bluuebunny/crossref_metadata_2025_split huggingface dataset:
EFFECT OF MESENCEPHALIC STIMULATION ON THE RELEASE OF GONADOTROPHINS
Authors: CARRER H. F. , TALEISNIK S. 
Published: December 2008

SUMMARY
Different regions of the midbrain were stimulated by electrolytic deposition of iron from stainless steel unipolar electrodes. Electrochemical stimulation of the ventral tegmental area (VTA), the raphe nuclei or the peri-aqueductal grey in rats in pro-oestrus was effective in preventing spontaneous ovulation. No blockade of ovulation was observed by stimulating other mesencephalic structures. After stimulation in the VTA there was a significant decrease of the elevated serum levels of luteinizing hormone (LH) found after an injection of progesterone into pro-oestrous rats or into ovariectomized—oestrogen-primed animals. In contrast, electrochemical stimulation of the dorsal mesencephalic tegmentum, lateral and inferior to the peri-aqueductal grey, in rats in which spontaneous ovulation had been blocked by continuous illumination, resulted in an ovulatory response. Serum LH was found to increase in gonadectomized—oestrogen-treated male and female rats after stimulating this area. No significant changes in serum follicle-stimulating hormone were found after stimulation in the ventral or dorsal tegmentum. It is concluded that both stimulatory and inhibitory influences on the release of gonadotrophin can be evoked by stimulating mesencephalic structures. The stimulatory and inhibitory effects could depend on the activation of noradrenergic and serotoninergic systems, respectively.
THE ROLE OF THE THYROID IN THE INTESTINAL EFFECT OF VITAMIN D ON RACHITIC RATS
Authors: WINTER M. , MORAVA E. , SIMON G. 
Published: December 2008

SUMMARY
The effect of 20 i.u. vitamin D3 on the intestinal absorption of calcium was investigated in thyroidectomized and control rachitic rats. Vitamin D3 increased both duodenal and jejunal calcium absorption in the absence of the thyroid glands. These results suggest that neither thyroxine nor calcitonin are necessary for the effect of vitamin D3 on intestinal calcium absorption.
PERIPHERAL PLASMA PROGESTERONE CONCENTRATION OF COWS DURING PUBERTY, OESTROUS CYCLES, PREGNANCY AND LACTATION, AND THE EFFECTS OF UNDER-NUTRITION OR EXOGENOUS OXYTOCIN ON PROGESTERONE CONCENTRATION
Authors: DONALDSON L. E. , BASSETT J. M. , THORBURN G. D. 
Published: December 2008

SUMMARY
Progesterone concentrations in the peripheral plasma of cows were measured by a protein-binding radioassay method. The mean concentration was lowest at oestrus (0·44 ng/ml) and then increased to a maximum of 6·8 ng/ml about day 14 of the 21-day cycle. The concentration decreased rapidly during the last 4 days of the cycle, reaching low levels on the day before oestrus. There were no significant changes in progesterone concentration during oestrus. After ovariectomy the plasma progesterone concentration decreased to a very low level (< 0·4 ng/ml). After hysterectomy, progesterone concentrations remained high for longer than in a normal cycle. At puberty, plasma progesterone concentrations indicated cyclic ovarian activity before the first observed oestrus.
Daily treatment of cows with oxytocin (0·4 u./kg body weight) from day 2 reduced the oestrous cycle length to 9 days, but did not significantly alter the slow increase in plasma progesterone concentration during the first 5 days of the cycle. Plasma progesterone concentrations decreased again after day 5 to low values. Plasma progesterone concentration during early pregnancy was similar to the luteal phase value (4–6 ng/ml), declined during mid-pregnancy and then increased to a maximum (7–8 ng/ml) at about 240 days gestation. The concentration declined 2–3 weeks before calving. During lactation progesterone concentrations were very low until the resumption of cyclic ovarian activity. The first post-partum cycle, whether accompanied by observed oestrus or not, was usually preceded by a small increase in plasma progesterone concentration 3–5 days before the start of the cycle.
Undernutrition significantly increased plasma progesterone concentrations in mid- and late pregnancy. Undernutrition of non-pregnant cows increased progesterone concentrations during the luteal phase of the first cycle, but reduced it in later cycles.
LACTOGENESIS IN PSEUDOPREGNANT RABBITS TREATED WITH ADRENOCORTICOTROPHIN AND ADRENAL CORTICOSTEROIDS
Authors: CHADWICK A. 
Published: December 2008

SUMMARY
The lactogenic effect of adrenocorticotrophin (ACTH) injected into pseudopregnant rabbits has been confirmed. A synthetic partial ACTH peptide (Synacthen) was also lactogenic. The sensitivity to local lactogenic stimuli of the mammary glands of ACTH-treated rabbits and rabbits treated with corticosteroids was greater than that in untreated rabbits. The findings are discussed in relation to the factors controlling lactogenesis.
STIMULATION OF THE SYNTHESIS OF MACROMOLECULES BY OVARIAN HORMONES DURING EARLY DEVELOPMENT OF THE MOUSE MAMMARY GLAND
Authors: BANERJEE M. R. , ROGERS FERNE M. 
Published: December 2008

SUMMARY
The influence of oestradiol and progesterone on nucleic acids and protein synthesis during early development of 3- to 4-week-old C3H mouse mammary gland in vivo was studied. The hormones were administered daily by subcutaneous injections for 6–9 days. Uptake of tritium-labelled appropriate nucleoside and amino acid precursors, as determined by radio-chemical and autoradiographic methods, was used as a measure of cellular biosynthesis. Administration of the steroid hormones induces a pronounced increase of RNA, protein, and DNA synthesis in the mammary parenchyma of both intact and ovariectomized mice. Increased RNA and protein synthesis were detectable after two injections of the hormones, the maximal level was reached after the 6th injection. Hormone-induced DNA synthesis rose sharply reaching a peak after four treatments. The stimulatory effect of the steroids on DNA synthesis was more pronounced on the end-bud cells up to the 4th injection but in the duct cells [3H]thymidine uptake continued to rise progressively even after the 6th injection. Autoradiographs showed that the hormones also cause a twofold increase in the silver grain count per nucleus indicating an accelerated uptake rate of the DNA precursor. In end-bud cells mitotic activity, used as a measure of cellular proliferative activity, rose to a sharp peak after four injections of the hormones but in duct cells it continued to rise even after the 6th injection. The significance of these results with respect to further lobulo-alveolar development of the mammary parenchyma is discussed.
THE LIPIDS OF THE CROP EPITHELIUM OF PIGEONS AFTER INJECTION WITH PROLACTIN FROM THE PITUITARIES OF DIFFERENT VERTEBRATE CLASSES
Authors: CHADWICK A. , JORDAN B. J. 
Published: December 2008

SUMMARY
The histological appearance, the lipid content and composition of the epithelium of the pigeon crop were investigated after intradermal injection of extracts containing prolactin from representatives of several vertebrate classes. Lipids from crop 'milk' and body depot fat were also studied. There was significantly more lipid in stimulated crop tissue than in the unstimulated crop but significantly less than in crop 'milk', which had approximately half the concentration present in depot fat. Although the lipid staining of histological sections of crops of pigeons injected with prolactin from different vertebrate classes differed strikingly, no difference in lipid concentration in the crop tissue was detected. Equally there were no striking differences between the fatty acid compositions of the triglycerides extracted from the different crops or between these and the triglycerides of crop 'milk' or depot fat. The implications of these findings regarding the effects of prolactin in the pigeon and possible attributes of prolactin from different vertebrate classes are discussed.
ENDOCRINE CONTROL OVER PRODUCTION AND ACTIVITY OF THE ANTI-AGGRESSION PHEROMONE FROM FEMALE MICE
Authors: MUGFORD R. A. , NOWELL N. W. 
Published: December 2008

SUMMARY
In an attempt to clarify the role of gonadal function in the release of anti-aggression pheromone into the urine of female mice, two experiments were carried out. Each involved recording the aggressiveness of 'fighter' male mice when presented with castrated male 'opponents' which had been treated either with urine from one of four categories of female donor mice, or with water.
In the first series of experiments it was shown that the urine from oestrous and dioestrous mice contained similar amounts of anti-aggression activity. Both spaying and testosterone propionate (TP) injection of the female urine-donors abolished this activity.
In a second series of experiments urine from spayed donors injected with TP greatly increased the aggression response to a level which exceeded that obtained with the urine of TP-treated intact mice. High doses of oestrogen resulted, in the spayed urine-donors, in an actual increase in aggression response. Both treatments increased clitoral gland weight, and it is concluded that androgen or high levels of oestrogen can stimulate the clitoral gland of the female, a possible consequence being a release of aggression-promoting pheromone.
The aggression-inhibiting pheromone, which depends on the ovary for its release, is probably the product of some other tissue, as yet unidentified.
ADRENAL STEROID SECRETION IN THE TASMANIAN DEVIL (SARCOPHILUS HARISII) AND THE EASTERN NATIVE CAT (DASYURUS VIVERRINUS). A COMPARISON OF ADRENOCORTICAL ACTIVITY OF DIFFERENT AUSTRALIAN MARSUPIALS
Authors: WEISS MAGDA , RICHARDS P. G. 
Published: December 2008

SUMMARY
Adrenal venous and peripheral blood was collected from three Tasmanian devils and three Eastern native cats.
Ten Δ4-3-oxosteroids were identified in the adrenal venous blood of the devils and nine from the native cats. Cortisol was the major steroid and its maximum corticotrophin (ACTH) stimulated secretion rate averaged 61 μg/h/100 mg adrenal in devils and 36 μg in cats. The cortisol: corticosterone ratio in two devils and two cats was approx. 2·5 and 5, respectively. Aldosterone secretion rates in devils ranged from 0·06 to 0·12 μg/h/100 mg adrenal and in cats from 0·12 to 0·93, the response to ACTH varied in different animals. 21-Deoxycortisol was found in all animals, it increased during ACTH stimulation (maximum range in devils: 8·5–19·5 μg/h/100 mg adrenal, and 0·6–5·4 in cats). Another unusual steroid isolated from adrenal venous blood was identified as 17α-hydroxy-20β-dihydroprogesterone. Its rate of secretion was higher in devils (range approx. 2–6 μg/h/100 mg adrenal). No relationship was found between adrenal blood flow and corticosteroid secretion. In the peripheral blood plasma only cortisol and corticosterone were identified. The female of both species had a significantly higher concentration of cortisol of the order of 7 μg/100 ml plasma. The combined adrenal weights/kg body weight averaged 168 mg/kg in the devils and 132 mg in the cats.
Since all three Superfamilies of Australian marsupials have now been investigated a comparison of the results obtained from seven representative species is made and they are also considered in relation to eutherian mammals.
EFFECT OF ADRENALECTOMY AND ADRENOCORTICOTROPHIC HORMONE ON SEBUM SECRETION IN THE RAT
Authors: THODY A. J. , SHUSTER S. 
Published: December 2008

SUMMARY
Adrenalectomy caused a decrease in the rate of sebum secretion of male rats.
On the other hand treatment with adrenocorticotrophic hormone (ACTH) produced a large increase in the rate of sebum secretion in hypophysectomized—castrated rats and restored it to the level in castrated rats. ACTH also stimulated sebum secretion in castrated rats after removal of the adrenals, although this increase was not significant.
These findings suggest that a pituitary—adrenal—sebaceous gland system may exist. Adrenal androgens may play a significant part in this relationship.
Although ACTH probably stimulates sebum secretion through its action on the adrenals it is possible that this pituitary hormone may have some direct effect on sebaceous gland activity.
A VERY EARLY PREGNANCY TEST FOR MAMMALS: ITS APPLICATION TO THE COW, EWE AND SOW
Authors: ROBERTSON H. A. , SARDA I. R. 
Published: December 2008

SUMMARY
A method is described for diagnosing the presence or absence of a conceptus soon after mating or insemination. It is applicable to a wide range of mammals and tests in the cow, sheep and pig have given an accuracy of approximately 90%. The method is based on the detection of a functional or regressed corpus luteum at a fixed time after mating by measuring the concentration of progesterone in peripheral blood. It is relatively simple to carry out.
THE EFFECTS OF HYPOPHYSECTOMY ON ADRENOCORTICAL FUNCTION IN THE DUCK (ANAS PLATYRHYNCHOS)
Authors: BRADLEY E. L. , HOLMES W. N. 
Published: December 2008

SUMMARY
The general effect of chronic hypophysectomy on organ and body weights, liver glycogen, blood glucose, peripheral plasma corticosterone concentrations, and blood pressure in the duck were similar to those described for several mammalian species.
The disappearance and distribution of radioactivity after the administration of [1,2-3H]corticosterone and [1,2-3H]aldosterone was studied according to a single compartment model system. When compared with sham-operated ducks, the apparent volumes of distribution and the biological half-lives of radioactivity in hypophysectomized ducks were significantly increased, and the estimated metabolic clearance rates of [1,2-3H] corticosterone and [1,2-3H]aldosterone were significantly decreased. The patterns of distribution of radioactivity and the rate of metabolism of both hormones returned towards normal when the chronically hypophysectomized ducks were treated with corticotrophin (ACTH).
Fourteen days after hypophysectomy the peripheral plasma concentration of corticosterone and the estimated rate of corticosterone secretion by the adrenal fell to 10 and 4%, respectively, of the values observed in sham-operated birds. Examinations of the peripheral plasma corticosterone concentration during the first 30 min after the removal of the adenohypophysis indicated a mean biological half-life for endogenous corticosterone of 13·7 min.
The rates of appearance of radioactivity in the bile, intestine and cloaca of the hypophysectomized birds suggested substantial declines in the rates of aldosterone and corticosterone metabolism. These declines could not be accounted for by the reduced rate of glomerular filtration in the hypophysectomized bird. Replacement therapy with ACTH restored the excretory patterns of both steroids towards normal. The quantitative similarities between the effects of hypophysectomy in the duck and several mammalian species make it unnecessary to postulate either a high degree of adrenal autonomy or an extrahypophysial source of ACTH in the control of adrenocortical function in the duck.
SOME LIGHT- AND ELECTRON-MICROSCOPICAL OBSERVATIONS ON THE PARS INTERMEDIA OF THE PITUITARY GLAND OF THE RABBIT
Authors: CAMERON E. , FOSTER C. L. 
Published: December 2008

SUMMARY
The cytological appearance of the pars intermedia of the rabbit both at the light and the electron microscopical (E.M.) levels, is described. Two types of cell,one stainable byperiodic acid—Schiff's reagent and aldehyde—fuchsin and the other chromophilic, non-granular and intercalated between the former, were observed. In E.M. sections the first type had two kinds of granule in its cytoplasm, a few electron-dense about 250 nm in diameter, mostly confined to the Golgi area, and numerous large 'vesicles' or granules of varying density about 500–600 nm in diameter generally distributed throughout the cytoplasm. The second type of cell when viewed in the electron microscope is characterized by microvilli projecting into intercellular spaces, and long, linked processes ramifying in between the principal cells. Varicose nerve fibres and abundant neurosecretory material were demonstrated in the pars intermedia with chrome alum—haematoxylin and Alcian blue. In E.M. sections these neurosecretory granules were similar to those in the infundibular process. At the point where nerve fibres appeared to be making contact with glandular cells, synaptic vesicles of about 50 nm in diameter were also observed.
THE EFFECT OF HYPOPHYSECTOMY, AND OF INJECTIONS OF THYROTROPHIN AND CORTICOTROPHIN INTO HYPOPHYSECTOMIZED ANIMALS, ON THE SLOUGHING CYCLE OF THE LIZARD, GEKKO GECKO L.
Authors: CHIU K. W. , PHILLIPS J. G. 
Published: December 2008

SUMMARY
Hypophysectomy resulted in a lengthening of the sloughing cycle for about 25 days as compared with the normal cycle. The increase is only in the resting phase, the renewal phase remains unaffected. Thyroid-stimulating hormone did not affect the epidermis directly but increased the activity of the thyroid gland in the hypophysectomized geckos as judged by the uptake of 131I and follicular cell height, and reduced the resting phase by about 7 days. Corticotrophin inhibited sloughing for at least 65 days, and possibly entirely, with the epidermis remaining in the resting condition.
GONADOTROPHIN REQUIREMENTS FOR IMPLANTATION IN THE MOUSE
Authors: BINDON B. M. 
Published: December 2008

SUMMARY
Gonadotrophins were injected into mated hypophysectomized and suckling mice in an attempt to induce implantation. In these two classes of animal implantation is normally delayed by absence or suppression of pituitary gonadotrophin release. Antibodies raised against ovine gonadotrophins were injected into mice soon after mating in an attempt to inhibit implantation.
Pregnant mare serum gonadotrophin (PMSG) was effective in inducing implantation in both hypophysectomized and in suckling mice. This may mean that a gonadotrophin with the qualities of PMSG normally initiates implantation. Alternatively, PMSG may have been effective by virtue of its long half-life rather than any special hormonal attributes. Human chorionic gonadotrophin was ineffective in both types of mouse. Mixtures of ovine follicle-stimulating hormone (FSH) and luteinizing hormone (LH) (100 μg of each), injected daily for 3 days, were necessary to induce implantation in hypophysectomized mice.
Implantation was readily induced in suckling mice by a single injection of FSH (equivalent to 12·5 μg NIH-FSH-S3) prepared from rat pituitary glands.
Implantation was readily inhibited by anti-ovine LH. Anti-ovine FSH was ineffective but this did not cross-react with mouse FSH.
PITUITARY FUNCTION AFTER YTTRIUM IMPLANTS AS MEASURED BY PLASMA GROWTH HORMONE LEVELS
Authors: STEWART HELEN J. , BENSON E. A. , ROBERTS M. MAUREEN , FORREST A. P. M. , GREENWOOD F. C. 
Published: December 2008

SUMMARY
Plasma growth hormone (GH) levels during insulin hypoglycaemia were measured in 30 women with implants of 90Y in the pituitary for advanced breast cancer. There was evidence of continued pituitary activity in six patients (20%), the rise in plasma GH level being greater than 4 ng/ml during hypoglycaemia. Thirteen patients (43%) were regarded as having complete ablations because they had no GH response and a fasting level of less than 4 ng/ml. In the remaining 11 patients (37%) there was no rise in the GH level during hypoglycaemia, but there were significant fasting levels. From the post-mortem evidence it was concluded that these patients also had adequate ablations.
This test is shown to be of more value in estimating residual pituitary function than routine tests of thyroid or adrenal function.
EFFECTS OF HYPOTHALAMIC IMPLANTS OF GONADAL STEROIDS ON COURTSHIP BEHAVIOUR IN BARBARY DOVES (STREPTOPELIA RISORIA)
Authors: HUTCHISON J. B. 
Published: December 2008

SUMMARY
To determine whether the display of male courtship behaviour depends on the action of androgen on discrete areas of the brain, single crystalline implants of testosterone propionate (TP) (mean weight 40 μg) were positioned unilaterally in the brains of castrated male Barbary doves. Implants in the preoptic, anterior hypothalamic and lateral hypothalamic areas induced the full courtship display consisting of chasing, bowing and nestsoliciting. None of these behaviour patterns was re-established at precastration levels measured in terms of duration of display. Durations of courtship displayed by implanted males were similar to those induced by daily intramuscular injections of TP (300 μg/day × 15) into castrated birds.
The effectiveness of implants of TP into other regions of the brain could be related to their proximity to the preoptic and anterior hypothalamic regions. There were marked deficits in the pattern of courtship of castrated doves with implants in areas adjacent to the preoptic and anterior hypothalamic regions — the neostriatum intermediale, the area basalis, and posterior hypothalamus; implants more distantly placed in the paleostriatum primitivum and lateral forebrain bundle area did not induce courtship behaviour.
Cholesterol implants (59 μg) and blank implant tubing in the preoptic and anterior hypothalamic areas did not affect behaviour.
The results obtained were not specific for TP implants; chasing and nest-soliciting displays were also induced by either testosterone implants (51 μg) or oestradiol-17β monobenzoate implants (47 μg). In both cases, the courtship display lacked bowing.
It is concluded that the preoptic and anterior hypothalamic areas are directly sensitive to testosterone and that these areas are associated with the control of courtship behaviour.
ANDROGEN SYNTHESIS IN VITRO BY ADRENAL TISSUE FROM A NEWBORN ANENCEPHALIC INFANT
Authors: SHAHWAN M. M. , OAKEY R. E. , STITCH S. R. 
Published: December 2008

SUMMARY
Incubation of slices of adrenal tissue from a newborn anencephalic infant with [14C]pregnenolone and [3H]progesterone yielded radioactive testosterone, androst-4-ene-3,17-dione and 11β-hydroxyandrost-4-ene-3,17-dione which were characterized by reverse isotope dilution techniques. These findings indicate the presence of C(17)—C(20) desmolase, steroid 11β-hydroxylase, 3β-hydroxysteroid dehydrogenase-isomerase and 17β-hydroxysteroid dehydrogenase enzymes in this tissue. Therefore, despite the deficient production of C19 3β-hydroxy-unsaturated steroids by the anencephalic foetus, as indicated by cord blood levels, a potential for synthesis of C19 3-oxo-4-unsaturated steroids has been demonstrated in vitro.
THE EFFECTS OF REMOVAL OF THE CEREBRAL NEUROSECRETORY CELLS ON HAEMOLYMPH AND TISSUE CARBOHYDRATE IN LOCUSTA MIGRATORIA MIGRATORIOIDES R. & F.
Authors: GOLDSWORTHY G. J. 
Published: December 2008

SUMMARY
In Locusta, removal of the cerebral neurosecretory cells results in a marked accumulation of carbohydrate in both the haemolymph and tissues. It is suggested that this is not due to a lack of carbohydrate-mobilizing factor, but is most likely the result of metabolic changes brought about in the absence of cerebral neurosecretion.
ANASTOMOSIS OF THE UTERO—OVARIAN AND ANTERIOR MAMMARY VEINS FOR COLLECTION OF UTERO—OVARIAN VENOUS BLOOD: PROGESTERONE SECRETION RATES IN CYCLIC EWES
Authors: THORBURN G. D. , MATTNER P. E. 
Published: December 2008

SUMMARY
The ovarian and part of the uterine venous drainage was diverted through the superficial anterior mammary vein leaving the ovary in its normal position and preserving utero—ovarian relationships. The operation has been performed successfully in 18 pregnant Merino ewes (70–120 days' gestation). Blood samples were collected by direct puncture of the mammary and jugular veins during the latter half of pregnancy and the subsequent breeding season. All ewes lambed normally after a gestation period of 146–151 days. Twelve of the 16 surviving ewes resumed cyclic oestrous behaviour. Plasma progesterone concentration was measured by a competitive proteinbinding assay. Utero—ovarian venous blood flow and rates of ovarian progesterone secretion were measured throughout the oestrous cycle. Progesterone secretion during the luteal phase of the cycle was in the range of 4·5–6·0 mg/day. The progesterone concentrations in peripheral plasma were similar to those found in normal ewes.