bluuebunny/crossref_metadata_2025_split huggingface dataset:
AGEING AND OVARIAN Δ5-3β-HYDROXYSTEROID DEHYDROGENASE IN THE PREGNANT MOUSE
Authors: WEHRENBERG W. B. , GOTTLIEB S. F. , ALBRECHT E. D. 
Published: December 2008

SUMMARY
Aged (12- to 14-month-old) C57BL oestrous mice exhibited significantly lower (P < 0·001) ovarian Δ5-3β-hydroxysteroid dehydrogenase (3β-HSD) concentration, specific activity and total content than young (3-month-old) oestrous mice, suggesting a decrease in the potential of the older animals to produce ovarian Δ4-3-oxosteroids. Mice in both age groups maintaining pregnancy to 10 or 18 days post coitum (p.c.) had similar values for activity of ovarian 3β-HSD. In the aged females in which foetal resorption had occurred, the majority of foetuses had been resorbed by 10 days p.c. However, ovarian 3β-HSD activity in these animals was not significantly different from that of young or aged mice maintaining pregnancy. By day 18, however, ovarian dehydrogenase activity in aged females failing to maintain pregnancy had decreased significantly. It is suggested that foetal death in aged mice is not the result of a deficiency in ovarian 3β-HSD, but rather may initiate luteal regression and consequently a decline in 3β-HSD.
INCORPORATION OF 14C-LABELLED AMINO ACIDS INTO CORTICOTROPHIN-LIKE INTERMEDIATE LOBE PEPTIDE AND α-MELANOCYTE-STIMULATING HORMONE BY THE RAT PITUITARY NEUROINTERMEDIATE LOBE IN VITRO, AND THE IDENTIFICATION OF FOUR NEW PARS INTERMEDIA PEPTIDES
Authors: SCOTT A. P. , LOWRY P. J. , VAN WIMERSMA GREIDANUS TJ. B. 
Published: December 2008

SUMMARY
At least seven radioactive peptides, which fractionated on Biogel P6, were found in rat neurointermediate lobes after incubation for 6 h with [14C]proline. Only three of these could be tentatively identified; one as α-melanocyte-stimulating hormone (α-MSH) and two as forms of corticotrophin-like intermediate lobe peptide (CLIP). One other crossreacted partially with a β-melanocyte-stimulating hormone (β-MSH) antiserum, was acidically charged and eluted on Biogel P6 in roughly the same position as ACTH. The other three peptides showed no resemblance to α-MSH, CLIP, β-MSH or ACTH.
EFFECTS OF CORTICOSTERONE ON ADRENOCORTICOTROPHIN-INDUCED MITOCHONDRIAL DIFFERENTIATION WITH SPECIAL REFERENCE TO 11β-AND 18-HYDROXYLATION
Authors: SALMENPERÄ M. , KAHRI A. I. , SAURE A. 
Published: December 2008

SUMMARY
The effects of corticosterone in concentrations found in adrenal venous plasma on ACTH-induced changes in cultured cortical cells derived from foetal rat adrenals were studied. Corticosterone at a concentration of 5·7 × 10−5 mol/l completely inhibited mitochondrial differentiation to fasciculate-like morphology. The same cultures revealed significant inhibition of 11β- and 18-hydroxylation compared with cultures treated with ACTH only. This was shown by the reduced formation of corticosterone and 18-OH-deoxycorticosterone (48%, P < 0·001) and simultaneous enhancement of deoxycorticosterone formation (33%, P < 0·05) from added [4-14C]progesterone. Similar inhibition was observed when dibutyryl cyclic AMP replaced ACTH as an inducer of differentiation. Lower concentrations of corticosterone (1·2 × 10−5 and 2·4 × 10−5 mol/l) inhibited ACTH-stimulated formation of corticosterone and 18-OH-deoxycorticosterone from endogenous precursors.
The results demonstrate that corticosterone regulates the stage of differentiation in cultured adrenocortical cells. The possible role of corticosterone in the regulation of growth and steroidogenic capacity of the adrenal cortex is discussed.
SERUM GONADOTROPHIN LEVELS DURING DEVELOPMENT IN MALE, FEMALE AND ANDROGENIZED FEMALE RATS AND THE EFFECT OF GENERAL DISTURBANCE ON HIGH LUTEINIZING HORMONE LEVELS
Authors: MACKINNON P. C. B. , MATTOCK J. M. , TER HARR M. B. 
Published: December 2008

SUMMARY
Serum LH, FSH and prolactin levels were measured in blood samples which were obtained by decapitation from groups of female, neonatally androgenized female and male Wistar rats at 2-day intervals from birth to maturity. An increase in serum FSH levels was observed between 4 and 24 days of age in both the female and androgenized female groups, while a much later increase, between 28 and 44 days of age, occurred in the males. Serum prolactin levels increased gradually from birth in all three groups until adult levels were attained. In contrast, serum LH levels were in general low in all three groups of animals, although very high levels (> 7 ng/ml) were recorded in 22 out of 168 females and 8 out of 192 males between 4 and 28 days of age, as well as in adult males; occasional high LH levels were also seen in the androgenized females.
The nature of the high serum LH levels was investigated in anaesthetized and unanaesthetized immature females by serial blood sampling using a number of techniques. Unexpectedly, only three out of 58 animals had high LH levels: two of these showed an episodic form of LH release during which levels increased to peak values and then declined within a period of about 30 min. On investigation it was found that general disturbance within the 45 min before decapitation could inhibit high LH levels in females aged between 23 and 30 days.
ON DIFFERENCES BETWEEN THE PREOVULATORY LUTEINIZING HORMONE SURGES OF 4- AND 5-DAY CYCLIC RATS
Authors: SCHUILING G. A. , DE KONING J. , ZÜRCHER A. F. 
Published: December 2008

SUMMARY
Preovulatory LH surges were studied in rats with ovarian cycles of 4 days (4d-rats) and 5 days (5d-rats). In 5d-rats the maximal peak height was about twice that observed in 4d-rats, whereas in 4d-rats peaks occurred about 1·5 h later than in 5d-rats and were much less consistently timed.
From experiments in which LH releasing hormone (LH-RH) was infused into pentobarbitone-blocked pro-oestrous rats, it was concluded that (a) differences between the two types of preovulatory LH surges originate within the central nervous system, and (b) prooestrous LH-RH secretion may not be restricted to the period in which increased LH levels in blood were found, but may exceed this period for a considerable time.
EFFECTS OF OESTRADIOL-17β, HYPOPHYSECTOMY AND AGE ON CYTOPLASMIC OESTRADIOL-17β RECEPTOR SITES IN RAT TESTIS INTERSTITIAL TISSUE
Authors: DE BOER WILLEM , MULDER EPPO , VAN DER MOLEN H. J. 
Published: December 2008

SUMMARY
After administration of oestradiol-17β to intact mature and immature rats, a decrease in the testicular concentration of specific oestradiol-binding sites was observed within 1 h. The binding capacity was replenished starting about 3 h after oestradiol administration and after 5 h the oestrogen receptor level had returned to control values. Exposure of intact animals to oestradiol-17β for longer periods (up to 24 h) did not result in an increase of receptor levels in testicular cytosol.
Mature animals which were hypophysectomized for periods of up to 10 days did not show a significant change in the number of specific oestradiol-binding sites in either total testicular tissue or dissected interstitial tissue. At 15 days or longer periods after hypophysectomy, an apparent increase in receptor concentrations in total testicular cytosol was observed due to a relative increase in the amount of interstitial tissue.
A specific oestradiol-binding protein is present in plasma of immature male rats aged less than 30 days. This plasma protein could also be demonstrated in the cytosol of testes of immature rats. In contrast to the cytosol receptor, which shows a moderate affinity for diethylstilboestrol (DES), the plasma protein did not bind DES. The sedimentation values of the plasma protein and the oestradiol receptor were 4 S and 8 S respectively. These differences in characteristics made it possible to demonstrate the presence of the oestradiol receptor in addition to the binding protein in testicular cytosol of rats from 14 days of age onwards. The nuclear receptor for oestradiol-17β could be demonstrated after incubation of testicular tissue of rats from 4 days of age onwards.
SELECTION FOR HIGH AND LOW ADRENAL WEIGHT IN MICE
Authors: BADR F. M. 
Published: December 2008

SUMMARY
Four strains of mice were used to found a heterogeneous stock from which one line was selected for high adrenal weight/100 g body weight and another line for low adrenal weight/100 g body weight. By the eighth generation of selection, two stocks of mice were produced, one with adrenals whose absolute weight was greater than any of the parental strains. The realized heritability estimates were 75% for females and 67% for males during the period of selection, showing that a large component of variation in adrenal weight was genetic in origin.
Asymmetry in response to selection was also noticed and attributed to possible variation in adrenal structure between sexes. Estimates of variances in each generation, particularly the eighth, did not show any decline which suggested that further responses to selection would be possible with further selection.
PRE-OVULATORY CHANGES IN STEROIDOGENESIS IN OVARIES FROM IMMATURE RATS TREATED WITH PREGNANT MARE SERUM GONADOTROPHIN
Authors: ECKSTEIN B. , LERNER N. , YEHUD S. 
Published: December 2008

SUMMARY
The metabolism of progesterone in the 1000 g supernatant fraction of homogenates of ovaries from PMSG-treated immature rats was determined. As early as 52 h after a single injection of 50 i.u. PMSG, still before the LH surge, 5α-pregnane-3α,20α-diol was identified as the main metabolite, together with smaller quantities of 3α-hydroxy-5α-pregnan-20-one and 5α-androstane-3α,17β-diol. Similar incubations of untreated rat ovaries at the same age did not produce 5α-pregnane-3α,20α-diol. The quantities of 3α-hydroxy-5α-pregnan-20-one and 5α-androstane-3α,17β-diol were reduced in PMSG-treated rat ovaries as compared with control ovaries. When progesterone metabolism was examined 64 h after PMSG administration, 5–7 h after the peak of the LH surge but still before ovulation, 75% of the substrate was converted to 5α-pregnane-3α,20α-diol, while 3α-hydroxy-5α-pregnan-20-one as well as 5α-androstane-3α,17β-diol could not be detected.
METABOLISM OF ANDROGENS IN VITRO BY HUMAN FOETAL SKIN
Authors: SHARP F. , HAY J. B. , HODGINS M. B. 
Published: December 2008

SUMMARY
Fresh scalp, genital, chest and axillary skin from human foetuses of 12–41 weeks' maturity was incubated in Krebs' improved Ringer I medium with [7α-3H]dehydroepiandrosterone, [7α-3H]testosterone and [7α-3H]androstenedione. The metabolites identified were androstenedione, 5α-androstane-3,17-dione, androsterone, 3-epiandrosterone, 5α-dihydrotestosterone, 5α-androstane-3α,17β-diol, 5α-androstane-3β,17β-diol, 5-androstene-3β,17β-diol and testosterone. The results provide evidence for the presence of 3β-hydroxysteroid dehydrogenase, Δ4–5 isomerase, 17β-hydroxysteroid dehydrogenase, Δ4-3-oxosteroid-5α-reductase and 3α-hydroxysteroid dehydrogenase in human foetal skin. There were quantitative differences in the various enzyme activities between different body sites and skin specimens of different gestational age. 5α-Reductase activity was particularly high in genital skin. 3β-Hydroxysteroid dehydrogenase Δ4–5 isomerase activity was low in skin from a 12-week foetus, but high in skin specimens from 28-, 38- and 41-week foetuses. 17β-Hydroxysteroid dehydrogenase activity was already high in the skin of the 12-week foetus and remained so in the older foetuses. These results were correlated with the development of the foetal sebaceous glands, and were in general agreement with a parallel enzyme histochemical study. The role of androgen metabolism in human foetal skin is discussed.
STIMULATION OF GROWTH IN THE LITTLE MOUSE
Authors: BEAMER W. G. , EICHER EVA M. 
Published: December 2008

SUMMARY
The new mouse mutation little (lit) in the homozygous state causes a pituitary deficiency involving at least growth hormone (GH) and prolactin. The resultant growth failure of lit/lit mice was shown to be reversed by experimental conditions that enhanced levels of GH or GH and prolactin in the circulation. Two measures of growth, actual weight gain and bone dimension, were significantly improved by the physiological processes of pregnancy and pseudopregnancy, by extra-sellar graft of a normal mouse pituitary, and by treatment with GH but not prolactin. These data confirmed pituitary dysfunction as the basic defect caused by the mutation lit and showed that the GH deficiency is responsible for growth failure. However, the biological site of gene action, the pituitary or hypothalamus, has not been established.
Little mice exhibit a number of characteristics similar to those of human genetic ateleotic dwarfism Type 1, namely genetic inheritance, time of onset of growth retardation, proportionate skeletal size reduction, and pituitary GH deficiency.
INFLUENCE OF THE VAGUS AND CAROTID SINUS NERVES ON PLASMA RENIN IN THE CAT
Authors: BROSNIHAN KATHLEEN B. , TRAVIS R. H. 
Published: December 2008

SUMMARY
Influence of the vagus and carotid sinus nerves on peripheral plasma renin was studied in the cat. Bilateral cervical vagotomy was followed by a sustained increase in plasma renin concentration (PRC) of anaesthetized cats made hypervolaemic by intravenous saline infusions. The increase in PRC is attributable to right vagotomy. Bilateral carotid artery occlusion in anaesthetized hypervolaemic cats, either with or without prior vagotomy, or with mechanical prevention of a rise in systemic blood pressure, resulted in no statistically significant increases in peripheral venous PRC, compared with the control animals.
CONCENTRATION OF OESTROGENS AND ANDROGENS IN HUMAN OVARIAN VENOUS PLASMA AND FOLLICULAR FLUID THROUGHOUT THE MENSTRUAL CYCLE
Authors: McNATTY K. P. , BAIRD D. T. , BOLTON A. , CHAMBERS P. , CORKER C. S. , McLEAN H. 
Published: December 2008

SUMMARY
The concentrations of androstenedione, testosterone, oestrone and oestradiol-17β were measured in peripheral and ovarian venous blood and follicular fluid of women at various stages of the menstrual cycle. The concentration of oestradiol was similar in small follicles (diameter < 8 mm) at all stages of the menstrual cycle and in large follicles (diameter ⩾ 8 mm) except during the mid- and late follicular phase when the concentration reached a peak (∼ 1500 ng/ml).
The concentration of androstenedione was lowest in large preovulatory follicles at mid-cycle at a time when the secretion into the ovarian vein was markedly increased. The concentration of testosterone in large follicles (⩾ 8 mm) was unchanged during the follicular phase whereas in small follicles there was a peak at mid-cycle.
The rise in the concentration of testosterone and androstenedione at mid-cycle in peripheral plasma may be due to increased secretion by the preovulatory follicle into the ovarian vein. It is suggested that the relatively low concentration of androstenedione in follicular fluid of the preovulatory follicle arises from increased aromatization by granulosa cells in the course of oestrogen synthesis.
METAL–ANDROGEN INTERRELATIONSHIPS IN CARCINOMA AND HYPERPLASIA OF THE HUMAN PROSTATE
Authors: HABIB F. K. , HAMMOND G. L. , LEE I. R. , DAWSON J. B. , MASON M. K. , SMITH P. H. , STITCH S. R. 
Published: December 2008

SUMMARY
Zinc and cadmium concentrations were measured by atomic absorption spectroscopy in normal and pathological human prostates. Our studies confirm that the values of zinc in normal tissue [6·84 ± 1·21 (s.e.m.) μmol/g] and benign prostatic hypertrophy (BPH) (6·91 ± 1·19 μmol/g) are similar, while in neoplastic tissues zinc concentrations were significantly lower (2·61 ± 0·45 μmol/g). The Cd2+ levels in BPH (23·11 ± 3·28 nmol/g) were, on the other hand, considerably higher than those found for normal tissues (5·15 ± 0·62 nmol/g). In agreement with other published reports, Cd2+ concentrations were found to be markedly increased in carcinomatous tissue (129·79 ± 22·22 nmol/g). No correlation was however established between the values for the two metals in either type of prostatic tissue.
An established specific radioimmunoassay was used for the measurement of testosterone and dihydrotestosterone (DHT) and a distinct pattern emerged upon comparing these results with those for the zinc and cadmium concentrations. It appears that the concentrations of DHT in benign hypertrophy and of testosterone and DHT in carcinoma were inversely proportional to the levels of Zn2+ in abnormal tissue. In contrast, the DHT levels in the hypertrophied and malignant tissue were proportional to the Cd2+ concentrations.
THE DEVELOPMENT OF ADRENOCORTICOTROPHIN-SENSITIVE ADENYLATE CYCLASE ACTIVITY IN THE FOETAL RABBIT ADRENAL: A CORRELATED BIOCHEMICAL AND MORPHOLOGICAL STUDY
Authors: ALBANO JANET D. M. , JACK PATRICIA M. , JOSEPH TERESA , GOULD R. P. , NATHANIELSZ P. W. , BROWN B. L. 
Published: December 2008

SUMMARY
Proliferation of the smooth endoplasmic reticulum, the site of some hydroxylating steroidogenic enzymes in foetal adrenocortical cells, is the first major change in the process of their differentiation into steroidogenic tissue. This was observed in our ultrastructural studies on foetal rabbit adrenals to begin at about day 19 of development. Morphological changes in the mitochondria, the site of production of other steroidogenic enzymes, occurred at about day 24. The elongated or rod-shaped forms of the earlier stages became flattened and rounded by this time, while the cristae were transformed from a flattened lamellar type of the earlier stages to the tubulo-vesicular form of the adult. Other changes observed included an increase in microvilli and in cell size, with a concomitant increase in thickness of the gland.
Adenylate cyclase activity in foetal adrenal homogenates was assessed in response to sodium fluoride (NaF) and ACTH. All preparations responded to NaF. While good responses to ACTH were observed at days 24, 27, 28 and in the neonate, there was a lack of any significant response in the day 19 gland. Foetal ACTH was depressed by administration of cortisol, and the effects of this treatment on both the morphological changes and adenylate cyclase activity was reassessed. The response of foetal adrenals to ACTH was depressed by this treatment and differentiation of the mitochondria was arrested.
These results suggest a circumscribed period for the development of ACTH-sensitive adenylate cyclase coinciding with the time at which final differentiation of the mitochondria is completed. Furthermore, both the differentiation of the mitochondria and the development of ACTH-sensitive adenylate cyclase in the foetal adrenal may be dependent on foetal ACTH secretion.
ROLE OF VASOPRESSIN IN THE MITOTIC RESPONSE OF RAT BONE MARROW CELLS TO HAEMORRHAGE
Authors: HUNT N. H. , PERRIS A. D. , SANDFORD P. A. 
Published: December 2008

SUMMARY
Two days after a severe haemorrhage plasma calcium concentrations and bone marrow mitotic activity in rats were significantly increased and so remained for a further 5–6 days until the haematocrit had returned to normal. The first 48 h after bleeding were characterized by hypocalcaemia. During this phase two significant peaks in mitotic activity were observed at 4 and 18 h after haemorrhage. The mitotic surge 4 h after bleeding was still present in adrenalectomized and parathyroidectomized animals but in rats which were either hypophysectomized or had congenital diabetes insipidus this mitotic response was absent. Vasopressin was shown to stimulate bone marrow mitotic activity both in vivo and in vitro whereas angiotensin, aldosterone and erythropoietin had no rapid, direct mitogenic action on these cells. This novel hypophysial–bone marrow system suggests that vasopressin may assist in post-haemorrhagic recovery in blood cell numbers in the circulation.
STATES OF ACTIVATION OF CHICK KIDNEY ADENYLATE CYCLASE INDUCED BY PARATHYROID HORMONE AND GUANYL NUCLEOTIDES
Authors: MICHELANGELI V. P. , HUNT N. H. , MARTIN T. J. 
Published: December 2008

SUMMARY
Several aspects of the activation of adenylate cyclase by guanosine 5′-triphosphate (GTP), 5′-guanylylimidodiphosphate (Gpp(NH)p) and bovine parathyroid hormone (bPTH) have been studied in chick kidney plasma membrane preparations. GTP (10−4 mol/l), Gpp(NH)p (10−4 mol/l) and bPTH (10 i.u./ml) activated adenylate cyclase without any significant time lag. However a 2 min delay was observed before the activity of the enzyme increased after the addition of bPTH (−6 → + 34) to incubations.
The early (0–3 min) effects of GTP and Gpp(NH)p upon chick kidney adenylate cyclase activity were antagonized by the addition of the alternative guanyl nucleotide. After 5 min of incubation with kidney plasma membranes, Gpp(NH)p induced a stable state of activation of adenylate cyclase which was not reversible by subsequent addition of GTP. GTP did not induce an irreversible state of enzyme activation. In pre-incubation studies, GTP did not produce a persistent enzyme activation and did not modify the effect of Gpp(NH)p added subsequently at the incubation stage. Gpp(NH)p produced a stable state of activation of adenylate cyclase which was not inhibited by addition of GTP at the incubation stage.
Bovine PTH (2–34) inhibited the effect of bPTH upon adenylate cyclase activity when the native hormone (10 i.u./ml) had been incubated with plasma membranes for up to 8 min before addition of the analogue (5 μg/ml). Incubation of plasma membranes with bPTH (2–34) for as little as 10 s prevented activation of adenylate cyclase by subsequent addition of bPTH. This pattern was confirmed in pre-incubation studies. After pre-incubation of kidney membranes with bPTH and bPTH (2–34), followed by washing, an acid extract of the membranes contained immunoreactive bPTH. Gpp(NH)p produced a greater increase in adenylate cyclase activity in membranes pre-incubated with bPTH or bPTH (2–34) than in membranes pre-incubated with buffer alone, suggesting that the hormone and analogue facilitated the interaction of Gpp(NH)p with adenylate cyclase.
OESTROGEN-INDUCED UTERINE PROTEIN: PRESENCE OF ASSOCIATED PHOSPHOPROTEIN PHOSPHATASE ACTIVITY BEFORE OESTROGEN TREATMENT
Authors: MAIRESSE N. , GALAND P. 
Published: December 2008

SUMMARY
The phosphoprotein phosphatase (PPPase) activity that is found associated with oestrogeninduced protein(s) is not itself induced by oestrogen. Indeed, this activity was found at the same electrophoretic position (i.e. the position of the oestrogen-induced protein) and in equal amounts relative to the total PPPase activity, whether the cytosol fraction from control or from stimulated uteri was tested.
THE USE OF CORTICOTROPHIN PRODUCTION BY ADENOHYPOPHYSIAL TISSUE IN VITRO FOR THE DETECTION AND ESTIMATION OF POTENTIAL CORTICOTROPHIN RELEASING FACTORS
Authors: BUCKINGHAM JULIA C. , HODGES J. R. 
Published: December 2008

SUMMARY
The cytochemical assay for ACTH has been adapted into a method for the detection and determination of potential corticotrophin releasing factors. Of the many putative transmitter substances tested, only the posterior pituitary polypeptides resembled hypothalamic extracts in causing dose-related increases in both pituitary ACTH content and release. Vasotocin was the most active of the compounds studied and, unlike the vasopressins, its dose–response relationships closely resembled those of hypothalamic extracts. The increase in ACTH release induced by hypothalamic extract or vasopressin was reduced by corticosterone, cortisol or progesterone but not by testosterone or oestradiol, but the increase in pituitary ACTH content was not affected by any of these steroids.