bluuebunny/crossref_metadata_2025 huggingface dataset:
CONTROL OF GLYCOLYTIC ENZYMES BY ANDROGENS IN THE RAT EPIDIDYMIS
Authors: BROOKS D. E.
Published: December 2008

The influence of steroids on the specific activities of glycolytic enzymes was studied in the caput and cauda epididymidis of the rat. In castrated animals, increases in enzyme activities were induced by the administration of androgenic steroids whilst oestradiol and progesterone were without effect. On the other hand, the 'antiandrogenic' steroid, cyproterone acetate (16 mg/kg per day for 2 weeks) did not cause a decrease in enzyme activities when administered to animals with ligated efferent ducts. Not all glycolytic enzymes responded to androgens, but more enzymes responded in the caput than in the cauda epididymidis. Administration of testosterone propionate to castrated animals demonstrated that maximum enzyme activity was produced at a dose of 0·1 mg/kg per day whilst higher doses were required to achieve maximum weight of the epididymis, seminal vesicles and prostate. Following castration of animals with ligated efferent ducts, no changes in enzyme activities were observed for approximately 2 days, but then activities declined over the next 2 weeks. When testosterone propionate was administered to castrated animals, a similar lag of approximately 2 days occurred before enzyme activities began to increase.
CHANGES IN UTERINE AND OVARIAN BLOOD FLOW DURING THE OESTROUS CYCLE IN RATS
Authors: HARVEY CAROL A. , OWEN D. A. A.
Published: December 2008

The rates of uterine and ovarian blood flow during the oestrous cycle in rats were measured using radioactive microspheres. Blood flow was highest in the ovaries and uteri during pro-oestrus and lowest during metoestrus. During pro-oestrus, mean ovarian blood flow was 676·2 ± 183·6 (s.d.) ml/min/100 g wet tissue and mean uterine blood flow was 249·7 ± 120·1 ml/min/100 g. During metoestrus mean ovarian blood flow was 117·4 ± 19·8 ml/ min/100 g and mean uterine blood flow was 38·5 ± 7·4 ml/min/100 g. In ovariectomized rats, uterine blood flow was 28·7 ± 10·5 ml/min/100 g.
STUDIES ON OVINE PLACENTAL LACTOGEN SECRETION BY HOMOLOGOUS RADIOIMMUNOASSAY
Authors: HANDWERGER S. , CRENSHAW C. , MAURER W. F. , BARRETT JANET , HURLEY T. W. , GOLANDER A. , FELLOWS R. E.
Published: December 2008

The concentrations of ovine placental lactogen (oPL) have been determined in maternal plasma, umbilical cord plasma, and allantoic fluid by an homologous radioimmunoassay for oPL which is sensitive to 0·1 ng hormone. Ovine placental lactogen was first detected in maternal plasma at 41–50 days of gestation and reached a peak concentration of 2547 ± 226 (s.e.m.) ng/ml at 121–130 days in ewes with singleton gestations. The oPL concentration in cord plasma was 336·4 ± 60·3 ng/ml and in allantoic fluid was 29·6 ± 6·4 ng/ml. After surgical removal of the placenta, oPL disappeared from maternal plasma with a half-life of 29·1 ± 1·3 min.
ADRENOCORTICAL FUNCTION IN A PROTOTHERIAN MAMMAL, TACHYGLOSSUS ACULEATUS (SHAW)
Authors: SERNIA C. , McDONALD I. R.
Published: December 2008

The peripheral plasma concentrations and production rates of corticosterone and cortisol were measured in the conscious, unrestrained echidna (Tachyglossus aculeatus) under basal conditions and during maximal ACTH stimulation.

Using Sephadex LH-20 column chromatography and radioligand assay, only cortisol and corticosterone could be detected in the peripheral blood plasma at very low concentrations of 0·07 ± 0·03 (s.e.m.) μg/100 ml and 0·14 ± 0·07 μg/100 ml respectively. Two-hourly sampling over periods of 36–48 h disclosed a diurnal periodicity in the combined plasma concentration of these corticosteroids, the high concentrations corresponding to periods of behavioural activity. Marked, short-term fluctuations in plasma corticosteroid concentration were also observed during periods of more frequent (20 min) sampling. Constant rate i.v. infusion of synthetic ACTH increased the plasma concentrations of both steroids to maximal values of 0·42 ± 0·23 μg cortisol/100 ml and 1·06 ± 0·56 μg corticosterone/100 ml at infusion rates of 1 i.u. ACTH/kg/h. This is approximately 1/160 of the potency of this ACTH in man.

The production rates of corticosterone and cortisol, measured by isotope dilution during constant rate i.v. infusion of 3H-labelled tracers, were only 0·35 ± 0·21 and 0·56 ± 0·26 μg/kg/h respectively during saline infusion, and increased to 2·86 ± 3·47 and 2·74 ± 2·07 μg/kg/h during the infusion of 1 i.u. ACTH/kg/h. The metabolic clearance rate of cortisol was greater than that of corticosterone and both were depressed by ACTH.

Plasma corticosteroid concentrations were increased after surgery during ether anaesthesia and in sick animals with heavy worm infestation. It is concluded that the adrenal cortex of echidnas responds to ACTH stimulation and stress in a similar way to eutherians, but the level of activity is much lower.
TEMPORAL RELATIONSHIPS BETWEEN THE DIURNAL RHYTHM OF HYPOTHALAMIC CORTICOTROPHIN RELEASING FACTOR, PITUITARY CORTICOTROPHIN AND PLASMA CORTICOSTERONE IN THE RAT
Authors: IXART GUY , SZAFARCZYK ALAIN , BELUGOU JEAN-LUC , ASSENMACHER IVAN
Published: December 2008

Plasma corticosterone (fluorometric assay), pituitary ACTH (bioassay using isolated adrenal cells) and hypothalamic corticotrophin releasing factor (CRF) (bioassay using isolated pituitary cells) were measured singly in groups of six female rats which were killed at 11.00, 15.00, 19.00, 21.00, 23.00, 01.00, 03.00, 05.00, 07.00 and 11.00 h, after 5 weeks of adaptation to a photoperiod of 12 h light:12 h darkness. Locomotor activity was recorded continuously, using actographic cages, and the waking/sleep pattern was recorded by electroencephalography from chronically implanted control rats during the first hours of the light span.

The three hormones measured fluctuated with a 24 h rhythmicity, with extreme values ranging between 4·12 ± 1·42 and 31·78 ± 194 (s.e.m.) μg/100 ml for corticosterone, 4486 ± 269 and 16629 ± 882μu./mg pituitary for ACTH, and 439 ± 20 and 1270 ± 39μu. ACTH production/hypothalamus/105 pituitary cells.

The onset of the ascending phase of the rhythm started during the first 2 h of light for CRF, 2 h later for ACTH, and again 2 h later for corticosterone. Similarly, the estimated acrophase of the rhythms occurred respectively, 9·4 (CRF), 10·3 (ACTH) and 14·4 h (corticosterone) after onset of light. These phase relationships point to a central origin of the adrenal rhythm.

The diurnal activation of CRF at the very beginning of the light phase was concomitant with an almost immediate reduction of the locomotor activity and onset of sleep. These correlations favour the hypothesis of a common temporal control of both the adrenal and the sleep/waking rhythms.
HYPOTHALAMIC LUTEINIZING HORMONE RELEASING FACTOR AND CORTICOTROPHIN RELEASING ACTIVITY IN RELATION TO PITUITARY AND PLASMA HORMONE LEVELS IN MALE AND FEMALE RATS
Authors: CHIAPPA SHARON A. , FINK G.
Published: December 2008

Hypothalamic corticotrophin releasing (CR) activity and LH-releasing factor (RF) content, and pituitary and plasma LH, FSH and ACTH were measured in adult male and female Wistar rats maintained under 14 h light per day. Hypothalamic LH-RF and pituitary and plasma hormones were estimated by radioimmunoassay while CR-activity was assessed by the amount of ACTH released from hemipituitaries in vitro. Two experiments were carried out on male animals. In the first, some of the animals were kept in a room, distant from the animal house, in which the lighting was reversed with respect to the external environment. In animals exposed to the reversed lighting régime, hypothalamic LH-RF content and pituitary gonadotrophin concentrations were significantly lower than the values in male rats kept in the animal house where they were in close proximity to female rats. In the second experiment, which was carried out on animals which had all been kept in the animal house, there were no significant differences between the LH-RF contents measured at 3–4 h intervals throughout the day. Pituitary LH and FSH contents, but not concentrations, were significantly increased at 12.00 h. There was little difference between the experiments in CR-activity, plasma ACTH concentrations and profiles of pituitary ACTH content and concentration. As expected there was a diurnal rhythm in plasma corticosterone concentrations (determined by competitive protein-binding assay) with the peak occurring between 15.00 and 18.00 h. The profiles of plasma and pituitary ACTH were similar to that of plasma corticosterone. Corticotrophin releasing activity dropped significantly between 12.00 and 16.00 h, but remained steady at the other times.
CHANGES IN THE CONCENTRATION OF ADRENOCORTICOTROPHIN AND CORTICOSTEROID IN THE PLASMA OF FOETAL SHEEP IN THE LATTER HALF OF PREGNANCY AND DURING LABOUR
Authors: JONES C. T. , BODDY K. , ROBINSON J. S.
Published: December 2008

The changes in plasma ACTH concentration of pregnant sheep and their foetuses during the latter half of pregnancy and during labour were studied. Before 140 days of gestation the mean concentration in foetal arterial plasma was 117 ± 19 (s.e.m.) pg/ml which rose to a mean of 286 ± 63 pg/ml. The rise in ACTH occurred at about the same time as, but not before, the rise in corticosteroid concentration in foetal plasma. The maternal plasma ACTH concentration did not change during the latter half of pregnancy and had a mean concentration of 64 ± 9 pg/ml. During labour there was a progressive rise in the ACTH concentration in foetal plasma which was not associated with any corticosteroid changes. Ethanol did not suppress labour but reduced the ACTH concentration in foetal plasma.
INFLUENCE OF OXYGEN TENSION ON SOMATOMEDIN ACTIVITY IN VITRO
Authors: DEHNEL JENNIFER M. , HAMBLEN D. L.
Published: December 2008

Somatomedins are the intermediaries through which growth hormone acts on the epiphyseal growth plate to effect linear skeletal growth.

Rat epiphyseal chondrocytes were isolated and cultured in vitro in the presence of somatomedin. Two sources of somatomedin were used, foetal calf serum and rat liver perfusates. The chondrocytes proliferated and synthesized sulphated glycosaminoglycans when grown in the presence of somatomedin from either source, but were not metabolically active in chemically defined medium alone. Some differences in the growth patterns in response to serum or liver somatomedins are reported and discussed.

Chondrocyte metabolic activity in the presence of somatomedin in vitro showed a graded response to alterations in the atmospheric oxygen, being greatest at low oxygen pressure, and almost completely inhibited at 95% oxygen. A gradient of local oxygen tension has been reported to exist across the epiphyseal plate in vivo. The effects of somatomedin combined with changing oxygen levels may help to explain the divergence of cell proliferation and matrix synthesis seen in the various regions of the growth plate.
PLASMA LEVELS OF HUMAN CHORIONIC SOMATOMAMMOTROPHIN, PROGESTERONE, UNCONJUGATED OESTRADIOL AND OESTRIOL, AND α-FOETOPROTEIN IN PATIENTS WITH HYDATIDIFORM MOLES
Authors: MIYAKAWA I. , YAGI K. , NAKAYAMA M. , MATSUO I. , MAEYAMA M.
Published: December 2008

Human chorionic somatomammotrophin (HCS), progesterone, and unconjugated oestradiol and oestriol were measured in the plasma of 13 patients with intact hydatidiform moles from week 9 to 19 of pregnancy and in 89 normal women from week 5 to 20 of pregnancy. Plasma α-foetoprotein (AFP) was also measured in 9 out of 13 patients and in 23 of the normal women from week 13 to 20 of pregnancy. All the compounds were measured by radioimmunoassay. The plasma HCS concentration in 35 samples from 13 patients with hydatidiform moles ranged from 10 to 910 ng/ml; this was lower than that in normal pregnancy of corresponding duration in eight patients, within the normal range in four patients and high in one patient. The plasma progesterone concentration ranged from 17·5 to 79·2 ng/ ml: it was higher than that in normal pregnancy in eight patients and within the normal range in five patients. The plasma unconjugated oestradiol concentration ranged from 1·82 to 8·10 ng/ml: it was higher than normal in six patients and within the normal range in seven patients. The plasma unconjugated oestriol concentration ranged from 0·168 to 1·37 ng/ml, the levels at 15–19 weeks of gestation being significantly lower than those in normal pregnancy at this time (P < 0·005). Plasma AFP was not detectable in the nine patients (< 10 ng/ml) whereas it ranged from 10 to 80 ng/ml in 18 out of 23 women in week 13–20 of normal pregnancy. The present results suggest that both plasma oestriol and AFP could be helpful in the diagnosis of hydatidiform mole at about 12–14 weeks though diagnosis could not be made with absolute certainty.
SIMULTANEOUS INFUSION OF PROSTAGLANDIN E2 ANTAGONIZES THE LUTEOLYTIC ACTION OF PROSTAGLANDIN F2α IN VIVO
Authors: HENDERSON K. M. , SCARAMUZZI R. J. , BAIRD D. T.
Published: December 2008

Corpora lutea of ewes bearing ovarian autotransplants were infused for 4 h with prostaglandin F2α (PGF2α) (10 μg/h), PGF2α + PGE2 (10 μg/h of each), PGE2 (10 μg/h) or saline on day 10 of the cycle. Ovarian venous blood obtained before, during, and up to 12 h after the infusion period, was assayed for progesterone. Prostaglandin F2α produced an immediate, rapid and sustained decline in progesterone secretion, but infusion of PGE2 together with PGF2α prevented the decline until after the infusion. Progesterone secretion was unaffected by infusion of PGE2 alone. Oestrous behaviour was observed in four out of seven animals infused with PGF2α but in only one out of six infused with PGF2α + PGE2. None of the animals infused with PGE2 alone or saline only came into heat.
EFFECT OF SEX AND AGE AT GONADECTOMY ON THE SEBACEOUS RESPONSE TO PROGESTERONE
Authors: SHUSTER SAM , HINKS WENDY M. , THODY A. J.
Published: December 2008

The effect of progesterone on the rate of sebum secretion was examined in intact and gonadectomized rats. In intact, adult, male rats, progesterone administered for 3 weeks decreased sebum secretion; after castration of adult males, progesterone increased sebum secretion and an even greater response occurred in males castrated at 21 days of age. In intact, adult, female rats progesterone slightly increased sebum production. As in the male, the response was affected by the time of gonadectomy, a greater response occurring after spaying at 21 days compared with 10 weeks of age. Thus, the response to progesterone in the adult rat differs in intact males and females and is affected by changes in the endocrine environment induced by gonadectomy, especially near the time of puberty.
DIFFERENCES BETWEEN IN-VITRO AND IN-VIVO POTENCIES OF CORTICOTROPHINS: AN INTERPRETATION IN TERMS OF METABOLIC STABILITY
Authors: McMARTIN COLIN , PURDON GILLIAN E. E. , SCHENKEL LOTTE , DESAULLES PIERRE-A. , MAIER RENÉ , BRUGGER MAX , RITTEL WERNER , SIEBER PETER
Published: December 2008

Relative activities of a series of corticotrophin analogues have been measured by means of five different bioassays using the rat.

Similarities in the relative potencies of various ACTH analogues determined using lipolysis or steroidogenesis in vivo and for the lipolytic and steroidogenic responses of fat pads and adrenal slices in vitro emerged and support the concept of a close structural relationship between the ACTH receptors in adipose and adrenal tissues in the rat.

Potencies based on the steroidogenic response of isolated adrenal cells, adrenal slices or in-vivo experiments differed markedly from each other. Inactivation of peptides did not occur in the isolated cell assay, so it is likely that this assay estimates potency at the receptor level. A number of arguments suggest that the difference between the isolated cell assay and the other steroidogenic assays lies solely in the effects of peptide inactivation in the latter, and this allows the relative metabolic stabilities for the peptide analogues in these assays to be calculated. In this way it can be shown that:

(1) Replacement of l-Ser by d-Ser in amino acid position 1 markedly increases the metabolic stability of the peptide and has only a slight effect on receptor properties.

(2) Shortening at the NH2-terminus reduces the activity of peptides at the receptor level by several orders of magnitude, but increases their relative metabolic stability.

(3) Introduction of amide groups at the CO2H-terminus markedly increases receptor potency of (1–16), (1–17) and (1–18) ACTH without affecting their metabolic stability in vivo. However, amidation of the CO2H-terminus does have a large effect on metabolic stability in the adrenal slice assay.

(4) Replacement of Arg by Lys in positions 17 and 18 of (1–18) ACTH increases potency at the receptor level (adrenal cells) but has little effect on metabolic stability.

The comparison of potencies obtained in the various assays, therefore, throws light on the significance of each assay. In addition, the effects of structural modification of analogues can be separately evaluated with respect to the metabolic stability of a peptide and its potency at the receptor level.
CIRCADIAN RHYTHM OF PINEAL UPTAKE OF 32P IN DOMESTIC FOWL
Authors: SACKMAN J. W.
Published: December 2008

The uptake of radioactive phosphorus by the pineal gland in White Leghorn cockerels (Gallus domesticus) showed a diurnal variation with maxima in the light phase and minima in the dark phase of the light:dark cycle. Constant light caused the rhythm to disappear while constant dark had no effect other than lowering the amplitude of the variations. These data indicate that the rhythm in pineal uptake of 32P is circadian.
CONCENTRATION OF PROSTAGLANDIN F2α AND STEROIDS IN THE HUMAN CORPUS LUTEUM
Authors: SWANSTON I. A. , McNATTY K. P. , BAIRD D. T.
Published: December 2008

The concentration of prostaglandin F2α (PGF2α), progesterone, pregnenolone, oestradiol-17β, oestrone, androstenedione and testosterone was measured in corpora lutea obtained from 40 women at various stages of the menstrual cycle. The concentration of PGF2α was significantly higher in corpora lutea immediately after ovulation (26·7 ± 3·9 (s.e.m.) ng/g, P < 0·005) and in corpora albicantia (16·3 ± 3·3 ng/g, P < 0·005) than at any other time during the luteal phase. There was no correlation between the concentration of PGF2α and that of any steroid. The progesterone concentration was highest in corpora lutea just after ovulation (24·9 ± 6·7 μg/g) and in early luteal groups (25·7 ± 6·8 μg/g) but declined significantly (P < 0·05) to its lowest level in corpora albicantia (1·82 ± 0·66 μg/g). The concentration of oestradiol-17β in the corpus luteum and luteal weight were significantly greater during the mid-luteal phase than at any other stage (concentration 282 ± 43 ng/g, P < 0·05; weight 1·86 ± 0·18 g, P < 0·005).

The results indicate that regression of the human corpus luteum is not caused by a rise in the ovarian concentration of PGF2α in the late luteal phase of the cycle.
SITE OF MODULATORY ACTION OF OESTROGEN AND PROGESTERONE ON GONADOTROPHIN RESPONSE TO LUTEINIZING HORMONE RELEASING FACTOR
Authors: FINK G. , HENDERSON S. R.
Published: December 2008

The effect of oestrogen and progesterone on the spontaneous release of gonadotrophins and on the gonadotrophin response to luteinizing hormone releasing factor has been examined in female rats subjected to hypothalamic deafferentation or pituitary stalk section. The results indicate that both steroids act at the level of the medial basal hypothalamus as well as the anterior pituitary gland; progesterone, for its full effect, also requires the integrity of connexions of the hypothalamus with other areas of the brain.
IMMATURE RAT PITUITARY GLANDS IN VITRO: AGE- AND SEX-RELATED CHANGES IN LUTEINIZING HORMONE RELEASING HORMONE-STIMULATED GONADOTROPHIN RELEASE
Authors: DULLAART J.
Published: December 2008

Pituitary glands from immature female and male rats aged between 5 and 30 days were incubated in vitro and the effect of LH releasing hormone (RH) on the release of LH and FSH was studied. Pituitary gonadotrophin contents were also measured.

Gonadotrophin release showed changes with age as well as sex differences: after LH-RH stimulation the female pattern of release of LH and FSH (expressed per mg pituitary tissue) showed a peak at day 15; the male pattern of LH release was characterized by a steady increase with age, whereas FSH release stayed more or less constant from day 10 onwards. In both sexes the LH:FSH ratio increased with age, both in pituitary gonadotrophin content and in the mixture of gonadotrophins released. It is discussed, that the prepubertal development of pituitary gonadotrophic function might be determined on the one hand by rather autonomous growth processes (more or less similar in female and male hypophyses) and on the other hand by modulating influences of sex steroid hormones, which are different in female and male animals.
RAT FOETAL ENDOCRINE PANCREAS IN EXPERIMENTAL DIABETES
Authors: AERTS L. , VAN ASSCHE F. A.
Published: December 2008

The endocrine pancreas of foetuses and newborn rats of experimental diabetic mothers showed morphological and ultrastructural changes. Islet hypertrophy and β cell hyperplasia were constantly present, but the β cells of foetuses of severely diabetic mothers were degranulated. The ultrastructural changes indicated hyperfunction in the β cells of foetuses of experimental diabetic mothers. The morphological changes mentioned were similar to those seen in human diabetic pregnancy.
STEROIDS IN THE AMNIOTIC FLUID OF THE RHESUS MONKEY (MACACA MULATTA)
Authors: CHALLIS J. R. G. , HARTLEY PHILLIDA , JOHNSON P. , PATRICK J. E. , ROBINSON J. S. , THORBURN G. D.
Published: December 2008

Representative C21, C19 and C18 steroids have been measured in the amniotic fluid and maternal femoral plasma of rhesus monkeys during the last 50 days of pregnancy. The concentrations of cortisol, progesterone, androstenedione, oestrone and oestrone sulphate all increased in amniotic fluid before spontaneous parturition. In contrast, amniotic fluid oestradiol levels remained low and unchanged, and were always less than the concentrations in the maternal plasma. The changes in progesterone, cortisol and oestrone concentrations in amniotic fluid occurred independently of significant changes in the concentration of these steroids in the maternal plasma.

Betamethasone administered to monkeys after day 150 of pregnancy suppressed amniotic fluid and maternal plasma cortisol. This treatment markedly suppressed the concentration of progesterone in amniotic fluid, but did not alter its concentration in maternal plasma. It is concluded that during late pregnancy in the rhesus monkey there is an increase in the concentration of some steroids in amniotic fluid independent of alterations in their concentrations in maternal plasma. These changes could reflect an increase in foetal adrenal steroid secretion.
BIOLOGICAL ACTIONS OF HUMAN SOMATOTROPHIN AND ITS DERIVATIVES ON MOUSE MAMMARY GLAND AND TELEOST URINARY BLADDER
Authors: DONEEN B. A. , BERN H. A. , HAO LI CHOH
Published: December 2008

These studies are concerned with the structural and functional evolution of the ancestrally related pituitary prolactins and somatotrophins. Prolactin-like biological activities of human somatotrophin (hGH) and its peptide fragments were bioassayed in vitro on the mouse mammary gland and the teleost urinary bladder. Plasmin modified-hGH was as active as hGH in both bioassays. The NH2-terminal 134-residue fragment possessed about 10% of the lactogenic and urinary bladder potency of hGH, whereas the CO2H-terminal 51-residue fragment was inactive at the concentrations observed. These results suggest that the same regions of primary structure are responsible for the prolactin-like actions of hGH on the target organs of lower and higher vertebrates. Alteration of the tertiary structure of hGH, human chorionic somatomammotrophin, and ovine prolactin by performic acid oxidation destroys the mammary gland activities of these hormones.
TEMPORAL CHANGES IN OVARIAN ORNITHINE DECARBOXYLASE AND CYCLIC AMP IN IMMATURE RATS STIMULATED BY EXOGENOUS OR ENDOGENOUS GONADOTROPHINS
Authors: JOHNSON D. C. , SASHIDA TATSURO
Published: December 2008

Pregnant mare serum gonadotrophin given intravenously to immature rats caused a maximal (×70) increase in ornithine decarboxylase activity (ODC) at 3 h; enzyme activity declined to about ten times the control level by 9 h and a second rise began after about 20 h. Anti-PMSG given 30 min after PMSG reduced the peak response by 70%. Actinomycin D, or cycloheximide, completely prevented an increase in ODC when given with PMSG, but only cycloheximide lowered the enzyme activity when given 18 h later.

Ovine FSH plus LH also produced a peak in ODC at 3 h but the activity decreased quickly and by 9 h it was at the control level. Secretion of endogenous FSH and LH, induced by hourly injections of LH releasing hormone (LH-RH) increased ODC to the same extent as did the exogenous hormones; ODC was still higher than in the controls 4 h after the last dose of LH-RH.

Increased endogenous levels of FSH and LH did not consistently raise ovarian cyclic AMP content and the increases found were much less than those obtained after injection of PMSG or FSH + LH.

The results indicate that increased ODC is induced and maintained by the continual presence of gonadotrophin. The dependence of increased ODC upon increased cyclic AMP cannot be unequivocally determined because of important differences in the timing of the responses and the difficulty in determining biologically significant changes in cyclic AMP.
EFFECTS OF TESTOSTERONE, TESTOSTERONE METABOLITES AND ANTI-ANDROGENS ON THE FUNCTION OF THE MALE ACCESSORY GLANDS IN THE RABBIT AND RAT
Authors: JONES ROY
Published: December 2008

The androgenic potencies of testosterone, 5α-dihydrotestosterone, 5α-androstane-3α,17β-diol and 5α-androstane-3β,17β-diol towards the prostate, glandula seminalis + glandula vesicularis, ampullae and epididymis were evaluated after administration to castrated rabbits. The influence of cyproterone acetate, stilboestrol and medrogestone on accessory gland function was also investigated in rabbits and rats.

In the rabbit it was found that the minimum dose of testosterone propionate that would maintain the function of all accessory glands at normal levels was approximately 200 μg/ animal/day. Higher levels of testosterone propionate overstimulated the function of the prostate, glandula seminalis + glandula vesicularis and ampullae, but did not affect the epididymis. Whereas testosterone propionate and 5α-dihydrotestosterone propionate were essentially equipotent in their capacity to support growth and secretory activity and stimulated all the accessory glands, 5α-androstane-3α,17β-diol dipropionate had a pronounced differential effect; it was considerably more potent than testosterone propionate in promoting secretion in the prostate, but was ineffective in maintaining the function of the epididymis. 5α-Androstane-3β,17β-diol dipropionate was the weakest androgen tested. Evidence also indicated that the potency of a steroid can depend on whether it is administered as its free or esterified form.

Cyproterone acetate suppressed fructose secretion in the prostate of the rabbit but had no adverse effects on the function of the epididymis in either the rabbit or rat. Stilboestrol was the most potent anti-androgen tested and medrogestone the least effective.
BIOCHEMICAL INVESTIGATIONS OF SEPARATED EPITHELIUM AND STROMA FROM BENIGN HYPERPLASTIC PROSTATIC TISSUE
Authors: COWAN R. A. , COWAN SHEILA K. , GRANT J. K. , ELDER H. Y.
Published: December 2008

Using arginase and hydroxyproline as biochemical markers, the yields and homogeneity of separated epithelial and stromal tissues from surgically removed benign hyperplastic prostate glands have been assessed. On the basis of these markers, about 30% of epithelial and 95% of stromal tissues were recovered. Dehydroepiandrosterone sulphate sulphatase activity was found predominantly in the epithelium, whereas testosterone 5α-reductase activity was predominantly in the stroma.
A PHYLOGENETIC STUDY OF SULPHATION FACTOR ACTIVITY IN 26 SPECIES
Authors: SHAPIRO B. , PIMSTONE B. L.
Published: December 2008

Somatomedin (sulphation factor) activity was measured in 26 species by a porcine cartilage bioassay. Although non-dialysable inhibitory factors were present in many species, sulphation factor activity was present in the sera of all the vertebrates studied but was absent from the invertebrates.
PLASMA RENIN ACTIVITY AND BLOOD CORTICOSTEROIDS IN THE AUSTRALIAN LUNGFISH NEOCERATODUS FORSTERI
Authors: BLAIR-WEST J. R. , COGHLAN J. P. , DENTON D. A. , GIBSON ANGELA P. , ODDIE CATHERINE J. , SAWYER W. H. , SCOGGINS B. A.
Published: December 2008

Plasma renin activity (PRA) and blood aldosterone and deoxycorticosterone levels were measured in Australian lungfish. Plasma renin activity was depressed after intravenous infusions of iso-osmotic (0·6%) NaCl but not after hypo-osmotic (0·3%) infusions. The presence of PRA in this fish is consistent with prior reports of renal renin activity in other sarcopterygian fishes. The results of the infusion experiments suggest that a fall in plasma osmolality or electrolyte concentrations may oppose the reduction in renin release in response to volume expansion.

Aldosterone and deoxycorticosterone were identified in the blood of Neoceratodus. The concentrations of both appeared higher in females than in males. Infusions of [5-valine]-angiotensin II amide for 2–4 h at rates known to increase blood pressure in this species did not alter blood aldosterone concentrations. This negative finding may suggest that the renin/angiotensin system is not involved in aldosterone regulation in Neoceratodus or that angiotensin receptors involved in regulation of steroidogenesis have a greater specificity for endogenous angiotensin than do vascular receptors.
INDUCTION OF PEROXIDASE IN THE RAT UTERUS UNDER VARIOUS ENDOCRINE CONDITIONS
Authors: JELLINCK P. H. , NEWCOMBE ANNE-MARIE
Published: December 2008

Department of Biochemistry, Queen's University, Kingston, Ontario K7L 3N6, Canada

(Received 25 January 1977)

Previous studies (Lyttle & Jellinck, 1972) have shown that an enzyme that catalyses the binding of oestradiol to protein and other high molecular weight substances in the presence of H2O2 is absent from the uteri of immature rats, but can be induced by physiological doses of oestradiol or pregnant mare serum gonadotrophin (PMSG).

We now report the effect of oestradiol and PMSG administered in vivo on the induction of peroxidase in the uteri of rats under various endocrine conditions. The effects of oestradiol and progesterone on the formation of the uterine enzyme after a priming dose of oestrogen were also investigated.

Uterine peroxidase was prepared from immature (26-29 days old) Holtzman rats weighing 70-90 g as described previously (Lyttle & Jellinck, 1972) and assayed by its ability to convert [4-14C] oestradiol to water-soluble products in the
RESPONSIVENESS OF FOETAL MOUSE TESTIS TO GONADOTROPHINS AT VARIOUS TIMES DURING SEXUAL DIFFERENTIATION
Authors: POINTIS G. , MAHOUDEAU J. A.
Published: December 2008

Laboratoire de Chimie Hormonale Maternité de Port-Royal, 75014 Paris, France and †Centre de Recherches Endocrinologiques, Hôpital Cochin, 27 rue du Faubourg St-Jacques, 75014 Paris, France

(Received 31 January 1977)

It has been suggested that testosterone production by the foetal testis is under gonadotrophin control (Catt, Dufau, Neaves, Walsh & Wilson, 1975; Warren, Haltmeyer & Eik-Nes, 1975), but the particular roles of foetal pituitary and/or chorionic gonadotrophin are not clearly understood. We have previously demonstrated that a substance with both the biological and radioimmunological properties of luteinizing hormone (LH) is present in the pituitary gland of the male mouse foetus at 18 days of gestation (Pointis & Mahoudeau, 1976a, b). In the present work, we attempted to determine whether the pituitary gland of the male mouse foetus exhibits gonadotrophic activity during earlier stages of genital tract differentiation.

On days 14-18 of gestation, the gonads and pituitary glands of male foetuses (Albino
EFFECT OF 5-HYDROXYTRYPTOPHAN ON PROLACTIN SECRETION IN THE MOUSE
Authors: LARSON B. A. , SINHA Y. N. , VANDERLAAN W. P.
Published: December 2008

Division of Diabetes and Endocrinology, Scripps Clinic and Research Foundation, La Jolla, California 92037, U.S.A.

(Received 9 February 1977)

When administered systemically, 5-hydroxytryptophan increases the concentration of prolactin in the serum of rats (Lu & Meites, 1973) and man (Maclndoe & Turkington, 1973). Ergocornine administered to the mouse depresses the concentration of prolactin in both the pituitary gland and the serum (Sinha, Selby & VanderLaan, 1974). This study was designed to examine whether 5-hydroxytryptophan induces the secretion of prolactin in the mouse and whether ergocornine will inhibit the effects of 5-hydroxytryptophan.

Male Swiss Webster mice aged 60-90 days and weighing 33-35 g were used. The mice were housed in plastic cages, five per cage. Blood specimens (100 μ) were collected without anaesthesia by orbital sinus puncture and the serum was separated and stored at −20°C for prolactin analysis by an homologous radioimmunoassay (Sinha, Selby, Lewis & VanderLaan, 1972). A 1:25 000
CHANGES IN NEUROMAST CHEMOSENSITIVITY IN XENOPUS LAEVIS KEPT UNDER VARIOUS ENVIRONMENTAL CONDITIONS
Authors: BLANCHI D. , GUARDABASSI A.
Published: December 2008

Istituti di Fisiologia generale e di Istologia ed Embriologia della Facoltà di Scienze Matematiche, Fisiche e Naturali, Università di Torino, Italy

(Received 18 February 1977)

In Xenopus laevis, chemosensitivity declines after subtotal hypophysectomy, but is restored to a normal level by injections of ovine prolactin (Blanchi, Camino & Guardabassi, 1976). Changes in the level of endogenous prolactin should, therefore, also give this effect. This might be shown experimentally in progressively desiccated toads, which would mimic the conditions prevailing in their natural habitat. The possibility was examined with animals housed in a thermostatic cupboard at 24–28 °C in containers lined in the bottom with a layer of drying mud. After 7days, to simulate a heavy shower, some toads were abruptly thrown into tap water. The neuromast chemosensitivity of six animals kept under dry conditions was compared with that of neuromasts from 'dry' animals returned to water for 12(1 animal), 24 (5)
EFFECTS OF PROTEIN SYNTHESIS INHIBITORS ON ANGIOTENSIN-STIMULATED AND ANGIOTENSIN-INHIBITED FLUID TRANSPORT BY RAT JEJUNUM IN VIVO
Authors: BOLTON JENNIFER E. , MUNDAY K. A. , PARSONS B. J.
Published: December 2008

A study has been made of the effects of protein synthesis inhibitors on the responses of rat jejunum in vivo to intravenous infusions of angiotensin. Actinomycin D, an inhibitor of the transcription stage of protein synthesis, was without effect on the stimulation of fluid transport which follows the infusion of low doses of angiotensin. Cycloheximide, an inhibitor of the translation stage of protein synthesis, blocked the stimulatory response to angiotensin, but was without effect on the inhibitory response to high doses of the hormone. It is concluded that low (physiological) doses of angiotensin stimulate fluid transport by a mechanism involving protein synthesis at a stage later than transcription whereas high doses of the hormone inhibit fluid transport by a process which does not require protein synthesis.
EFFECTS OF ANGIOTENSIN II ON ARGININE-VASOPRESSIN IN PHYSIOLOGICAL AND PATHOLOGICAL SITUATIONS IN MAN
Authors: PADFIELD P. L. , MORTON J. J.
Published: December 2008

Studies were designed to determine whether angiotensin II has a direct stimulatory effect on arginine-vasopressin in man and to determine the role, if any, played by angiotensin II in the control of vasopressin release in physiological and pathological conditions.

Acute infusion of angiotensin II in normal volunteers produced small but definite increases in plasma levels of arginine-vasopressin (5·4 ± 0·3 (s.e.m.) to 6·4 ± 0·2 pg/ml) only when plasma angiotensin II levels were supraphysiological.

Concurrent measurements of plasma arginine-vasopressin and angiotensin II were made during acute changes in fluid balance and posture in normal volunteers and in clinical conditions characterized by high plasma levels of angiotensin II (Addison's disease and Bartter's syndrome). The results of these studies allow us to conclude that there is little to suggest a direct effect of angiotensin II which is likely to be relevant to the normal physiological control of arginine-vasopressin in man.
THE PRESENCE OF LACTOGEN BUT NOT GROWTH HORMONE BINDING SITES IN THE ISOLATED RAT HEPATOCYTE
Authors: HERINGTON A. C. , VEITH N. M.
Published: December 2008

The binding of 125I-labelled human growth hormone (hGH) and bovine growth hormone (bGH) has been studied in hepatocytes isolated from female rats by perfusion with collagenase in situ. The cells appeared to retain normal membrane function, in that amino acid ([14C]α-aminoisobutyric acid) transport was both saturable and temperature-dependent. Amino acid ([14C]leucine) incorporation into protein was also linear over 3 h and was inhibited by cycloheximide. Binding of 125I-labelled hGH was dependent on time, temperature, hepatocyte concentration and hGH concentration. At 22 °C, binding reached a steady-state after 2·5 h and had a half-life of dissociation of 2–3 h. Hormone specificity studies indicated that binding was specific for hormones with prolactin-like activity (hGH, prolactins) and not for growth hormones themselves (bGH). Scatchard analysis revealed a single class of binding site with a binding capacity of 26·74 ± 3·73 fmol/106 cells and a binding affinity of 1·24 × 109 ± 0·17 × 109 (s.e.m.) l/mol (n = 10). There was a significant sex difference in binding (female > male) and binding was subject to marked regulation by oestrogens (stimulation of binding) and by androgens (inhibition). The lactogen-binding sites, therefore, were comparable in many respects to those previously reported in rat liver membranes. No distinct GH binding sites were demonstrable as shown by the lack of specific binding by 125I-labelled bGH, purified either by Sephadex chromatography or by binding to and elution from GH receptors in rabbit liver membranes. The value of receptor purification of tracer for use in hormone binding studies was indicated by a substantial lowering of non-specific binding.
EPISODIC SECRETION OF GROWTH HORMONE IN A MALE TRANS-SEXUAL DURING TREATMENT WITH OESTROGEN BOTH BEFORE AND AFTER ORCHIDECTOMY
Authors: LENTON E. A. , MILNER GILLIAN R. , COOKE I. D. , JENNER F. A. , SAMPSON G. A.
Published: December 2008

*University Department of Obstetrics and Gynaecology, Jessop Hospital for Women, Sheffield, S3 7RE, †University Department of Paediatrics, Childrens Hospital, Sheffield, S10 2TH and ‡Medical Research Council Unit for Metabolic Studies in Psychiatry, Middlewood Hospital, Sheffield, S6 1TD

(Received 22 February 1977)

In 1965, Frantz & Rabkin reported a difference between the mean concentrations of growth hormone (GH) in the plasma of men and women during fasting, and recently the level of GH in the plasma has been shown to fluctuate from minute to minute (Finkelstein, Roffward, Boyar, Kream & Hellman, 1972). This work describes the spontaneous episodic pattern of GH secretion in a 27-year-old male trans-sexual before and after stilboestrol therapy, and after gonadectomy, again with and without oestrogen supplementation.

Blood samples were collected for 15 min on four occasions: the patient as a normal male (test 1); several months after the patient had been prescribed diethylstilboestrol (5 mg daily,
DEVELOPMENTAL CHANGES IN THE DEGRADATION OF THYROTROPHIN RELEASING HORMONE BY THE SERUM AND BRAIN TISSUES OF THE MALE RAT
Authors: OLIVER C. , PARKER C. R. , PORTER J. C.
Published: December 2008

*Laboratoire de Médecine Expérimentale, UER Médecine Nord, Boulevard Pierre Dramard, 13326 Marseille Cedex 3, France and †Department of Obstetrics and Gynecology, Southwestern Medical School, 5323 Harry Hines Boulevard, Dallas, Texas 75235, U.S.A.

(Received 15 March 1977)

Thyrotrophin releasing hormone (TRH) is rapidly degraded when incubated at 37 °C with plasma (Redding & Schally, 1969) or brain homogenates (Bassiri & Utiger, 1974) from adult rats. However, immunoreactive TRH is stable in serum obtained from rats less than 2 weeks old (Oliver, Taurog & Porter, 1974). No loss of biological or immunological TRH activity occurs during incubation with serum from 4- or 16-day-old rats (Neary, Kieffer, Federico, Mover, Maloof & Soodak, 1976). In this report, we have determined the TRH degrading activity of brain homogenates and serum obtained from male rats at various stages of development after birth.

Synthetic TRH (1 ng, Beckman Instruments, Inc.) diluted in 50 μl phosphate-buffered saline (0·01
EFFECTS OF LUTEINIZING HORMONE RELEASING HORMONE ON THE ULTRASTRUCTURE OF GONADOTROPHS IN THE FOETUS OF THE RHESUS MONKEY NEAR TERM
Authors: TSENG M. T.
Published: December 2008

Eighty micrograms of synthetic luteinizing hormone releasing hormone (LH-RH) were infused systemically into male and female foetuses of rhesus monkeys near term. Control animals were given infusions of saline. Morphologically, the control gonadotrophs varied from cells filled with secretory granules to highly stimulated cells with numerous cytoplasmic vesicles. In the LH-RH-treated animals, however, many cells showed depletion of secretory granules, dilatation of the endoplasmic reticulum and condensed nuclear chromatin. It is concluded, therefore, that foetal gonadotrophs can respond to administration of synthetic LH-RH.
IMMUNOLOGICAL STUDIES ON PARATHYROID HORMONE: CHARACTERIZATION OF ANTISERA AGAINST SYNTHETIC 1–34 HUMAN PARATHYROID HORMONE AND EVIDENCE THAT POSITION 30 IN HUMAN PARATHYROID HORMONE IS ASPARTIC ACID
Authors: VISSER T. J. , BUURMAN C. J. , BIRKENHÄGER J. C.
Published: December 2008

Radioimmunoassays for the measurement of the 1–34 human parathyroid hormone fragment (1–34 hPTH) were developed using antisera raised in rabbits against synthetic 1–34 hPTH-N (amino acid sequence proposed by Niall). Binding of 125I-labelled 1–34 hPTH-N to these antisera was optimal at pH 5·5. Limits of detection varied between 25 and 200 pg/ml. Cross-reactivity of 1–34 bovine PTH was substantial in all assays; 1–34 hPTH-B (structure proposed by Brewer), 1–84 hPTH and 1–29 hPTH cross-reacted only with antisera from one animal. 1–29 Human PTH was obtained from partial hydrolysis of both 1–84 hPTH and 1–34 hPTH-N. Production of 1–29 hPTH from 1–84 hPTH was demonstrated by comparison of the elution profiles of the reaction product and 1–29 bovine PTH on Sephadex G-50. Thus, evidence was obtained that position 30 in native hPTH is occupied by an aspartic acid residue.
LACTOGENIC ACTIVITY IN THE SERUM OF RABBITS DURING PREGNANCY AND EARLY LACTATION
Authors: DURAND P. , DJIANE J.
Published: December 2008

The levels of lactogenic activity in the serum of rabbits during pregnancy and early lactation have been determined. The accuracy and sensitivity of the radioreceptor assay used were increased by several technical improvements. Lactogenic activity remained low throughout pregnancy and increased at parturition; the highest values were reached on day 5 of lactation. No lactogenic activity was detected in placental extracts of rabbits, suggesting that the lactogenic activity measured in the serum is solely of pituitary origin. These results are discussed in relation to the main stages of development of rabbit mammary glands.
ANDROGENIC CONTROL OF THE HARDERIAN GLAND IN THE MALE GOLDEN HAMSTER
Authors: PAYNE A. P. , McGADEY J. , MOORE M. R. , THOMPSON G.
Published: December 2008

In the golden hamster, there are marked sex differences in the Harderian gland. Male glands (which are heavier than female glands) possess two cell forms (Type I and Type II cells); female glands only exhibit the former. Female (but not male) glands contain large amounts of porphyrin, which are readily visible as solid depositions within the lumina.

The weight, histology and porphyrin content of the Harderian gland was examined in intact adult male hamsters and in male hamsters castrated for 1, 2 or 8 months. Castration resulted in a significant reduction in the weight of the gland, the disappearance of Type II cells, and the presence in the gland of solid porphyrin accretions. The levels of copro- and (especially) protoporphyrin were greatly increased. These changes were more marked with time after castration. When the ability of diverse androgens (testosterone, 5α-dihydrotestosterone, androst-4-ene-3,17-dione (androstenedione), dehydroepiandrosterone and androsterone) to prevent these changes was tested, testosterone and androstenedione maintained glandular weight. All the androgens maintained normal frequencies of Type II cells and all except dehydroepiandrosterone prevented deposition of porphyrin. The potencies of the various androgens in maintaining normal Harderian gland morphology and activity are compared with their effects on other somatic variables and sexual behaviour.
ACTION OF RAT PROLACTIN ON PLASMA SOMATOMEDIN LEVELS IN THE RAT AND ON SOMATOMEDIN RELEASE FROM PERFUSED RAT LIVER
Authors: HILL D. J. , FRANCIS M. J. O. , MILNER R. D. G.
Published: December 2008

Rat prolactin at a concentration of 50 ng/ml perfusion medium stimulated the production of somatomedin-like activity (SLA) from the perfused liver of normal rats. The effect was demonstrable in perfusions performed at 11.00 h in which rat prolactin caused a mean (±s.e.m.) increase in the uptake of [35S]sulphate into rat costal cartilage in vitro of 64 ± 14% in comparison with controls, but at 15.00 h no effect was observed. No effect of rat prolactin on hypophysectomized rat liver was detectable at 11.00 h.

Hypophysectomized and sham-operated rats were given five intravenous injections of 50 μg rat prolactin or a similar volume of hormone solvent at 12 h intervals. Plasma somatomedin activity (SMA) and cartilage metabolism, measured by the uptake of radioactive sulphate and thymidine by costal cartilage in vitro, were similar in hypophysectomized animals given rat prolactin or hormone solvent. Sham-operated rats given rat prolactin showed a significant increase of plasma SMA and cartilage metabolism compared with control animals.

The production of SLA by rat liver in response to rat prolactin may be related to the density of specific hepatic lactogenic receptors, since these are absent or present only in low numbers in hypophysectomized animals.
A PRIMING EFFECT OF LUTEINIZING HORMONE RELEASING FACTOR WITH RESPECT TO RELEASE OF FOLLICLE-STIMULATING HORMONE IN VITRO AND IN VIVO
Authors: PICKERING A. J. M. C. , FINK G.
Published: December 2008

Pituitary incubation studies were carried out which showed that in the rat luteinizing hormone releasing factor (LH-RF) can exert a priming effect on FSH secretion in vitro. It was found that, as for LH, the effect depends on protein synthesis. The priming effect of LH-RF with respect to FSH could also be demonstrated in vivo; however, the effect was less dramatic than for LH.