bluuebunny/crossref_metadata_2025 huggingface dataset:
MORPHOLOGICAL AND BEHAVIOURAL EFFECTS OF AN 'ANTIANDROGEN' IN MALE RATS
Authors: BEACH F. A. , WESTBROOK W. H.
Published: December 2008

Male rats injected with 10 mg. cyproterone acetate daily for 28 days were given weekly mating tests with receptive females. At the conclusion of testing the animals were killed and the testes and seminal vesicles were weighed. These organs and the glans penis were then prepared for microscopic analysis. The experimental treatment had no detectable effect upon copulatory behaviour nor upon the testis or the cornified papillae in the integument of the glans penis. The seminal vesicles of treated males appeared to be non-secretory and were lighter than those of control rats but heavier than the vesicles of untreated castrates. It is concluded that although cyproterone acetate partially blocked the action of endogenous androgen on the seminal vesicles it had neither a blocking effect on the penile papillae nor on the central nervous mechanisms which mediate mating responses.
THE ROLE OF OESTROGEN IN THE INDUCTION OF OVULATION IN THE GONADOTROPHIN-TREATED IMMATURE RAT
Authors: GRAYBURN J. A. , BROWN-GRANT K.
Published: December 2008

The effects of different doses of pregnant mare serum gonadotrophin (PMS) were examined in 29-day-old immature rats; a dose great enough to produce follicles capable of ovulating in response to the additional injection of human chorionic gonadotrophin (HCG) 56 hr. later in the majority of animals also caused significant oestrogen secretion as judged by uterine weight. Maximal uterine growth resulted from doses of PMS that led to a significant incidence of 'spontaneous' ovulation. In contrast, administration of ovine follicle-stimulating hormone (FSH) resulted in the ripening of large numbers of follicles with much less evidence of oestrogen secretion; 'spontaneous' ovulation did not occur in FSH-treated animals but ovulation could be induced by additional treatment with oestrogen and progesterone in combination but not by either steroid alone. Previous exposure to oestrogen appears to be necessary for the facilitatory action of progesterone on luteinizing hormone release to be demonstrable and the FSH-primed immature rat is a convenient preparation to study this interaction.
A STUDY OF BLASTOCYSTS DURING DELAY AND SUBSEQUENT IMPLANTATION IN LACTATING MICE
Authors: McLAREN ANNE
Published: December 2008

Blastocysts were studied on the 5th and 8th day of pregnancy in lactating mice, in the fresh state, flushed from the uterus, in squash preparations and in serial sections. At the earlier period some mitosis was observed. Tritiated thymidine incorporation studies gave some evidence of DNA synthesis on the 5th and 6th days of pregnancy. By the 8th day the blastocysts were longer, contained more cells, and mitosis had ceased. They were located at the anti-mesometrial end of the uterine lumen, closely apposed to the uterine epithelium, and with their long axes parallel to the long axis of the uterine horn. Implantation could be induced, either by the removal of the litter, or by the injection of an appropriate dose of oestrogen on the 5th or 7th (but not the 4th) day of pregnancy. Both treatments were followed by the appearance of W-bodies in the neighbourhood of the blastocysts, the disappearance of the shed zonae, and the appearance of Pontamine Blue reactivity, oedema of the uterine stroma and formation of the primary decidual zone, in that order.
INFLUENCE OF THE ANTERIOR PITUITARY ON THE ALDOSTERONE SECRETORY RESPONSE TO DIETARY SODIUM RESTRICTION IN THE RAT
Authors: LEE T. C. , van der WAL B. , de WIED D.
Published: December 2008

Studies of the rate of aldosterone production in vitro of adrenals of rats hypophysectomized before dietary sodium restriction showed that hypophysectomy not only prevented the increases in aldosterone production observed in intact, Na-deprived rats, but also depressed the level of aldosterone production to below that of intact rats maintained on a normal diet. Rats hypophysectomized for a similar period of time but maintained on the normal diet showed a similar decrease.

Experiments on adeno- and neuro-hypophysectomized rats indicated that the pituitary factor required for the normal mineralocorticoid response to dietary sodium restriction resides in the anterior pituitary.

Treatment of hypophysectomized rats during dietary sodium restriction with doses of a long-acting corticotrophin (ACTH) prevented adrenal atrophy and maintained a normal glucocorticoid response to intravenous injections of ACTH, but failed to increase aldosterone production rates in vitro to levels above that of intact rats on a normal diet; it also failed to restore the enhanced adrenocortical sensitivity to the stimulating effect of aldosterone production of intravenously injected ACTH which is characteristic of acutely hypophysectomized, Na-deficient rats. Treatment with anterior pituitary powder (8–12 mg./day) for similar periods, however, restored the aldosterone production of adrenals in vitro of hypophysectomized, Na-deprived rats to levels nearly indistinguishable from those of acutely hypophysectomized, Na-deprived controls. The same doses of anterior pituitary powder were shown not to have any demonstrable effect on the aldosterone production of adrenals in vitro of intact rats on a normal diet.

These results are interpreted as indicating the existence of a pituitary factor other than ACTH which stimulates aldosterone secretion. This factor does not appear to act directly on the adrenal cortex or to stimulate the secretion of specific glomerulotropic substances, but probably exerts its effect by maintaining the normal functional capacity of some as yet undefined tissues which secrete glomerulotropic substances in response to dietary sodium restriction.
STEROID BIOSYNTHESIS IN VITRO BY THE COMPONENT TISSUES OF THE OVARY OF DOGFISH (SCYLIORHINUS CANICULUS L.)
Authors: SIMPSON T. H. , WRIGHT R. S. , HUNT S. V.
Published: December 2008

Ovaries of dogfish were separated into their component tissues and incubated separately with [4-14C]dehydroepiandrosterone and androstenedione. Production of Δ4-3-oxosteroids from the former was localized in the follicular membrane, in the post-ovulatory corpora lutea and in the egg yolk. Reduction of androstenedione to testosterone was higher in corpora lutea than in corpora atretica and higher in follicular membranes and yolks taken from ripe follicles than in those taken from atretic eggs. Production of oestradiol-17β from androstenedione was limited to the follicular membranes of ripe follicles and to the ovarian stroma; oestrone production was demonstrated, additionally, in corpora atretica and their membranes. There was no indication of oestriol formation.
THE INFLUENCE OF PLASMA MAGNESIUM CONCENTRATION ON PARATHYROID HORMONE SECRETION
Authors: BUCKLE R. M. , CARE A. D. , COOPER C. W. , GITELMAN H. J.
Published: December 2008

The influence of plasma magnesium concentration on parathyroid gland function has been evaluated by perfusion at a constant rate of an isolated parathyroid gland in five goats and one sheep with whole blood of varying magnesium content. The concentration of magnesium in fresh whole blood was adjusted either by dialysis or by the addition of magnesium chloride before the perfusion. In each experiment, the concentration of calcium was maintained constant or was slightly altered to oppose the possible influence of magnesium on the rate of release of parathyroid hormone. Parathyroid hormone concentration in parathyroid venous plasma was estimated by a specific radioimmunoassay.

In each experimental animal we observed that the concentration of parathyroid hormone in the effluent plasma diminished when the concentration of magnesium was raised or increased when the concentration of magnesium was lowered. These observations demonstrate a specific influence of magnesium on the rate of release of parathyroid hormone.
ULTRAMICROCHEMICAL STUDIES ON THE SITE OF FORMATION OF DEHYDROEPIANDROSTERONE SULPHATE IN THE ADRENAL CORTEX OF THE GUINEA-PIG
Authors: JONES T. , GRIFFITHS K.
Published: December 2008

Although dehydroepiandrosterone sulphate has been recognized as one of the major secretory products of the human adrenal gland neither its biosynthetic pathway nor its site of formation within the cortex have been extensively studied. Ultramicrochemical techniques, which relate enzymic activity to well-defined groups of cells, have been used in the work now described to study the sulphation of dehydroepiandrosterone in the zones of the guinea-pig adrenal cortex. It has been shown that dehydroepiandrosterone sulphokinase activity resides only in the compact cell of the zona reticularis.
RENAL FUNCTION IN THE EUROPEAN EEL (ANGUILLA ANGUILLA L.): CHANGES IN BLOOD PRESSURE AND RENAL FUNCTION OF THE FRESHWATER EEL TRANSFERRED TO SEA-WATER
Authors: JONES I. CHESTER , CHAN D. K. O. , RANKIN J. C.
Published: December 2008

A method for the study of renal function and measurement of mean ventral and dorsal aortic blood pressure for the freshwater and seawater-adapted eel, and during transfer of the animal from fresh water to sea-water, is described.

Freshwater eels have higher resting blood pressure, p-aminohippuric acid (PAH) and inulin clearance rates and urine flow than seawater eels. Urine from freshwater animals has low Na, K, Ca, Mg and Cl concentrations, while the clearance rate of inorganic phosphate exceeded that of inulin. Urine from seawater animals has high Na, Ca, Mg and Cl concentrations while that of inorganic phosphate was low. Clearance rates for Ca and Mg greatly exceeded those of inulin.

During transfer from fresh water to sea-water there was an initial fluctuation in blood pressure, urine flow and PAH and inulin clearance rates which lasted about 2 hr. Thereafter these gradually declined to values observed for the seawater-adapted animal.

The significance of PAH and inulin clearance rates in the study of renal function in the eel and in teleosts in general is discussed.
RENAL FUNCTION IN THE EUROPEAN EEL (ANGUILLA ANGUILLA L.): EFFECTS OF THE CAUDAL NEUROSECRETORY SYSTEM, CORPUSCLES OF STANNIUS, NEUROHYPOPHYSIAL PEPTIDES AND VASOACTIVE SUBSTANCES
Authors: JONES I. CHESTER , CHAN D. K. O. , RANKIN J. C.
Published: December 2008

Removal of the caudal neurosecretory system from freshwater eels did not affect urine flow or urinary Na excretion. There was, however, a marked initial increase in K, Ca and Mg excretion which later declined to very low levels by the 4th day after operation.

Intravenous injection of saline extracts of Mugil or Anguilla urophyses elicited a rise in urine flow and inulin clearance rates. This response was correlated with rises in blood pressure in the dorsal aorta. Urinary Na concentration also increased.

Injection of saline extracts of corpuscles of Stannius at the dose of two glands/kg. body weight generally caused an initial decline in inulin clearance rates while urine volume increased. Smaller doses caused the reduction of inulin clearance rates only.

Isotocin, amongst the neurohypophysial peptides, was the most effective in causing a diuresis and increases in p-aminohippuric acid and inulin clearance rates. There was little or no change in urinary Na concentration. Oxytocin and arginine vasotocin were effective but less potent. Arginine or lysine vasopressin had no effect even at large doses.

Angiotensin II and adrenaline induced diuresis and natriuresis followed occasionally by a transient antidiuresis.
THE INDUCTION OF OVULATION IN THE CHINCHILLA
Authors: WEIR B. J.
Published: December 2008

Forty-five adult chinchilla (Chinchilla laniger) were used to investigate the ovulatory response to pregnant mare serum (PMS) and human chorionic gonadotrophin (HCG) administered by intraperitoneal injection according to various regimes. Ovulation occurred (even during pregnancy) only when both PMS and HCG were given; 87·5% animals ovulated with a mean number of 3·7 ova, but only 26 out of the 119 ova were recovered. The range of ova ovulated per ovary was 1–7 and the range per animal was 1–12. The reasons for the low recovery rate of eggs and the general efficacy of the hormone regimes are discussed.
EFFECT OF LUTEINIZING HORMONE AND HUMAN CHORIONIC GONADOTROPHIN ON CORPORA LUTEA IN RATS BEARING PITUITARY AUTOGRAFTS
Authors: STOLZENBERG S. J. , EGGERT R. G. , HARRINGTON F. E. , LINKENHEIMER W. H.
Published: December 2008

Rats bearing pituitary autotransplants received injections of luteinizing hormone (LH) for 9 days or human chorionic gonadotrophin (HCG) for 6 days. Both compounds caused significant increases in ovarian and uterine weights as well as vaginal mucification, observed 1 day after the last injection. Luteal regression and a decrease in uterine weight compared to control animals were observed 35 days after final injection with each compound. Continuous dioestrous vaginal smears were observed in all groups. In hypophysectomized rats, HCG, but not LH, caused an increase in ovarian weight which was statistically significant on the day after the final injection in one of two experiments. Uterine weights were increased after LH and HCG treatments. Vaginal cornification was evident 3–4 days after initiation of treatment with either hormone. When ovariectomy preceded hypophysectomy, there was no increase in uterine weight and no vaginal cornification in response to HCG treatment indicating the essential role of the ovaries. The effects in rats bearing auto-transplanted pituitaries as well as in hypophysectomized rats are attributed to the stimulation of oestrogen secretion from the ovaries. It is suggested that the rapid rate of luteal regression in rats bearing transplanted pituitaries is initiated by an increase in metabolic activities due to LH or HCG.
THE TIME AND SITE OF CONTRACEPTIVE ACTION OF AN INTRA-UTERINE DEVICE IN THE MOUSE
Authors: MARSTON J. H. , KELLY W. A.
Published: December 2008

In the mouse, a unilateral intra-uterine device (IUD) exerted a bilateral contraceptive effect by causing the elimination of embryos from both uterine horns and the bilateral inhibition of the decidual cell reaction. Both uterine horns showed leucocytic infiltration into the endometrium and uterine lumen.

The bilateral effect was correlated with the existence of luminal continuity between the two uterine horns. Conception proceeded normally in the control uterine horn that had been completely separated from the IUD horn.

An IUD did not usually disturb the function of the Fallopian tube, but tube-locking of embryos occasionally occurred as an artifact. The contraceptive effects of an IUD were exerted within the uterus during the period immediately before implantation.
THE PRODUCTION OF SEBUM IN YOUNG RATS: EFFECTS OF AGE, SEX, HYPOPHYSECTOMY AND TREATMENT WITH SOMATOTROPHIC HORMONE AND SEX HORMONES
Authors: NIKKARI T. , VALAVAARA M.
Published: December 2008

The secretion rate of sebum in rats aged 3–14 weeks was determined by measuring the amount of acetone-extractable skin surface lipids produced during 2 days. The results were expressed as mg. sebum/100 g. body weight/2 days. The secretion rate of male rats was found to increase with age (from 16 mg./100 g. at 3 weeks to 35 mg./100 g. at 14 weeks), while that of female rats (16 mg./100 g.) remained unchanged. Hypophysectomy of 3-week-old female rats resulted in lowering of the secretion rate to 13 mg./100 g. at 10 weeks. No change in the secretion rate of the hypophysectomized animals occurred during either growth hormone or oestradiol treatment, but testosterone in doses of 1 mg. and 0·2 mg./day increased sebum production (to 37 mg./100 g. and 24 mg./100 g., respectively). The increase obtained with testosterone (0·2 mg./day) was smaller (20 mg./100 g.), when oestradiol (3 μg./day) was given simultaneously.
ENDOCRINE CONTROL OF CALCIUM HOMEOSTASIS
Authors: COPP D. HAROLD
Published: December 2008

Two endocrine glands of branchial origin are involved in regulation of calcium metabolism—the parathyroids which secrete parathormone (parathyroid hormone) in response to hypocalcaemia, and the ultimobranchial glands which release calcitonin (thyrocalcitonin) during hypercalcaemia. The ultimobranchial glands are distinct organs in most vertebrates but in mammals the cells become embedded in the internal parathyroid and thyroid where they constitute the parafollicular 'C' cells. Calcitonin can be extracted from mammalian thyroid (hence the alternative name, thyrocalcitonin) but it is present in much higher concentrations in the ultimobranchial glands of lower vertebrates. In mammals, both hormones appear to act primarily on bone resorption and calcium mobilization from the skeleton, which is stimulated by parathormone and inhibited by calcitonin. Secretion or release of both hormones is determined by the level of calcium in the blood, and the two constitute a dual endocrine control comparable to that of insulin and glucagon in regulation of blood glucose. The ultimobranchials are the older glands phylogenetically for they are found in sharks and bony fishes, while the parathyroids appear first in amphibians.
LACK OF EFFECT OF DEXAMETHASONE ON THE ADRENOCORTICAL RESPONSE TO CORTICOTROPHIN IN SHEEP WITH ADRENAL AUTOTRANSPLANTS
Authors: HART D. S. , BEAVEN D. W. , FRANCE N. C. , ESPINER E. A.
Published: December 2008

Sheep with adrenal autotransplants were used to study the direct effect of dexamethasone on the adrenal response to corticotrophin (ACTH).

When the adrenal cortex, under constant ACTH stimulation, was infused with dexamethasone at rates from 9·5 to 41 μg./min., no significant change in cortisol secretion occurred. Since concentrations of dexamethasone as high as 2 to 4 μg./ml. of infusing blood were maintained for up to 70 min., it is concluded that short-term administration of dexamethasone has no important effect on the adrenal sensitivity to ACTH in sheep under physiological conditions.
INDUCTION BY ANDROGENS OF NIDATION IN PREGNANT RATS DEPRIVED OF GONADOTROPHIN SECRETION BY TRIFLUOPERAZINE INJECTIONS AND BY LACTATION
Authors: VARAVUDHI PUTTIPONGSE
Published: December 2008

Intact pregnant rats in which gonadotrophin secretion was suppressed by administration of the tranquillizer trifluoperazine (Stelazine) were very sensitive to testosterone propionate (TP), dehydroepiandrosterone (DHA) and androstenedione as inducers of nidation but insensitive to 5α-androstan-3α-ol-17-one. The minimum effective dose of the former steroids was 0·025 mg. intramuscularly or 0·005 mg. injected under the ovarian capsule. This effect of androgens seems to be indirect, inasmuch as 0·005 mg. TP was ineffective when applied locally to the uterine mesometrium. Moreover, 2 mg. TP failed to induce nidation after ovariectomy (followed by daily administration of progesterone), although adrenalectomy did not prevent the action of this dose of TP. MER-25, 20 mg., given simultaneously with 2 mg. TP invariably prevented nidation.

Nidation was also induced in lactating pregnant rats by intramuscular injection of 1–2 mg. TP. In the absence of the ovaries such animals failed to respond to 1·0 mg. TP. Lactating pregnant rats also failed to respond to 0·05 mg. TP applied to the ovaries but nidation was induced when this dose was injected into the spleen.

It is concluded that the ovaries of pregnant rats under the influence of Stelazine more readily convert androgens into oestrogens than the ovaries of lactating pregnant animals. It is suggested that the suppression of gonadotrophin secretion caused by trifluoperazine or lactation induces a deficiency in the secretion of androgenic steroids by both the ovaries and adrenals. However, the ovaries do not lose the enzyme system capable of converting androgens into the oestrogens required for nidation. Finally, it is suggested that the oestrogen surge from the ovaries during the critical period before nidation is not necessarily due to an acute release of pituitary luteinizing hormone, as is ovulation, since androgens from the adrenals can be converted by ovarian tissue(s) to the oestrogen required for nidation.
STUDIES ON TISSUE CULTURE OF EQUINE OVARIAN CELL TYPES: PATHWAYS OF STEROIDOGENESIS
Authors: CHANNING CORNELIA P.
Published: December 2008

Equine granulosa cell cultures were incubated with various labelled steroid hormone precursors, and the products of these incubations were purified and characterized by a combination of paper chromatography, derivative formation and recrystallization. Sodium acetate, cholesterol and pregnenolone were converted mainly to progesterone in addition to significant amounts of 20α-hydroxypregn-4-en-3-one and 17-hydroxyprogesterone plus small amounts of dehydroepiandrosterone, androstenedione and oestradiol-17β.

Both androstenedione and testosterone were converted to oestrone and oestradiol-17β. Testosterone was converted to androstenedione but the converse did not apply. These experiments demonstrated that equine granulosa cells in culture contain all the enzymes for converting acetate to progesterone and oestradiol-17β and that the pathways are similar to those of luteal tissue.
THE INDUCTION OF OVULATION DURING PREGNANCY IN THE RAT
Authors: BROWN-GRANT K.
Published: December 2008

Ovarian follicles develop to the stage where they are competent to ovulate in response to exogenous gonadotrophin at the same rate during early pregnancy as in a normal 4-day cycle in the rat. The length of time during which this competency is retained appears to be shorter than after the blockade of ovulation by pentobarbitone administered at pro-oestrus in rats that are not pregnant. Evidence from oviduct:plasma (O:P) and uterus:plasma (U:P) 131I ratio measurements indicating high progesterone and low oestrogen levels at this stage of pregnancy may be relevant to this finding. Some evidence for a 3-day cycle of follicle development after day 6 of pregnancy was obtained but the high O:P ratios suggest that little oestrogen secretion is associated with this.

Oestradiol benzoate (6·25–100 μg.) administered after day 3 of pregnancy will induce ovulation when competent follicles are present. The thyroid:plasma (T:P) concentration ratio for 131I does not rise in association with ovulation induced by exogenous gonadotrophin. After oestrogen administration, the T:P ratio may increase regardless of whether ovulation is induced or not. The results are discussed in relation to the studies of other workers on the induction of ovulation during pregnancy and to earlier work on the relationship between ovulation and changes in thyroid gland activity.
ROLE OF TESTOSTERONE IN PROGESTERONE-INDUCED INCUBATION BEHAVIOUR IN MALE RING DOVES (STREPTOPELIA RISORIA)
Authors: STERN JUDITH M. , LEHRMAN D. S.
Published: December 2008

The effectiveness of progesterone (100 μg./day, × 7) in inducing incubation behaviour in male ring doves is markedly diminished by castration. Priming with testosterone propionate (200 μg./day, × 14) restored the effectiveness of progesterone in eliciting this behaviour to the levels in intact males. The synergistic relationship of these two hormones with regard to incubation behaviour contrasts with the inhibition by progesterone of an androgen-dependent male courtship display, the bowing-coo. The behavioural changes observed after these endocrine treatments are fully consistent with the normal sequence of changes in behaviour characterizing the transition from the courtship phase to the incubation phase of the reproductive cycle.
LUTEAL FUNCTION IN THE MERINO EWE AND THE EFFECT OF EXOGENOUS PROGESTAGEN
Authors: SMITH J. F. , ROBINSON T. J.
Published: December 2008

Progesterone levels were determined in the ovarian and jugular vein plasma and the corpus luteum of 68 cyclic Merino ewes (controls) and of 32 ewes which had been treated with intravaginal sponges containing a synthetic progestagen (Cronolone, Searle). The weight and diameter of the corpus luteum and the rate of flow of the ovarian vein blood were also recorded. No corrections for procedural losses were made.

The control ewes showed highly significant (P < 0·001) cyclic changes in the progesterone contents of the ovarian vein plasma and the corpus luteum, and in the mass of the corpus luteum. There were positive correlations (P < 0·001) between ovarian vein plasma progesterone concentration and the weight (r = 0·651), diameter (r = 0·692), total progesterone content (r = 0·775) and progesterone concentration (r = 0·574) of the corpus luteum.

Cyclic changes in the progesterone content of the jugular vein failed to attain significance (0·1 < P < 0·2) but the levels were positively correlated with those in the ovarian vein (r = 0·465, P < 0·001) and with weight (r = 0·432, P < 0·001) and diameter (r = 0·303, P < 0·05) of the corpus luteum.

The Cronolone-treated ewes showed cyclic changes in luteal function similar to those in controls, with the exception of animals treated on the day of oestrus. In ewes in which ovulation was not suppressed, the duration of activity of the corpus luteum, as measured by progesterone concentration in ovarian vein plasma, and concentration and content in the corpus luteum was significantly reduced. By the 12th day of the cycle the corpus luteum had almost completely regressed both morphologically and functionally.
A REFRACTORY PERIOD FOLLOWING OESTROGENIC STIMULATION OF CELL DIVISION IN THE MOUSE UTERUS
Authors: FINN C. A. , MARTIN L. , CARTER JANET
Published: December 2008

A single injection of oestradiol given to ovariectomized mice pretreated with progesterone for several days stimulates a large increase in cell division in the uterine stroma which reaches a maximum 24 hr. later. A second injection 48 hr. after the first, also stimulates stromal cell division, but a second injection 12–36 hr. after the first does not. This failure to respond is not due simply to depletion of the stock of cells ripe for division. Rather it appears that the uterus becomes insensitive to further stimulation for approximately 36 hr. Although a second injection 24 hr. after the first injection does not increase stromal cell division, it does lengthen the refractory period so that a third injection given at 48 hr. has no effect.
AFFERENT PATHWAYS OF STRESSFUL STIMULI: CORTICOTROPHIN RELEASE AFTER PARTIAL DEAFFERENTATION OF THE MEDIAL BASAL HYPOTHALAMUS
Authors: MAKARA G. B. , STARK E. , PALKOVITS M. , RÉVÉSZ T. , MIHÁLY K.
Published: December 2008

Corticotrophin (ACTH) release induced by various stressful stimuli has been studied in rats with antero-lateral deafferentation of the medial basal hypothalamus (MBH). The plasma corticosterone level was determined as an index of ACTH release.

In rats with antero-lateral deafferentation of the MBH, ACTH release was prevented after exposure to noise and vibration, sham adrenalectomy and s.c. injection of 1% formalin. ACTH release induced by the injection of histamine (1 mg./100 g., i.p.) and capsaicin (0·25 mg./100 g., s.c.) was significantly less than in the controls. Escherichia coli lipopolysaccharide (25 μg./100 g., i.p.) induced an ACTH release that could not be distinguished from that in the controls.

We suggest that (a) noise and vibration, sham adrenalectomy and injection of 1% formalin trigger ACTH release through neural pathways arriving at the MBH from anterior, lateral and dorsal directions, (b) histamine or capsaicin releases ACTH partly through antero-lateral neural afferents to the MBH. In contrast, the ACTH-releasing stimulus of bacterial endotoxin injection reaches the hypothalamo—hypophysial unit by humoral pathways and/or posterior nerve fibres.
THE RENIN—ANGIOTENSIN SYSTEM IN A MARSUPIAL (TRICHOSURUS VULPECULA)
Authors: REID I. A. , McDONALD I. R.
Published: December 2008

Using an enzyme kinetic technique, a substance with the properties of renin was assayed in extracts of kidney and peripheral blood from the Australian marsupial Trichosurus vulpecula. The renin concentration in peripheral venous plasma varied from 10 to 855 units/ml. and plasma renin activity from 1·0 to 3·6 ng. angiotensin/ml./hr. High plasma renin concentration and plasma renin activity was associated with an appetite for salt and were significantly reduced by ingestion of 0·9% NaCl solution. Animals with low renin levels did not have a salt appetite. Sodium deficiency caused by mercurial and non-mercurial diuretics increased plasma renin concentration and plasma renin activity, and induced an appetite for salt. Plasma renin concentration and plasma renin activity also increased after haemorrhage.

Granulation of juxtaglomerular cells, demonstrated with Bowie's stain, increased considerably during sodium deficiency.

It is concluded that T. vulpecula has the eutherian type of renin—angiotensin system.
GROWTH HORMONE ACTIVITY IN MAN OF CHYMOTRYPTIC DIGESTS OF BOVINE GROWTH HORMONE
Authors: SONENBERG M. , DELLACHA J. M. , FREE C. A. , NADLER A. C.
Published: December 2008

Bovine growth hormone (BGH) digested with chymotrypsin showed a significant retention of biological activity after the hydrolysis of six bonds and the formation of 20% non-precipitable nitrogen.

Disk electrophoresis of ½ and 3 hr. digests demonstrated complete loss of the major electrophoretic component of BGH with the appearance of one or more components of greater anodal mobility.

Administration of the chymotryptic digests of BGH to three hypopituitary patients resulted in an anti-insulin response, aggravation of diabetes mellitus or anabolic effects.
THE SECRETION OF INSULIN FROM FOETAL AND POSTNATAL RABBIT PANCREAS IN VITRO IN RESPONSE TO VARIOUS SUBSTANCES
Authors: MILNER R. D. G.
Published: December 2008

Pieces of pancreas from 24-day and 30-day rabbit foetuses, 1-day-old rabbits and rabbits aged approximately 8 weeks were incubated in vitro and insulin secretion into the incubation medium was measured in response to a variety of stimuli. Glucagon, leucine, ouabain and potassium were effective stimuli at all ages studied. By the criteria of response chosen for these experiments, glucose did not stimulate insulin secretion from 24-day foetal pancreas but did so when pancreas from older animals was studied. It was concluded that the foetal β cell of the rabbit on the 24th day of gestation, although morphologically immature, shows evidence of functional competence.
THE EFFECT OF BOVINE ANTERIOR PITUITARY EXTRACT ON LIPID MOBILIZATION IN THE RAT AND MAN
Authors: HOLLAND MARGARET J.
Published: December 2008

The lipolytic properties of a fraction of bovine pituitary extract were investigated. It was inactive in the rat and man under normal conditions, but after fasting for 48 hr., the extract promoted free fatty acid release from rat and human adipose tissue.

Its significance as a fat-mobilizing hormone and its possible relationship to a fat-mobilizing substance excreted in the urine are discussed.
STEROIDOGENESIS IN A CASE OF HYDATIDIFORM MOLE
Authors: COUTTS J. R. T. , MACNAUGHTON M. C. , ROSS P. E. , WALKER J.
Published: December 2008

In a case of hydatidiform mole accompanied by theca lutein cysts there was a greatly increased urinary excretion of pregnanetriol. Incubation of the mole tissue with [4-14C]pregnenolone resulted in the formation of 17α-hydroxypregnenolone, progesterone, 16α-hydroxyprogesterone and 16βhydroxyprogesterone.

Cholesterol, pregnenolone, 17α-hydroxypregnenolone, pregnanediol, pregnanetriol and androstenedione were isolated from both the mole tissue itself and from the ovarian cyst fluid. Progesterone and 17α-hydroxyprogesterone were characterized only from the cyst fluid. Greater quantities of the metabolic intermediates between pregnenolone and pregnanetriol were isolated from the cyst fluid than from the mole tissue.

On the basis of these results it is concluded that although the mole tissue is active in steroid metabolism the increased urinary excretion of pregnanetriol is a function of the polycystic ovaries.
MECHANISM OF THE INHIBITION OF IMPLANTATION IN SUCKLING MICE
Authors: BINDON B. M.
Published: December 2008

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

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

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

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

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

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

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

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

[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

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

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

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

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

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.