bluuebunny/crossref_metadata_2025_split huggingface dataset:
MECHANISM OF THE INHIBITION OF IMPLANTATION IN SUCKLING MICE
Authors: BINDON B. M. 
Published: December 2008

SUMMARY
The conditions under which implantation is delayed in mice mated at the post-partum oestrus have been investigated. The critical litter size for the effect was shown to lie between three and nine pups per female. Delay of implantation was dependent on the presence of the litter until at least day 3 and the length of the delay could be significantly shortened by temporary litter removal on days 2 and 4. A study of the effect of parity showed that delayed implantation after post-partum mating continued to occur until the 4th litter. The incidence and length of implantation delay were reduced after five or more litters.
During suckling-induced delay of implantation the increase in uterine capillary permeability which occurs on day 4 of normal pregnancy was shown to be delayed to as late as day 14. The rate of development and time of entry into the uterus of zygotes was also retarded in comparison with normal pregnancy. This pattern resembled that seen after hypophysectomy on day 1 of normal pregnancy.
MICRO-DETERMINATION OF CORTICOSTEROIDS IN OVINE PERIPHERAL PLASMA: EFFECTS OF VENIPUNCTURE, CORTICOTROPHIN, INSULIN AND GLUCOSE
Authors: BASSETT J. M. , HINKS N. T. 
Published: December 2008

SUMMARY
A sensitive method for the determination of corticosteroids in 0·1 ml. or less of ovine plasma is described. The method uses the steroid-binding properties of corticosteroid-binding globulin (CBG) and gel filtration on small columns of Sephadex G-25 (fine) at 4° for separation of CBG-bound and free steroids. Cortisol was found to be the predominant corticosteroid in ovine plasma and accounts for about 90% of the value determined by this method. The corticosteroid concentration in peripheral plasma of unstressed sheep was in the range 0·1–1·0 μg./100 ml. In untrained animals, venipuncture increased corticosteroid concentration substantially; training reduced the effect. An infusion of cortisol sodium succinate (100 μg. cortisol/min.) increased the plasma corticosteroid level to 9·5 ± 0·49 μg./100 ml. Intravenous infusion of the synthetic adrenocorticotrophic preparation Synacthen at rates of 10 and 20 μg./hr. for 2 hr. increased peripheral corticosteroid concentrations to 8 μg./100 ml. Single i.v. injections of 0·2–0·8 μg. Synacthen also significantly increased peripheral corticosteroid concentrations 7–15 min. later. The injection of 0·05 and 0·1 μg. Synacthen significantly increased the corticosteroid concentration too, but the increase was not significantly greater than that produced by the injection of acidified saline diluent alone. Injection of insulin (0·25 unit/kg. body weight, i.v.) caused a fivefold increase in the corticosteroid concentration 30–60 min. later, in both adult sheep and lambs. Glucose (0·25 g./kg. body weight, i.v.) had no effect on corticosteroid concentration.
VARIATIONS IN THE YIELD AND COMPOSITION OF THE MILK DURING LACTATION IN THE RABBIT AND THE GALACTOPOIETIC EFFECT OF PROLACTIN
Authors: COWIE A. T. 
Published: December 2008

SUMMARY
The daily milk yields and the concentrations of fat, protein and lactose in the milk were studied throughout lactation in New Zealand White (NZW) and Dutch rabbits. The highest daily milk yields, 270 g. in the NZW and 140 g. in the Dutch rabbits, occurred at the end of the third week of lactation; on a body weight basis the yields were similar being 61·0 and 62·3 g. milk/kg. body weight for the NZW and Dutch rabbits respectively. Over a 6-week period the total milk yields were 6940 g. for the NZW and 3820 g. for the Dutch rabbits.
In both breeds considerable changes occurred in the composition of the milk after the third week of lactation. During the first 3 weeks the concentrations of fat, protein and lactose were approximately 15–17, 11 and 1·8–2·0 g./100 ml. milk respectively, but during the fourth to the sixth week the values for fat and protein increased to 25–30 and 18–20 g./100 ml. respectively, while lactose declined to 0·5 g./100 ml. or less.
Sheep prolactin (25 i.u. injected s.c. twice daily for 2 days) in late lactation was galactopoietic, augmenting both the daily milk yield and the concentration of lactose in the milk.
From days 9 to 31 of lactation the NZW litters gained 0·45 g. body weight/g. of milk consumed, the Dutch litters gained 0·38 g./g. of milk. This difference in weight increment was highly significant (P < 0·001) and was apparently due not to a higher calorie content of the milk of the NZW does but to a greater efficiency of milk utilization by the NZW litters.
THYROGLOBULIN BIOSYNTHESIS IN SEVERELY IODINE-DEFICIENT RATS
Authors: THOMSON J. A. , BISSETT JOYCE M. 
Published: December 2008

SUMMARY
Studies of the in-vivo biosynthesis of thyroglobulin in rats on a low iodine diet have been extended to produce more severe degrees of goitre formation. In this situation the protein in the thyroglobulin region did not become less than 18S and both 125I and [3H]leucine were rapidly incorporated into this protein. These results confirm and extend previous observations.
IMMUNOCHEMICAL STUDIES OF HUMAN GROWTH HORMONE, OVINE PROLACTIN, BOVINE GROWTH HORMONE AND A TRYPTIC DIGEST OF BOVINE GROWTH HORMONE
Authors: SUNDARAM KALYAN , SONENBERG M. 
Published: December 2008

SUMMARY
Agar gel double diffusion and immunoelectrophoresis of human growth hormone (HGH), ovine prolactin, bovine growth hormone (BGH) and a tryptic digest of BGH (TBGH) were performed. Antisera to BGH, TBGH, HGH and ovine prolactin were used for the tests. Both BGH and TBGH were found to contain material that precipitated with antiserum to ovine prolactin. Immunological analysis of various fractions of BGH and TBGH separated by chromatography on DEAE-cellulose showed that BGH and TBGH were eluted before prolactin. No differences between BGH and TBGH in their immunological reactions were found. HGH did not cross-react with BGH, TBGH or ovine prolactin.
BLOOD FLOW IN THE REPRODUCTIVE ORGANS OF THE MOUSE AFTER HYPOPHYSECTOMY, AFTER GONADOTROPHIN TREATMENT, DURING THE OESTROUS CYCLE AND DURING EARLY PREGNANCY
Authors: BINDON B. M. 
Published: December 2008

SUMMARY
The indicator fractionation technique was examined and found to be of value in the measurement of organ blood flow in the anaesthetized female mouse with [131I]iodoantipyrine as the indicator substance. Blood flow per unit weight of the brain and ovary was shown to decline rapidly after hypophysectomy. A single injection of pregnant mare serum gonadotrophin (PMS), given 4 days after hypophysectomy, restored the blood flow of these organs to normal levels. Uterine blood flow was unaffected by hypophysectomy, and was significantly increased by PMS injection.
Significant changes in brain, ovarian and uterine blood flow were observed during the oestrous cycle, early pregnancy and in mice induced to ovulate by injections of gonadotrophin. There was a tendency for brain and ovarian blood flow to decline before ovulation. By contrast, significant transient increases in blood flow to the brain and ovary were observed on day 3 of pregnancy. It is thought that these changes are related to the mechanisms which initiate implantation. Uterine blood flow was lowest in mated and unmated mice on the day of oestrus and rose to peak levels 2 days later. In pregnancy, however, peak uterine blood flow was recorded between days 3 and 4 and was higher than at any stage in the oestrous cycle. Although it tended to fall after day 3, uterine blood flow in pregnancy did not decline again to low levels as it did in the oestrous cycle.
The possible physiological significance of the results is discussed, and the limitations to their interpretation are considered.
ANTIBODIES TO A PHYTO-OESTROGEN: ANTIGENICITY OF GENISTEIN COUPLED TO A SYNTHETIC POLYPEPTIDE
Authors: BAUMINGER S. , LINDNER H. R. , PEREL E. , ARNON R. 
Published: December 2008

SUMMARY
An antigen containing the phyto-oestrogen genistein (5,7,4′-trihydroxyisoflavone) was prepared by coupling genistein-2-carboxylic acid to a copolymer of tyrosine, glutamic acid and lysine. Immunization of rabbits with this antigen resulted in the production of antibodies to the carrier and to the hapten. Genistein-specific antibodies were isolated by means of an immunoadsorbent containing genistein linked to a heterologous carrier; these reacted with genistein-containing antigens in the passive cutaneous anaphylaxis, complement fixation and 125I-labelled antigen binding tests. The antibodies failed to cross-react with oestradiol-17β coupled to ovalbumin.
The reaction of the genistein—polypeptide conjugate with the purified antibodies was inhibited by genistein and by the closely related oestrogenic isoflavone biochanin-A. No such inhibition was produced by oestradiol-17β, nor were the anti-genistein antibodies capable of binding 14C-labelled oestradiol.
The potential use of immunization with isoflavone conjugates for the protection of livestock against phyto-oestrogens is discussed.
A COMPARISON BETWEEN THE UPTAKES OF RADIOACTIVE PERCHLORATE AND IODIDE BY RAT AND GUINEA-PIG THYROID GLANDS
Authors: CHOW S. Y. , CHANG L. R. , YEN M. S. 
Published: December 2008

SUMMARY
Previous studies indicated that 36Cl-labelled perchlorate is concentrated by rat and rabbit thyroid gland. However, the extent of concentration of radioactive perchlorate in the gland was much less than that of iodide. Since perchlorate itself has a marked effect on anion transport in the thyroid and the specific activity of available [36C]perchlorate is very low, the stable anion as a carrier present in the injected radioactive perchlorate solution may affect the uptake of this radioactive compound by the gland. In this study, radioactive solutions of perchlorate and iodide containing different amounts of stable perchlorate or iodide (dosages ranged from 0·005 to 5 m-equiv./kg. body weight) were injected into groups of rats and guineapigs, and the thyroid: plasma concentration ratios of radioactive perchlorate and iodide were calculated and compared. These experiments were also repeated in animals pretreated with thyroid-stimulating hormone (TSH), after chronic administration of propylthiouracil (PTU), as well as in hypophysectomized animals. At the same dose levels of perchlorate, there was no difference in thyroid: plasma concentration ratios of radioactive perchlorate and iodide in control rats and guinea-pigs or in treated ones.
PROGESTERONE METABOLISM IN THE EWE
Authors: STUPNICKI R. , McCRACKEN J. A. , WILLIAMS K. I. H. 
Published: December 2008

SUMMARY
[4-14C]Progesterone was administered intravenously to five ewes with chronic bile-duct fistulae and to one intact animal. The mean percentage of the injected dose, calculated as 'excretable' when extrapolated to infinite time, was 95·5% (range: 81–104%). The time of excretion of half the radioactivity as estimated from excretion curves of the accumulated activity was 2·9 hr. (range: 1·5–7·8 hr.). The mean urinary 'excretable' fraction was 25·5% (range: 8–53% of the injected dose, that of bile was 70·0%. Urine contained relatively more of the polar material (presumable double conjugates of the metabolites) than bile.
ENDOCRINE CONTROL OF THE METABOLISM OF OESTRADIOL BY RAT LIVER MICROSOMES
Authors: JELLINCK P. H. , GARLAND MAUREEN 
Published: December 2008

SUMMARY
The effect of age and the role of the pituitary and gonads on the change in liver oestrogen hydroxylase activity induced by oestrone and testosterone has been investigated. Testosterone increased the hydroxylation of oestradiol in immature rats but had no effect in adult female animals unless they had been ovariectomized. In male rats, hypophysectomy resulted in a rapid decrease in oestrogen metabolism which could not be reversed by treatment with testosterone. Oestrone produced reversible changes in oestrogen hydroxylation in adult male rats in contrast to the irreversible effects observed in immature animals. The significance of these results in the control of oestrogen metabolism is discussed.
THE CLEARANCE OF RENIN FROM THE PERIPHERAL PLASMA OF THE MARSUPIAL TRICHOSURUS VULPECULA
Authors: REID I. A. , McDONALD I. R. 
Published: December 2008

SUMMARY
In the marsupial Trichosurus vulpecula, the decay curve of plasma renin concentration against time, during a period of 4 hr. immediately after either bilateral nephrectomy or i.v. injection of a partially purified homologous renin, could be resolved into two exponential components. The curves in both types of experiment were similar, suggesting a simple twopool system of renin distribution. The half-times of the first and second components were 11·1 ± 2·6 (s.d.) and 217 ± 71·5 min. respectively.
As in dogs, the initial volume of distribution of injected renin was equivalent to approximately 10% of body weight. Using this value, and the derivative of the post-nephrectomy decay curve at the time of removal of the second kidney, the renin production rate at this time was calculated to be in the range of 123–1170 units/min. This calculation was justified by demonstrating that the surgical manipulations did not cause any increase in plasma renin concentration. Renal renin production rates, measured in other possums from the difference in renin concentrations of arterial and renal venous plasma, were within the range calculated from the postnephrectomy decay curves.
Metabolic clearance rates calculated from the post-nephrectomy decay curves averaged 3·5 ml./min./kg.; and those calculated from the post injection decay curves averaged only 1·9 ml./min./kg. Circulatory changes, due to nephrectomy or renin injection, are the most likely reasons for this discrepancy.
EFFECTS OF AMYGDALOID LESIONS ON REGIONAL BRAIN RNA BASE RATIOS
Authors: ELEFTHERIOU B. E. , CHURCH R. L. , ZOLOVICK A. J. , NORMAN R. L. , PATTISON M. L. 
Published: December 2008

SUMMARY
Bilateral lesions produced by electrocoagulation in the basolateral and medial amygdaloid nuclei, subtotal amygdalectomy as well as implants of actinomycin D and cholesterol were all found to have profound effects on brain ribonucleic acid (RNA) base percentages and ratios. The most consistent effect was that on the pituitary and was produced by all treatments. Generally, the hypothalamus and frontal cortex showed varying effects due to the treatments, but the cerebellum uniformly showed no responses to the various treatments. Lesions placed in the medial amygdaloid complex and subtotal amygdalectomy had the greatest effect in changing the RNA base ratio. The bases adenosine monophosphate (AMP), cytidine monophosphate (CMP), guanosine monophosphate (GMP), and uridine monophosphate (UMP) were found to be the most affected. The newly synthesized RNA was found to be rich in UMP and deficient in AMP and CMP when compared to normal animal brain tissue. The assumption is made that lesions in the amygdala bring about an activation or stimulation of a genomic nature to produce specific RNA for a particular neural function.
UPTAKE OF ALDOSTERONE BY HUMAN SKIN AND STIMULATION OF RNA SYNTHESIS IN THE SWEAT GLAND IN VITRO
Authors: DIXON K. , SCHWARZ V. 
Published: December 2008

SUMMARY
Autoradiography of human skin, after incubation with tritiated aldosterone or pregnenolone, showed both steroids to be concentrated in all types of cells. Binding of [3H]aldosterone in skin was investigated in the presence and absence of a large excess of unlabelled hormone. The capacity of the cells to bind aldosterone in a manner suggesting attachment to receptor sites was estimated to be 5 × 10-13 moles/g. The rate of RNA synthesis was measured in the various cells of the sweat gland: it was shown to be significantly increased by aldosterone. This stimulation was observed in the inner and outer cells of the sweat duct and probably also in the secretory tubule.
THE EFFECT OF A SECOND DOSE OF CADMIUM SALTS ON VASCULAR PERMEABILITY IN THE RAT TESTIS
Authors: CLEGG E. J. , CARR IAN , NIEMI M. 
Published: December 2008

SUMMARY
Two doses of cadmium chloride were given to rats at intervals varying from 76 to 194 days. After the second dose the blood vessels in the testis and initial segment of the epididymis showed increased permeability as demonstrated by intravascular markers. In the testis, leaking vessels were usually found in areas immediately deep to the tunica albuginea, where interstitial cells were abundant.
THE EFFECT OF THYROXINE ON PERIPHERAL THYROID HORMONE METABOLISM
Authors: GOOLDEN A. W. G. , GARTSIDE JUNE M. , OSORIO C. 
Published: December 2008

SUMMARY
Blood samples obtained from normal people after an oral dose of 0·4 mg. l-thyroxine showed a depression in the uptake of [131I]tri-iodothyronine ([131I]T3) by the red cells, whereas the uptake by a resin sponge was increased. This depression did not occur when the test was carried out at 20° instead of at 37°. It was reversed when methylthiouracil, which is known to inhibit deiodination, was added to the blood in vitro. These findings are indicative of deiodination as the cause of the depression of T3-red cell (RBC) uptake. T3-RBC uptake was similarly depressed after the administration of l-tri-iodothyronine, and it was concluded that deiodination was promoted in the red cell system whenever there was an increase in the level of circulating thyroid hormone.
The radioactive product of deiodination, which may be an artifact rather than a natural metabolite, has not been identified. Analysis of plasma obtained from blood after incubation with [131I]T3 under the conditions of the T3-RBC test, has not shown any [131I]iodide other than that present as an impurity in the [131I]T3 preparation. It could be shown that the product of deiodination is bound by the red cells but is eluted from them more readily than [131I]T3. It is suggested that the fall in T3-RBC uptake after thyroxine is due to deiodination which results in the formation of some radioactive product which is eluted from the red cells in the washing procedure.
THE IN-VIVO EFFECTS OF SHEEP PITUITARY GONADOTROPHINS ON THE SECRETION OF STEROIDS BY THE AUTOTRANSPLANTED OVARY OF THE EWE
Authors: McCRACKEN J. A. , UNO A. , GODING J. R. , ICHIKAWA Y. , BAIRD D. T. 
Published: December 2008

SUMMARY
The transplanted ovary preparation in the ewe permits long-term access to both the arterial and venous sides of the ovarian circulation in the unstressed, unanaesthetized animal. However, these animals are not completely normal, as the separation of the ovary from the uterus results in ovarian cycles with a prolonged luteal phase and the infrequent manifestation of behavioural oestrus. Treatment with exogenous gonadotrophins made it possible to carry out direct infusion experiments on the transplanted ovary on a more uniform basis. The effect on ovarian blood flow and on ovarian steroid secretion following the infusion of ovine luteinizing hormone (LH), ovine follicle-stimulating hormone (FSH) or ovine prolactin directly into the arterial supply of the transplanted ovary of the ewe is described. Four infusions of each of the three ovine pituitary gonadotrophins were made into the ovary at rates varying from 0·1 μg./hr. to 1000 μg./hr. LH infusions produced an increase in both ovarian blood flow and steroid secretion at all dosage levels employed. Androstenedione showed the greatest increase (600%) in secretion rate after LH, followed by testosterone (400%), oestradiol (more than 50%) and progesterone (less than 50%). Progesterone however showed the greatest increase in terms of mass of steroid secreted. There was no measurable change in the secretion of oestrone. Ovarian blood flow increased by at least 20% (range 20–125%) within 1 hr. of beginning the LH infusion. On the other hand FSH and prolactin infused at the same or at a higher rate than LH, had essentially no effect on ovarian blood flow or steroid secretion rate. In two out of four FSH infusions there appeared to be a transient fall in progesterone secretion rate. The infusion of 0·9% NaCl solution into the ovary as a control had no effect on blood flow or on steroid secretion.
DEVELOPMENT OF GOITRE AFTER METHYLTHIOURACIL TREATMENT OF MICE WITH HYPOTHALAMIC LESIONS
Authors: MOLL J. , MARTENS E. , JANSEN H. G. 
Published: December 2008

SUMMARY
Lesions aimed at the area of the paraventricular hypothalamic nuclei were made by means of stereotaxic electrocoagulation in intact and gonadectomized mice, which were subsequently treated with methylthiouracil. Lesions could be placed with an acceptable degree of precision and with moderate postoperative mortality. Correctly placed lesions made in intact females and castrated males caused a marked inhibition of goitre development, indicating a depressed secretion of thyrotrophin. However, in intact males and spayed females inhibition of goitre formation could not be demonstrated convincingly.
THE CLEARANCE OF HOMOLOGOUS CALCITONIN
Authors: WEST T. E. T. , O'RIORDAN J. L. H. , CARE A. D. 
Published: December 2008

SUMMARY
The plasma clearance of calcitonin (TC) was studied by following the disappearance of radioactivity after intravenous injection of labelled TC, and the disappearance of bio-assayable activity after intravenous injection of unlabelled hormone. The turnover was shown to be rapid: two exponential components were involved with half times of 4–5 and 35–40 min. respectively. Similar values were obtained in experiments in which TC was infused to obtain raised, steady concentrations after which the disappearance of biologically active material was followed for up to 100 min. The normal concentration of TC in porcine peripheral plasma was calculated to be about 9 μu./ml.
OVULATION AND CORPUS LUTEUM FUNCTION IN THE LLAMA (LAMA GLAMA)
Authors: ENGLAND B. G. , FOOTE W. C. , MATTHEWS D. H. , CARDOZO ARMANDO G. , RIERA S. 
Published: December 2008

SUMMARY
Results in 53 llamas (33 mated animals and 20 controls) showed that ovulation is copulation-induced in this species. Ovulation without copulation occasionally occurred during the height of the recognized breeding season in Bolivia.
The first mating during the luteal phase (12–24 days after the preceding ovulation) resulted in ovulation in four out of ten llamas.
Determination of pituitary luteinizing hormone (LH) content showed the highest level on the day before mating (9·00 μg./mg.) and the lowest level on day 4 (6·25 μg./mg.). LH level on day 8 was significantly higher than on day 4 (7·62 μg./mg.). Corpora lutea (c.l.) were well formed on day 4 after mating (408 mg.), reached a maximum size by day 8 (1920 mg.) and rapidly decreased in size to day 16 (136 mg.). The corpus albicans remained as an entity but decreased in size to 21 mg. on day 120. Similar changes were found in c.l. histology and progesterone content. The combined results indicate that the functional life of the c.l. in a non-pregnant llama is 16 days or less.
Treatment with 25 i.u. human chorionic gonadotrophin was sufficient to cause ovulation in 50% of the animals treated.
A large (150 mg.) dose of norethandrolone did not cause morphological regression of the c.l. when measured 5 days after treatment. Treatment with 5 mg. daily for 14 days caused regression of c.l. as compared with untreated controls and animals treated with oestradiol valerate.