bluuebunny/crossref_metadata_2025_split huggingface dataset:
UPTAKE AND METABOLISM OF TRITIATED OESTRADIOL AND OESTRONE BY HUMAN ENDOMETRIAL AND MYOMETRIAL TISSUE IN VITRO
Authors: GABB R. G. , STONE G. M. 
Published: December 2008

SUMMARY
Human endometrial and myometrial tissues were incubated in vitro with [3H]oestradiol-17β and [3H]oestrone to study the uptake and interconversion of these two steroids by the tissues. Endometrial tissue displayed a higher capacity for oestrogen interconversion than myometrial tissue and the oxidation of oestradiol-17β to oestrone was favoured, rather than the reverse reaction. A greater degree of oxidation was found in tissue taken from uteri in the secretory phase than in the proliferative phase. A study of the distribution of radiometabolites between 'soluble' and 'particulate' fractions of tissue homogenates showed that a greater proportion of the tissue radioactivity was associated with the 'particulate' fraction in the proliferative phase than in the secretory phase. After incubation of endometrial tissue from the secretory phase with tritiated oestrogens there was evidence of the formation of chloroform-insoluble radiometabolites and some of these were tentatively identified as oestrogen sulphates. In a second experiment, the uptake and metabolism of the same two oestrogens by tissue from leiomyomata uteri (fibroids) and normal myometrial tissue were compared. No significant difference between these tissues was found.
The results suggest that the levels of 17β-hydroxysteroid dehydrogenase in the human uterus may be dependent upon the levels of oestrogens in the blood. The lack of a difference in the treatment of oestrogens by fibroid and normal myometrial tissue suggests that these tissues may have a similar mechanism for the uptake and retention of oestrogens.
FURTHER STUDIES ON THE STIMULATION OF PROSTATIC RIBONUCLEIC ACID POLYMERASE BY 5α-DIHYDROTESTOSTERONE—RECEPTOR COMPLEXES
Authors: DAVIES PETER , GRIFFITHS KEITH 
Published: December 2008

SUMMARY
The stimulation in vitro of prostatic RNA polymerase activity by prostatic 5α-dihydrotestosterone—receptor complexes has been previously reported. Further investigations into the nature of the stimulation have now been carried out. By use of the selective inhibitor, α-amanitin, and by varying the concentration of ammonium sulphate in the assay media, both the nucleolar and extranucleolar forms of RNA polymerase could be stimulated, depending upon the ionic conditions employed. High ionic strength inhibited stimulation, either by interference with the association between steroid—receptor complexes and chromatin components, or by blocking the conversion of cytoplasmic complexes to a more 'active' form of the complex. 5α-Dihydrotestosterone—receptor complexes appeared to affect the template availability of prostatic chromatin, possibly in a way similar to that of the chromatin-associated proteins.
EFFECT OF ACUTE REDUCTION IN MILK REMOVAL FROM SOME GLANDS UPON THE ABILITY OF A SINGLE RABBIT MAMMARY GLAND TO SECRETE MILK
Authors: MENA F. , REYES G. , AGUAYO D. , GROSVENOR C. E. 
Published: December 2008

SUMMARY
Milk yield fell in a single rabbit mammary gland within 24 h after the litter had been reduced from six to eight pups to one pup. The diminished secretion lasted 2–3 days, then rebounded to the expected level over the next 1–2 days and thereafter maintained this level. During early to mid-lactation the decrease in milk secretion after reduction of the litter to one pup was prevented either by s.c. injections of prolactin or by s.c. injections of the β-adrenergic blocking drug, propranolol. These results suggest that milk secretion was reduced in the single gland as the result of sympathetic activation, triggered possibly by the turgid state which developed in the remaining glands after the litter was reduced. The results suggest also that the depression of milk secretion by the sympathetic system was due to a reduction in the effective amount of prolactin and probably of other adenohypophysial hormones reaching the mammary secretory cells rather than to an impairment of their release from the anterior pituitary.
The magnitude of the depression and rebound in milk secretion of a single rabbit mammary gland, and the effectiveness of the preventive action of either propranolol or prolactin, was considerably less during late as compared with early to mid-lactation. We postulate from these results that the mammary gland of the rabbit has a functional lability, i.e. responsiveness, which diminishes as lactation progresses and which dictates the extent to which local, neural and humoral factors may alter the milk secretory function of the mammary gland. Since suckling in the rabbit does not change from a once-a-day frequency throughout lactation, a diminishing lability may be an important factor in the decline and cessation of lactation in this species.
AN IN-VITRO BIOASSAY FOR PROLACTIN BASED ON STIMULATION OF CASEIN SYNTHESIS BY A DISPERSED CELL PREPARATION FROM MOUSE MAMMARY GLAND
Authors: BULLOUGH W. A. , WALLIS M. 
Published: December 2008

SUMMARY
An in-vitro bioassay for prolactin has been devised, based on the stimulation of casein synthesis in a mouse mammary gland preparation. Dispersed mammary gland cells were superior to intact explants for this purpose. Casein synthesis by dispersed cells was stimulated by added prolactin, and a linear log dose—response curve was established (for the range 5–20 μg prolactin/ml).
The precision of the assay was high (λ = 0·10–0·15). Sensitivity was rather low, but could be improved by increasing the concentration of amino acids in the medium. The response to prolactin was not influenced by thyroxine, adrenocorticotrophin or oestradiol, but thyrotrophin appeared to inhibit it slightly. Both human placental lactogen and bovine growth hormone showed lactogenic activity in the assay.
ALDOSTERONE, SODIUM DEPLETION AND HYPOTHYROIDISM ON THE ATPASE ACTIVITY OF RAT COLONIC EPITHELIUM
Authors: THOMPSON B. D. , EDMONDS C. J. 
Published: December 2008

SUMMARY
Transmucosal electrical potential difference and short-circuit current of an in-vitro preparation of mucosal epithelium of rat colon were almost abolished and active sodium transport ceased when ouabain (1 mmol/l) was present on the serosal side of the epithelium.
A considerable fraction of the total ATPase activity in the mucosa was sodium dependent and concentrations of ouabain of 0·5 mmol/l or more completely eliminated the activity of this fraction.
Adenosine triphosphatase activities in mucosa taken from normal, hypothyroid, aldosterone-treated and sodium-depleted rats were compared. The activity of the ouabain-sensitive, sodium-dependent fraction was similar in all groups except for the hypothyroid rats in which it was considerably reduced.
There was no evidence from the present study that the increased active sodium transport by colonic mucosa, associated with aldosterone action or sodium depletion, depended upon a change in ATPase activity. In hypothyroidism, reduction of ouabain-sensitive ATPase activity may be responsible for the observed impairment of the sodium transport mechanism.
A RADIOIMMUNOASSAY FOR OVINE CALCITONIN: AN EVALUATION OF CALCITONIN SECRETION DURING GESTATION, LACTATION AND FOETAL LIFE
Authors: GAREL J. M. , CARE A. D. , BARLET J. P. 
Published: December 2008

SUMMARY
A radioimmunoassay capable of measuring ovine calcitonin in unextracted ovine plasma has been developed. Guinea-pig antisera to partially purified porcine calcitonin were highly specific for calcitonin and were capable of detecting 5 pg porcine calcitonin. One of these antisera cross-reacted significantly with pure ovine calcitonin and with foetal ovine plasma. The mean basal calcitonin secretion rate for the left thyroid lobe found in sheep foetuses 10 days before term was 3·36 ng/min/kg body weight. An infusion of calcium into the foetus was followed by an increase in the calcitonin secretion rate. The mean fasting calcitonin concentration in samples from the jugular vein of five pregnant ewes 10 days before term was 5·28 ng/ml. An infusion of calcium into the mother induced a sevenfold increase in plasma calcitonin concentration whereas the calcitonin concentration was unchanged in the foetal thyroid venous plasma. At parturition the plasma calcitonin concentration fell in the mother (1·85 ng/ml), and a sharp increase was observed during lactation (11·60 ng/ml). In the lamb from birth to 6 weeks post partum the calcitonin concentration was very high (8·10–10·40 ng/ml).
A BIOASSAY FOR PARATHYROID HORMONE USING WHOLE MOUSE CALVARIA IN TISSUE CULTURE
Authors: WEBSTER LESLEY A. , ATKINS D. , PEACOCK M. 
Published: December 2008

SUMMARY
A parallel-line bioassay for parathyroid hormone based on the release of stable calcium from whole mouse calvaria in tissue culture has been developed from the method of Zanelli, Lea & Nisbet (1969). There has been no change in either the dose range (0·06–1·2 units/2 ml culture) or the bioassay statistics over a prolonged working period but the total assay time has been shortened and the preparative stages made easier.
EFFECTS OF LUTEINIZING HORMONE RELEASING HORMONE AND THYROTROPHIN RELEASING HORMONE ON RABBIT ADIPOSE TISSUE
Authors: MURTHY G. G. , MODESTO R. R. 
Published: December 2008

SUMMARY
The effects of luteinizing hormone releasing hormone (LH-RH) and thyrotrophin releasing hormone (TRH) on rabbit adipose tissue were studied. LH-RH increased [14C]glucose oxidation and incorporation into fatty acids and had lipolytic activity, at the same time decreasing [14C]glucose incorporation in glyceride—glycerol fractions. TRH had no significant effect on glucose oxidation or lipolysis but decreased [14C]fatty acid synthesis and [14C]glucose incorporation into glyceride—glycerol fractions.
SEPHADEX GEL FILTRATION ANALYSIS OF IMMUNOREACTIVE THYROTROPHIC HORMONE IN HUMAN URINE
Authors: KUKU S. F. , HARSOULIS P. , YOUNG J. L. , QUE N. D. , FRASER T. R. 
Published: December 2008

SUMMARY
To assess whether urinary immunoassayable thyroid-stimulating hormone (TSH) differed from pituitary and serum TSH, urinary concentrates from two hypothyroid subjects were analysed by Sephadex G-100 gel filtration.
The elution profiles, measured by radioimmunoassay, were then compared with those of neat sera from hypothyroid patients and human pituitary TSH preparations. The pituitary preparations and the hypothyroid serum were eluted as a comparable single symmetrical peak corresponding to that obtained from a highly purified radio-iodinated human TSH of pituitary origin; no evidence of 'big' TSH emerged. In contrast, however, the material eluted from the hypothyroid urine concentrates not only revealed an asymmetrical peak corresponding to that described above but several other minor peaks eluting later and probably corresponding to fragments of TSH.
When human pituitary TSH was infused into two normal subjects, gel filtration analysis of concentrates from urinary samples obtained during and at fixed periods after the infusion revealed a single peak during the infusion but more peaks appeared with the later samples.
A MODIFIED BIOASSAY FOR THYROID-STIMULATING HORMONE AND LONG-ACTING THYROID STIMULATOR
Authors: NUTT J. , HUMPHREYS K. , CLARK F. 
Published: December 2008

SUMMARY
After iodine depletion of mice, the time needed for the bioassay of long-acting thyroid stimulator (LATS) and thyroid-stimulating hormone (TSH) can be shortened to allow the completion of two assays per week. Suppression of mouse TSH with 0·1 μg tri-iodothyronine was necessary in the TSH assay and with 5 μg thyroxine in the LATS assay. These can be administered as a single i.p. injection with the 131I. The response of the assay mice to TSH can be improved by giving theophylline (0·5 mg) just before, with and after the stimulus.
EFFECTS OF SEX HORMONES AND ENVIRONMENTAL LIGHTING ON RAT HARDERIAN GLAND PORPHYRIN
Authors: ULRICH RENÉE , YUWILER ARTHUR , GELLER EDWARD , WETTERBERG LENNART 
Published: December 2008

SUMMARY
Ovariectomy of adult female rats significantly decreased the porphyrin content of the Harderian glands compared with intact control rats. Treatment of ovariectomized rats for 5 days with testosterone propionate, progesterone or oestradiol did not alter porphyrin content or concentration; however, administration of oestradiol plus progesterone significantly increased Harderian gland porphyrin content to values indistinguishable from those of intact controls. Additionally, oestradiol treatment lowered the weight of the Harderian glands.
Constant light or constant darkness for 35 days significantly decreased Harderian gland porphyrins compared with those of rats kept in diurnal lighting conditions. Constant light significantly lowered porphyrin values compared with those obtained from rats maintained in constant darkness. The effects of constant light were not altered by either ovariectomy or enucleation. Harderian gland weight was reduced in all groups kept in constant light.
PLASMA LEVELS OF OESTROGEN AND PROGESTERONE IN PREGNANT AND LACTATING HAMSTERS
Authors: BARANCZUK RICHARD , GREENWALD G. S. 
Published: December 2008

SUMMARY
Oestrone (OE1), oestradiol (OE2) and progesterone were measured by radioimmunoassay in the same samples of peripheral plasma from pregnant and lactating hamsters. The levels of progesterone during most of pregnancy did not exceed the values found during the first 2 days of the oestrous cycle. However, on day 14 of pregnancy (2 days before parturition) the level of progesterone abruptly increased to 29 ng/ml and fell rapidly thereafter. Hysterectomy on day 12 of pregnancy resulted in baseline levels of progesterone ( < 2 ng/ml) on day 13 and no peak in progesterone comparable to the one observed on day 14 of normal gestation. Injecting progesterone on day 14 or later prolonged gestation and caused maternal and foetal death.
Oestradiol concentration showed peaks on days 7 (67·3 pg/ml), 11 (117·6 pg/ml) and 14 (81·8 pg/ml) of pregnancy and dropped precipitously between days 14 and 16 of pregnancy. The highest values obtained on day 11 correlated with the maximal proliferation of antral follicles. The abrupt decline of oestrogen concentration at parturition is different from the pattern found in the mouse and rat but is consistent with the lack of post-partum ovulation in the hamster. Injecting 50–150 μg oestradiol cyclopentylpropionate between days 12 and 16 did not interfere with parturition by the morning of day 16. Oestrone was detectable throughout pregnancy; the levels were lower than for OE2. In general, the oestrogen patterns were parallel.
During lactation, progesterone secretion remained relatively constant at about 10–11 ng/ml, presumably synthesized by the hypertrophied interstitium which is the dominant ovarian tissue. In most instances OE1 and OE2 were not detectable during lactation, consistent with the absence of antral follicles.
METABOLISM OF [7α-3H]DEHYDROEPIANDROSTERONE AND [4-14C]ANDROSTENEDIONE IN VITRO BY TESTICULAR TISSUE FROM ADULT AND PREPUBERTAL WISTAR RATS
Authors: RICHARDS GWEN , NEVILLE A. MUNRO 
Published: December 2008

SUMMARY
The metabolism of [7α-3H]dehydroepiandrosterone (DHA) and [4-14C] androstenedione in vitro was investigated in 30-day-old (prepubertal) and adult rat testicular tissue in the presence of cyanoketosteroid, a 5-ene-3β-hydroxysteroid oxidoreductase inhibitor.
Whereas both substrates were converted to 5α-reduced steroids by the prepubertal testis, 4-ene-steroid-5α-reductase activity was negligible in the adult gland. Cyanoketosteroid prevented the formation of 5α-reduced steroids from DHA by the prepubertal testis indicating testosterone and androstenedione as intermediates in their production.
EFFECT OF OESTROGEN ADMINISTERED IN EARLY OR LATE LACTATION ON THE YIELD AND COMPOSITION OF MILK IN SHEEP
Authors: FULKERSON W. J. , McDOWELL G. H. 
Published: December 2008

SUMMARY
Subcutaneous injections of oestradiol benzoate (OB) were given daily to lactating ewes for 7 days beginning 20 (early lactation) or 46 (late lactation) days after parturition.
Injections of 50 and 500 μg OB enhanced milk yield in ewes during late lactation and resulted in significant increases in the proportion and daily production of milk components. During early lactation, injections of 500 μg OB failed to enhance milk yield but significant increases in the fat content of milk were recorded.
The administration of 5000 μg OB resulted in a marked decline in milk yield. In milk from these ewes there was a fall in lactose content with a concomitant rise in the number of leucocytes and proportion of vacuolated macrophages suggesting that mammary involution had begun.
SECRETIN-LIKE ACTIVITY IN SUBCELLULAR FRACTIONS OF CHICKEN INTESTINAL MUCOSA
Authors: FIDDES I. J. S. , TROTMAN C. N. A. 
Published: December 2008

SUMMARY
Differential centrifugation of chicken intestinal mucosal homogenates showed that particles containing a material with secretin-like activity can be sedimented. The activity appeared to be contained in structures smaller than mitochondria. Approximately 70% of the stimulatory effect of the whole homogenate was sedimented in 10 min at 15000 g. The secretin-like material was released from the particles by treatment with hydrochloric acid and partially purified by heat denaturation of large proteins at pH 3. The relationship between relative dose of mucosal extract and secretory response in the anaesthetized cat was slightly different from that of porcine secretin.
THE BREAST CANCER DISCRIMINANT: EFFECT OF AGE, OBESITY, HIRSUTISM, STARVATION, AND CHANGES IN ADRENOCORTICAL AND GONADAL ACTIVITY
Authors: METCALF MARY G. 
Published: December 2008

SUMMARY
The relationship between 17-oxogenic steroid excretion and the urinary output of certain 17-oxosteroids has been widely used to select women with metastatic breast cancer for ablation of endocrine organs. In this report, the effect of factors other than breast cancer on the ratio of androsterone plus aetiocholanolone to the 17-oxogenic steroids in urine is examined. For 83 normal women the mean value of the ratio was 0·351 ± 0·121 (s.d.). In menstruant women the ratio did not correlate with oestrogen excretion, and was little affected by increasing age, the taking of oral contraceptive tablets, obesity, and the presence of reversible amenorrhoea. Factors causing a marked reduction in the ratio were the absence of functional ovaries (47 women, mean ratio 0·116 ± 0·066), food deprivation (15 obese women, mean decrease by the 9th day of starvation, 53·4 ± 11·7%), and adrenocortical stimulation (14 women, mean decrease on day 2 of corticotrophin infusion, 52·0 ± 17·0%). Suppression of adrenocortical function with dexamethasone treatment caused no systematic change in the value of the ratio, and hirsutism was associated with a significant increase (67 women, mean value 0·447 ± 0·165). The variability of the ratio from day to day in individual women (coefficient of variation, 20·7%) suggests that it is inadvisable to select patients for treatment on the basis of measurements made on a single 24 h sample of urine.
DIURNAL CHANGES IN PLASMA TESTOSTERONE AND STUDIES ON PLASMA CORTICOSTEROIDS IN NON-ANAESTHETIZED MALE RHESUS MONKEYS (MACACA MULATTA)
Authors: MICHAEL R. P. , SETCHELL K. D. R. , PLANT T. M. 
Published: December 2008

SUMMARY
The assays of testosterone and corticosteroids in plasma from adult male rhesus monkeys using competitive protein-binding and radioimmunoassay techniques are described. The radioimmunoassay for testosterone was conducted without chromatography and, therefore, additionally estimated 17β-hydroxy-5α-androstan-3-one (dihydrotestosterone). Levels of testosterone in the peripheral plasma of 14 intact male rhesus monkeys showed marked fluctuations over a period of 24 h. Concentrations of testosterone at 22.00 h (1776 ± 814 ( ± s.d.) ng/100 ml) were approximately double those at 08.00 h (858 ± 407 ng/100 ml), 12.00 h (898 ± 316 ng/100 ml) and 16.00 h (784 ± 530 ng/100 ml). Castration resulted in low plasma testosterone levels (85 ± 29 ng/100 ml), and the increases at 22.00 h were no longer observed. In intact males, the 'basal' plasma corticosteroidlevel(08.00 h) was 22·4 ± 6·0 μg/100 ml. Administration of synthetic corticotrophin raised plasma corticosteroid levels without changing plasma testosterone concentration. Because plasma testosterone levels were not related to changes in adrenocortical activity, the noctural rises appear to be due to changes in testicular secretion.
EFFECTS OF OESTROGEN PRIMING ON THE UPTAKE, METABOLISM AND BIOLOGICAL ACTIVITY OF PROGESTINS IN THE MOUSE UTERUS
Authors: CLARK B. F. 
Published: December 2008

SUMMARY
The effects of single subcutaneous injections of progesterone on uterine stromal and uterine epithelial mitosis and morphology varied non-linearly during the 6 days after oestrogen priming. Retention of locally applied progesterone was significantly less and recovery of its metabolites greater on day 1 after oestrogen priming than on day 6. Recovery of metabolites of two potent synthetic progestins, megestrol acetate and medroxyprogesterone acetate, was negligible after injection on either day. Retention of these progestins was the same whether given on day 1 or day 6, and was similar to the retention of progesterone when injected on day 6.
BINDING OF THYROID HORMONE IN RABBIT SERUM: DEFINITION OF A PREALBUMIN AND EFFECTS OF STRAIN VARIATION ON BINDING
Authors: DAVIS P. J. , LAIRD C. W. , FOX R. R. 
Published: December 2008

SUMMARY
Sera from inbred rabbit strains have been studied to determine radio-thyroxine distribution after electrophoresis, to measure protein binding capacity for thyroxine (T4) and to examine possible interrelationships of binding capacity and serum protein-bound iodine (PBI). In electrophoretic studies at pH 7·4, serum albumin and prealbumin, the latter a previously unrecognized carrier of T4 in the rabbit, are the principal transport proteins. At pH 9·0, prealbumin is the major carrier (61% of tracer). Prealbumin also binds significant quantities of tri-iodothyronine. The mean binding capacity of serum prealbumin for T4 in 12 rabbit strains was 500 μg/100 ml.
Protein-bound iodine levels are known to be strain-dependent in the rabbit. In the current studies, however, there was no strain-specificity of prealbumin binding capacity, and no correlation between PBI and binding capacity of prealbumin, the principal T4-specific transport protein. These observations suggest that factors other than the capacity of binding proteins for T4 may be primary determinants of hormone levels (PBI) in blood in the rabbit.
PARTURITION IN THE COW: ENDOCRINE CHANGES IN ANIMALS WITH CHRONICALLY IMPLANTED CATHETERS IN THE FOETAL AND MATERNAL CIRCULATIONS
Authors: COMLINE R. S. , HALL L. W. , LAVELLE R. B. , NATHANIELSZ P. W. , SILVER MARIAN 
Published: December 2008

SUMMARY
Intravascular catheters were placed in the umbilical, uterine and maternal peripheral circulations of 16 Jersey cows between 240 and 260 days of gestation. Foetal plasma cortisol, blood gases and pH, and maternal plasma oestrogen, progesterone and cortisol were measured in ten animals during late pregnancy and throughout spontaneous parturition; all delivered live foetuses although parturition was earlier than normal and the placenta was generally retained. The gradual pre-partum rise in foetal plasma cortisol during the last week of gestation (from 10–20 ng/ml 7 days before parturition to 51 ± 5 ng/ml in the last 3 h before delivery) was much less marked than the abrupt increase immediately after birth when the cortisol concentration invariably doubled. Maternal plasma oestrogen rose from 0.35 ± 0.04 ng/ml to 1·20 ± 0.11 ng/ml during the week before parturition. Progesterone concentrations remained stable until a sudden fall 1–2 days before delivery. The slight alterations in maternal plasma cortisol during this period were not statistically significant. The maternal plasma oestrogen levels were higher in the uterine vein than in the periphery, whereas uterine venous progesterone concentrations were significantly lower than in the peripheral circulation.