bluuebunny/crossref_metadata_2025_split huggingface dataset:
DEVELOPMENTAL STUDY OF PITUITARY-ADRENOCORTICAL RESPONSE IN MICE: PLASMA AND BRAIN CORTICOSTERONE DETERMINATION AFTER HISTAMINE STRESS
Authors: KAKIHANA RYOKO , BLUM STEPHEN , KESSLER SEYMOUR 
Published: December 2008

SUMMARY
The development of the pituitary-adrenocortical stress response was studied in CBA/J × DBA/2J hybrid mice. On the basis of the plasma corticosterone response 15 min after a subcutaneous injection of histamine dihydrochloride (50 mg/kg), the first three neonatal weeks could be divided into stress-nonresponsive (3–211 days) and stress-responsive 16–21 days) periods. During the former period, corticosterone levels in the brains of the non-stressed control mice were 63% higher than those of comparable mice during the latter period. Histamine stress significantly increased corticosterone concentrations in the brain during both these periods, but the increase was much greater (88%) during the stress-responsive period than during the stress-nonresponsive period (29%).
PURIFICATION AND CHARACTERIZATION OF CAPRINE PROLACTIN
Authors: McNEILLY A. S. , ANDREWS P. 
Published: December 2008

SUMMARY
Prolactin was isolated from frozen goat pituitary glands by a simple procedure involving gel filtration and chromatography on DEAE-cellulose. The major product (yield, 2·5 mg/g pituitary tissue) had high pigeon crop sac-stimulating activity (27 i.u./mg) and was free of growth hormone and other pituitary hormones. The molecular weight was similar to that of ovine prolactin.
Caprine prolactin was immunologically indistinguishable from ovine prolactin in radioimmunoassays, in which ovine prolactin antiserum and either ovine or caprine prolactin labelled with 125I were used.
The results indicate that caprine and ovine prolactin are closely related and that radioimmunoassay for ovine prolactin may be used to estimate caprine prolactin in serum.
OESTRADIOL-17β AND TESTOSTERONE IN RAT TESTIS TISSUE: EFFECT OF GONADO-TROPHINS, LOCALIZATION AND PRODUCTION IN VITRO
Authors: de JONG F. H. , HEY A. H. , van der MOLEN H. J. 
Published: December 2008

SUMMARY
Concentrations of oestradiol-17β and testosterone were estimated in testicular tissue from intact and hypophysectomized rats. Within 30 min after intravenous injection of human chorionic gonadotrophin (HCG) or follicle-stimulating hormone (FSH) to intact animals the tissue concentrations of both steroids were not significantly changed. Prolonged s.c. administration of HCG (5 days) caused an increase in the tissue levels of both steroids, which was further increased when the prolonged treatment was followed by an intravenous injection with this trophic hormone. FSH had no influence on tissue concentrations of oestradiol-17β or testosterone in hypophysectomized rats.
Assay of separated seminiferous tubules and interstitial tissue indicated that oestradiol-17β and testosterone were mainly localized in the interstitial tissue. Incubations of these constituents showed that oestradiol-17β was produced in the seminiferous tubules, while testosterone was produced in the interstitial compartment.
EFFECTS OF THYROIDECTOMY ON THE CHEQUERED WATER-SNAKE, NATRIX PISCATOR
Authors: THAPLIYAL J. P. , GUPTA S. C. , GARG R. K. 
Published: December 2008

SUMMARY
Thyroidectomy decreased the body weight and the height of the cells lining the sex-segment of the kidney of the Chequered Water-snake, Natrix piscator maintained at 30 °C; at 40 °C the liver, kidney and gonad were also affected. At the higher temperature, thyroidectomy influenced significantly protein, carbohydrate and lipid metabolism. At 30 °C, only a decrease in the rate of esterification of the free fatty acids in the liver and of their release from the adipose tissue was observed. The difference in the effect of thyroidectomy at 30 and 40 °C is explained by suggesting that thyroid activity was low in animals maintained at the lower temperature and high in those kept at the higher temperature.
A RE-EXAMINATION OF THE TADPOLE IN METAMORPHIC STASIS AS A RECIPIENT IN A BIOASSAY FOR THYROID-STIMULATING HORMONE
Authors: CHING MELVIN 
Published: December 2008

SUMMARY
The tadpole, in metamorphic stasis, has been used as a bioassay recipient for thyroid-stimulating hormone (TSH). The validity of its use for this purpose, however, has not been tested critically, particularly with respect to the effect of other hormones, most notably, growth hormone (GH) and luteinizing hormone (LH). Growth hormone has been shown to influence thyroid function and LH is a common contaminant of pituitary TSH preparations. Tadpoles of Rana pipiens, arrested at a particular metamorphic stage, received various concentrations of LH alone, a combination of doses of GH and TSH, or GH and rat anterior pituitary extract. Growth hormone was ineffective in re-inducing metamorphosis in 78% of cases, whereas LH stimulated metamorphosis in the tadpoles.
PLASMA CORTICOSTERONE CONCENTRATIONS AND PITUITARY PROLACTIN CONTENT IN LATE PREGNANCY AND THEIR WITHIN-DAY FLUCTUATIONS IN THE RAT
Authors: ÔTA KATUAKI , ÔTA TAKAO , YOKOYAMA AKIRA 
Published: December 2008

SUMMARY
Levels of plasma corticosterone and of pituitary prolactin were studied in the mornings (10.00–10.30 h) and evenings (17.00–18.00 h) during the last week of pregnancy in the rat. Morning levels of plasma corticosterone started to rise on day 19 and reached a peak on day 21. The concentration of corticosterone in plasma on the morning of day 21 was about 2·3 times higher than that on day 15. Both content and concentration of prolactin in the pituitary began to fall on the morning of day 19 of pregnancy and the minimum values for both content and concentration were reached on the morning of day 21. Plasma corticosterone concentration and pituitary prolactin content measured in the evening, however, remained high throughout the period examined and there were no appreciable changes in the levels at the different stages of pregnancy.
The results obtained on day 22 of pregnancy, the expected day of parturition, indicated that a surge of pituitary prolactin secretion and a temporary depression of corticosterone secretion occurred at about the time of parturition.
INDUCTION BY GONADAL HORMONES OF HEPATIC LIPOGENIC ENZYME ACTIVITY IN IMMATURE PULLETS
Authors: BALNAVE D. , PEARCE J. 
Published: December 2008

SUMMARY
The effect of gonadal hormone administration on hepatic lipogenic enzyme activity, and some physiological parameters was investigated in immature pullets.
Pullets (aged 4 weeks) were allocated to treatment groups and received intramuscular injections of oestradiol, testosterone, progesterone or oestradiol + testosterone (all in 0·3 ml corn oil) or corn oil alone (control group). There was no evidence of any hormone-induced changes in the specific activity of hepatic ATP-citrate lyase 1, 3, 6 and 12 h after hormone administration. NADP-malate dehydrogenase exhibited significant variations in specific activity over this period of time and it is probable that these changes reflected an increased requirement for NADPH for synthetic purposes in hormone-treated birds.
The effect of 1, 2, 4 and 9 days of hormone administration was also investigated. In testosterone-treated birds there were significant increases in the specific activities of both lipogenic enzymes after 1 day of hormone treatment whereas for birds receiving oestradiol the maximum specific activities were found on the second day. Similarly, the liver lipid content of oestradioltreated birds showed a substantial increase on day 2. After 9 days of hormone administration no significant differences in the specific activity of ATP-citrate lyase were observed between treatments but the specific activity of NADP-malate dehydrogenase was significantly reduced in oestradiol- or mixed hormone-treated birds; it is possible that the reduced enzyme activity is associated with a reduced requirement for NADPH and in this connexion there were no further increases in liver lipid content or liver weight after 4 days of hormone administration. The liver RNA:DNA ratio tended to be greatest in birds receiving oestradiol or oestradiol + testosterone.
Studies utilizing inhibitors of RNA and protein synthesis showed that such compounds abolished the increases in lipogenic enzyme activity following hormone administration suggesting that these increases were hormone-induced effects.
These results are discussed in relation to the effects of the various hormones on liver lipid metabolism and also in relation to the situation in the mature laying hen.
RELATIONSHIP BETWEEN THE SEX OF THE FOETUS AND THE AMOUNT OF HUMAN CHORIONIC GONADOTROPHIN IN PLACENTAE FROM THE 10TH TO THE 20TH WEEK OF PREGNANCY
Authors: WIDE LEIF , HOBSON BRUCE 
Published: December 2008

SUMMARY
Sixty-seven placentae were obtained by abdominal hysterotomy, between the 10th and 20th weeks of pregnancy, from women who had had a therapeutic abortion. Human chorionic gonadotrophin (HCG) in extracts from these placentae was assayed by a biological and a radioimmunological method. When the concentration and total amount of HCG in placentae was related to the sex of the foetus no significant difference between 'male' and 'female' placentae was found. This is contrary to findings at term when there is a significant (P < 0·005) difference in the concentration of HCG/g and/placenta in 'male' and 'female' placentae. The amount of biologically active HCG in 'female' placentae significantly increased but was unchanged in 'male' placentae when the periods 10–20 and 37–41 weeks were compared. Similarly, the amount of immunologically active HCG in 'female' placentae was unchanged but in 'male' placentae it decreased. The possible reasons for the different results obtained with the biological and the radioimmunological assays are discussed.
EFFECT OF NEONATAL ADMINISTRATION OF DIFFERENT ANDROGENS IN THE FEMALE RAT: CORRELATION BETWEEN AROMATIZATION AND THE INDUCTION OF STERILIZATION
Authors: McDONALD P. G. , DOUGHTY CYNTHIA 
Published: December 2008

SUMMARY
Groups of neonatal female rats were treated once daily for the first 5 days of life with oil, 1 μg testosterone propionate, or 10 μg of one of the following androgens; androstenedione-enol-propionate, 19-hydroxytestosterone propionate, 5α-dihydrotestosterone propionate, 5α-androstanedioneenol-propionate, androsterone propionate, 5α,3α-androstenediol dipropionate, 5α,3β-androstanediol dipropionate. A final group was given 100 μg 5α,3β-androstanediol dipropionate as a single injection on day 1 of life. Only those androgens which are aromatizable were effective in preventing cyclicity whilst the 5α-reduced androgens were ineffective or only partially effective. All treatments significantly increased the ano-genital distance compared with oil-treated control animals. There were no clear relationships between aromatization and the effects on suppressing sexual behaviour after oestrogen and progesterone treatment. The results are discussed in terms of the role of aromatization in the hormonal control of hypothalamic differentiation.
DIURNAL VARIATIONS IN THE ACTION OF INSULIN ON MUSCLE GLYCOGEN SYNTHESIS
Authors: GAGLIARDINO J. J. , PESSACQ MARÍA TERESA 
Published: December 2008

SUMMARY
The effect of a single dose of insulin i.u./kg, i.p.) injected every 4 h during a 24-h period was studied in normal mice. The glycogen content of the diaphragm muscle and serum glucose levels were determined every 15 min throughout a period of 60 min after the hormone injection. Although insulin always produced an increase in glycogen and a decline in serum glucose, neither the sequential changes observed during the 60 min after injection nor the magnitude of these changes were constant throughout the 24 h of the day. The two circadian variations in the action of insulin (on glycogen and glucose) did not display any well-defined relationship, i.e. the most marked decline in glucose was not followed by a correspondingly marked increase in glycogen. These observations suggest that the results obtained from the administration of a single dose of insulin at an arbitrary time of day might be misleading. The circadian variations found could represent another component of the complex homeostatic mechanisms in which insulin is involved.
METABOLIC FATE OF HUMAN CALCITONIN IN THE DOG
Authors: CLARK MARY B. , WILLIAMS CLAIR C. , NATHANSON BRENDA M. , HORTON RIMA E. , GLASS H. I. , FOSTER G. V. 
Published: December 2008

SUMMARY
The metabolism of human calcitonin by the liver and kidneys was studied in dogs. Hormone was infused into anaesthetized animals and plasma samples for radioimmunoassay collected from catheters placed in the aorta, hepatic and renal veins. Compared with arterial levels, 30·1 ± 3·3 (S.E.M.)% less hormone was measured in renal vein samples and 8·3 ± 3·0% less in hepatic vein samples. From estimates of blood volume and renal blood flow, it was calculated that the kidneys removed 8% of the circulating hormone/min. Further studies demonstrated that (i) removal of the kidneys prolonged the disappearance of the hormone, (ii) less than 0·3% of infused stable hormone appeared in urine, (iii) radioactivity in kidneys of dogs infused with 131I-labelled calcitonin was concentrated in the cortex, (iv) this uptake of radioactivity was decreased by prior perfusion with stable hormone, and (v) unlabelled hormone disappeared when incubated with homogenates of kidney. From these findings, it is concluded that the kidney plays the major role in the clearance of human calcitonin from the blood and that this clearance is due probably to enzymic degradation.
RELATIONSHIP OF PROLACTIN AND GROWTH HORMONE TO MAMMARY FUNCTION DURING PREGNANCY AND LACTATION IN THE C3H/ST MOUSE
Authors: SINHA Y. N. , SELBY F. W. , VANDERLAAN W. P. 
Published: December 2008

SUMMARY
The secretion of prolactin and growth hormone (GH) in C3H/St mice, a strain having a high incidence of spontaneous mammary tumours, was studied at intervals throughout pregnancy and lactation. Serum and pituitary concentrations of prolactin and GH were measured by specific, homologous radioimmunoassays. Crude extracts of mouse placentae did not cross-react in these assays, indicating that the assay systems measured prolactin and GH of hypophysial origin. Except for a small, brief rise on day 5, prolactin secretion was low throughout most of pregnancy; the serum concentration of prolactin increased appreciably only near term. During lactation, prolactin in serum averaged from 5 to 10 times basal levels (30–40 ng/ml) until day 15 of lactation, after which the concentration declined. In contrast, GH secretion increased early in pregnancy, the concentration rising both in serum and in the pituitary gland consistently after day 5. The serum concentrations reached 3–10 times basal levels (8–12 ng/ml) between days 10 and 20 of pregnancy. There were successive decreases in serum GH concentration after parturition; the concentration reached basal levels on day 5, but it increased thereafter and was maintained at over three times basal levels for the remainder of lactation. The levels of GH in serum were highly correlated with mammary DNA and RNA contents during pregnancy, while prolactin concentration was more strongly correlated with mammary function during lactation.
EFFECT OF RELAXIN ON OESTROGEN-INDUCED UTERINE LUMINAL FLUID ACCUMULATION IN THE OVARIECTOMIZED RAT
Authors: KENNEDY T. G. 
Published: December 2008

SUMMARY
Uterine luminal fluid accumulation (ULFA) was induced in ovariectomized rats by twice daily treatment for 3 days with 0·5 μg oestradiol-17β. At the end of this treatment, rats were given a single subcutaneous injection of 0·2 ml 0·9% saline containing 0, 0·1, 1, 10, or 100 guinea-pig units (GPU) of relaxin, and ULFA was determined 15–17 h thereafter. It was reduced in animals receiving ≥ 1 GPU relaxin. This reduction in ULFA commenced 12 h after treatment of rats with 10 GPU relaxin, and was completed by 24 h. Ligation of the cervical end of the uterus prevented the loss of fluid in response to a single injection of relaxin, indicating the cervix as the route of fluid loss. Uterine luminal fluid accumulation was reduced to a greater extent by treatment of rats with 1 mg progesterone than by 10 GPU relaxin. Given concomitantly with oestrogen, relaxin had no effect on ULFA in horns which were ligated at the cervical end, indicating that relaxin did not inhibit luminal fluid formation. It is concluded from these results that the effects of progesterone on ULFA are not mediated by relaxin. The results, however, do not allow rejection of the hypothesis that the effect of prolactin on ULFA is mediated by relaxin.
DNA SYNTHESIS AND THE SECRETION OF PROLACTIN AND GROWTH HORMONE BY THE PITUITARY GLAND OF THE MALE RAT: EFFECTS OF DIETHYLSTILBOESTROL AND 2-BROMO-α-ERGOCRYPTINE METHANESULPHONATE
Authors: DAVIES CAROL , JACOBI JOAN , LLOYD H. M. , MEARES J. D. 
Published: December 2008

SUMMARY
The effects of 2-bromo-α-ergocryptine methanesulphonate on the response of the pituitary gland of the male rat to diethylstilboestrol dipropionate were studied by radioimmunoassay of prolactin and growth hormone and measurements of DNA synthesis. Given before diethylstilboestrol, 2-bromo-α-ergocryptine prevented the oestrogen-induced rise in serum prolactin and partly inhibited pituitary DNA synthesis. Given on days 4–6 of a 6-day period after a single dose of diethylstilboestrol, 2-bromo-α-ergocryptine rapidly increased pituitary prolactin concentration, diminished serum prolactin, reduced pituitary DNA synthesis and did not affect the growth hormone response to oestrogen.
THE HYPERCALCAEMIC RESPONSE TO PARATHYROID HORMONE IN JAPANESE QUAIL
Authors: KENNY A. D. , DACKE C. G. 
Published: December 2008

SUMMARY
The nature of the rapid hypercalcaemic response in birds to intravenously administered parathyroid hormone (PTH) has been studied using the Japanese quail and, to a lesser extent, the chicken. The response has been examined in acutely 45Ca-labelled birds. Parathyroid hormone, synthetic (Beckman 1–34 peptide) bovine PTH, was given with or without the simultaneous administration of a calcium load of 51 mm-CaCl2. It is concluded that the hypercalcaemic response in birds is complex involving two or more underlying mechanisms. The initial phase (30 min or less) is characterized by an increase in plasma 45Ca levels; interpretation of this response in terms solely of bone resorption is difficult. It is suggested that inhibition of bone accretion is the basis for the initial phase. The later phase (30 min or longer) can be interpreted as being largely due to bone resorption. In calciumloaded birds, which were used in recently described avian bioassay methods for PTH, similar results, and therefore interpretations, pertain. No immediate hypocalcaemic response to PTH was found in immature Japanese quail or chickens.
INVOLVEMENT OF NEURONES CONTAINING 5-HYDROXYTRYPTAMINE IN THE MECHANISM OF PROLACTIN RELEASE INDUCED BY OESTROGEN
Authors: CALIGARIS L. , TALEISNIK S. 
Published: December 2008

SUMMARY
Oestradiol benzoate (OB) injected into spayed rats induced high levels of serum prolactin (measured by radioimmunoassay) in the afternoon of the third day after the injection. When progesterone was injected into spayed rats primed 3 days before with OB, a release of prolactin was observed in the morning. These rises in serum prolactin were prevented either by treatment with p-chlorophenylalanine (PCPA), a compound which depletes 5-hydroxytryptamine (5-HT) from the brain or by injecting the 5-HT antagonist methysergide, into the third ventricle. The blockade of prolactin release by PCPA treatment of OB-injected rats was partially reversed by the administration of 5-hydroxytryptophan. These results indicate that 5-HT containing neurones mediate the effect of ovarian steroids on prolactin release. Further support of this view was provided by experiments showing that the injection of 5-HT into the third ventricle raised serum prolactin levels.
The rise in serum prolactin observed after the ovarian steroid treatment was blocked to a great extent by the injection of picrotoxin or strychnine. Picrotoxin also blocked the rise in serum prolactin induced by the injection of 5-HT into the third ventricle but failed to affect the rise in serum prolactin after i.v. injection of thyrotrophin-releasing hormone or α-methyl-p-tyrosine treatment. The results suggest that an inhibitory neuronal mechanism mediated by 5-HT neurones is involved in the release of prolactin induced by ovarian steroids.
NEUROPHYSIN-LIKE PROTEIN IN BOVINE PINEAL GLAND
Authors: REINHARZ A. C. , CZERNICHOW P. , VALLOTTON M. B. 
Published: December 2008

SUMMARY
Neurophysin-like proteins have been extracted and purified from bovine pineal glands and were found to share the biochemical and immunological properties of neurophysin I and neurophysin II respectively, and to be associated with at least one biologically and immunologically active neurohormone, probably vasotocin.
EFFECT OF BETAMETHASONE ON THE PRODUCTION OF GLUCOSE FROM PROPIONATE BY SHEEP
Authors: FORD E. J. H. , WINCHESTER J. G. 
Published: December 2008

SUMMARY
Primed continuous intraruminal infusions of tracer amounts of [2-14C]propionate were used to measure propionate production and the incorporation of propionate carbon into glucose by six sheep on a diet of 1000 g chopped hay/day. Primed continuous intravenous infusions of [U-14C]glucose were used to measure the rate of glucose entry in the same sheep. The measurements were repeated 24 h after a single intramuscular injection of betamethasone.
Maximum hyperglycaemia and a significant increase in glucose entry occurred after 24 h but there was no significant change in propionate production or in the synthesis of glucose from propionate.
It is concluded that the increase in glucose entry must arise from substrates other than propionate such as amino acids.
EFFECT OF HYPOTHALAMIC LESIONS ON MATURATION AND ANNUAL CYCLICITY OF THE FERRET TESTIS
Authors: BAUM M. J. , GOLDFOOT D. A. 
Published: December 2008

SUMMARY
Sexually immature male ferrets received electrolytic lesions in the rostral mediobasal hypothalamus, and another group of males received sham operations. Testicular size, as estimated by weekly palpation, increased rapidly after the placement of lesions. Four weeks after the operation the right testis and epididymis were found to weigh significantly more in lesioned than in sham-operated animals, whereas body weight was the same in the two groups. The right testis of lesioned ferrets had a significantly higher Leydig cell index as well as significantly larger luminal and outer diameters of the seminiferous tubules. In addition, histological examination and classification of the seminiferous tubules showed that spermatogenesis was advanced in lesioned ferrets, with pachytene spermatocytes being the most advanced germ-cell type present in a significantly higher percentage of tubules, and spermatogonia being the most advanced germ-cell type present in a significantly lower percentage of tubules. Finally, at this time the concentration of testosterone per testis was significantly higher in lesioned than in sham-operated ferrets. When the remaining testis was biopsied 20 weeks after the operation it was found that spermatogenesis was still more advanced and the concentration of testosterone in blood was significantly higher in lesioned ferrets. By the time autopsy was performed 38 weeks after the operation, all parameters of testicular function in the sham-operated male ferrets had caught up with those of lesioned animals.
In a second experiment it was found that hypothalamic lesions accelerated testicular growth without interfering with the subsequent occurrence of an annual regression and recrudescence of the testes.