system is considered to be useful in the study of thyroidal iodine metabolism.
Effects of TSH, temperature and pH of the medium were examined and a unique effect of pH was observed on the iodoamino acid synthesis. As the pH was elevated from 6.8 to 7.9, 131I-uptake, MIT/DIT ratio, T4/DIT ratio and T3/T4 ratio increased. The effect of slightly alkaline pH was considered to be similar to that observed in iodine-deficiency.
It was found that the rubber stoppers which are commonly used in shortterm incubation contain a kind of potent inhibitor of thyroid hormone synthesis. The pattern of inhibition was similar to that of thionamide compounds.
REGULATORY HYPERPARATHYROIDISM IN A PIG BREED WITH VITAMIN D DEPENDENCY RICKETS
Authors: Wilke R. , Harmeyer J. , von Grabe C. , Hehrmann R. , Hesch R. D. 
Published: December 2008

ABSTRACT
A radioimmunoassay for porcine parathyroid hormone has been developed and applied to measure immunoreactive parathyroid hormone (PTH) in plasma of pigs with hereditary vitamin D dependency rickets (VDDR) (pseudovitamin D deficiency rickets). Levels of 25-hydroxycholecalciferol (25-(OH)-D3) in plasma were measured by a protein binding assay. Both plasma concentrations of PTH and 25-(OH)-D3 showed an approximately 4-fold increase compared to normal pigs. PTH levels increased with duration of the disease. Daily dosing of the animals with 1–4 μg of 1,25-dihydroxycholecalciferol (1,25-(OH)2-D3) reduced PTH concentrations and resulted in clinical healing. Iv administration of 10 μg of 25-(OH)-D3/day did not alter PTH concentrations nor the clinical symptoms. The results suggest that these animals suffer from regulatory hyperparathyroidism. The metabolic defect could be due to a failure of the kidney to convert 25-(OH)-D3 to 1,25-(OH)2-D3.
EFFECT OF A SEQUENTIAL OESTROGEN-PROGESTIN THERAPY ON THE PLASMA LEVEL OF OESTROGENS AND LIPIDS IN POST-MENOPAUSAL WOMEN
Authors: Lillienberg L. , Adlercreutz H. , Svanborg A. 
Published: December 2008

ABSTRACT
With the aim of minimizing side effects of substitution therapy a natural synthetic oestrogen, oestrone sulphate, and norethisterone acetate were administered to 6 oophorectomized women and 4 women with physiological menopause cyclically in order to follow the pattern of physiological variations during the menstrual cycle as closely as possible, without causing bleedings. In addition to assessing the clinical effects and analyses of plasma oestrone and oestradiol-17β, the metabolic effects on plasma triglycerides, cholesterol and individual phospholipid levels, as well as on the fatty acid composition of lecithin were followed.
The oral administration of oestrone sulphate in doses varying with the "cycle" from 0.5 to 1.5 mg/day gave in these women plasma concentrations of oestrone in the lower pre-menopausal physiological range causing cyclic variations in plasma lipids similar to those during a physiological menstrual cycle but did not normalize the plasma oestradiol concentrations and did not give acceptable therapeutic effect. Total phospholipids, total and free cholesterol, triglycerides and the percentage of lecithin were higher, and the percentage of lysolecithin lower in the oestrogen phase, than in the progestin phase. The changes in linoleic acid in lecithin varied inversely with changes in arachidonic acid in lecithin and cyclic variations also occurred in the content of palmitic and stearic acid in lecithin.
When previous treatment with ethinyloestradiol was exchanged with oestrone sulphate the total cholesterol values in plasma varied in the opposite direction. The results obtained in this and previous studies suggest different effects of ethinyloestradiol and oestrone (oestrone sulphate?) in the metabolism of certain sterols, and that the effect of oestrone (or oestrone sulphate?) on plasma cholesterol dominates during physiological condition in the follicular phase of the menstrual cycle.
HCS REGULATION IN CULTURED PLACENTA: ACTION OF GLUCOSE
Authors: Belleville F. , Lasbennes A. , Nabet P. , Paysant P. 
Published: December 2008

ABSTRACT
The regulation of HCS secretion on placenta cultures in the presence of [3H] leucine was studied.
When Eagle's medium containing 0.0055 m of glucose per liter is used, it it noted that the HCS increases regularly in the culture medium, whereas it diminishes in the explants. [3H] HCS represents about 50 % of the [3H] proteins, and among these proteins HCS is preferentially secreted in the culture medium.
The absence of glucose in the medium provokes a decrease in all of the cellular metabolism as well as a decrease in protein and HCS secretions, with an accumulation of preformed HCS in the tissues.
An increase in the glucose level in the medium 0.011 and 0.027 m provokes a selective decrease of HCS secretion with an accumulation of preformed HCS in the tissues, determining a long term decrease in HCS synthesis. Insulin added in the mediums (60 μU/ml) does not change the results significantly.
The use of structural analogues of the glucose shows that the point of impact of the HCS secretion regulation by the glucose is membranous; however, it seems that at a second stage one or some glucose metabolites also intervene.
There is no self regulation of HCS secretion in vitro.