bluuebunny/crossref_metadata_2025_split huggingface dataset:
INTERNATIONAL REFERENCE PREPARATION OF HUMAN CHORIONIC GONADOTROPHIN FOR IMMUNOASSAY: POTENCY ESTIMATES IN VARIOUS BIOASSAY AND PROTEIN BINDING ASSAY SYSTEMS; AND INTERNATIONAL REFERENCE PREPARATIONS OF THE α AND β SUBUNITS OF HUMAN CHORIONIC GONADOTROPHIN FOR IMMUNOASSAY
Authors: STORRING P. L. , GAINES-DAS ROSE E. , BANGHAM D. R. 
Published: December 2008

The preparation and nature of the International Reference Preparation of Human Chorionic Gonadotrophin (HCG) for Immunoassay (IRP), as well as that of a second batch of ampoules (HCG 75/589) prepared identically from the same HCG preparation, are described.
A collaborative study of these materials was carried out by 11 laboratories in eight countries, using different bioassay and immunoassay methods. Using the various in-vivo and in-vitro bioassays and receptor assays, the mean log potency estimates for each method within each laboratory of the HCG content of ampoules of the IRP, in terms of the Second International Standard of Human Chorionic Gonadotrophin for Bioassay (IS), were homogeneous and gave an overall weighted geometric mean (95% confidence limits) of 650 (632–669) International Units (i.u.)/ampoule.
There was considerable heterogeneity of potency estimates of the IRP in terms of the IS both within and between many of the immunoassay systems (reflecting the impurity of the IS), and hence attempts to calibrate the IRP with immunoassay systems of different specificities were invalid.
Immunoassay estimates of the HCG content of preparations of serum and urine, in terms of the IRP, showed considerable heterogeneity between assay systems (although the degree of this heterogeneity was no greater than that observed using the IS as standard), but the ranking order between preparations was consistent.
Confirmation was obtained that contamination of the IRP with HCG-α and HCG-β subunits was insignificant. Accelerated degradation studies of the IRP stored at increased temperatures suggested that its stability under normal storage conditions would be satisfactory.
It was agreed that the IRP was suitable to serve as an international reference preparation for immunoassay, and it was assigned a unitage of 650 i.u./ampoule on the basis of bioassay calibration.
Since the ampoules of HCG (75/589) did not differ significantly from the IRP in any of the assay systems studied, it appeared to be equally suitable as a reference preparation.
The International Reference Preparations of the α and β Subunits of Human Chorionic Gonadotrophin for Immunoassay are also described.
INHIBITION BY INDOMETHACIN OF OVULATION INDUCED BY HUMAN CHORIONIC GONADOTROPHIN IN IMMATURE RATS PRIMED WITH PREGNANT MARE SERUM GONADOTROPHIN
Authors: MORI TAKAHIDE , KOHDA HEIGO , KINOSHITA YASUSHI , EZAKI YOJIRO , MORIMOTO NORIHIKO , NISHIMURA TOSHIO 
Published: December 2008

Treatment of immature rats with pregnant mare serum gonadotrophin followed by human chorionic gonadotrophin (HCG) caused an acute and temporary increase in concentrations of progesterone, testosterone and oestradiol in plasma with maximum levels 3 h after the administration of HCG.
Concurrent injection of indomethacin and HCG reduced, in a dose-dependent manner, the mean number of ova shed and this was accompanied by a dose-dependent decrease in concentrations of plasma progesterone and testosterone but not of oestradiol when they were measured 3 h after the injection of HCG. The minimum effective dose that blocked ovulation completely at 0 h abolished the acute increase of progesterone and testosterone, suggesting that prostaglandins act on ovulation by stimulating steroidogenesis at an early stage in the preovulatory process. The anti-ovulatory action of the minimum effective dose at 0 h became progressively less potent as the time between injection of HCG and administration of indomethacin was increased, although plasma concentrations of progesterone and testosterone measured at autopsy 18 h after treatment with HCG had not changed appreciably. When indomethacin was administered 10 h after HCG, the relationship between the dose of indomethacin and the mean number of ova differed from that observed when simultaneous injections of indomethacin and HCG were given, and the minimum effective dose that prevented ovulation was much higher than that at 0 h, suggesting that prostaglandins act differently on ovulation in the later stage of the preovulatory process.
It was concluded that prostaglandins may mediate the action of HCG on ovulation through two mechanisms which operate at different stages of the preovulatory process.
REGULATION OF THE METABOLISM OF PITUITARY NUCLEIC ACIDS IN FEMALE RATS
Authors: BÍRÓ J. 
Published: December 2008

SUMMARY
Ovariectomy caused an increase in the metabolism of pituitary nucleic acids. This effect was reversed in vivo by a biphasic action of oestradiol-17β which first facilitated RNA metabolism after 8 h and then inhibited it 16 h after intraperitoneal injection. To analyse the origin of this biphasic effect the roles of LH releasing hormone (LH-RH) and hysterectomy were examined.
Incorporation of uridine into the RNA of the anterior pituitary gland of female rats was inhibited both in vivo and in vitro by LH-RH. Hysterectomy augmented the increase in the RNA metabolism caused by ovariectomy whereas steroid-free uterine extracts inhibited the increase significantly.
We have concluded that extrapituitary factors may be involved in the effects of oestrogen on the metabolism of pituitary nucleic acids.
CONCENTRATIONS OF PLACENTAL LACTOGEN IN CHRONICALLY CATHETERIZED EWES AND FETUSES IN LATE PREGNANCY
Authors: TAYLOR M. J. , JENKIN G. , ROBINSON J. S. , THORBURN G. D. , FRIESEN H. , CHAN J. S. D. 
Published: December 2008

SUMMARY
The concentration of ovine placental lactogen (oPL) was measured by radioimmunoassay in plasma samples from chronically catheterized ewes and their fetuses from day 110 of gestation to term (about day 145).
Concentrations of oPL in the plasma of the mother and fetus were raised after surgery, and remained raised for 3–5 days after the operation. Concentrations of oPL were greatest in the fetus at days 120–124 of gestation, and then declined until delivery. Mean concentrations of oPL in the fetus in late pregnancy for single, twin and triplet pregnancies were 101±6 (s.e.m.), 100±11 and 117±59 ng/ml respectively and were not significantly different.
Mean concentrations of oPL in the mother in late pregnancy for single, twin and triplet pregnancies were 718±227, 1387±160 and 1510±459 ng/ml respectively; the difference between these means was significant (P <0·05). Peak concentrations were noted at days 130–139 of gestation after which concentrations fell and were significantly lower on the day of delivery (P <0·01). Concentrations of oPL in the mother showed no circadian rhythm. The mean concentrations of oPL in maternal plasma during late pregnancy was significantly correlated to the combined fetal weight at birth (r = 0·624, P <0·01).
INHIBITION BY CALCITONIN OF HYPERCALCAEMIA INDUCED BY 1,25-DIHYDROXYCHOLECALCIFEROL
Authors: BARLET J.-P. 
Published: December 2008

SUMMARY
The influence of injections of calcitonin on the hypercalcaemia and hyperphosphataemia induced by 1α-hydroxycholecalciferol (1α-OHD3) and 1,25-dihydroxycholecalciferol (1,25-(OH)2D3) was studied in growing lambs and lactating cows respectively.
In lambs, the hypercalcaemic and hyperphosphataemic effect of 0·1 μg 1α-OHD3/kg body weight (i.v.) was completely inhibited by 20 units calcitonin/kg body weight, injected subcutaneously in four equal doses at intervals of 12 h, the first injection of calcitonin occurring immediately after injection of 1α-OHD3. Moreover, the same dose of calcitonin partly inhibited the hypercalcaemia and hyperphosphataemia observed after injection of 0·25 μg 1α-OHD3/kg body weight.
In lactating cows, four injections of calcitonin (5 u./kg body weight each, at intervals of 12 h) prevented the rise of plasma calcium and phosphate levels occurring after injection of 1,25-(OH)2D3 (0·01 μg/kg body weight).
The results indicated that high plasma calcitonin levels can inhibit the hypercalcaemic and hyperphosphataemic effects of 1,25-(OH)2D3 in ruminants. Thus, hypocalcaemia might occur in parturient cows in spite of raised concentrations of 1,25-(OH)2D3 in plasma.
EFFECTS OF VAGAL STIMULATION, VAGOTOMY AND ADRENALECTOMY ON RELEASE OF INSULIN IN THE RAT
Authors: SAKAGUCHI TAKEO , YAMAGUCHI KEN'ICHI 
Published: December 2008

SUMMARY
To evaluate the physiological role of the vagus nerve in the secretion of insulin in the rat, changes in plasma levels of insulin and sugar were examined after vagotomy with and without adrenalectomy. Male rats, fasted for 22 h, weighing about 300 g and anaesthetized with pentobarbitone sodium were used. Thirty minutes after unilateral or bilateral adrenalectomy, the first blood sample was taken just before pancreatic vagotomy and a second sample was taken 15 min after vagotomy. Pancreatic vagotomy significantly decreased levels of plasma insulin in bilaterally adrenalectomized rats. It was also confirmed that electrical stimulation of the pancreatic vagus nerve provoked an increase in levels of insulin associated with a reduction of carbohydrates in the blood. These observations support the theory that there is a vagal mechanism which modulates the secretion of insulin and suggest that the vagal mechanism is a potent factor although such a mechanism may be masked by the activity of the adrenal gland.
DEVELOPMENT OF HOMOLOGOUS IMMUNOLOGICAL ASSAYS FOR HUMAN PARATHYROID HORMONE
Authors: MANNING R. M. , HENDY G. N. , PAPAPOULOS S. E. , O'RIORDAN J. L. H. 
Published: December 2008

SUMMARY
Antisera to a trichloroacetic-acid precipitate of human parathyroid hormone (PTH) were produced in goats. Two of these antisera (G36 and G31) were of high affinity, and the bovine and porcine hormones were less reactive. Synthetic peptides containing the amino-terminal region of human PTH reacted with both antisera; the 1–34 peptide (PTH-(1–34)), with the sequence proposed by Niall, Sauer, Jacobs, Keutmann, Segre, O'Riordan, Aurbach & Potts in 1974, was more reactive than that having the sequence proposed by Brewer, Fairwell, Ronan, Sizemore & Arnaud in 1972. The antisera were further characterized with a number of other native and synthetic fragments of human PTH and reacted poorly with fragments from the carboxy-terminal region of the molecule. Since the amino-terminal fragments did not account for all the immunoreactivity, it is assumed that the antisera had some recognition sites for the central part of the molecule.
Highly purified human PTH-(1–84) was labelled with 125I and radioimmunoassays were developed using this tracer and antiserum G36. To avoid the problems associated with labelling human PTH with 125I, a labelled antibody assay was developed with G36 and an immunoadsorbent consisting of human PTH-(1–34) (sequence of Niall et al.) coupled to cellulose. A sensitive homologous amino-terminal specific assay was developed in this way.
INCORPORATION OF [U-14C]GLUCOSE IN VITRO BY THE VARIOUS PARTS OF THE FALLOPIAN TUBE AND UTERUS OF THE RABBIT DURING OVUM TRANSPORT
Authors: PURI R. K. , ROY S. K. 
Published: December 2008

Incorporation of [U-14C]glucose in vitro was determined in ampullary, ampullary–isthmic junction and isthmic segments of the Fallopian tube and uterus of intact (oestrous) rabbits and also at various times after mating. In the oestrous animals, incorporation was slightly higher in the ampullary segment compared with the isthmic and the ampullary–isthmic junction and finally the uterus. The pattern changed significantly in the pregnant animals. At 14 and 24 h post coitum, the pattern of incorporation was similar to that found at oestrus except for an increase in uterine incorporation. However, at 48 and 72 h post coitum, incorporation by the isthmic segment and the uterus was significantly increased compared with corresponding values at oestrus, and 14 and 24 h post coitum.
The implication of these changes during egg transport through the Fallopian tube is discussed.
EFFECT OF EQUOL ON OESTROGEN RECEPTORS AND ON SYNTHESIS OF DNA AND PROTEIN IN THE IMMATURE RAT UTERUS
Authors: TANG B. Y. , ADAMS N. R. 
Published: December 2008

In immature, 3-week-old female rats, 5 mg equol given by subcutaneous injection increased uterine wet weight 24 h later to the same degree as did 5 μg oestradiol-17β. At this dose there was more receptor complex binding to the nucleus in the equol-injected rats than in the rats injected with oestradiol-17β even after 6 h. However, the equol–receptor complex that bound to the nucleus was more extractable with 0·3 m-KC1.
In the equol-injected rats the duration of uterine growth was shorter and there was less receptor replenishment and synthesis of protein and DNA than in the rats injected with oestradiol-17β 30 h after either injection.
It was concluded that equol is a weakly oestrogenic compound which is antagonistic to oestradiol-17β by competing with oestradiol–receptor complex for nuclear binding and yet fails to initiate the replenishment of oestrogen receptors effectively in the cytoplasm.
PROSTATIC INDUCTION: INTERACTION OF EPITHELIUM AND MESENCHYME FROM NORMAL WILD-TYPE MICE AND ANDROGEN-INSENSITIVE MICE WITH TESTICULAR FEMINIZATION
Authors: LASNITZKI ILSE , MIZUNO TAKEO 
Published: December 2008

The prostate gland develops from the urogenital sinus as epithelial buds projecting into the surrounding mesenchyme. The role of the mesenchyme in this process was determined using sinuses from normal and androgen-insensitive Tfm mice which are deficient in androgen receptors. Epithelium and mesenchyme from both types of sinus were separated and recombined and the recombinants grown in organ culture in the presence of testosterone.
Recombinants consisting of normal epithelium and normal mesenchyme developed epithelial buds projecting into the surrounding mesenchyme but no buds were formed in recombinants of epithelium and mesenchyme from mutant mice. In recombinants of epithelium from mutant mice with normal mesenchyme the epithelium developed prostatic buds and the number was similar to that found if normal epithelium was associated with normal mesenchyme. In contrast, normal epithelium combined with mesenchyme from mutant mice failed to form prostatic buds. The results suggested that the mesenchyme determines the development of prostatic buds and that the lack of inductive capacity of the mesenchyme from mutant mice may be due to a deficiency of mesenchymal androgen receptors.
A RADIOIMMUNOASSAY OF GASTRIC INHIBITORY POLYPEPTIDE IN HUMAN PLASMA
Authors: SARSON D. L. , BRYANT M. G. , BLOOM S. R. 
Published: December 2008

A sensitive radioimmunoassay for the measurement of human gastric inhibitory polypeptide (GIP), using pure porcine GIP, has been developed. Cross-reactivity of the antiserum with all available mammalian gut peptide preparations was negligible with the exception of glucagon when it was approximately 1%. Two major molecular forms of GIP were detectable in plasma and tissue extracts, one of large molecular size and the other corresponding to the elution coefficient of pure porcine standard.
Concentrations of GIP in plasma from 50 normal subjects after overnight fasting were 9 ± 1·0 (s.e.m.) pmol/l rising to a peak of 34 ± 2·8 pmol/l following the ingestion of a small mixed test meal. Ingestion of glucose or fat resulted in a similar rise of plasma GIP, whereas no change was observed after the ingestion of protein.
EFFECTS OF HUMAN GROWTH HORMONE ON THE SECRETION OF RAT GROWTH HORMONE
Authors: WILLOUGHBY J. O. , MENADUE MARGARET , ZEEGERS P. , WISE P. H. , OLIVER J. R. 
Published: December 2008

Human growth hormone (hGH) was administered to chronically cannulated male rats and its effect upon the physiological secretory patterns of rat growth hormone (rGH) and prolactin were observed.
In comparison with injected control animals, a reduction in the size of spontaneous secretory bursts of rGH was apparent when hormone concentrations were compared 3–6 h after administration of hGH (136·27 ± 27·31 (s.e.m.) v. 76·22 ± 20·98 ng/ml respectively). However, the mean frequency of secretory episodes of rGH was unaltered.
It is therefore postulated that endogenous rGH may modulate the amplitude but not the rhythmicity of secretory episodes of rGH.
SOMATOMEDIN-LIKE ACTIVITY IN CATTLE: THE EFFECT OF BREED, LACTATION AND TIME OF DAY
Authors: FALCONER J. , FORBES J. M. , BINES J. A. , ROY J. H. B. , HART I. C. 
Published: December 2008

Somatomedin-like activity (SLA) was measured in plasma samples from cattle using the porcine costal cartilage disk bioassay. In 40-day-old pre-ruminant bull calves, SLA was highest in the plasma of eight Friesians (mean potency 0·97±0·06 (s.e.m.) units/ml), lowest in five Aberdeen Angus × Friesians (0·78±0·03, P<0·05) and intermediate in six Hereford × Friesians (0·89±0·09). Plasma levels of SLA were significantly (P<0·01) lower in eight lactating Friesian (high-yielding) cows (0·53 ± 0·04) than in five dry cows (0·76±0·06). Levels of SLA in the plasma of a further eight lactating Hereford × Friesian (low-yielding) cows (0·76±0·07) were similar to the levels in the plasma of the five dry dairy cows.
Large diurnal changes in plasma SLA occurred in lactating Hereford × Friesian and Friesian heifers. In three Hereford × Friesian heifers plasma levels of SLA were lowest at 19.00 h (0·39±0·07) and highest at 03.00 h (0·77±0·08). A similar pattern was present in plasma samples from three Friesian heifers; the lowest levels of SLA being at 21.00 h (0·37±0·07) and the highest at 05.00 h (0·61±0·13). Throughout the period of 24 h the overall mean levels of SLA were significantly (P<0·01) higher in the plasma samples from the three Hereford × Friesian heifers (0·6 ±0·01) than in the samples from the three Friesian heifers (0·49 ± 0·02 units/ml).
PITUITARY CONTENT OF OXYTOCIN, VASOPRESSIN AND α-MELANOCYTE-STIMULATING HORMONE IN THE FETUS OF THE RAT DURING LABOUR
Authors: BOER K. , DOGTEROM J. , PRONKER H. F. 
Published: December 2008

The pituitary contents of oxytocin, vasopressin and α-MSH were measured in fetal and newborn rats to assess possible changes in their release during the process of labour. In the 24 h period during which delivery is likely to occur in the Wistar rat, both the oxytocin and vasopressin content of the fetal pituitary gland increased, whereas α-MSH content remained the same. During and/or just before labour, the oxytocin content was found to decrease by 30%, indicating an enhanced fetal release of the hormone at this stage. It was concluded that the expulsion of each fetus did not provide an extra stimulus for release of oxytocin by the fetus.
In addition, if the fetus remained in the uterus after decapitation of the mother, the oxytocin content of the fetal pituitary gland decreased a further 30%. Neither vasopressin nor 30%. content was altered by the process of labour or by the fetus remaining in the uterus after decapitation of the mother. The levels of vasopressin and α-MSH were, however, 20 times higher than the oxytocin content in the fetus and the newborn, which might have obscured the demonstration of a relatively small change in levels of these two hormones.
EFFECTS OF NEONATAL TREATMENT WITH OESTROGEN AFTER OVARIECTOMY ON DIURNAL PERIODICITIES IN PLASMA LEVELS OF PROLACTIN, THYROTROPHIN AND CORTICOSTERONE IN ADULT RATS
Authors: KÜHN E. R. , NOUWEN E. J. , NIEUWBORG L. , HEYNS W. , BERTIAU F. 
Published: December 2008

Rats were ovariectomized 2–4 h post partum and injected with oil or 100 μg oestradiol benzoate (OB). At 65 days of age, they were decapitated at various times and circadian plasma levels of prolactin, TSH and corticosterone were measured. Rats injected with OB had a significantly raised mean concentration of plasma prolactin, whereas levels of TSH and corticosterone did not differ from those of control rats. Plasma levels of corticosterone and prolactin were positively correlated both in oil-treated controls and oestrogenized rats. A small but not significant negative correlation existed between the levels of TSH and corticosterone in oil-treated control rats. This correlation became positive in rats neonatally injected with OB. Prolactin and TSH were positively correlated in oestrogenized rats but no correlation was found in control animals. It was possible to fit the diurnal variations of all hormones in oil-treated control and OB-injected rats to a significant sinusoidal curve. The acrophase for prolactin, but not for TSH and corticosterone, shifted significantly from 22·30 h in control rats to 14·69 h in oestrogenized rats. In oil-treated control rats, the acrophases of prolactin and corticosterone differed significantly by about 12 h from the TSH peak. In rats injected neonatally with OB, however, no difference between the acrophases of the hormones was seen.
It was, therefore, possible that the shift in prolactin release and the high plasma levels were both mediated by mechanisms which are common to TSH and prolactin and whose increased susceptibility is oestrogen-dependent. The role of this abnormal phasing relationship between prolactin, corticosterone and TSH which occurred in the oestrogenized rats is discussed in relation to the high incidence of various spontaneous or induced tumours which occur during later life in these rats.
CONVERSION OF PROGESTERONE TO 5α- AND 5β-REDUCED METABOLITES IN THE BRAIN OF THE HEN AND ITS POTENTIAL ROLE IN THE INDUCTION OF THE PREOVULATORY RELEASE OF LUTEINIZING HORMONE
Authors: SHARP P. J. , MASSA R. 
Published: December 2008

In the laying hen, progesterone was shown to be converted in vitro in the pituitary gland and the hypothalamus to 5β-pregnane-3,20-dione (5β-DHP), 5β-pregnan-3α-ol-20-one (5β,3α-ol) and 5α-pregnane-3,20-dione (5α-DHP) and in the hyperstriatum dorsale to 5β-DHP and 5β,3α-ol. The conversion of progesterone to 5β-reduced metabolites was greater in the hyperstriatum dorsale than in the hypothalamus (P<0·001) and greater in the hypothalamus than in the pituitary gland (P <0·01). The conversion of progesterone to 5β-reduced metabolites was greater than its conversion to 5α-DHP in the pituitary gland (P <0·01) and the hypothalamus (P < 0·001).
The possibility was investigated that 5α-DHP and 5β-DHP may act as metabolic intermediaries in the mechanism by which progesterone exerts a positive feedback effect on LH release. Progesterone, 5α-DHP and 5β-DHP were injected into laying hens at doses of 0·05,0·25 and 1·25 mg/kg and the changes in the concentration of plasma LH were followed for 4 h thereafter. Secretion of LH was stimulated after treatment with progesterone or 5α-DHP but not 5β-DHP. Progesterone stimulated LH release more effectively than did 5α-DHP, since an increase in the concentration of plasma LH was observed after 0·25 mg progesterone/kg but not after the same dose of 5α-DHP. It was concluded that in the hen 5α-DHP is unlikely to play a role in the induction of the preovulatory release of LH.