bluuebunny/crossref_metadata_2025 huggingface dataset:
DISULPHATES OF NEUTRAL STEROIDS IN THE AMNIOTIC FLUID FROM ANENCEPHALIC PREGNANCIES
Authors: LUUKKAINEN T. , MICHIE E. A. , VIHKO R.
Published: December 2008

Steroid disulphate fractions were obtained by chromatography on Sephadex LH-20 from samples of amniotic fluid from three pregnancies complicated by anencephaly. Several of the steroids with a 3β-hydroxy-5-ene structure found in normal amniotic fluid could not be detected. 5-Androstene-3β,17α-diol, the main steroid disulphate in normal amniotic fluid was present in concentrations of <5% of the values at normal term. The disulphates of neutral steroids found in highest concentrations in the amniotic fluid of anencephalic pregnancies were those of isomeric pregnanediols; 5α-pregnane-3α,20α-diol, 5α-pregnane-3β,20α-diol and 5β-pregnane-3α,20α-diol. The quantities of these metabolites of progesterone in the amniotic fluid of anencephalic pregnancies were similar to those in normal pregnancies. A saturated 18-hydroxylated C19 steroid, most probably 3α,18-dihydroxy-5α-androstan-17-one, was identified by gas—liquid chromatography and gas chromatography—mass spectrometry. Although this compound has been previously identified in human bile and in normal pregnancy urine, this appears to be the first identification of a saturated C19 steroid in amniotic fluid.
STRUCTURAL CHANGES ASSOCIATED WITH INHIBITION OF INVOLUTION OF THE MAMMARY GLAND IN THE ALBINO RAT
Authors: RICHARDS R. C. , BENSON G. K.
Published: December 2008

Litters were removed from post-parturient rats on day 4 of lactation and the mothers were then treated with various hormones and pharmacological substances. All treatments (oxytocin, reserpine, prolactin (PR), prolactin+ growth hormone (GH), prolactin + adrenocorticotrophin (ACTH)) resulted in a significant retardation of mammary involution. Both oxytocin and reserpine treatment had little effect on the maintenance of the ultrastructure of the mammary epithelial cells, although after reserpine treatment fat droplets were more frequently observed in the epithelial cells. Treatment with PR, PR + GH and PR + ACTH resulted in a progressive maintenance of the ultrastructure of the epithelial cells, with increased fat present in these cells. However, all treatments failed to alter the distribution of the macrophage-like cells and no alteration in the lysosomes was apparent. The factors involved and the mechanisms by which these treatments might have exerted their effect are discussed.
PARTIAL FRACTIONATION OF OESTRADIOL-BINDING CHROMATIN FROM DIMETHYLBENZANTHRACENE-INDUCED RAT MAMMARY TUMOUR
Authors: POOLEY A. S. , KING R. J. B.
Published: December 2008

The distribution of [6,7-3H]oestradiol-17β binding in chromatin from dimethylbenzanthracene-induced rat mammary adenocarcinoma was studied by differential centrifugation of sonicated nuclei. The evidence suggests that more oestradiol-17β is associated with the 'light' chromatin sedimenting at a higher centrifugal force than with the 'heavy' chromatin. Electron microscopy showed that heterochromatin was present in intact tumour nuclei, but it dispersed during isolation of the nuclei, and probably did not account for the fractionation of chromatin that occurred. No heterochromatin was observed in the centrifuged fractions. The template activity appeared to be higher in the fractions that had bound oestradiol. These results are compatible with the view that oestradiol binds to restricted regions of the chromatin and stimulates local increases in transcription.
THE MECHANISM OF OESTRADIOL BINDING IN RAT HYPOTHALAMUS: EFFECT OF ANDROGENIZATION
Authors: VÉRTES MARIETTA , KING R. J. B.
Published: December 2008

The uptake of [6,7-3H]oestradiol in vivo and in vitro by cell fractions from regions of rat brain and the anterior pituitary gland has been studied. Cytoplasmic and nuclear receptors were detected in anterior and posterior hypothalamus but not in brain cortex.

After labelling in vivo, tissues took up [6,7-3H]oestradiol in the following order of magnitude: anterior pituitary > anterior hypothalamus > posterior hypothalamus > cortex. With the exception of the cortex, all extracts from mature tissues had a higher uptake/mg protein than did extracts from immature animals. In the in-vitro system, oestradiol-17β competed with [6,7-3H]oestradiol-17β in the hypothalamus whereas progesterone, testosterone and oestradiol-17α did not. In the pituitary, oestradiol-17α and 17β competed for binding sites.

A single injection of testosterone propionate on the second day of life affected [6,7-3H]oestradiol binding in later life. By 28 days of age, the androgenized animals had a lower nuclear and higher cytoplasmic uptake of [6,7-3H]oestradiol in anterior hypothalamus. This effect was not seen in the posterior hypothalamus or cortex. Binding was decreased in all fractions from the pituitary. In mature animals (60 days old), binding fell in both nuclear and cytoplasmic fractions from anterior hypothalamus and pituitary. The nuclei from posterior hypothalamus also took up less [6,7-3H]oestradiol after androgenization. Androgenization affected specific binding in uteri at both 28 and 60 days of age.
EFFECTS OF CORTICOTROPHIN AND DEXAMETHASONE ON THE LEVELS OF CORTICOSTEROIDS, ADRENALINE AND NORADRENALINE IN THE ADRENAL GLANDS OF CATS
Authors: RIVAS CARMEN , BORRELL SARA
Published: December 2008

The concentration of adrenaline, noradrenaline and corticosteroids in the adrenal glands of intact cats was studied after administration of corticotrophin (ACTH) or dexamethasone. The animals were treated with ACTH for 3, 7 or 14 consecutive days and killed 3 h (group A) or 24 h (group B) after the last injection. In group A the levels of corticosteroids were significantly increased. Significant decreases were found in group B. A significant decrease in noradrenaline concentration was found in all experiments after administration of both ACTH and dexamethasone. No significant change in the adrenaline level was observed after only 3 days of ACTH or dexamethasone administration, but significant decreases were obtained in both groups after injection of ACTH for 7 to 14 days. These findings suggest that the decrease in adrenal adrenaline may be secondary to the significant and greater decrease in adrenal noradrenaline and that in the intact cat the glucocorticoid levels, although regulating the activity of the adrenal enzyme for methylation of noradrenaline, may not be the only factor involved in the control of adrenaline production by the adrenal gland.
A COMPETITIVE PROTEIN-BINDING ASSAY FOR TESTOSTERONE IN THE PLASMA OF THE BULL AND THE RAM
Authors: KATONGOLE C. B.
Published: December 2008

A method is described for the measurement of testosterone in peripheral blood plasma by competitive protein binding, using a 1:80 dilution of human late-pregnancy plasma and Sephadex for separating protein-bound from unbound steroid. The reliability criteria were examined in detail for plasma from bulls and rams. Testosterone was measured with a high degree of accuracy, and with a precision of 4·9–7·9% in the concentration range of 4–24 ng/ml. The specificity of the method was checked by comparing it with a gas-chromatographic technique, and the agreement was good. The testosterone concentrations in the peripheral plasma of bulls and rams were found to range between 2 and 24 ng/ml.
RESPONSE OF NORMAL, HYPOTHYROID AND HYPOTHALAMO-PITUITARY INSUFFICIENT CHILDREN TO SYNTHETIC THYROTROPHIN-RELEASING HORMONE
Authors: MILHAUD G. , RIVAILLE P. , MOUKHTAR M. S. , BINET E. , JOB J. C.
Published: December 2008

Thyrotrophin-releasing hormone (TRH) was synthesized by the solid phase technique, administered to 13 children, and the time-course changes in the serum level of thyroid-stimulating hormone (TSH) assessed. In eight normal children, peak levels of TSH occurred 20 min after the injection, and circulating TSH remained significantly raised for 60 min. In three hypothyroid children, the increase in serum TSH was much greater than in normal children, suggesting the existence of large pituitary TSH stores. In two hypopituitary children with TSH deficiency, TSH reserves seemed normal. One of these patients had a craniopharyngioma; after operation, the increase in serum TSH was reduced. These results show that assay of serum TSH after administration of synthetic TRH provides a test which distinguishes pituitary from hypothalamic defects affecting TSH secretion.
FERTILITY AND MATING BEHAVIOUR OF ANDROGENIZED MICE
Authors: PETERS HANNAH , SØRENSEN I. N.
Published: December 2008

Female Bagg mice injected with 1 mg testosterone propionate when 5 days old (androgenized mice) were sterile when they were mated at the age of 3 months. It was shown that the sterility was not due to a failure to ovulate but rather to aggressive behaviour towards the male which apparently prevented sexual consummation. The results of this study are compared with those of an earlier study (Peters & Sørensen, 1970) in which androgenized Bagg mice were mated immediately after weaning at the age of 1 month. These animals showed reduced fertility, but were not sterile. Fighting in this group of mice was only moderate and copulation and impregnation took place throughout maturity.

The possible reasons for the different fertility and behaviour towards the male in androgenized mice that are mated at different ages are discussed. Androgenized females housed with males from the time of weaning, however, behave in a manner similar to that of mice which have been reared together: they fight rarely and then only moderately. It is thought that in androgenized mice a stimulus (probably a pheromone) activates their brain, previously programmed for aggression, when their first contact with a male is in adulthood: they do not become sensitive to the stimulus if they remain in constant contact with a male from the time they are weaned.

Consequently, androgenized mice that are first mated when they are adult, fight their male mates, preventing insemination: those reared with a male accept and permit sexual contact when they are adult.
CHRONIC MEDIAN EMINENCE LESIONS AND OVARIECTOMY: EFFECTS ON FOLLICLE-STIMULATING HORMONE SECRETION IN THE RAT
Authors: CRAMER E. B. , TRAUM R. E. , D'ANGELO S. A.
Published: December 2008

Pituitary and serum follicle-stimulating hormone (FSH) concentrations were determined by the Steelman—Pohley ovarian augmentation bioassay method in normal adult rats and in rats subjected to ovariectomy and/or electrolytic lesioning of the tuberal hypothalamus 10, 30 or 90 days previously. Ovariectomy resulted in a rapid, significant increase in FSH concentration of the adenohypophysis. Pituitary FSH concentrations were increased sixfold 10 and 30 days after ovariectomy and by 90 days were increased by 700%. (Hormone stores in the adenohypophysis increased correspondingly.) Serum FSH levels in ovariectomized rats also increased but at a slower rate. Ten days after ovariectomy, serum FSH levels were still normal. Thirty and ninety days postoperatively, serum FSH titres were doubled and quintupled, respectively. Chronic median eminence lesions eventually caused obesity, a marked atrophy of the reproductive system and significant increase in the FSH concentration of the adenohypophysis. Follicle-stimulating hormone was not detected in the sera of rats with short-term lesions but serum hormone levels were in the normal range 30 and 90 days after the lesions were made.

Complete destruction of the median eminence in ovariectomized rats was associated with further increase in pituitary FSH concentration and content. Ninety days after simultaneous lesioning and ovariectomy, FSH concentration of the adenohypophysis was almost twice that of the ovariectomized control and the hormone content was about 14 times that in the normal pituitary. In contrast, the raised FSH serum levels observed after long-term ovariectomy were significantly reduced (50%). It is concluded that chronic median eminence lesions which induce obesity and ovarian atrophy in rats differentially affect synthesis and release of FSH by the adenohypophysis.
THE 'FACILITATORY'EFFECT ON OVULATION OF THE RETROSTEROID 1,6-DEHYDRO-6-CHLORO-RETROPROGESTERONE (Ro 4–8347)
Authors: KALRA PUSHPA SETH , MARTINI L.
Published: December 2008

The 'facilitatory' activity of the retroprogesterone derivative 6-chloro-9β,10α-pregna-1,4,6-triene-3,20-dione (Ro 4-8347) on ovulation induced by pregnant mare serum gonadotrophin in immature Sprague—Dawley rats was studied. This retrosteroid is significantly more active in this test than progesterone, dydrogesterone (9β,10α-pregna-4,6-diene-3,20-dione) or chlormadinone (6-chloro-17α-acetoxy-pregna-4,6-diene-3,20-dione).
INTERACTION BETWEEN THYROTROPHIN, CORTICOTROPHIN AND GROWTH HORMONE SECRETION IN MAN
Authors: BESSER G. M. , RATCLIFFE J. G. , KILBORN J. R. , ORMSTON B. J. , HALL R.
Published: December 2008

Thyrotrophin (TSH) release in response to intravenous synthetic thyrotrophin releasing hormone (TRH) was unaltered by simultaneous corticotrophin (ACTH) and growth hormone secretion induced by hypoglycaemia or methylamphetamine in normal subjects. Secretion of growth hormone was the same whether or not TSH was secreted. While the increments in plasma corticosteroids and ACTH after methylamphetamine administration were not different whether TRH or a control injection was given, they rose more during insulin-induced hypoglycaemia when TRH was given as well. This could have been due to a slightly greater degree of stress after TRH + insulin than insulin alone. Overnight dexamethasone suppression of basal ACTH secretion did not alter the TSH response to TRH. Unlike the rat, there is no evidence suggesting competition between pituitary mechanisms involved in ACTH, growth hormone and TSH release in man.
THE ROLE OF THE MEDIAL FOREBRAIN BUNDLE IN MEDIATING ADRENOCORTICAL RESPONSES TO NEUROGENIC STIMULI
Authors: FELDMAN S. , CONFORTI N. , CHOWERS I.
Published: December 2008

The effects of ether stress and of photic and acoustic stimulation on adrenocortical responses were studied in normal rats and in rats with bilateral lesions in the medial forebrain bundle (MFB). While the response to ether stress was slightly reduced, the neurogenic stimuli produced much lower plasma corticosterone levels in the lesioned animals compared with intact rats. The neural pathways and the role of the MFB in mediating adrenocortical responses to neurogenic stimuli are discussed.

The present results demonstrate that the MFB is the main final afferent pathway through which neural impulses to the hypothalamus are propagated, thus activating the secretion of adrenocorticotrophin.
THE DEVELOPMENT OF A RADIOIMMUNOASSAY FOR OXYTOCIN: THE EXTRACTION OF OXYTOCIN FROM URINE AND DETERMINATION OF THE EXCRETION RATE FOR EXOGENOUS AND ENDOGENOUS OXYTOCIN IN HUMAN URINE
Authors: BOYD N. R. H. , JACKSON D. B. , HOLLINGSWORTH STELLA , FORSLING MARY L. , CHARD T.
Published: December 2008

A method is described for the extraction and concentration of oxytocin from urine, satisfactory for the radioimmunoassay of this peptide. The recovery of added oxytocin was 64·8 ± 12·6 (s.d.)% from urine samples with an osmolality less than 770 mosm./kg, and 44·9 ± 13·5% for urine samples of greater osmolality. Infusions of oxytocin at a rate of 1 mu./min into male and female volunteers showed a direct relationship between the volume of urine and the total amount of oxytocin excreted during any 1-h period. Extracts of normal male urine contained an immunoreactive material which behaved identically with synthetic oxytocin in two systems of chromatography.
OESTROGEN SYNTHESIS FROM [4-14C–1,2-3H]TESTOSTERONE BY PLACENTAL MICROSOMES FROM BABOONS
Authors: MILEWICH L. , AXELROD L. R.
Published: December 2008

Washed, lyophilized placental microsomes from baboons were incubated with [4-14C–1,2-3H]testosterone and NADPH in air; labelled oestrone, 17β-oestradiol, androstenedione, 19-hydroxytestosterone, 19-hydroxyandrostenedione and unchanged substrate were isolated from the incubations by paper chromatography and were further characterized by crystallization to constant specific activity. When NADPH was omitted, androstenedione was the only metabolite and its yield was greatly diminished. Oestrone and 17β-oestradiol had similar 3H: 14C ratios and the amount of tritium retained in these metabolites was about 28% of that present in the substrate. The amount of tritium retained in oestrone and 17β-oestradiol suggest that aromatization by the baboon placenta proceeds through the same pathway as that demonstrated for the human placenta. A slight decrease in the 3H:14C ratio was observed in androstenedione, 19-hydroxytestosterone and 19-hydroxyandrostenedione. The recovered substrate had an unchanged ratio.
STEROID AND PHYTO-OESTROGEN BINDING TO SHEEP UTERINE RECEPTORS IN VITRO
Authors: SHUTT D. A. , COX R. I.
Published: December 2008

The binding affinities and receptor specificity of sheep uterine cytosol for steroid oestrogens and also for weak plant oestrogens of the isoflavone and coumestan groups and some synthetic compounds were studied. The binding affinities of the weak oestrogens fall within a range which has usually been neglected. Relative molar binding (RMB) affinities for the steroid oestrogens confirmed the importance of the phenolic 3-hydroxyl group and the influence of substitutions at C-16 and C-17, as seen with uterine cytosols from other species. Relative molar binding affinities were very much lower when the oestrogens were present as sulphate esters, glucosiduronate and methyl ether derivatives; acetates showed similar RMB affinities to their parent compounds. Phyto-oestrogens were found to compete with oestradiol for binding sites. Coumestrol and miroestrol had the highest RMB affinities of about 5 (oestradiol-17β = 100) when incubated at 25 °C, and values for genistein, equol, daidzein and O-desmethylangolensin lay between 1 and 0·05. The mono-methoxy compounds, biochanin A, formononetin and 4′-methoxy-coumestrol had RMB affinities of less than 0·01. Incubation at 37, 25 and 4 °C showed that RMB affinities were greater at the lower temperatures.

Relative molar binding affinities of the phyto-oestrogens in vitro compared with their oestrogenic potencies in vivo showed that the ranking of most of the compounds by these two criteria was similar. Structure-activity correlations were deduced from the results. A similar relationship of RMB affinity to biological potency was also noted for the steroid oestrogens and a homologous series of stilbenediols. The results obtained are relevant to competitive protein-binding analyses and to the mechanism of action of oestrogens and phyto-oestrogens.
PROLONGED GESTATION IN EWES INGESTING VERATRUM CALIFORNICUM: MORPHOLOGICAL CHANGES AND STEROID BIOSYNTHESIS IN THE ENDOCRINE ORGANS OF CYCLOPIC LAMBS
Authors: VAN KAMPEN K. R. , ELLIS L. C.
Published: December 2008

Prolonged gestation associated with cyclopia in offspring of ewes ingesting Veratrum californicum is described. In single or multiple pregnancies where all foetuses are cyclopic, foetal hypophysial aplasia, foetal thyroidal and adrenal hypoplasia, and foetal gonadal hypertrophy were associated with prolonged gestation. Cyclopic foetuses that were twins to normal foetuses were delivered at term and, with the exception of hypophysial aplasia, other endocrine organs (thyroid, adrenal and gonads) showed no morphologic abnormalities.

In sheep, during prolonged gestation, comparative studies of the ability of maternal and foetal endocrine glands to synthesize steroids indicated that the foetal ovary was capable of transforming more substrates (pregnenolone and progesterone) into steroid metabolites than the maternal ovary, even though the same group of metabolites is formed by foetal and maternal ovaries. Foetal adrenals produced more testosterone than maternal adrenals, but synthesized very little cortisol, corticosterone and cortisone. Foetal adrenals were incapable of forming water-soluble steroids although the ovaries from cyclopic foetuses and maternal adrenals possessed this capability.
TELEOST CAUDAL NEUROSECRETORY SYSTEM: SPERM DUCT CONTRACTION INDUCED BY UROPHYSIAL MATERIAL
Authors: BERLIND A.
Published: December 2008

Extracts of the urophysis of the teleost Gillichthys mirabilis and material released from intact cells induced contraction of the Gillichthys sperm duct in vitro. Acetylcholine and 5-hydroxytryptamine also caused sperm-duct contraction, but specific blocking substances left the response to urophysial material unaltered. Adrenaline and noradrenaline inhibited the response of the sperm duct to urophysis extracts. The active factor was destroyed by trypsin, and had similar chromatographic properties to the peptidic teleost bladder-contracting factor also found in the urophysis. A role of this agent in spawning or other aspects of reproduction is suggested.
THE CHEMICAL COMPOSITION OF FLUSHINGS FROM RAT UTERI WITH AND WITHOUT INTRA-UTERINE DEVICES
Authors: BREED W. G. , PEPLOW P. V. , ECKSTEIN P. , BARKER S. A.
Published: December 2008

Saline flushings from the uterine horns of rats with unilateral silk sutures (IUD's) were obtained at pro-oestrus, oestrus and on Day 5 of pseudopregnancy, and examined chemically.

Protein and reducing sugar were invariably present and significantly increased in horns containing an IUD. The number of protein bands identified by disc electrophoresis varied between individual animals, but showed no marked differences between the experimental and control horns at either pro-oestrus or oestrus.

Among enzymes, amylase activity was consistently raised on the IUD side compared with the control side; it was also significantly higher in the IUD horn during pseudopregnancy than in the control horns at pro-oestrus and oestrus. Lysozyme activity was found at pro-oestrus in IUD horns but not in the control horns; at oestrus and during pseudopregnancy little activity was measurable. Proteinase activity, using haemoglobin as substrate, was significantly increased in IUD horns at acid pH, but undetectable at pH 7·7; with casein as substrate at pH 7·7, activity was usually present but did not vary significantly between the two sides. Trypsin activity was also measurable at pH 7·7, but was unchanged in the presence of an IUD. Ribonuclease and phosphatase were usually detectable at pro-oestrus and oestrus, but their activities were not significantly altered by an IUD; on Day 5 of pseudopregnancy, however, much lower levels were found in both horns. Neither hyaluronidase nor neuraminidase could be detected in any flushings assayed.

The possible biological implications of these findings are discussed.
PROLACTIN TURNOVER IN RAT ADENOHYPOPHYSES IN VIVO: ITS EVALUATION AS A METHOD FOR ESTIMATING SECRETION RATES
Authors: SWEARINGEN KAREN C. , NICOLL C. S.
Published: December 2008

The kinetics of prolactin turnover were investigated in female rat adenohypophyses in vivo. The animals received an intravenous injection of [3H]leucine and groups were killed at various times thereafter. The prolactin in their adenohypophyses was separated and measured by disc electrophoresis and densitometry. The hormone band was cut from the gel columns and counted by liquid scintillation procedures. The specific activity data (c.p.m./μg) were fitted to single or double exponential functions by the method of least squares, using a computer program. The slow component of the double exponential, or the single component of the single exponential were assumed to represent secretion and their rate constants were multiplied by the hormone content of the gland to obtain an estimate of secretion rate. The assumptions involved in this method of estimating secretion rates are discussed and evaluated.

The rate constant for prolactin in oestrogen + reserpine-treated females (0·10–0·08 h−1) was higher than that obtained in rats treated with oestrogen alone (0·05–0·06), and approximately three times that in rats treated with reserpine only (0·03). The prolactin concentration in the adenohypophysis was highest in reserpine-treated rats (8·2 μg/mg) while in glands from oestrogen-treated (4·1–6·0 μg/mg) and oestrogen + reserpine-treated animals (5·0–6·2 μg/mg) it was similar. The average prolactin secretion rates in oestrogen-treated (0·26 μg/mg/h) and reserpine-treated (0·25 μg/mg/h rats were similar, while the average rate in reserpine + oestrogen-treated rats (0·54 μg/mg/h) was twice as high. The results with reserpine-treated animals (low rate constant, high gland content), with oestrogen + reserpine-treated animals (high rate constant), and of those previously obtained by us in ectopic adenohypophysial transplants (high rate constant, low gland content) are discussed in terms of possible involvement of a prolactin stimulating factor. It is concluded that this method provides useful estimates of secretion rates as well as information on the intrapituitary turnover of prolactin.
PLASMA AND PITUITARY LUTEINIZING HORMONE CONCENTRATIONS AND PERIPHERAL PLASMA OESTRADIOL CONCENTRATION DURING EARLY PREGNANCY AND AFTER THE ADMINISTRATION OF PROGESTATIONAL STEROIDS IN THE RAT
Authors: BROWN-GRANT K. , CORKER C. S. , NAFTOLIN F.
Published: December 2008

Plasma luteinizing hormone (LH) concentrations were already lower on Day 2 of pregnancy than at the same time after the preceding ovulation in the non-pregnant rat, and fell progressively up to Day 16 of pregnancy. No evidence was obtained of any increase at the time when the ovulatory surge of LH would have occurred if the animal had not become pregnant. Pituitary LH concentration was lower in mated rats on the morning of Day 0 of pregnancy than in unmated controls on the morning of the day of oestrus. Subsequently it increased slowly to reach a level higher than at any stage of the oestrous cycle by Day 8 of pregnancy and remained high until at least Day 16 of pregnancy. Peripheral plasma oestradiol concentration increased late on Day 2 of pregnancy and was still raised on Day 4 but was never more than about one fourth of the peak concentration seen on the morning of prooestrus during the oestrous cycle. There were similar changes in plasma LH and oestradiol concentrations in the 48 h after a single injection of 2·5mg progesterone on the morning of the day of dioestrus, a procedure that delays ovulation by 1 or 2 days. Administration of a synthetic progestational compound (medroxyprogesterone acetate) to pregnant rats delayed blastocyst implantation and the delay was associated with a marked decrease in peripheral plasma LH to levels below those of normal pregnancy.
IDENTIFICATION AND METABOLIC CLEARANCE OF CORTISOL AND CORTISONE IN A MARINE TELEOST, THE SEA RAVEN HEMITRIPTERUS AMERICANUS GMELIN (FAMILY SCORPAENIDAE)
Authors: OWEN W. H. , IDLER D. R.
Published: December 2008

Cortisol and cortisone were identified and their levels determined in sea raven plasma by a double isotope derivative assay involving acetylation with [1-3H]acetic anhydride, purification by thin-layer and paper chromatography, followed by recrystallization to constant 3H: 14C ratios. The mean level of cortisol in four plasma samples was 7·2±1·0 μg/100 ml (range 4·0–9·2) and the mean level for cortisone in three samples was 1·1 ± 0·2 μg/100 ml (range 0·7–1·5).

Metabolic clearance rates (MCR) were determined for both corticosteroids by the method of continuous infusion over an 8-h period. The mean MCR for cortisol in five fish was 126 ± 17 ml/kg/h, and for cortisone 449 ± 48 ml/kg/h in six fish. The mean percentage conversion of [1,2-3H]cortisol to cortisone was 9·4 ± 2·9%. There was no evidence of any significant conversion of cortisone to cortisol.
IDENTIFICATION OF PROSTAGLANDIN F2α IN UTERINE FLUID FROM THE NON-PREGNANT SHEEP WITH AN AUTOTRANSPLANTED OVARY
Authors: HARRISON F. A. , HEAP R. B. , HORTON E. W. , POYSER N. L.
Published: December 2008

In four sheep with an autotransplanted ovary, cyclic oestrous behaviour was abolished due to the persistence of a corpus luteum in the transplant. Fluid recovered from the uterus was viscous, odourless and sterile, and was present in amounts of 10 to 1900 ml. Uterine fluid contained prostaglandin F2α, the total amount recovered ranging from 150 ng to 7·6 mg (15–4000 ng/ml). The identity of prostaglandin F2α was confirmed by gas chromatography-mass spectrometry. No prostaglandins of the E series were found.

Biopsy specimens of the uterine wall showed that the uterine and glandular epithelium comprised tall, columnar cells typical of the luteal phase of the normal cycle. The uterine glands were considerably distended and stromal oedema was appreciable.

These findings are discussed in the context of the hypothesis that the uterine luteolytic factor (luteolysin) is prostaglandin F2α.
PERINIDATORY OVARIAN OESTROGEN SECRETION IN THE PREGNANT RAT, DETERMINED BY GAS CHROMATOGRAPHY WITH ELECTRON CAPTURE DETECTION
Authors: NIMROD A. , LADANY SHOSHANA , LINDNER H. R.
Published: December 2008

A sensitive and specific method is described for the determination of oestradiol-17β and oestrone in blood by gas-liquid chromatography with the use of an electron capture detector. The rate of secretion of these steroids into the ovarian venous blood of rats was determined on the day of pro-oestrus (six animals) and at various times during the first 8 days of pregnancy (240 animals). Oestradiol output (pg/ovary/30 min, mean ± s.e.m.) was low during day 1 (the day sperm were present in the morning vaginal smear) and until 11.00 h on day 2 (59 ± 13), but rose rapidly and significantly on the afternoon of day 2 (299 ± 46). From day 3 to day 8 an increased secretion rate was maintained (451 ± 26), though this was well below the level found on the day of pro-oestrus (mean 8·8 ng oestradiol and 1·2 ng oestrone/ovary/30 min). Oestradiol secretion during early pregnancy tended to be higher in the afternoon than in the morning.

Oestrone output roughly paralleled that of oestradiol, but was only about one third as high. No distinct peak in the rate of secretion of either steroid was demonstrable on day 4. The results strengthen the view that ovarian oestrogen secretion has an essential role in ovum implantation in the rat, but are incompatible with the hypothesis that the time of uterine receptivity to the blastocyst and of uterine sensitivity to atraumatic deciduoma induction is determined by a discrete discharge of oestradiol or oestrone from the ovary on the afternoon of the 4th day post coitum — the so-called 'oestrogen surge' theory.
CLOMIPHENE CITRATE IN MEN: INCREASE OF CORTISOL, LUTEINIZING HORMONE, TESTOSTERONE AND STEROID-BINDING GLOBULINS
Authors: MARSHALL J. C. , ANDERSON D. C. , BURKE C. W. , GALVAO-TELES A. , FRASER T. RUSSELL
Published: December 2008

The effects of clomiphene citrate were studied in nine normal men, in three patients with partial panhypopituitarism, and in four patients with isolated gonadotrophin deficiency. The administration of this drug to the normal subjects in a dosage of 3 mg/kg/day for 10 days resulted in a mean rise in serum luteinizing hormone (LH) of 107%, in plasma 17β-hydroxyandrogens (17-OHA) of 114%, and in plasma total cortisol of 86%. The rise of testosterone concentration in normal subjects was associated with a doubling of the non-protein bound fraction, and also with increased binding of testosterone to sex hormone-binding globulin (SHBG). In contrast, plasma non-protein bound and urinary unconjugated cortisol remained unchanged. The percentage of plasma cortisol not bound to protein fell, indicating that the rise in total plasma cortisol was secondary to increased protein binding. This was confirmed by finding increased binding of both cortisol and testosterone to their specific binding globulins at 1 °C, due apparently to increased concentrations of SHBG and corticosteroid-binding globulin after clomiphene administration. All the responses to clomiphene were prevented by simultaneous administration of fluoxymesterone in two normal subjects.

All the hypopituitary patients showed no rise of LH, 17-OHA or cortisol. The hypogonadotrophic patients, however, showed a normal total cortisol rise.

It is suggested that clomiphene has two actions. First, it interferes with the hypothalamic feed-back mechanisms for testosterone, resulting in increased LH secretion, and secondly it has an oestrogen-like effect in stimulating production of steroid-binding globulins.
THE RELATIONSHIP BETWEEN THE UTERUS AND OVARIES DURING EARLY PREGNANCY IN THE GUINEA-PIG
Authors: BLATCHLEY F. R. , DONOVAN B. T.
Published: December 2008

In mated guinea-pigs one uterine horn was rendered sterile by ligation of the oviduct 2 or 3 days after finding spermatozoa in the vaginal smear. Two glass beads were inserted into the sterile horn on each of days 3–12 and on day 14 in experimental animals but not in controls. At autopsy on day 20 large corpora lutea were present in both ovaries of the control animals. The presence of beads that had been introduced on days 3 and 4 and on days 10–14 resulted in marked regression of the corpora lutea in the adjacent ovary, in the absence of a decidual reaction in the uterus, while luteal enlargement typical of pregnancy occurred in the contralateral ovary. Beads inserted on days 5–8 caused decidualization in the sterile horn but did not induce premature luteal regression in the ipsilateral ovary.
THE EFFECT OF PROLACTIN AND GROWTH HORMONE ON FATTY ACID SYNTHESIS BY PREGNANT MOUSE MAMMARY GLAND IN ORGAN CULTURE
Authors: WANG D. Y. , HALLOWES R. C. , BEALING J. , STRONG C. R. , DILS R.
Published: December 2008

The effect of various hormones on the incorporation of [14C]acetate into the fatty acids of pregnant mouse mammary gland explants in organ culture was studied.

Of the hormones insulin (I), ovine prolactin (P), bovine growth hormone (GH) and cortisol (F) tested singly, only insulin stimulated fatty acid synthesis. There was synergism between cortisol or prolactin with insulin. The greatest stimulation in fatty acid synthesis occurred when explants were incubated in a medium containing either I + F + P or I + F + GH.

Analysis by radio-gas-liquid chromatography of the fatty acids synthesized by explants after 14C labelling, showed that the pattern of fatty acids formed in the presence of I + F was distinctly different from that produced in the presence of I + F + P or I + F + GH. In the presence of I + F, the pattern of fatty acids resembled that found in mouse adipose tissue, whilst with I + F + P or I + F + GH the pattern resembled that of mouse milk fat.

Synthesis of RNA was essential for the stimulation of fatty acid synthesis in explants incubated in medium containing I + F + P or I + F + GH. Results obtained when DNA synthesis was blocked with mitomycin C suggest that mitosis is important for the induction of milk-fatty acid synthesis.

Puromycin had no effect for up to 8 h on explants which had been previously cultured in medium containing I + F, I + F + P or I + F + GH. This suggests a slow turnover rate of the enzymes involved in the synthesis of milk fatty acids.
THE SITES OF IODIDE CONCENTRATION IN THE OVIDUCT AND THE UTERUS OF THE RAT
Authors: BROWN-GRANT K. , ROGERS A. W.
Published: December 2008

Previous studies have shown that under the influence of progesterone the concentrations of radioiodide in the uterus and oviduct of the rat are maintained at levels higher than that in the plasma. In the present experiments the uterus and oviducts from rats killed 2 h after the injection of Na125I were autoradiographed by a technique which permits the localization of diffusible radioactive material. In intact non-pregnant rats and ovariectomized rats not injected with progesterone, uniformly low grain densities were observed over sections of oviduct and uterus with the exception of the epithelium and lumen of the oviduct where some increase in grain density was observed. In intact and ovariectomized rats treated with progesterone and in rats killed on Day 3 or 4 of pregnancy, grain densities over the epithelium and lumen of the oviduct were very high but the fimbria of the oviduct were consistently unlabelled. The stroma underlying the oviduct epithelium was also labelled. In the uteri of these animals the principal site of concentration of radioiodide was the luminal epithelium, but for technical reasons it was not possible to exclude the stroma immediately adjacent to the luminal epithelium as a less active site of concentration of iodide. No other site in the uterus concentrated radioiodide. The luminal epithelium occupies less than 3% of the volume of the uterus in ovariectomized rats: if this tissue is taken as the sole site of iodide concentration in the uterus, the levels reached in these cells must be at least a hundred times that of the plasma when the overall uterus: plasma concentration ratio for radioiodide is 4 or more.
CORTICOTROPHIN RELEASE INDUCED BY SURGICAL TRAUMA AFTER TRANSECTION OF VARIOUS AFFERENT NERVOUS PATHWAYS TO THE HYPOTHALAMUS
Authors: MAKARA G. B. , STARK E. , MARTON J. , MÉSZÁROS T.
Published: December 2008

Corticotrophin (ACTH) release induced by surgical trauma under pentobarbitone anaesthesia was studied in rats. The plasma corticosterone level was used as an index of 'rapid' ACTH release.

One hour after surgical trauma the plasma corticosterone level had risen in rats with various cuts around the medial basal hypothalamus except in the group with lateral cuts. After stress no significant difference was found between the plasma levels of the controls and those of the rats with anterior, 'low' superior, 'low' anterosuperior, and 'short' posterior cuts. In contrast, in rats with 'high' superior, 'high' anterosuperior, 'long' posterior and lateral cuts the plasma corticosterone level was lower than in the appropriate sham-operated controls.

It is suggested that the nerve fibres initiating ACTH release after surgical trauma ascend the spinal cord to the medulla and mid-brain whence the pathways pass forward in the region of the dorsal longitudinal fasciculus and/or the median forebrain bundle to the lateral hypothalamic area, and from there to the medial basal hypothalamus.
PROGESTERONE CONCENTRATION IN THE PERIPHERAL PLASMA OF PREGNANT GOATS
Authors: IRVING G. , JONES D. E. , KNIFTON A.
Published: December 2008

Plasma progesterone concentration was measured by a competitive protein-binding method in serial samples of jugular venous blood from 21 pregnant goats, 11 with twin and 10 with single foetuses.

Progesterone levels in twin pregnancies were significantly greater than in singletons. The mean progesterone concentration (ng/ml plasma) in the twin pregnancies was greatest during the 3rd month of gestation (10·7 ± 0·4 (s.e.m.)) and in the singletons during the 4th month (7·8 ± 0·2 (s.e.m.)). There was a significant decrease in mean progesterone concentration in the last month of pregnancy due to a steady decline in the last 7 days before parturition.

The mean progesterone concentrations at parturition in five twin and eight single pregnancies were 2·2 ± 0·4 and 1·5 ± 0·2 (s.e.m.) ng/ml plasma respectively; there was no significant difference between these values. In cord blood from nine kids immediately after delivery the progesterone concentration was 0·9 ± 0·1 ng/ml.
THE EFFECT OF PROSTAGLANDIN F2α AND PROSTAGLANDIN E2 UPON LUTEAL FUNCTION AND OVULATION IN THE GUINEA-PIG
Authors: BLATCHLEY F. R. , DONOVAN B. T.
Published: December 2008

The effect of treatment with prostaglandin F2α (PGF2α on luteal function was examined in hysterectomized guinea-pigs. Regression of corpora lutea was found to occur when 0·25 mg (or more) was injected daily for 3 days and ovulation usually ensued within 5 days after treatment. The administration of 1 mg PGF2α daily for 7 days caused marked luteolysis but ovulation did not occur. Ovulation was blocked in three of four intact female guinea-pigs given 1 mg PGF2α/day for 7 days from day 15, but took place normally in five females injected with 0·25 mg/day. Treatment of hysterectomized guinea-pigs with 0·62 mg adrenaline hydrochloride/day, 1·97 mg atropine sulphate/day or 0·52 mg histamine dihydrochloride/day did not cause luteal regression, while the injection of 0·25 mg or 1 mg prostaglandin E2 daily for 3 days was likewise ineffective.
DIFFERENTIAL EFFECTS OF CASTRATION AND DENERVATION ON PROTEIN SYNTHESIS IN THE LEVATOR ANI MUSCLE OF THE RAT
Authors: BUREŠOVÁ M. , GUTMANN E. , HANZLÍKOVÁ V.
Published: December 2008

The effects of testosterone on weight changes, incorporation of labelled precursors into RNA and proteins, and on ultrastructure of the levator ani muscle of male rats in which castration or denervation was performed, were studied.

No increase of weight occurred in the denervated levator ani muscle after castration. There was no increase in the incorporation of labelled precursors into RNA and proteins in vitro in mature rats, if the muscle was denervated. However, incorporation still increased when denervation was performed in sexually immature animals. The levator ani muscle, which normally undergoes postnatal involution in the female rat, could be maintained even after postnatal denervation if testosterone was administered at birth, the hormone acting as a nerve-independent trophic agent.

The increase of protein synthesis in the levator ani of mature, male, castrated animals, induced by testosterone administration, was abolished after denervation of the muscle. The activating influence of testosterone upon protein synthesis was, however, still present in immature male animals.
LUTEAL MAINTENANCE IN THE HYPOPHYSECTOMIZED PSEUDOPREGNANT RABBIT: EFFECT OF OVINE LUTEINIZING HORMONE AND FOLLICLE-STIMULATING HORMONE
Authors: DAVIES J. , HOFFMAN L. H. , DAVENPORT G. R.
Published: December 2008

Ovine luteinizing hormone (LH) (300 μg/day in divided subcutaneous doses) had a luteotrophic effect of limited duration in intact and hypophysectomized 10-day pseudopregnant rabbits (6–10 days in intact animals; 3–6 days in hypophysectomized animals). Higher dose levels caused reovulation in which case luteolysis occurred. Suppression of reovulation with anti-ovine follicle-stimulating hormone (FSH) serum permitted the daily dose of LH to be raised to 750 μg without causing luteolysis or reovulation. Anti-LH serum was luteolytic in the intact animals. A combination of ovine FSH (200 μg) and LH (300 μg) was indistinguishable from LH alone in terms of its luteotrophic effect in hypophysectomized 10-day pseudopregnant rabbits. Ovine FSH at large daily dose levels (1000 μg) was more effectively luteotrophic than LH alone in a significant number of animals for 10 days after hypophysectomy: endometrial changes in these animals resembled those only seen in normal pregnancy. The luteotrophic effect of 1000 μg FSH was believed to be dependent on a small but significant content of LH, estimated to be about 10 μg. Ovine FSH and anti-FSH serum in intact pseudopregnant rabbits had no detectable effect on luteal function. Animals hypophysectomized at the 7th day and treated with 300 or 500 μg LH/day showed no luteal maintenance for 6 days nor was reovulation induced. Sensitivity to the luteotrophic effect of LH was deemed, therefore, to be greater at 10 than at 7 days of pseudopregnancy. Endometrial criteria were found to be reliable indicators of luteal function. The appearance of ciliated cells was correlated with the decline of the corpora lutea. When reovulation occurred, a new progestational cycle was rapidly superimposed on the existing one.
EFFECTS OF PROGESTERONE, MEDROXYPROGESTERONE ACETATE (PROVERA) AND OESTRONE ON SHEDDING AND DISSOLUTION OF THE ZONA PELLUCIDA IN THE RAT
Authors: DICKMANN Z.
Published: December 2008

The effects of progesterone, medroxyprogesterone acetate (MPA), and oestrone on shedding and dissolution of the zona pellucida were studied in intact pregnant rats, ovariectomized pregnant, and ovariectomized pseudopregnant rats into whose uteri blastocysts had been transferred. Treatment with progesterone, MPA and oestrone delayed shedding of the zona. The highest percentage of blastocysts delaying, and with the longest delay period, occurred in ovariectomized, progesterone-treated rats. Ovariectomy of pregnant rats, and treatment of ovariectomized rats with progesterone, MPA or oestrone, delayed dissolution of the zona. Oestrone together with progesterone caused both shedding and dissolution of the zona within 24 h. It is deduced that in the intact pregnant rat, the synergistic action of oestrogen superimposed on progesterone synchronizes shedding and dissolution of the zona so that they occur together at a specified time.
CALCITONIN CLEARANCE IN THE PIG AND IN THE ISOLATED PERFUSED PIG LIVER
Authors: GREENBERG P. B. , MARTIN T. J. , MELICK R. A. , JABLONSKI P. , WATTS J. McK.
Published: December 2008

The metabolic clearance rate (MCR) of porcine calcitonin in six gilts was 13·0 ± 0·7 (s.e.m.) ml/min/kg and in four isolated, perfused pig livers was 16·1 ± 1·1 ml/min, with constant infusions of porcine calcitonin and measurement of calcitonin concentration by radioimmunoassay.

After single injections of 125I-labelled porcine calcitonin, the MCR of 125I-labelled porcine calcitonin was 29·2 ± 2·8 ml/min in six isolated, perfused pig livers.

125I-labelled salmon calcitonin was cleared at a slower rate than porcine calcitonin after single injections into the gilt. 125I-Labelled human calcitonin and 125I-labelled salmon calcitonin were not significantly cleared by the isolated, perfused pig liver.
EFFECT OF VARIOUS ADRENERGIC RECEPTOR STIMULATING AND BLOCKING AGENTS ON HUMAN GROWTH HORMONE SECRETION
Authors: MASSARA F. , CAMANNI F.
Published: December 2008

The effects of various adrenergic substances, either alone or in association with alpha and beta blocking agents, on human plasma growth hormone (GH) were studied in 36 normal volunteers.

Plasma GH levels were unaffected by i.v. adrenaline (10 μg/min for 30 min) or by propranolol (1·5 mg/min for 10 min). Given together at the same doses, these drugs provoked sharp increases in plasma GH (from 8·5 to > 100 ng/ml; a mean increase of 30±8·02 (s.e.m.)). Reduction of the adrenaline dose to 7 μg/min produced a positive response in four out of six cases.

The GH response to propranolol plus adrenaline was suppressed by simultaneous administration of phentolamine, but not significantly altered by glucose and aminophylline. Noradrenaline (7–14 μg/min for 30 min) produced no changes in plasma GH levels in six cases, while its association with propranolol was followed by an increase in only one out of four cases. Phenylephrine and tyramine were without effect, with or without propranolol.

In five out of six cases, GH values gradually increased after oral administration of 1 g l-DOPA (from 4·2 to 85 ng/ml; mean, 30·2). This response was totally suppressed by phentolamine.

It is considered that stimulation of GH by propranolol plus adrenaline and l-DOPA is mediated by alpha-adrenergic receptors. The possible role of a beta-inhibiting effect is discussed.