bluuebunny/crossref_metadata_2025 huggingface dataset:
GONADOTROPHIN REQUIREMENTS FOR IMPLANTATION IN THE MOUSE
Authors: BINDON B. M.
Published: December 2008

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

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

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

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

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

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.
THE ONSET OF FIRST OESTRUS IN THE GUINEA-PIG AND THE EFFECTS OF GONADOTROPHINS AND OESTRADIOL IN THE IMMATURE ANIMAL
Authors: MILLS P. G. , REED MAY
Published: December 2008

The immature female guinea-pig approaching first oestrus and ovulation has been studied. A clear relationship between the rate of growth of the animal and the age at puberty has been found. The 'crucial period', a time just before first oestrus, when external signs of endogenous hormonal activity give an indication of the presence of ripening follicles in the ovary, has been defined. At this time premature ovulation can be regularly induced by a single injection of gonadotrophin (guinea-pig anterior pituitary homogenate, purified luteinizing hormone or follicle-stimulating hormone). Injection of oestrogen advanced vaginal opening but, in contrast to the rat, did not cause premature ovulation.
EFFECT OF CYPROHEPTADINE (PERIACTIN) ON ACCUMULATION OF [14C]5-HYDROXYTRYPTAMINE IN PREGNANT RATS
Authors: PFEIFER Y. , SADOVSKY E. , POLISHUK Z. , SULMAN F. G.
Published: December 2008

Subcutaneous injection of the 5-hydroxytryptamine (5-HT) antagonist cyproheptadine hydrochloride (Periactin) produced a significant decrease in uptake of [14C]5-HT (serotonin) in the myometrium and to a lesser degree in the ovaries, foetuses and heart of pregnant rats. This effect of cyproheptadine was considerably increased in rats pretreated with the monoamine oxidase inhibitor pargyline hydrochloride. These results suggest that the anti-abortive effect of cyproheptadine is based on specific inhibition of the contractile effect of 5-HT on the myometrium. The hypothesis is advanced that cyproheptadine competes with serotonin for its receptors and thus blocks the effect of serotonin.
RELATIONSHIP BETWEEN BLOOD LEVELS OF LUTEINIZING HORMONE AND TESTOSTERONE IN BULLS, AND THE EFFECTS OF SEXUAL STIMULATION
Authors: KATONGOLE C. B. , NAFTOLIN F. , SHORT R. V.
Published: December 2008

Luteinizing hormone (LH) and testosterone were measured in the peripheral plasma of two bulls by radioimmunoassay and competitive protein binding techniques. Samples were collected from an indwelling jugular catheter once an hour for 24 h, and then at more frequent intervals after a number of experimental procedures.

Each bull showed its own characteristic pattern of cyclic LH changes, with 5–10 peaks during 24 h that were apparently unrelated to daylight, feeding or sleep. Each LH peak was associated with a testosterone peak; the LH concentrations ranged from 5 to 50 ng/ml, and those of testosterone from 2 to 20 ng/ml.

Sexual stimulation, such as the sight of a cow, or 'teasing', or on one occasion the act of ejaculation itself, caused an immediate release of a large amount of LH. If the testosterone levels were low at the time, the LH peak was followed by a testosterone peak. But when the testosterone levels were high at the time of LH discharge, the testis seemed to be unable to respond any further. An intravenous injection of 500 i.u. human chorionic gonadotrophin was associated with LH release and caused the testosterone levels to rise to maximal values of 22 ng/ml within 1½ h.

It is concluded that the cyclical pattern of LH release is due to some inherent central rhythm, and that each transient LH peak results in transient maximal stimulation of testicular testosterone secretion.
CORRELATION OF WATER AND ELECTROLYTE DISTRIBUTION IN THE THYROID GLAND WITH ITS FUNCTIONAL STATE IN RATS AND GUINEA-PIGS
Authors: CHOW S. Y. , WOODBURY D. M.
Published: December 2008

In the thyroid gland of rats and guinea-pigs, follicular cell fluid volume was increased and luminal fluid volume was decreased after a single injection of thyroid-stimulating hormone (TSH) (1 i.u./animal) or long-term administration of propylthiouracil (PTU) (0·1% in drinking water for 2 weeks). In rats, follicular cell fluid volume was decreased and luminal fluid volume was increased after hypophysectomy. Interstitial fluid volume remained fairly constant in different functional states of the thyroid gland in both species. As a result of the decrease in luminal colloid content by TSH and PTU treatments, the Cl− concentration in the luminal compartment of the thyroid gland was increased. Luminal Cl− concentration decreased in hypophysectomized rats. In the cellular compartment of the thyroid gland, TSH and PTU treatments caused an increase in K+ and Cl− concentrations and a decrease in Na+ concentration, whereas hypophysectomy caused a decrease in K+ and Cl− and an increase in Na+ concentrations. Water and electrolytes in the thyroid gland of rats younger than 5 weeks were distributed in the same pattern as that of adult guinea-pigs and hypophysectomized adult rats; all these animals probably had lower TSH activity than intact adult rats.
RESULTS OF RADIOIMMUNOASSAYS OF RAT PITUITARY AND SERUM PROLACTIN AFTER ADRENALECTOMY AND PERPHENAZINE TREATMENT IN RATS
Authors: BEN-DAVID M. , DANON A. , BENVENISTE R. , WELLER C. P. , SULMAN F. G.
Published: December 2008

Treatment for 5 days of female rats with perphenazine (5 mg/kg/day) induced full lobulo—alveolar differentiation. Long-standing adrenalectomy (12 days) decreased this mammotrophic effect of perphenazine. The mechanism of this reaction was studied in male rats in order to avoid fluctuations of the prolactin content in the anterior pituitary. Adult male rats were adrenalectomized and injected s.c. after 12 days with perphenazine (10 mg/kg). Two hours later the rats were killed and pituitary and serum prolactin levels assayed by double antibody radioimmunoassay. In intact rats, perphenazine treatment enhanced serum prolactin up to 104 ± 4 (s.e.m.) ng/ml (± 350%). Adrenalectomy alone increased serum prolactin from 30± 5 to 47 ± 6 ng/ml (+56%), and augmented the perphenazine-induced release of prolactin from the pituitary into the blood from 104 ± 4 to 147 ± 10 ng/ml (+ 42%).

In chronically adrenalectomized adult female rats extremely high amounts of prolactin (+ 1617%) were detected in the serum at the end of 5 days' treatment with perphenazine (5 mg/kg/day).

These results indicate that removal of the adrenals in male and female rats does not interfere with the ability of the pituitary to secrete prolactin. Moreover, they also show that in adrenalectomized rats the impaired mammotrophic effect of perphenazine is not due to prolactin deficiency (since high serum levels of this hormone were present) but to the absence of corticosteroids at the target organ.
THE RELATIONSHIP BETWEEN THE α-MANNOSIDASE ACTIVITY AND THE ZINC CONTENT OF MAMMALIAN SEX ORGANS
Authors: SNAITH SYBIL M. , HAY A. J. , LEVVY G. A.
Published: December 2008

The α-mannosidase activity and the zinc content of rat epididymis increased with age and there was a positive correlation between the two parameters. After castration of rats, epididymal α-mannosidase activity and zinc content both fell; subsequent administration of testosterone caused a partial restoration in enzyme activity, but not in zinc content. In zinc-deficient rats, the epididymal α-mannosidase activity reached little more than half the normal value for adults. In sucrose homogenates of rat epididymis and liver, α-mannosidase activity was concentrated in the cytoplasmic granules, but this was not accompanied by enrichment in zinc. In ovaries from cattle, pigs and women, the very low level of α-mannosidase activity in follicular fluid was reflected in a virtual absence of zinc: the zinc content of the corpus luteum was similar to that of the remaining ovarian tissue, in spite of the greater α-mannosidase activity of the former.
THE EFFECTS OF NEUROHYPOPHYSECTOMY ON THE PATTERN OF RENAL EXCRETION IN THE DUCK (ANAS PLATYRHYNCHOS)
Authors: BRADLEY E. L. , HOLMES W. N. , WRIGHT A.
Published: December 2008

Renal excretion in intact, sham-operated and neurohypophysectomized ducks was studied. Neurohypophysectomy produced immediate and profound polydipsia and polyuria. These conditions steadily diminished during the first 2 weeks after the operation and by the 14th day they had stabilized at levels which were approximately three times higher than the corresponding values in sham-operated birds. The stabilized levels of polydipsia and polyuria persisted throughout the remainder of the 60–90 day experimental period. The rates of excretion of Na+, Cl− and total osmotically active material were also increased when compared with intact or sham-operated birds. No change in the rate of K+ excretion was observed.

The i.m. administration of vasopressin reduced the rate of urine flow to that observed in the control birds but the rates of electrolyte excretion were not restored to normal. Synthetic oxytocin had no antidiuretic effect in the neurohypophysectomized birds. Arginine vasotocin treatment restored the rates of both water and ion excretion to values very close to those observed in intact and sham-operated birds.
THE RESPONSE OF THE SEBACEOUS GLANDS OF THE HYPOPHYSECTOMIZED—CASTRATED MALE RAT TO 5α-DIHYDROTESTOSTERONE, ANDROSTENEDIONE, DEHYDROEPIANDROSTERONE AND ANDROSTERONE
Authors: EBLING F. J. , EBLING ERIKA , McCAFFERY VIRGINIA , SKINNER J.
Published: December 2008

5α-Dihydrotestosterone and androstenedione (0·2 mg/24 h for 24 days), but not testosterone, significantly increased sebum production in hypophysectomized—castrated rats. Dehydroepiandrosterone and androsterone, even in doses ten times greater, could not be shown to do so, though all the steroids increased the incidence of mitoses in the sebaceous glands. In rats with intact pituitaries, however, the greatest effect on sebaceous secretion was produced by testosterone. A significant increase was also produced by 5α-dihydrotestosterone; androstenedione was only effective at ten times the dose, and androsterone was without significant effect. Dehydroepiandrosterone was not tested.

A possible interpretation of the results is that within the sebaceous glands, either the release of testosterone from its conjugates or its conversion to an active metabolite is under pituitary control. The results also support the view that there are at least two distinct points of action of steroids on the sebaceous glands, namely mitosis and intracellular synthesis of sebum.
GENETIC VARIATION IN THE NEUROHYPOPHYSIAL HORMONES OF THE MOUSE, MUS MUSCULUS
Authors: STEWART A. D.
Published: December 2008

The possibility of genetic variation in the amino acid composition of neurohypophysial hormones of the mouse was investigated. Acetic acid extracts from acetone-dried neurohypophyses from six strains of mice were subjected to thin-layer chromatography. Extracts from two strains were tested for natriferic potency on a toad bladder preparation. Extracts from three strains of mice were purified on a carboxymethylcellulose column, and the amino acid composition determined by paper electrophoresis at pH 2.

All six strains of mice were found to elaborate an oxytocic principle with the chromatographic properties of oxytocin. All results were compatible with the view that five of the strains elaborate the usual mammalian vasopressin, [8-arginine]-vasopressin. However, chromatography, natriferic assays and analyses of amino acid composition indicated that the Peru strain of mice elaborated [8-lysine]-vasopressin. These mice would be the first mammals outside the Suina which possess this hormone, and the difference between the strains of mice is almost certainly genetic in origin. The significance of genetic variation within a species in the structure of a hormone is discussed in terms of its physiological and evolutionary consequences.
EFFECT OF A PHENOTHIAZINE TRANQUILLIZER ON PLASMA MELANOPHORE-STIMULATING ACTIVITY IN SPANISH GOATS
Authors: PEASLEE MARGARET H. , MILBURN S. E.
Published: December 2008

A phenothiazine tranquillizer was administered intravenously to Spanish goats. An increase of plasma melanophore-stimulating activity ranging from 300 to 2000% above base level was observed usually within 15 min after injection.
SEX-ATTRACTANT PROPERTIES OF ETHER EXTRACTS OF VAGINAL SECRETIONS FROM RHESUS MONKEYS
Authors: KEVERNE E. B. , MICHAEL R. P.
Published: December 2008

Vaginal secretions were collected by lavage from ovariectomized, oestrogen-treated female rhesus monkeys. Ether extracts of these secretions were applied to the sexual skin of long-ovariectomized, untreated females immediately before mating tests with males. Application of extracts resulted in an immediate and marked stimulation of the sexual activity of males which had been inactive with these females during pretreatment tests when control material was applied. Extracts caused increases in male mounting activity, in ejaculations and in male grooming times, in the apparent absence of any behavioural or genital tract signs of female receptivity. It is concluded from these and other observations that male sex-attractant pheromones, with powerful behavioural effects, are present in ether extracts of oestrogen-stimulated vaginal secretions: this will facilitate their chemical characterization.
EFFECT OF GROWTH HORMONE ON THE ALDOSTERONE SECRETORY RESPONSE TO SODIUM RESTRICTION IN CORTICOTROPHIN-MAINTAINED HYPOPHYSECTOMIZED NEPHRECTOMIZED RATS
Authors: PALKOVITS M. , STRIK J. J. T. W. A. , de JONG W. , de WIED D.
Published: December 2008

The rate of aldosterone production in vitro by adrenal glands from rats hypophysectomized 7 days previously, treated with corticotrophin (ACTH) and subjected to dietary sodium restriction for 2 weeks, was decreased 6 h after nephrectomy. However, 18 h and 48 h after nephrectomy there was a marked increase in the rate of aldosterone production in vitro. In addition there was a rise in the plasma potassium concentration. These results indicated that in order to detect whether the influence of growth hormone on aldosterone secretory response to sodium restriction in hypophysectomized rats was mediated by the kidney, studies had to be performed within 6 h after removal of the kidneys.

Since the effect of growth hormone on aldosterone production requires 2 days to develop (Palkovits, de Jong, van der Wal & de Wied, 1971), rats hypophysectomized 54 h previously were used. The kidneys were removed 6 h before decapitation. In these animals, the administration of growth hormone in the presence of ACTH restored the aldosterone secretory response to sodium deficiency.

The results suggest that growth hormone maintains the aldosterone secretory response to sodium restriction in hypophysectomized rats in the absence of the kidneys.
THE ACTION OF CLOMIPHENE IN THE FERRET
Authors: DONOVAN B. T.
Published: December 2008

In an attempt to interfere pharmacologically with the feedback action of oestrogen in the ferret, clomiphene citrate was given to anoestrous animals for 10 days, and to oestrous females for 7 or 14 days, in doses ranging from 10 μg to 1000 μg daily. With the higher doses oestrogenic effects on the uterus were observed, while arrest of follicular development in the ovaries indicated inhibition of gonadotrophin secretion. Enhancement of gonadotrophin secretion in anoestrous females was not encountered, although ovulation in oestrous females was an occasional consequence of treatment with the drug.
HORMONAL IODINE IN THE DOG
Authors: FARRAN HELEN E. A. , BUSH B. M.
Published: December 2008

The nature and rate of formation of hormonal iodine in the dog has been studied by radioactive and chemical methods. A rapid appearance of protein-bound iodine (PBI) which was not extractable with acid butanol was noted during the first few hours after the administration of 131I. The butanol-insoluble fraction of PBI was not detectable 2–3 days after the dose when the residual activity was found to consist of approximately equal amounts of thyroxine and tri-iodothyronine. This unexpectedly high proportion of circulating tri-iodothyronine was checked by saturation analysis. It is suggested that relatively high levels of tri-iodothyronine in some dogs may in part account for the low PBI levels found in normal canine sera.
DETERMINATION OF PLASMA OESTRIOL IN NORMAL PREGNANCY AND LABOUR USING GAS-LIQUID CHROMATOGRAPHY
Authors: COOPER W. , COYLE M. G. , MILLS J. A.
Published: December 2008

A method is described for estimating oestriol in 2–10 ml samples of human pregnancy peripheral plasma. It incorporates acid hydrolysis, chemical purification, methylation, chromatography on alumina columns, formation of a derivative and quantitative determination by gas chromatography. A radioactive internal standard was added to correct for procedural losses. Plasma oestriol determinations in five normal patients throughout pregnancy and delivery are reported.
EFFECTS OF STILBOESTROL ON GROWTH HORMONE SECRETION AND PITUITARY CELL PROLIFERATION IN THE MALE RAT
Authors: LLOYD H. M. , MEARES J. D. , JACOBI JOAN , THOMAS FRANCES J.
Published: December 2008

A single 12 mg dose of stilboestrol dipropionate given to 100-day-old male rats resulted in increased pituitary mitotic activity, pituitary weight and serum growth hormone; the latter rose from a mean value of 20 ng/ml to a maximum of 342 ng/ml 9 days later. Serum growth hormone and pituitary mitotic activity then gradually diminished but were still slightly increased on day 28. Serum growth hormone and pituitary weight were significantly correlated during the periods of rapidly rising and of sustained high levels of serum growth hormone. Indices of mitotic activity were correlated with serum growth hormone during the periods of rapidly rising and of falling levels of serum growth hormone.
SYNTHESIS OF ANDROGENS IN VITRO BY TESTES OF RATS ACCLIMATIZED TO A HOT ENVIRONMENT
Authors: BEDRAK E. , SAMOILOFF V. , SOD-MORIAH U. A. , GOLDBERG S.
Published: December 2008

The relative activities of enzymes participating in the biosynthesis of testosterone via the 4-ene pathway were determined in testicular homogenates of rats acclimatized to a hot environment (33–35 °C, 25–40% relative humidity). Acclimatized animals showed an increase in activity of 17α-hydroxylase, 17,20-lyase and 20α-hydroxysteroid oxidoreductase, whereas the activity of 17β-hydroxysteroid oxidoreductase was markedly decreased. Histological examination of the testes disclosed that neither the germinal epithelium nor the Leydig cells were adversely affected by the increased environmental temperature. The results are discussed in relation to the synthesis and release of the gonadotrophins.

A similar degree of acclimatization, as determined by the comparable decrease in oxygen uptake, was achieved by either of two methods: daily 4 h exposure to a high ambient temperature for 4 weeks or continuous maintenance at 35 °C. The former procedure, however, appeared to be the preferred method for acclimatization of male rats since it did not inhibit growth rate and was free of mortality.
THE EFFECT OF CORTISOL ON THE TOLERANCE TO GLUCOSE OF THYROIDECTOMIZED CALVES
Authors: EDWARDS A. V. , NATHANIELSZ P. W. , VAUGHAN N. J. A.
Published: December 2008

The results of serial glucose tolerance tests in cortisol-treated, thyroidectomized calves indicate that there is a progressive reduction in the tolerance to glucose and that this is associated with a diminution in the rise in plasma insulin concentration which normally occurs in response to hyperglycaemia. These experimental conditions also stop growth within 12–14 days. All these effects are reversed by injections of thyroxine at a dose which raises the plasma thyroxine concentration to normal values for 7 days in spite of the continued administration of cortisol.

These results suggest that, in the unweaned thyroidectomized calf, daily injections of cortisol reduce the sensitivity of the insulin release mechanism, which may provide an explanation for the severe diabetic syndrome which is known to develop under these conditions.
EFFECT OF RESERPINE ON GROWTH HORMONE RESPONSE TO INSULIN HYPOGLYCAEMIA AND TO ARGININE INFUSION IN NORMAL SUBJECTS AND HYPERTHYROID PATIENTS
Authors: CAVAGNINI F. , PERACCHI M.
Published: December 2008

The effect of reserpine on growth hormone (GH) secretion induced by insulin hypoglycaemia and by arginine infusion was studied in ten normal subjects and ten hyperthyroid patients. In both groups of subjects, oral reserpine administration resulted in a reduction of GH response to hypoglycaemia, but caused no significant change of GH release after arginine infusion. These results strongly support the theory of an adrenergic control of GH secretion and indicate that arginine stimulates GH secretion in a different way from insulin and independently of catecholamines.
EVIDENCE OF ANTAGONISM BETWEEN PROLACTIN AND GONADOTROPHIN SECRETION: EFFECT OF METHALLIBURE ON PERPHENAZINE-INDUCED PROLACTIN SECRETION IN OVARIECTOMIZED RATS
Authors: BEN-DAVID M. , DANON A. , SULMAN F. G.
Published: December 2008

Perphenazine has previously been shown to stimulate prolactin secretion in intact and to a lesser degree in ovariectomized virgin female rats. The question whether the oversecretion of gonadotrophins (follicle-stimulating hormone and luteinizing hormone) occurring in ovariectomized animals interferes with the ability of the pituitary cells to secrete prolactin was investigated in sham-operated and ovariectomized rats after separate and combined treatment with methallibure (ICI-33828, a non-steroidal gonadotrophin suppressor) and perphenazine which served as a prolactin releaser. Pituitary and serum prolactin were measured simultaneously by radioimmunoassay. Serum prolactin detected at the end of 5 days' treatment with perphenazine (5 mg/kg/day, s.c.) was found to be increased (81 ng/ml) compared with controls (29 ng/ml). Similar treatment given to ovariectomized animals increased serum prolactin levels from 13·7 ng/ml to only 27 ng/ml. Although high doses of methallibure alone (20 mg/kg/day, s.c.) given to ovariectomized rats for 17 days restored prolactin secretion to the levels occurring in intact non-treated animals, a dose of 10 mg was ineffective. However, when 10 mg methallibure were given to perphenazine-treated ovariectomized rats, serum prolactin rose again to 80·1 ng/ml.

These results provide substantial evidence that, when the pituitary is secreting high amounts of gonadotrophin, its prolactin secretion is reduced and its ability to secrete prolactin after perphenazine challenge is limited. Once the gonadotrophic oversecretion is suppressed, more prolactin is secreted and the pituitary can again secrete high amounts of prolactin when challenged by perphenazine. The results show that in rats there exists an antagonism between gonadotrophin and prolactin secretion.
THE CONTROL OF THE APOCRINE GLANDS OF THE RABBIT BY STEROID HORMONES
Authors: WALES N. A. M. , EBLING F. J.
Published: December 2008

The rabbit has specialized apocrine glands in the submandibular (chin), inguinal and anal regions. The glands enlarge at puberty and are heavier and more active in mature males than females. Prepubertal castration causes the adult male to have lighter and less active glands than intact mature animals; this effect can be reversed by administration of testosterone (0·6 mg/24 h).

Severe reduction in gland weight and activity below the level of the castrated animals was produced by administration of oestradiol (10–20 μg/24 h) either when given alone to intact males or together with testosterone to castrated males. The degree of depression by oestradiol varied between the three glandular regions.

Progesterone (0·6 mg/24 h) was unable to stimulate the glands of castrated male rabbits but did modify the suppressive action of exogenous oestradiol.

The sebaceous glands of the inguinal complex showed the same fluctuations in weight with hormone treatment as did the inguinal apocrine glands.
BIOASSAY OF OXYTOCIN BY CHANGES IN LIGHT PENETRATION THROUGH RAT MAMMARY GLAND TISSUE IN VITRO
Authors: BÍLEK J. , MIKULÁŠ I. , SLABA J. , SKÁLA I.
Published: December 2008

A method for the bioassay of oxytocin in the lactating rat mammary gland in vitro is described. The changes in transparency induced by oxytocin in a flat segment of the gland are recorded by means of a CdS photoresistor and a simple Wheatstone bridge. The sensitivity of the assay in routine use is about 0·5–10 μu. oxytocin, the index of precision being about 0·1.
THE PRODUCTION OF 'SULPHATION FACTOR' BY RAT LIVER
Authors: McCONAGHEY P.
Published: December 2008

Rat liver when treated with bovine growth hormone produced a humoral factor ('sulphation factor') which stimulated cartilage growth directly; the results indicate that this humoral factor differs from growth hormone.

Perfusion of rat liver and incubation of rat liver slices with bovine growth hormone stimulated the production of 'sulphation factor' as measured by the uptake of 35S into rat cartilage. The liver required a long exposure to the hormone before the 'sulphation factor' was produced and was still capable of 'sulphation factor' production after growth hormone treatment had ceased.

The age and condition of the animal influenced the time necessary for growth hormone to act on the liver and the persistence of its effects. Disruption of liver slices by freezing and thawing, and by homogenization, destroyed their ability to produce 'sulphation factor' on addition of growth hormone.
REGULATION OF STEROID SYNTHESIS IN RABBIT OVARIAN HOMOGENATES BY LUTEINIZING HORMONE, CYCLIC AMP AND PYRIDINE NUCLEOTIDES
Authors: SCOON V. , MAJOR PATRICIA W.
Published: December 2008

Luteinizing hormone and cyclic AMP stimulate synthesis of progestational steroids in rabbit ovarian homogenates. Both progesterone and 20α-hydroxypregn-4-en-3-one are produced and, in contrast to ovarian slice preparations, progesterone is the predominant steroid formed.

Steroid synthesis in homogenates from interstitial tissue is stimulated to a greater extent than in homogenates of luteal tissue. Synthesis of these steroids by the homogenates can also be increased by addition of NADP+ and NADPH. The amount and nature of the steroid synthesized varies with the amount of cofactor added and with its form (oxidized or reduced). When both forms of cofactor were added to the system in vitro, the ratio of the oxidized to the reduced form appeared to be important in determining the form of the steroid produced.
BINDING OF LONG-ACTING THYROID STIMULATOR TO 4S THYROID PROTEIN COUPLED TO SEPHAROSE
Authors: SMITH B. R.
Published: December 2008

Long-acting thyroid stimulator (LATS) and LATS binding protein (LAA) were made insoluble by coupling to Sepharose-4B. LATS was bound by insoluble LAA and the bound LATS was recovered in high yield by treatment with sodium thiocyanate. Insoluble LATS was bound to LAA but LAA could not be recovered from the complex since it was destroyed under the conditions required to dissociate the LATS—LAA bond. The implications of the results are discussed in relation to the purification of LATS and LAA and the development of a radioimmune type assay for LATS.
EFFECT OF REPEATED OESTROGEN ADMINISTRATION ON OESTROUS BEHAVIOUR IN OVARIECTOMIZED EWES
Authors: SCARAMUZZI R. J. , LINDSAY D. R. , SHELTON J. N.
Published: December 2008

The effects of repeated injections of oestradiol benzoate (ODB) on the behavioural oestrous responses of ovariectomized ewes were studied using a pool of 144 animals. Oestradiol benzoate (15·6–421·2 μg) injected at intervals of 4 or 6 days produced a gradual decrease in the number of ewes showing induced oestrous behaviour. The response eventually fell below 10% at which time the ewes were defined to be refractory to oestrogenic stimulation of behavioural oestrus. When a continuous variable was used as a measure of response an immediate effect was observed; after the second injection of ODB the duration of oestrous behaviour decreased while the time to onset of oestrous behaviour showed a corresponding increase when compared with the first injection. However the proportion of ewes responding remained unaltered, indicating that continuous variables are a more sensitive measure of refractoriness. Treatment of refractory ewes with the progestagens progesterone, SC-9880 or Nilevar restored normal oestrous behaviour. These results are interpreted to mean that oestrogens (15–400 μg) act to increase thresholds for subsequent oestrogen stimulation of behavioural oestrus, while progestagens (1–10 mg) act to decrease this threshold.
THE DEVELOPMENT OF A RADIOIMMUNOASSAY FOR ARGININE-VASOPRESSIN: PRODUCTION OF ANTISERA AND LABELLED HORMONE; SEPARATION TECHNIQUES; SPECIFICITY AND SENSITIVITY OF THE ASSAY IN AQUEOUS SOLUTION
Authors: EDWARDS C. R. W. , CHARD T. , KITAU MURIEL J. , FORSLING MARY L. , LANDON J.
Published: December 2008

A radioimmunoassay for vasopressin was developed using antibodies produced against conjugated and non-conjugated arginine vasopressin. Despite the fact that the vasopressin molecule has only eight amino acids, cross reactivity studies showed that these antibodies were specific for different amino acid sequences.

Labelled hormone of high specific activity (350–800 μCi/μg) was produced by a modification of the chloramine-T method. Unreacted iodide was removed by the batchwise addition of an ion-exchange resin. Other techniques of purification produced no advantage over this simple method.

Several methods of separating antibody-bound and free hormone were studied. All except chromatoelectrophoresis proved satisfactory. Ammonium sulphate or ethanol precipitation of bound hormone was chosen because of simplicity, speed and reproducibility.

The lower limit of detection of the assay was 80 pg arginine vasopressin/ml diluent buffer. Therefore an extraction and concentration procedure is necessary for the measurement of basal circulating levels of the hormone.
EFFECT OF SOME TRIPHENYLETHYLENES ON OESTRADIOL BINDING IN VITRO TO MACROMOLECULES FROM UTERUS AND ANTERIOR PITUITARY
Authors: SKIDMORE J. , WALPOLE A. L. , WOODBURN J.
Published: December 2008

The effects of a series of triphenylethylenes (I.C.I. 46,474, I.C.I. 47,699 and clomiphene isomers A and B) on oestradiol binding to receptors from rat, rabbit and mouse uteri and rat anterior pituitary were studied. Binding of oestradiol to receptors from uteri was inhibited competitively by I.C.I. 46,474. Receptors from uteri of the three species and from rat anterior pituitary have very similar affinities for oestradiol and the four triphenylethylenes. The order of activity of the triphenylethylenes as inhibitors of oestradiol binding is: clomiphene B > I.C.I. 46,474 > I.C.I. 47,699 > clomiphene A. Some correlations are made with the activity of the compounds in vivo.
A RADIOIMMUNOASSAY FOR AVIAN LUTEINIZING HORMONE
Authors: FOLLETT B. K. , SCANES C. G. , CUNNINGHAM F. J.
Published: December 2008

A radioimmunoassay for avian luteinizing hormone (LH) is described, using antisera raised against chicken pituitary gonadotrophins of varying degrees of purity, and purified chicken LH for radio-iodination. A postprecipitation double antibody method was developed with a sensitivity to 30–60 pg of purified chicken LH.

The specificity of the method was investigated. Fractions of follicle-stimulating hormone with high biological activity showed little immunological activity, whilst all the fractions of LH tested showed strong immunological potency. Human, ovine and bovine LH showed virtually no cross-reaction.

The method measures immunoreactive LH in 25–200 μl plasma from chickens and quail. The plasma levels correlate well with known physiological processes, being absent in hypophysectomized birds and low in sexually immature quail. When testicular growth begins in quail the level rises eightfold; castration increases it still further while the level is lowered by testosterone. Manipulation of the pituitary-thyroid system in quail did not significantly affect the level of plasma activity.

Estimates of activity are independent of either the antiserum or the iodinated preparation of LH used in the assay.

The antisera used all blocked gonadotrophic activity in vivo.
ISOLATION AND PURIFICATION OF LUTEINIZING HORMONE FROM PORCINE PITUITARY GLANDS
Authors: ANDERSON F. B. , O'GRADY J. E.
Published: December 2008

A method is described for the isolation of a purified luteinizing hormone (LH) from the anterior lobes of porcine pituitary glands. This includes fractional precipitation, gel filtration and isoelectric focusing. The preparation, which can be recovered in a fairly short time, is of high potency (equivalent to 3·4 mg standard NIH-LH-B7/mg and 6800 i.u. LH/mg).
FACILITATION OF LUTEINIZING HORMONE SECRETION IN THE FEMALE RAT BY PROGESTERONE
Authors: BROWN-GRANT K. , NAFTOLIN F.
Published: December 2008

Progesterone injected intramuscularly at 09.00 h on the day of prooestrus in the 4-day cycle of the rat decreased plasma luteinizing hormone (LH) concentration for 2 to 3 h, but by 5 h after injection had triggered an abrupt, premature, and sustained increase in LH secretion. Between 4 and 5 h after injection sufficient LH had been secreted to raise the plasma LH concentration to more than 20 ng/ml and to induce ovulation in the majority of rats. The facilitatory effect of progesterone on LH secretion could be prevented, or extinguished after it had begun, by the administration of sodium pentobarbitone. The effects observed after administration at the prooestrous stage of the cycle are compared with those seen after progesterone injection under other conditions.
EFFECTS OF PROSTAGLANDIN F2α ON SOME REPRODUCTIVE PROCESSES OF HAMSTERS AND RATS
Authors: LABHSETWAR A. P.
Published: December 2008

In an attempt to characterize the endocrine profile of prostaglandin F2α (PGF2α) in relation to the female reproductive system, the compound (racemic form) was administered to hamsters and rats in various reproductive states. The prostaglandin terminated pregnancy when given once a day either subcutaneously (50 μg/hamster) or orally (1·5–2 mg/hamster) from Days 4 to 6 of pregnancy inclusive, or as a single subcutaneous injection (50 μg/animal) on Day 4. In the rat, higher (500 μg/injection) and more frequent (twice daily) s.c. injections were required to get even foetal resorption. Concomitant administration of progesterone (4 mg/animal) in either species protected pregnancy. Prostaglandin F2α terminated pregnancy without interfering with the Pontamine blue reaction, suggesting that its antifertility effects were not mediated by inhibition of implantation. In both hamsters and rats the prostaglandin markedly reduced the size of deciduomata which could be restored to normal by administration of progesterone. Prostaglandin F2α delayed passage of zygotes through the Fallopian tubes in a proportion of rats but failed to accelerate egg transport in rats and hamsters. Furthermore, it caused a marked histological degeneration of the corpora lutea and induced formation of a fresh set of corpora lutea in pseudopregnant, pregnant and pseudopregnant—hysterectomized hamsters. These deleterious effects of prostaglandin were accompanied, in hamsters, by the appearance of freshly ovulated tubal ova. Most of the endocrine effects of PGF2α observed in this study can be accounted for by its luteolytic property.
SKIN VIRILISM IN WOMEN WITH HIRSUTISM
Authors: BURTON J. L. , JOHNSON C. , LIBMAN L. , SHUSTER S.
Published: December 2008

Thirteen hirsute women were studied and found to have significantly increased mean rates of sweat and sebum excretion and plasma testosterone concentration compared with control women. These same patients had previously been shown to have an increased total skin collagen content. These findings suggest that the whole skin is virilized in hirsutism. This may be the result of cutaneous androgen synthesis.
ANALYSIS OF THE EFFECTS OF PROGESTERONE ON THE SYNTHESIS OF RNA AND PROTEIN IN THE UTERUS OF THE OVARIECTOMIZED RAT AND ON THE DEVELOPMENT OF AN IODIDE CONCENTRATING MECHANISM
Authors: BROWN-GRANT K. , JOHN P. N. , ROGERS A. W.
Published: December 2008

Concentration of radioiodide in the cells of the luminal epithelium of the ovariectomized rat after a single injection of progesterone was abolished by 300 μg cycloheximide/100 g body weight given with or 4 h after the progesterone. Actinomycin D at 32 or 80 μ/100 g body weight given with the progesterone did not inhibit the development of the iodide concentrating mechanism. Oestradiol given 16 h before or 2 h after progesterone inhibited the iodide response in a dose-dependent manner. The incorporation of [3H]uridine into histologically fixed material was significantly increased in all tissues of the uterus 1 h after progesterone. The incorporation of [3H]lysine into histologically fixed material was increased significantly in luminal epithelium at 3 h and in all uterine tissues at 7 and 24 h. These findings are consistent with the view that gene transcription may be stimulated by progesterone, resulting in the synthesis of proteins in the different tissues of the uterus. In the luminal epithelium however, progesterone may also stimulate protein synthesis and the development of the iodide response in the absence of gene transcription.
A COMPARISON OF STEROIDOGENESIS IN VITRO IN TWO TELEOSTS, THE MARINE HERRING, CLUPEA, AND THE FRESHWATER ATLANTIC SALMON, SALMO
Authors: SANGALANG G. B. , TRUSCOTT B. , IDLER D. R.
Published: December 2008

Cortisol was the principal steroid biotransformed from [16-3H]pregnenolone incubated with interrenal tissues of the Atlantic herring, Clupea harengus harengus, and of the Atlantic salmon, Salmo salar. Corticosterone was the preferred product from [4-14C]progesterone in herring, and cortisol in salmon. In these two teleosts 3H:14C recrystallization ratios of cortisol produced from the equimolar amounts of precursors at various times of incubation suggested that pregnenolone was the better precursor of cortisol and that the favoured pathway to cortisol was via 17-hydroxylated rather than 17-deoxy intermediates.

It was demonstrated that interrenal tissues of herring and salmon both have the capacity to 17-hydroxylate corticosterone to cortisol; aldosterone was not detected in any of the interrenal incubates. The 17-hydroxylation of 11-deoxycorticosterone to 11-deoxycortisol was shown in vitro by interrenal tissues of the Atlantic salmon, a conversion that has not been previously demonstrated in fish or in normal tissues of other vertebrates. When interrenal tissue of Atlantic salmon was incubated with equimolar amounts of [1,2-3H] 11-deoxycorticosterone plus [4-14C]corticosterone, there was more conversion of 11-deoxycorticosterone to 11-deoxycortisol (0·39%) than of corticosterone to cortisol (0·12%) and only a small amount (1·0%) of the 3H-labelled precursor was associated with corticosterone after 4 h incubation.

Biotransformed cortisol was isolated from both herring and salmon interrenals incubated with each of the following pairs of equimolar substrates: [3H]21-deoxycortisol plus [4-14C]11-deoxycortisol, [3H]21-deoxycortisol plus [4-14C]corticosterone, and [7-3H]11-deoxycortisol plus [4-14C]corticosterone. Isotope ratios of product cortisol suggested that, under the in-vitro conditions employed, substrate efficiency to cortisol synthesis was in the order: 11-deoxycortisol ⪢ 21-deoxycortisol > corticosterone. The results indicated that steroid hydroxylations at C-11, C-17 and C-21 could occur in any order in vitro in interrenals of herring and of salmon.
DETERMINATION OF DEHYDROEPIANDROSTERONE AND DEHYDROEPIANDROSTERONE SULPHATE IN HUMAN PLASMA USING ELECTRON CAPTURE DETECTION OF 4-ANDROSTENE-3,6,17-TRIONE AFTER GAS-LIQUID CHROMATOGRAPHY
Authors: de JONG F. H. , van der MOLEN H. J.
Published: December 2008

A method for the measurement of dehydroepiandrosterone (DHA) and of its sulphate (DHAS) in human peripheral plasma is described and evaluated. After isolation of DHA from the sample the steroid is oxidized to 4-androstene-3,6,17-trione, which is measured with an electron capture detector after gas—liquid chromatography. It is possible to detect 100 pg 4-androstene-3,6,17-trione. The smallest amount of DHA per sample that can be distinguished from zero is approximately 4 ng, when recovery (27·9 ± 8·8%) and method blank (0·23 ± 0·38 ng) are taken into account. The oxidation to 4-ene-3,6-diones is specific for steroidal 5-en-3-ols. Specificity for DHA is ensured by several chromatographic steps. Repeated estimation of 10 ng DHA gave a mean value of 9·6 ± 1·45 (s.d.) ng (n = 35). Mean concentrations and their standard deviations for DHA and DHAS in peripheral plasma from 18 individuals were 0·50 ± 0·25 and 78 ± 40 μg/100 ml, respectively, at 08.30 h and 0·32 ± 0·17 and 84 ± 34 μg/100 ml, respectively, at 17.00 h of the same day. Levels of plasma cortisol in the same plasma samples estimated with a competitive protein-binding method were 16·7 ± 1·8 and 11·9 ± 3·8 μg/100 ml, respectively. No significant differences between the sexes were observed by any of the three assays. The mean values of the plasma concentrations of cortisol and DHA in the morning were significantly higher than those in the evening (P < 0·001 and P < 0·005, respectively). In contrast, the mean value of the plasma levels of DHAS in the morning was significantly lower than that in the evening (P < 0·025).