bluuebunny/crossref_metadata_2025_split huggingface dataset:
EFFECTS OF CARP PITUITARY FRACTIONS ON VITELLOGENESIS, OVARIAN MAINTENANCE, AND OVULATION IN HYPOPHYSECTOMIZED CATFISH, HETEROPNEUSTES FOSSILIS (BLOCH)
Authors: SUNDARARAJ B. I. , ANAND T. C. , SINHA V. R. P. 
Published: December 2008

SUMMARY
Carp pituitary extracts obtained from the puntius carp, Puntius gonio-notus, the grass carp, Ctenopharyngodon idellus, and the big head carp, Aristichthys nobilis, were subjected to gel filtration on Sephadex G-100. The water-soluble proteins in the pituitary extracts resolved into three distinct components, referred to as fractions I, II and III. They were tested for their gonadotrophic activity in the female catfish, Heteropneustes fossilis, by evaluating ovarian maintenance and ovulation in hypophysectomized gravid specimens during the spawning season (July—August), and the induction of oogenesis and vitellogenesis in the regressed ovaries of hypophysectomized specimens during the preparatory period (February). Daily treatment with the puntius carp pituitary fraction II (100 or 300 μg) reinitiated and restored oogenesis and vitellogenesis. The grass carp pituitary fraction II (300 μg) induced vitellogenesis but its potency was much less than that of the puntius carp pituitary fraction II. The big head carp pituitary fraction II was ineffective. Daily treatment with the puntius carp pituitary fraction II (1 or 5 μg) maintained the yolky oocytes in the gravid ovaries and prevented atresia. Ovulation and spawning were induced in hypophysectomized gravid catfish by a single dose of the puntius carp pituitary fraction II (100 or 150 μg). The first and third fractions from the three species of carps were ineffective. Thus, all the reproductive processes in the hypophysectomized female catfish were initiated and/or maintained solely by the puntius carp pituitary fraction II.
PLASMA LEVELS OF LUTEINIZING HORMONE IN WOMEN AND IN RATS AS MEASURED BY BIOASSAY
Authors: WATSON J. 
Published: December 2008

SUMMARY
Plasma levels of luteinizing hormone (LH) in normally cyclic women during the menstrual cycle and in rats during the oestrous cycle were measured by bioassay. With the human subjects, it was possible to establish a mid-cycle peak of LH and correlate it with basal body temperature, while with the rats a peak of LH secretion was noted between 15.00 and 19.00 h on the day of pro-oestrus. The levels of LH in both groups of subjects were of the same order as those measured by other assay techniques.
THE EFFECTS OF CITRIC ACID CYCLE INTERMEDIATES, α-GLYCEROPHOSPHATE AND LACTIC ACID ON STEROID SYNTHESIS IN RABBIT OVARIAN HOMOGENATES
Authors: SCOON V. , MAJOR PATRICIA W. 
Published: December 2008

SUMMARY
Rabbit ovarian homogenates were incubated in Krebs—Ringer bicarbonate buffer with or without glucose in the presence of citric acid cycle intermediates, α-glycerophosphate and lactic acid. The effects of these compounds on steroid synthesis were then observed. The inclusion of glucose alone in the medium was sufficient to increase progesterone biosynthesis. Succinate stimulated total progestational steroid synthesis both in the presence and absence of glucose in the medium, while citrate had an inhibitory effect in both cases. Malate stimulated synthesis only in the absence of glucose, while oxaloacetate and α-glycerophosphate stimulated synthesis only when glucose was present in the medium. Lactic acid had no effect in the absence of glucose, but significantly inhibited synthesis when glucose was present in the medium.
EFFECT OF ELECTRICAL STIMULATION OF THE HYPOTHALAMUS ON GONADOTROPHIN RELEASE AND THE ONSET OF PUBERTY
Authors: MEIJS-ROELOFS H. M. A. 
Published: December 2008

SUMMARY
Electrical stimulation of the hypothalamus with biphasic pulses was performed in immature female rats. When performed at 27 days of age or later, electrical stimulation in the arcuate nucleus region advanced puberty in all animals, as did stimulation of the anterior hypothalamus at 29 days of age or later. Stimulation in younger rats did not uniformly advance puberty. The responsiveness to electrical stimulation thus seems to develop a few days earlier in the arcuate nucleus region than in the anterior hypothalamus.
In a second experiment the possible involvement of follicle-stimulating hormone (FSH) in the advancement of puberty was investigated: the simplified augmented ovarian weight assay for endogenous FSH was performed in rats stimulated in the arcuate nucleus region as well as in controls. A marked increase in ovarian weight, indicating increased FSH levels, was demonstrated in all animals stimulated on day 27 or later; at earlier ages only a percentage of the stimulated animals responded. This percentage paralleled the percentage of animals that showed advancement of puberty.
It is concluded that electrical stimulation in both the arcuate nucleus region and the anterior hypothalamus advances the onset of puberty. It is suggested that electrical stimulation causes increased plasma FSH levels and, in consequence, precocious puberty.
ACTIVATION OF SOLUBILIZED STEROID-TRANSFORMING ENZYMES OF ADRENAL MICROSOMAL ORIGIN BY SERUM PROTEINS
Authors: HAMILTON MARGOT A. , McCUNE R. W. , ROBERTS SIDNEY 
Published: December 2008

SUMMARY
The reactions which result in the conversion of pregnenolone to progesterone and of progesterone to deoxycorticosterone in undisrupted microsomal preparations from rat adrenal glands were stimulated by homologous serum. The active materials were shown to be firmly associated with serum proteins. The dialysable fraction of serum was either without effect on these transformations or was inhibitory. The enzyme systems involved were partially solubilized by exposure of the microsomal preparation to prolonged sonic treatment or to 1% Triton N-101. After either treatment, 35–40% of the original specific activity of the steroid 21-hydroxylase system responsible for the conversion of progesterone to deoxycorticosterone was found in the supernatant fraction after high-speed centrifugation. However, this solubilized system did not respond to serum preparations. The same procedures also resulted in a supernatant fluid which showed about 50–60% of the initial specific activity of the multi-enzyme system involved in the conversion of pregnenolone to progesterone. In these instances, the stimulatory effect of serum was retained or accentuated. Acetone powders prepared from the adrenal microsomal fraction were also active in the conversion of pregnenolone to progesterone and responded to serum with enhanced activity. Earlier observations that activation of steroid 21-hydroxylase by homologous rat serum was specific for the β-globulin fraction were confirmed in the present investigations. In contrast, stimulation of the conversion of pregnenolone to progesterone was apparently due principally to the albumin fraction. Albumin preparations from a number of other sources, as well as whole human serum protein, were also effective in this regard. The active protein preparations selectively stimulated 4-ene-3β-hydroxysteroid dehydrogenase activity, but did not activate 5-ene-3-oxosteroid isomerase in the microsomal fraction. This finding suggested that activation of 5-ene-3β-hydroxysteroid dehydrogenase was responsible for stimulation of progesterone synthesis from pregnenolone. The results indicate that the protein-bound factor in rat serum which was capable of stimulating the conversion of progesterone to deoxycorticosterone in microsomal preparations from rat adrenal glands was different from that which activates the conversion of pregnenolone to progesterone. Moreover, these diverse factors appeared to act by different mechanisms.
GROWTH AND REGRESSION OF THE CORPORA LUTEA FORMED IN GUINEA-PIGS IN RESPONSE TO TREATMENT WITH EXOGENOUS GONADOTROPHIN
Authors: DONOVAN B. T. , LOCKHART A. N. 
Published: December 2008

SUMMARY
The growth and functional activity of luteal bodies formed in the ovaries of guinea-pigs given exogenous gonadotrophin was examined. Folliclestimulating hormone, luteinizing hormone, both hormones together, and both hormones supplemented with prolactin, were given on day 13. Vaginal oestrus occurred 8–12 days later, irrespective of the kind of hormone given. The sizes of luteal bodies induced in intact and hysterectomized guinea-pigs were compared with those of similarly aged naturally formed corpora lutea 8 and 11 days after ovulation. The artificially induced bodies were smaller than normal corpora lutea, but grew to match their size after hysterectomy.
EFFECT OF l-DOPA ADMINISTRATION ON GROWTH HORMONE SECRETION IN NORMAL SUBJECTS AND PARKINSONIAN PATIENTS
Authors: CAVAGNINI F. , PERACCHI M. , SCOTTI G. , RAGGI U. , PONTIROLI A. E. , BANA R. 
Published: December 2008

SUMMARY
The effect of both oral and intravenous administration of l-DOPA on growth hormone (GH) secretion was studied in a group of normal volunteers: a significant rise of serum GH levels was observed in both cases.
Growth hormone release in response to insulin hypoglycaemia and to arginine infusion was evaluated in a group of Parkinsonian patients before and after 25 days' treatment with l-DOPA plus a DOPA-decarboxylase inhibitor. In addition, GH response to the above stimuli was studied in a group of patients who had been under treatment for more than 6 months with l-DOPA alone. In untreated Parkinsonian patients, GH response to insulin hypoglycaemia was at the lower limit of normal range while arginine-induced GH release was significantly reduced. Treatment with l-DOPA did not increase GH responses. Some possible interpretations of the results are discussed.
The findings support the possibility that dopamine plays a role in the physiological regulation of GH secretion, as in the case of luteinizing hormone, follicle-stimulating hormone and prolactin release.
EFFECTS OF ADMINISTERING ANTISERA TO MOUSE GROWTH HORMONE AND PROLACTIN ON GAIN IN LITTER WEIGHT AND ON MAMMARY NUCLEIC ACID CONTENT OF LACTATING C3H MICE
Authors: SINHA Y. N. , LEWIS U. J. , VANDERLAAN W. P. 
Published: December 2008

SUMMARY
The effects of administering antiserum to mouse growth hormone (GH) and prolactin on lactation and mammary nucleic acid content of C3H mice were studied. Injections of either antisera to lactating mothers suppressed the gain in body weight of their suckling young, GH antiserum more readily than prolactin antiserum. A combined injection of the two antisera resulted in an immediate retardation of the gain in body weight of the young. Although both antisera reduced DNA and RNA content of the mammary gland, GH antiserum appeared to affect DNA content predominantly whereas prolactin antiserum affected RNA: DNA ratio, suggesting involvement of GH primarily in cell proliferation and of prolactin in protein synthesis. Both antisera abolished the gain in maternal body weight. Mouse GH antiserum decreased maternal adrenal weight whereas both antisera reduced ovarian weight. The results suggest that both GH and prolactin may be involved in normal lactation and in maintenance of body weight in C3H mice.
OESTRONE AND OESTRADIOL IN JUGULAR VEIN PLASMA DURING THE OESTROUS CYCLE OF THE COW
Authors: MASON B. D. , KRISHNAMURTI C. R. , KITTS W. D. 
Published: December 2008

SUMMARY
The concentrations of oestrone and oestradiol in jugular vein plasma during the bovine oestrous cycle were measured using a fluorescence assay. The highest levels of both oestrogens were found on the 19th and 20th days of a standardized 21-day cycle, with the peak of oestrone occurring slightly before that of oestradiol. Oestrone values ranged from 23·1 to 226·9 ng/100ml and oestradiol varied between 17·6 and 117·5 ng/100 ml. Relatively high values for oestrone concentrations were found on days 6, 7 and 8. These values are comparable to those observed in the ovarian vein blood of the ewe, using both the present method and radioimmunoassay.
The relationship between the oestrogen concentrations reported here and the levels of other hormones during the bovine oestrous cycle is discussed.
ULTRASTRUCTURE OF THE UTERINE EPITHELIUM DURING THE HORMONAL INDUCTION OF SENSITIVITY AND INSENSITIVITY TO A DECIDUAL STIMULUS IN THE MOUSE
Authors: POLLARD ROSEMARY M. , FINN C. A. 
Published: December 2008

SUMMARY
Uterine sensitivity and insensitivity to a decidual stimulus were induced in ovariectomized mice by daily treatment with progesterone and oestradiol. Uteri from these animals were examined with the electron microscope in an attempt to correlate ultrastructural changes with these states.
Progesterone alone brings the uterus to a state of 'presensitivity' and this is characterized by closure of the uterine lumen with interdigitation of microvilli from opposite luminal surfaces. This state can be held for long periods but when oestrogen is also given the uterus becomes sensitive for a short period and then insensitive. Morphologically the latter state is characterized by very close apposition of the luminal surfaces with the loss of the microvillous structure. This is referred to as the second stage of closure and is usually reached after 4 or 5 days of treatment with low sensitizing doses of oestradiol, but with higher doses, which induce insensitivity to a decidual stimulus, it is reached prematurely.
THE SPLANCHNIC AND HEPATIC UPTAKE OF CORTISOL IN CONSCIOUS AND ANAESTHETIZED SHEEP
Authors: PATERSON J. Y. F. , HARRISON F. A. 
Published: December 2008

SUMMARY
The uptake of cortisol by the gastro-intestinal tract and by the liver was estimated in sheep by measurement of [3H]cortisol concentrations in portal and hepatic venous plasma during constant infusion of tritium-labelled cortisol, with simultaneous measurement of plasma flows.
The total splanchnic uptake of cortisol was 57 ± 4 (s.e.m.)% of the measured rate of cortisol secretion, 45% by the liver and the remainder by the gastro-intestinal tract. The splanchnic extraction of cortisol could be related to plasma flow, and was less efficient at higher flows. It could also be related to plasma cortisol concentration, and was more efficient at higher concentrations. The splanchnic uptake of cortisol was closely correlated with the flow of unbound cortisol into the region, and was 1·61 times that influx. There is therefore partial dissociation of plasma protein-bound cortisol during the splanchnic uptake.
About 25% of secreted cortisol is converted to cortisone at extrahepatic sites, and is removed from plasma by the liver.
SALURETIC ACTION OF ALDOSTERONE IN THE PRESENCE OF INCREASED SALT INTAKE AND RESTORATION OF NORMAL ACTION BY PROLACTIN OR BY OXYTOCIN
Authors: BURSTYN P. G. , HORROBIN D. F. , MANKU M. S. 
Published: December 2008

SUMMARY
The effects of aldosterone on sodium, potassium and water excretion during various treatment regimes were studied in six Merino ewes. Urine was collected from 12.00 to 14.00 h and from 14.00 to 16.00 h each day. Intravenous injections of either 1 ml isotonic saline or 500 μg aldosterone were given at 13.30 h and excretion during the second collection period compared with that in the first. When each animal was given a salt (NaCl) supplement of 80 mequiv./day by i.v. injection, aldosterone caused marked sodium retention with no effect on potassium. When salt supplements of 400 mequiv./day were given, aldosterone lost its sodium-retaining action in all animals and caused a marked saluresis with a small increase in potassium excretion in five sheep out of six. Injections of sheep pituitary prolactin or of oxytocin restored the sodium-retaining action of aldosterone in spite of a continued high salt intake. The animals gained very little weight when treated with 400 mequiv. salt alone but did gain significantly when treated with salt plus prolactin. The weight gain was rapidly lost when the prolactin and high salt intake were discontinued.
NUCLEIC ACID AND PROTEIN CONTENT IN THE PARS DISTALIS OF THE PITUITARY AND HYPOTHALAMUS OF THE FROG, RANA ESCULENTA: EFFECTS OF GONADECTOMY AND CAPTIVITY
Authors: RASTOGI R. K. , CHIEFFI G. 
Published: December 2008

SUMMARY
The protein, RNA and DNA content was measured in the pars distalis, hypothalamus and cerebral cortex of gonadectomized frogs (Rana esculenta) and compared with the levels in captive and in wild controls. Short-term (35 days) gonadectomy increased the weight of the pars distalis and also its RNA and protein content, whilst gonadectomy for a longer period (135 days, females only) depressed these parameters below control levels. In the hypothalamus, short-term gonadectomy increased the protein concentration, and long-term gonadectomy the RNA content. Captivity alone for 135 days caused a diminution in the weight and protein content of the pars distalis, although the various parameters showed an increase which correlated with the annual reproductive cycle. The DNA content (μg/mg tissue) of the pars distalis was similar in all groups suggesting that any weight changes were not due to changes in cell numbers. Neither gonadectomy nor captivity altered the nucleic acid and protein content of the cerebral cortex. The pars distalis weighed more in female frogs and contained more RNA and protein per mg.
LIPOLYTIC ACTIVITY OF HUMAN PITUITARY FRACTIONS ON HUMAN ADIPOSE TISSUE CELLS
Authors: STORRING P. L. , BURNS T. W. , FURNIVAL BRIDGET E. , HALES C. N. , LANGLEY P. , HARTREE ANNE STOCKELL 
Published: December 2008

SUMMARY
Attempts to isolate, free of thyroid-stimulating hormone (TSH), the peptide(s) responsible for the lipolytic activity of a fraction of acetone-dried human pituitary powder are described. It was not found possible to separate the lipolytic and TSH activities, even by isoelectric focusing which gave fractions consisting predominantly of single protein components. In the four lipolytic fractions isolated by electrofocusing, the two activities paralleled one another. It is therefore concluded that the TSH present is responsible for the lipolytic activity of this human pituitary fraction, though some evidence suggests that luteinizing hormone (LH), which is a minor contaminant, might also be lipolytic.
The minimum effective lipolytic concentration of the most potent fraction isolated was in the range 0·1–1·0 μg/ml. This is far in excess of plasma concentrations of TSH or LH encountered physiologically. Hence the lipolytic action of these molecules is unlikely to be of physiological significance.
SOME ASPECTS OF CHANGING BODY COMPOSITION OF MICE DURING SUCCESSIVE PREGNANCIES AND LACTATIONS
Authors: JOHNSON C. L. 
Published: December 2008

SUMMARY
Mice that had produced and reared three successive litters gained more weight than virgins. No differences in skeletal size were noted between the two groups but the mated mice accumulated a deficit of calcium and phosphorus. They also showed a rhythmical variation in body composition.
ERYTHROPOIETIN-INDUCED CHANGES IN PLASMA CALCIUM AND BONE MARROW MITOSIS IN THE RAT
Authors: HUNT N. H. , PERRIS A. D. 
Published: December 2008

SUMMARY
Subcutaneous injections of ovine erythropoietin preparations caused parallel increases in bone marrow mitotic activity and plasma calcium concentrations. These activities appeared to be a specific property of the erythropoietin molecule and were not due to an impurity. The increased mitosis and hypercalcaemia which followed erythropoitein injection in normal rats did not occur in the aparathyroid animal. Although a functional parathyroid gland was essential for the erythropoietin-induced changes, the mode of interaction between erythropoietin and the parathyroid gland remains to be established.
DISCHARGE PATTERNS OF SUPRAOPTIC AND PARAVENTRICULAR NEURONES IN RATS GIVEN A 2% NaCl SOLUTION INSTEAD OF DRINKING WATER
Authors: DYBALL R. E. J. , POUNTNEY PHILIPPA S. 
Published: December 2008

SUMMARY
The firing rates of antidromically identified neurones in the supraoptic and paraventricular nuclei were monitored in control animals, animals which had received a 2% Nacl solution instead of drinking water for 3 days and animals (recovery group) which after treatment were again allowed to drink tap water for 2 days. Treatment with NaCl depleted the pituitary stores of vasopressin and oxytocin and significantly increased the firing rate of antidromically activated neurones but not that of other hypothalamic neurones. In the recovery group the neurohypophysial stores of vasopressin and oxytocin had increased but were still significantly below control levels and the firing rates of the antidromically identified neurones were similar to those in control animals. Since the firing rates were increased by NaCl treatment and returned to control values when the treatment ceased it may be concluded that the excitation was due to stimulation of the neurosecretory neurones by the NaCl treatment.
THE EFFECT OF VASOPRESSIN (PITRESSIN) ADMINISTRATION ON SODIUM, POTASSIUM AND UREA EXCRETION IN RATS WITH AND WITHOUT DIABETES INSIPIDUS (DI), WITH A NOTE ON THE EXCRETION OF VASOPRESSIN IN THE DI RAT
Authors: LAYCOCK J. F. , WILLIAMS P. G. 
Published: December 2008

SUMMARY
The effect of the administration of vasopressin as subcutaneous Pitressin Tannate in oil (PTO) was studied in the Brattleboro rat. Rats with hereditary hypothalamic diabetes insipidus (DI), and rats heterozygous for this abnormality, were used. A minimum dose of 1000 mu. of PTO/24 h was necessary to restore the urinary volume and osmolality of DI rats to values comparable with those of heterozygous rats. The urinary excretion of antidiuretic activity in DI rats was shown to be related to the dose of PTO. Sodium and urea excretion, but not potassium excretion, were reduced by up to 50% in the DI rat. No comparable changes were produced in the heterozygous rat. The possible mechanisms of these actions of vasopressin are discussed.
THE BIOSYNTHESIS OF THYROXINE: INCORPORATION OF [U-14C]TYROSINE INTO THYROGLOBULIN BY MOUSE THYROID GLANDS IN VIVO AND IN VITRO
Authors: WAIN W. H. 
Published: December 2008

SUMMARY
The incorporation in vivo of [U-14C]tyrosine into 19S thyroglobulin by mice was achieved to a level of 2·85 c.p.m./μg. This level of incorporation was insufficient to permit the isolation of 14C-labelled iodinated tyrosines or residues. Isolated mouse thyroid lobes were used as an in-vitro system for the synthesis of 19S thyroglobulin. The lobes continued to incorporate 131I into 19S thyroglobulin for at least 48 h and this incorporation of iodine was specifically inhibited by propylthiouracil. The isolated mouse thyroid lobe in-vitro system was used to incorporate 14C-labelled amino acids into 19S thyroglobulin. [U-14C]Tyrosine was incorporated to a level of 1150 c.p.m./μg. Electrophoretic separations of enzymic hydrolysates of [14C]tyrosine-labelled 19S thyroglobulin showed the presence of [14C]tyrosine, [14C]monoiodotyrosine, [14C]di-iodotyrosine and [14C]thyroxine. The presence of [14C]tyrosine, [14C]monoiodotyrosine and [14C]thyroxine was demonstrated by chromatography of the eluates from the electrophoretic separations.
The results provide evidence for the utilization of tyrosyl residues within the thyroglobulin molecule for iodination and subsequent coupling to form thyroxine.
FORMATION OF PROGESTERONE AND PREGNENOLONE FROM [4-14C]CHOLESTEROL BY THE INTACT MID-TERM HUMAN FOETO—PLACENTAL UNIT PERFUSED IN VITRO
Authors: BAIRD D. T. , COCKBURN F. , GALBRAITH A. , KELLY R. , LIVINGSTONE J. R. B. 
Published: December 2008

SUMMARY
A system for perfusing in vitro the mid-term human pregnant uterus containing the entire foeto-placental unit is described. After termination by hysterectomy, circulation was established within 15 min by cannulation of the uterine arteries. In two experiments the foetal heart rate remained reasonably steady during the perfusion (107 and 127 min respectively). The rates of secretion of pregnenolone and progesterone into the uterine veins were within the range calculated for the period of gestation. Conversion of [4-14C]cholesterol to pregnenolone and progesterone was observed in both experiments although in neither could it account for the total secretion of progesterone.