bluuebunny/crossref_metadata_2025_split huggingface dataset:
INCREASED PRODUCTION OF FOLLICLE-STIMULATING HORMONE IN IMMATURE FEMALE RATS BY A SINGLE INJECTION OF ANDROGEN OR OESTROGEN
Authors: NAQVI R. H. , JOHNSON D. C. 
Published: December 2008

SUMMARY
An increase in ovarian weight in immature rats after the injection of chorionic gonadotrophin (HCG) was used to measure variations in endogenous follicle-stimulating hormone (FSH) after steroid treatment. A single injection of several steroids (testosterone, androstenediol, androstenedione, oestradiol benzoate) given 12–96 hr. before treatment with HCG caused a 30–200% increase in ovarian weight. This was not a direct effect of the steroids since hypophysectomy abolished the response, and administration of the compounds concurrently with HCG was ineffective. Within certain limits an increase in the duration of pretreatment enhanced the ovarian response while an increase in the dose of steroid had little effect.
Pretreatment with testosterone propionate did not change pituitary FSH activity, indicating that the increase in circulating FSH was due to an increased production of hormone. On the other hand, pituitary FSH in animals treated with oestradiol benzoate was significantly lowered within 72 hr. suggesting an increased release of FSH.
OESTROGEN-PROGESTERONE RELATIONSHIPS IN THE INDUCTION OF OESTRUS IN SPAYED HEIFERS
Authors: CARRICK M. J. , SHELTON J. N. 
Published: December 2008

SUMMARY
Experiments were conducted to examine the behavioural response of spayed heifers to oestrogen, and its modification by progesterone.
In two groups of heifers, the median effective doses (MED) of oestradiol benzoate (ODB) were 121 and 132 μg. Repeated doses of ODB at physiological levels did not induce a state of refractoriness; in this respect the heifer is dissimilar to the ewe. However, repeated doses of 10 mg. ODB induced refractoriness to 400 μg. ODB. When such refractory heifers were treated with 10 mg. progesterone/day for 5 days, they showed a normal response to 400 μg. ODB given 3 days later. This return to normal sensitivity was not sustained, and pretreatment with progesterone was necessary for a normal response to subsequent small doses of ODB. The transient removal of the refractory state appears not to be due to a simple synergistic effect of residual progesterone, but to an effect of preconditioning a neural centre to respond to oestrogen. Increasing the duration of pretreatment with progesterone beyond 5 days did not result in a greater sensitivity to ODB.
Pretreatment with progesterone in heifers not made refractory to ODB did not result in an increased sensitivity to ODB. Moreover, up to 7 days after termination of the progesterone treatment, the response to ODB was reduced and the slope of the dose-response line was less steep than when ODB was injected alone. The reduction of the response was more pronounced with 40 mg. progesterone/day than with 10 mg.
The possible significance of these results in intact animals is discussed.
THE INFLUENCE OF THE PITUITARY ON THE RESPONSE OF THE SEBACEOUS AND PREPUTIAL GLANDS OF THE RAT TO PROGESTERONE
Authors: EBLING F. J. , EBLING ERIKA , SKINNER J. 
Published: December 2008

SUMMARY
Progesterone, given as an implant releasing 0·1–0·2 mg./day for 24 days, failed to increase sebum production or preputial gland weight in castrated or hypophysectomized-castrated male rats. A dose of 10 mg./day in arachis oil also failed to increase sebum production or mitoses in the sebaceous glands, though it increased by 70% preputial gland weight in the presence of the pituitary.
Hypophysectomy greatly reduced preputial gland wt, and the response of hypophysectomized rats to 10mg. progesterone/day was much less than when the pituitary was present. A porcine growth hormone preparation, known to facilitate the response of the sebaceous gland to testosterone in the hypophysectomized rat, failed to facilitate the response of the preputial gland to progesterone.
It is concluded that 'sebum-permissive' activity (the facilitation of the response of the sebaceous gland to testosterone) may be distinct from ' sebotropic' activity (facilitation of the response of the preputial gland to progesterone), and it is argued that each of these activities may prove to be separable from somatotrophic activity.
EVALUATION OF HUMAN FOLLICLE-STIMULATING HORMONE PREPARATIONS
Authors: BARKER S. A. , GRAY C. J. , KENNEDY J. F. , BUTT W. R. 
Published: December 2008

SUMMARY
A procedure for the purification of human pituitary follicle-stimulating hormone (FSH) is outlined. Various methods of protein determination were applied to the preparation (CP 150), and the results obtained compared with those of amino acid analysis. The composition of CP 150 with respect to amino acid and carbohydrate components is reported, and is suggested as the most suitable basis for expression of biological activity and stability. CP 150 sedimented as a single boundary with S20,w = 2·8s. The composition of various reported FSH preparations including CP 150 are compared, and attention is drawn to some striking similarities.
THE INSULINOGENIC RESPONSE TO INTRAVENOUS GLUCOSE IN DOGS FED DIETS OF DIFFERENT PROTEIN VALUE
Authors: HEARD C. R. C. , HENRY PAMELA A. J. 
Published: December 2008

SUMMARY
Dogs were fed diets of high, suboptimal or low protein value (NDpCal% = 10, 7 or 5) from weaning at approximately 6 weeks of age. Immunoreactive plasma insulin levels were measured during intravenous glucose tolerance tests at 8, 13 and 20 weeks of age. In the dogs fed on diets of suboptimal or low protein value, the assimilation coefficient (K) increased within the first 2 weeks on diet, without any corresponding increase in insulin output. Later, as glucose tolerance tended to become impaired, the insulin output increased significantly. A significant increase in insulin response also occurred in dogs fed the high protein diet, at approximately 6 months of age, when the growth rate had slowed down. The increase in insulin response to i.v. glucose, observed in dogs fed the diets of low protein value, did not occur in animals which became marasmic through loss of appetite. Such animals had a very feeble insulin response. The findings are discussed in relation to human protein-calorie deficiency syndromes (kwashiorkor and marasmus).
EFFECT OF CYPROTERONE ACETATE ON SEXUAL DIMORPHISM OF THE EXORBITAL LACRIMAL GLAND IN RATS
Authors: HAHN J. D. 
Published: December 2008

SUMMARY
Adult male rats were treated with daily s.c. doses of 10 mg. cyproterone acetate for 3 weeks. Histological examination of the exorbital lacrimal glands at the end of treatment showed distinct differences compared with male controls: the histological picture showing greater resemblance to the glands of female controls. In orchidectomized rats receiving substitution treatment with testosterone propionate, cyproterone acetate 'neutralized' the effect of testosterone propionate on the exorbital lacrimal gland to a considerable extent. The possibility that this gland may play a part in the sexual behaviour of the rat is discussed.
PREMATURE DELIVERY OF FOETAL LAMBS INFUSED WITH GLUCOCORTICOIDS
Authors: LIGGINS G. C. 
Published: December 2008

SUMMARY
Dexamethasone caused premature delivery when infused into foetal lambs at rates of 0·06–4·0 mg./24 hr. but it had no effect when administered to pregnant ewes at the rate of 4·0 mg./24 hr. Infusions into the foetus of deoxycorticosterone or corticosterone were ineffective; mixtures of dexamethasone and deoxycorticosterone did not cause parturition more rapidly than dexamethasone alone. Thus, the ability of corticosteroids to cause premature parturition appears to depend on glucocorticoid rather than mineralocorticoid activity.
Parturition induced by dexamethasone was not delayed by administration of 100 mg. progesterone/24 hr. to the ewe or to the foetus. This suggests either that withdrawal of inhibitory effects of progesterone on the myometrium can occur independently of the progesterone concentration in peripheral plasma, or that the mechanism of parturition provoked by corticosteroids in the foetus can override any regulatory influence of progesterone on myometrial contractility.
Partial aeration of the lungs was observed in lambs born vaginally at 117–123 days of gestation after receiving dexamethasone. It is suggested that this may be the result of accelerated appearance of surfactant activity.
INTERACTION BETWEEN PROLACTIN AND THYROXINE IN MOUSE MAMMARY GLAND LOBULO-ALVEOLAR DEVELOPMENT IN VITRO
Authors: SINGH D. V. , BERN H. A. 
Published: December 2008

SUMMARY
Intact female BALB/cCrgl mice, 3–4 weeks old, were pretreated with oestrogen and progesterone for 9 days. Whole mammary glands from these mice were cultivated for 5 days in a synthetic medium supplemented with aldosterone (A), prolactin (MH) and insulin (I), with and without thyroxine (T4) at concentrations ranging from 0·01 to 5 μg./ml.
A medium containing 1 μg. A +5 μg.MH +5 μg.I/ml. was generally optimal for lobulo-alveolar development. Addition of thyroxine to this combination resulted in a decrease in development which was highly significant at higher concentrations. However, when cultures were maintained in media containing suboptimal or low amounts of prolactin (1 μg. A + 3 μg. MH +5 μg. I/ml. and 1 μg. A + 1 μg. MH +5 μg. I/ml., respectively), the results indicate two possible effects of thyroxine: lower amounts of thyroxine had synergistic effects, whereas greater amounts had antagonistic effects on lobulo-alveolar development.
EFFECT OF HYPOTHALAMIC DEAFFERENTATION ON THE CONTROL OF LUTEINIZING HORMONE SECRETION
Authors: TALEISNIK S. , VELASCO M. E. , ASTRADA J. J. 
Published: December 2008

SUMMARY
The influence that the interruption of the neural afferents to the hypothalamus exerts on ovulation and on the release of luteinizing hormone (LH) was studied in the rat. Animals with retrochiasmatic sections interrupting the neural connexions between the medial hypothalamus and the preoptic area (POA) showed constant oestrus and failed to ovulate. Animals in which the dorsal neural afferents to the POA were transected had oestrous cycles and ovulated normally. The positive feedback effect of progesterone on LH release in spayed animals primed either with 20 μg. oestradiol benzoate or 2·5 mg. testosterone propionate 3 days before was studied. Transection of the dorsal afferents to the POA favoured an increase in plasma LH, but in animals with retrochiasmatic sections the response was abolished. However, the negative feedback effect of ovarian steroids operated after both types of transection because an increase in plasma LH occurred after ovariectomy. It is concluded that the negative feedback effect of ovarian steroids acts on the medial hypothalamus which can maintain a tonic release of gonadotrophins in the absence of steroids. In contrast, the POA involved in the positive feedback effect of progesterone is concerned with the phasic release of LH.
THE GLYCOGEN CONTENT OF THE EARLY PREGNANT FEMALE HAMSTER GENITAL TRACT, THE FERTILE CONCEPTUS AND ARTIFICIALLY-INDUCED DECIDUOMATA
Authors: GREGOIRE A. T. , RICHARDSON D. W. 
Published: December 2008

SUMMARY
The quantitative changes in glycogen content of the hamster uterus, cervix, upper and lower vagina during the first 8 days of pregnancy were measured. The amount of glycogen in the conceptual sites on days 6, 7 and 8 was determined and compared with that of artificially induced deciduomata. The greatest concentration of glycogen was demonstrated in the tissue of the upper portion of the vagina. While no significant differences were found in the uterus, cervix and lower vagina during the time-interval investigated, significant increases in glycogen in upper vaginal tissue occurred on the 6th, 7th and 8th day of pregnancy.
Uterine glycogen during the first 5 days, or the interdecidual sites on days 6, 7 and 8, did not differ significantly in their glycogen content. On day 6, when the conceptual site becomes discernible, the glycogen values were increased by 370% over the uterine levels of day 5 followed by a 28- and 31-fold increase on days 7 and 8.
The glycogen content of deciduomata induced non-mechanically (saline, oil, air) or by trauma (scratching) did not differ significantly from that of the conceptual sites of normal pregnancy.
These findings demonstrate that on day 6 a glycogenic stimulus is evoked which results in local stimulation of glycogen production in the decidual sites and the upper vagina. Induction of deciduomata by different procedures results in quantitatively similar amounts of the polysaccharide. The glycogenic factor, therefore (a) stimulates localized glycogen synthesis and (b) can be evoked by either natural or artificial means.
EFFECT OF HUMAN CHORIONIC GONADOTROPHIN ON THE UTERUS AND OVARIES OF HYPOPHYSECTOMIZED RATS
Authors: STOLZENBERG S. J. , WILBUR R. D. 
Published: December 2008

SUMMARY
In hypophysectomized rats, with and without pituitary autografts, human chorionic gonadotrophin (HCG) induced an increase in ovarian and uterine weights on the day after a number of injections. In hypophysectomized rats, ovarian and uterine weights remained higher than those of controls 35 days after the final HCG injection but this difference was statistically significant for uterine weight only. In rats with pituitary autografts, both ovarian and uterine weights were below control values 35 days after the final injection. HCG treatment stimulated an increase in size of corpora lutea and proliferation of interstitial cells, but no apparent follicle development in hypophysectomized rats. All three ovarian structures were stimulated by similar treatment of rats with pituitary autografts. Continuous daily injections of HCG for 4–48 days in rats with pituitary autografts resulted in progressive increases in ovarian and uterine weights reaching a maximum at 12 days. Large antral follicles, in addition to large corpora lutea and proliferated interstitial cells, were observed at 12 days. At 24 and 48 days, ovarian but not uterine weights were significantly below control values. All ovarian structures were in a state of degeneration, which was most pronounced at 48 days. The lowest effective HCG dose that induced the vaginal cornification and an increase in uterine weight in hypophysectomized rats was 1 i.u. This dose caused slight but nonsignificant increases in ovarian and uterine weights in rats with pituitary autografts. However, sharp decreases in ovarian and uterine weights and a degeneration of ovarian structures resulted 35 days after treatment.
THE MECHANISM OF ACTION OF PARATHYROID HORMONE: LACK OF EVIDENCE FOR THE MEDIATION BY CYCLIC ADENOSINE 3′, 5′-MONOPHOSPHATE OF PARATHYROID HORMONE-STIMULATED PHOSPHATURIA
Authors: SALLIS J. D. 
Published: December 2008

SUMMARY
The excretion of phosphate in the rat after renal infusion of parathyroid hormone or cyclic adenosine 3,′5′-monophosphate (AMP) is described. The hormone stimulated an immediate phosphaturia, but no such response was measurable in the presence of cyclic AMP. Adenyl cyclase activity in kidney cortex was assessed by measuring the conversion of [14C]adenosine 5′-triphosphate to [14C]cyclic AMP. Previous infusion of kidneys with parathyroid hormone did not alter adenyl cyclase activity but the addition of the hormone to kidney tissue in vitro caused a significant increase in the activity of this enzyme. It is suggested that the parathyroid hormone-stimulated phosphaturia is not mediated by cyclic AMP.
SYNTHESIS OF CORTICOSTEROIDS BY THE INTERRENAL GLAND OF SELACHIAN ELASMOBRANCH FISH
Authors: SIMPSON T. H. , WRIGHT R. S. 
Published: December 2008

SUMMARY
The capacity of the interrenal tissue of the elasmobranch fish Squalus acanthias L., Scyliorhinus canicula L. and Galeus melastomus Rafinesque to synthesize corticosteroids in vitro has been examined and found to be augmented by the presence of NADPH or its generating system.
Homogenates of cold-stored interrenal tissue from all three species converted [4-14C]pregnenolone to labelled progesterone, corticosterone and 11-deoxycorticosterone. Homogenates from freshly killed S. canicula formed, additionally, 1α-hydroxycorticosterone. No indication of the synthesis of aldosterone, of 17α-hydroxycorticosteroids or of C19 steroids was obtained.
INFLUENCE OF PROLACTIN AND PITUITARY ISOGRAFTS ON SPERMATOGENESIS IN DWARF MICE AND HYPOPHYSECTOMIZED RATS
Authors: BARTKE A. , LLOYD C. W. 
Published: December 2008

SUMMARY
This work was undertaken to study the influence of purified prolactin on spermatogenesis in hypophysectomized rats with or without testosterone propionate maintenance therapy and in prolactin-deficient hereditary dwarf mice. In addition some dwarf mice were given heterotopic isografts of non-dwarf mice pituitaries. In rats, 25 i.u. ovine prolactin given daily for 33 days had no effect on the maintenance of spermatogenesis. In untreated dwarf mice spermatogenesis progressed to completion but had a low yield due to cell loss, especially during premeiotic divisions. Both 10 i.u. prolactin daily for 28 days and pituitary grafts resulted in marked stimulation of spermatogenesis. The number of preleptotene and pachytene spermatocytes and step 7 spermatids was significantly increased in both inbred and F1 dwarf mice regardless of age. Since seminal vesicles were also considerably heavier in treated dwarfs, it was concluded that the observed stimulation of spermatogenesis was most likely due to elevated testicular androgen production indicating that, in the male mouse, prolactin may be involved in pituitary regulation of Leydig cell function.
THYROXINE UTILIZATION IN LAMBS IN NATURAL AND CONTROLLED ENVIRONMENTS
Authors: FALCONER I. R. , MARCHANT B. 
Published: December 2008

SUMMARY
The rate of thyroxine utilization has been measured from the rate of degradation of [125I]thyroxine and the concentration of plasma proteinbound iodine in ewe lambs. Repeated measurements were made between 10 and 60 weeks of age in two groups of lambs, one in conditions including temporarily inadequate nutrition and outdoor ambient temperatures, and the other in a controlled environment with free access to food.
The lambs in the controlled environment showed an increase in thyroxine utilization with increasing age throughout the experiment, whereas the 'outdoor lambs' showed a decrease in hormone utilization until after 34 weeks of age. The 'outdoor lambs' also lost bodyweight between the 20th and 26th week of age due to the poor quality of the pasture, and this undernutrition is considered to have caused the lowered rate of thyroxine utilization. After 26 weeks of age the nutrition of these lambs was adequate but thyroxine utilization did not increase until after 34 weeks of age, when the mean environmental temperature was about 5°. It was concluded that undernutrition caused a marked depression in thyroxine utilization of young lambs.
EFFECTS OF CYPROTERONE ACETATE ON AGGRESSIVE BEHAVIOUR AND THE SEMINAL VESICLES OF MALE MICE
Authors: EDWARDS D. A. 
Published: December 2008

SUMMARY
Cyproterone acetate exerted strong anti-androgenic effects on the seminal vesicles of mice, but failed to affect androgen-dependent aggressive behaviour in mice. Groups of adult castrated male mice were treated with (1) testosterone propionate (TP); (2) TP plus cyproterone acetate; or (3) neither TP nor cyproterone acetate, for 5 weeks and given weekly tests for aggressive behaviour. The seminal vesicles were removed after the last test for aggression. Although treatment of mice with cyproterone acetate in combination with TP almost totally suppressed the stimulatory effect of TP on seminal vesicle weight, aggressive behaviour was not affected by cyproterone acetate. It was concluded that cyproterone acetate probably does not influence central nervous tissue and non-neural tissue in the same manner.
ANTIGENIC STRUCTURE OF HUMAN GONADOTROPHINS: PITUITARY LUTEINIZING HORMONE
Authors: MORI K. F. 
Published: December 2008

SUMMARY
Immunological relationship between human pituitary luteinizing hormone (LH) and human chorionic gonadotrophin (HCG) was measured by microcomplement fixation, and a value of 1·17 was obtained for the immunological index of dissimilarity determined from the reactions of a highly purified human LH with rabbit antiserum to HCG. Treatment with neuraminidase of the LH preparation did not affect either the biological activity, as measured by ovarian ascorbic acid depletion, or the complement-fixing activity. The biological and immunological activities of LH were also not influenced by treatment with β-glucosidase or with neuraminidase plus β-glucosidase. Partial tryptic hydrolysis of LH caused decreases in both the biological and immunological activities, the greater loss being in the former. The biological and immunological activities of LH were nearly completely destroyed by treatment with urea, and removal of urea by dialysis did not restore the two activities. When the LH preparation was exposed to increased temperatures for various periods of time or to extremes of pH, the two activities were affected to variable degrees. These results indicate that the protein but not the carbohydrate moiety of the LH molecule is essential for both biological and immunological activities of the hormone and that the conformational integrity of certain parts of the protein moiety is also important for these activities.
PLASMA GROWTH HORMONE CONCENTRATIONS IN SHEEP MEASURED BY RADIOIMMUNOASSAY
Authors: WALLACE A. L. C. , BASSETT J. M. 
Published: December 2008

SUMMARY
Plasma growth hormone (GH) concentrations in adult sheep and lambs were measured by radioimmunoassay. Mean values before feeding were 3·1 (s.e. − 0·4, + 0·5) ng./ml. in lactating ewes and 3·9 (− 0·5, + 0·7) ng./ml. in their lambs. In adult wethers the mean GH concentration before feeding was 2·3 (−0·2, + 0·3) ng./ml.
After one i.v. injection of 400 μg. ovine GH, the hormone disappeared from the plasma of adult sheep with a half-time of 7–8 min. Plasma GH concentrations decreased at a similar rate after the establishment of high concentrations of endogenously secreted GH. The results suggest a shorter half-life than has been reported for human GH in man. GH could not be recovered in an immunologically recognizable form in urine. Fasting for 4 days led to no systematic change in plasma GH concentrations. Feeding did not increase plasma GH. Intravenous injection of saline resulted in some increase in plasma GH in both ewes and lambs. In adult sheep intravenous glucose (0·25 g./kg.) did not cause any greater change than that seen after saline, but in lambs an increase occurred. Intravenous injection of insulin (0·25 unit/kg.) resulted in an increase in plasma GH at 15–30 min. and this effect was found in both lambs and ewes. Infusion of adrenaline at either 25 μg. or 50 μg./min. into adult wethers (average body wt 51 kg.) caused a decrease in plasma GH concentration. It was concluded that the changes in plasma GH concentration of sheep in a number of physiological situations differ from those reported to occur in man.