bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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

SUMMARY
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.