bluuebunny/crossref_metadata_2025 huggingface dataset:
THE Δ5-3β-HYDROXYSTEROID DEHYDROGENASE OF BOVINE ADRENAL MICROSOMES
Authors: NEVILLE A. M. , ORR J. C. , ENGEL L. L.
Published: December 2008

The Δ5-3β-hydroxysteroid dehydrogenase activity of an acetone powder of bovine adrenal microsomes has been studied using 3β-hydroxyandrost-5-en-17-one and 3β-hydroxypregn-5-en-20-one as substrates. The products were separated, identified and quantitated by gas—liquid chromatographymass spectrometry. The Michaelis constants for both steroid substrates and for NAD have been derived and are of the order of 10−6 m. Although kinetic studies indicate the existence of a single Δ5-3β-hydroxysteroid dehydrogenase, the possibility of a non-enzymic rate-limiting step common to both steroid substrates and to NAD must be entertained.
PURIFICATION OF CHICKEN PITUITARY FOLLICLE-STIMULATING HORMONE AND LUTEINIZING HORMONE
Authors: HARTREE ANNE STOCKELL , CUNNINGHAM F. J.
Published: December 2008

Separation and partial purification of chicken pituitary follicle-stimulating hormone (FSH) and luteinizing hormone (LH) has been obtained by methods which were effective in the purification of the corresponding human and horse hormones. Increases in chicken LH activity were observed after chromatography on DEAE-cellulose and on Amberlite IRC-50 suggesting removal of an LH inhibitor. The biological potencies of chicken FSH and LH preparations when assayed in mammals were very much lower than those of the corresponding mammalian fractions on a weight basis. A weak immunological cross-reaction between chicken and human pituitary LH was used to estimate LH in chicken pituitary fractions and the results were compared with bioassays of the same fractions.
THE MAINTENANCE OF LACTATION IN THE RABBIT AFTER HYPOPHYSECTOMY
Authors: COWIE A. T. , HARTMANN P. E. , TURVEY A.
Published: December 2008

Twenty-one rabbits were hypophysectomized during the second week of lactation. Hypophysectomy inhibited milk secretion within 3–7 days. Restoration of the milk yield to pre-operative levels was obtained when daily injections of either sheep prolactin (50 or 100 i.u.) or human growth hormone (HGH) (2·5 or 5 mg.) were administered; partial recovery of the milk yield was obtained with 25 i.u. sheep prolactin/day or 1·25 mg. HGH/day. Neither bovine growth hormone (BGH), adrenocorticotrophin (ACTH) nor cortisol acetate had any significant restorative effects on milk secretion or synergistic effects when combined with sheep prolactin or HGH. The probable development of immune responses to sheep prolactin and HGH was observed. After hypophysectomy, changes in milk composition were found which were similar in trend to the more gradual normal changes observed in late lactation. Sheep prolactin and HGH restored the composition of the milk as well as the yields to normal levels, and both hormones caused rapid increases in lactose yields.

The pigeon crop-stimulating potency of the HGH preparation was low (equivalent to 3·7 i.u. sheep prolactin/mg.), yet its lactogenic and galactopoietic potencies were high thus emphasizing the unreliability of assessing the mammotrophic potencies of HGH preparations in birds.
DESMOLASE ACTIVITY OF NORMAL AND MALIGNANT HUMAN BREAST TISSUE
Authors: ADAMS J. B. , WONG M. S. F.
Published: December 2008

[4-14C]Cholesterol was cleaved to pregnenolone and progesterone by a washed particulate fraction isolated from involved lymph nodes obtained from a radical mastectomy specimen. Difficulties were experienced in isolating subcellular fractions from primary breast tumours and normal breast tissue. However, an acetone powder fraction, obtained from normal tissue derived from a radical mastectomy specimen, yielded pregnenolone from [4-14C]cholesterol.

[7α-3H]17α-Hydroxyprogesterone was converted to androstenedione and to 17α,20α-dihydroxypregn-4-en-3-one and its 17α,20β-epimer by homogenates of secondary breast carcinoma tissue and normal breast tissue obtained from radical mastectomy specimens. These results, in conjunction with those obtained previously (Adams & Wong, 1968a), show that human breast carcinoma tissue contains the enzymes necessary to convert cholesterol to androgens and oestrogens.
PROGESTERONE AND 20α-HYDROXYPREGN-4-EN-3-ONE LEVELS IN OVARIAN VEIN BLOOD OF THE RAT THROUGHOUT LACTATION
Authors: TOMOGANE H. , ÔTA K. , YOKOYAMA A.
Published: December 2008

Changes in the rate of progesterone and 20α-hydroxypregn-4-en-3-one (20α-OH-P) secretion by the rat ovary during the course of lactation were investigated. The level of progesterone in the ovarian vein blood, which was very low on day 1 of lactation, increased progressively up to day 8 (355 μg./100 ml. blood), then declined to day 18 (45·5 μg./100 ml.) and day 21 of lactation. A high concentration of 20α-OH-P in blood was observed on day 1 and day 21 of lactation, but from day 4 to day 18 the secretion of this steroid was relatively low. The ratio of progesterone to 20α-OH-P exceeded unity from day 4 to day 16, and in the middle of lactation the concentration of progesterone in ovarian venous blood was about four times greater than that of 20α-OH-P. These changes in the secretory pattern of progestins during lactation are discussed in connexion with the effects of the suckling stimulus on prolactin and gonadotrophin secretion from the anterior pituitary gland.
UPTAKE OF RADIOACTIVITY BY UTERUS, VAGINA AND SKELETAL MUSCLE OF IMMATURE MICE AFTER ADMINISTRATION OF [3H]OESTRADIOL
Authors: FOLMAN Y. , POPE G. S.
Published: December 2008

Loss of uptake during 24 hr. after administration of [3H]oestradiol showed approximately linear relationships between log uptake and time for uterus and vagina but not for skeletal muscle; these relationships were similar for mice pretreated with oestradiol. Uptake by uterus and vagina was less by about 50% when [3H]oestradiol was given to mice whose uteri and vaginae had reached maximum weight after pretreatment with oestradiol but cessation of growth of these organs was apparently not due to failure of their ability to take up oestradiol.

The relationship of uptake levels maintained in the uterus and vagina during 3 days and their consequent growth rate was studied.

When a second dose of [3H]oestradiol was given at various times after the first, new uptake, measured 1 hr. later, by uterus and vagina (but not skeletal muscle) was greatest when uptake remaining from the first dose was also greatest.

When a single dose of [3H]oestradiol (0·0039–2·5 μg.) was given to previously untreated mice or to mice with considerable oestradiol-induced uterine and vaginal growth, the only indications of any reduction of normal uptake ability were for the uterus when uptake was measured 1 hr. after doses greater than 0·11 μg.
INFLUENCE OF PINEAL GLAND PRINCIPLES ON GONADOTROPHIN-PRODUCING CELLS OF THE RAT ANTERIOR PITUITARY GLAND: AN ELECTRON MICROSCOPIC STUDY
Authors: CLEMENTI F. , DE VIRGILIIS G. , MESS BELA
Published: December 2008

The effects of the pineal gland on the ultrastructure of pituitary gonadotrophs have been studied. The results of luteinizing hormone (LH) estimations in the same rats have already been reported (Clementi, De Virgiliis, Fraschini & Mess, 1966; Fraschini, Mess & Martini, 1968). It was found that pinealectomy in normal animals greatly increases the pituitary content of gonadotrophins without significantly changing the ultrastructure of gonadotrophs.

Pinealectomy in castrated animals did not induce an increase in pituitary gonadotrophin stores above the level found after castration alone; the ultrastructure of the 'castration cells' was also unchanged.

Implants of melatonin or of pineal tissue into the median eminence or the reticular formation of the midbrain of castrated animals reduced the pituitary content of LH and, morphologically, the gonadotrophs reverted to a nearly normal state with a reduction in volume of the cisternae of the endoplasmic reticulum.

The relationship between gonadotrophin content and the ultrastructural appearance of the gonadotrophs is discussed.
RELEASE OF GONADOTROPHIN IN OVARIECTOMIZED MICE AFTER EXPOSURE TO MALES
Authors: BRONSON F. H. , DESJARDINS C.
Published: December 2008

Gonadectomized female C57BL/6J mice were caged with males to determine the effect of male stimuli on release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Concentrations of hypophysial and plasma FSH were significantly higher after 3 days of exposure to males when compared with controls maintained in the absence of a male. Hypophysial and plasma concentrations of LH were also higher in females caged with males, but not significantly so. Ovariectomized females were given 0·01 μg. oestradiol benzoate daily for 4 days in a second experiment and the effect of cohabitation re-evaluated. There were no significant effects of exposure to males on either FSH or LH after the oestradiol injections. Therefore the presence of males enhances synthesis and release of FSH in gonadectomized females. In addition, the results of the second experiment suggest that oestrogen interferes with this response in some way, possibly blocking the neural pathway utilized by male stimuli.
THE EFFECT OF ALDOSTERONE ON THE ELECTRICAL ACTIVITY OF RAT COLON
Authors: EDMONDS C. J. , MARRIOTT JANE C.
Published: December 2008

The effect of aldosterone on the colonic transmucosal potential difference (p.d.) was examined in normal, adrenalectomized and Na+ depleted rats. Continuous intravenous infusion of aldosterone in conscious animals was more effective than single i.v. injection and over the dose range 0·5–50 μg./hr. for 6 hr., p.d. increased linearly with log dose and returned to the pre-infusion levels 16–24 hr. after stopping infusion. Only a region 2–4 cm. from the anus responded to low doses, but with high doses an increasing length of colon responded. Cortisone (250 μg. daily) intramuscularly maintained adrenalectomized rats even when severely Na+ depleted without affecting the p.d. Cortisone (2·5 mg. daily, i.m.) raised the p.d. but the effect of low doses of aldosterone was unchanged. Neither Na+ depletion nor pentobarbitone anaesthesia affected the action of aldosterone but large doses of spironolactone reduced it. Aldosterone was effective when applied locally by submucosal injection in very low dose but was almost ineffective even in very large dose in the lumen. Again the most sensitive region was 2–4 cm. from the anus. Ouabain (10-3m) injected into the submucosa rapidly reduced the increased p.d. but was ineffective in the lumen.
THE ACTIVE NEUROHYPOPHYSIAL PRINCIPLES OF TWO PRIMITIVE BONY FISHES, THE BICHIR (POLYPTERUS SENEGALIS) AND THE AFRICAN LUNGFISH (PROTOPTERUS AETHIOPICUS)
Authors: SAWYER W. H.
Published: December 2008

Active neurohypophysial principles were separated from pituitary glands from a primitive actinopterygian, Polypterus senegalis, and the African lungfish, Protopterus aethiopicus. Both species appeared to possess arginine vasotocin (8-arginine oxytocin) and a more nearly neutral principle resembling oxytocin. In the case of Polypterus the neutral principle was pharmacologically indistinguishable from isotocin (4-serine, 8-isoleucine oxytocin). When subjected to partition chromatography on a Sephadex column the neutral Polypterus principle appeared homogeneous and emerged at an elution volume identical with that of isotocin. The neutral principle from Protopterus neurohypophysial extracts resembled mesotocin (8-isoleucine oxytocin) pharmacologically. On partition chromatography it appeared to be a single peptide with mobility comparable to that of mesotocin. No evidence was found for the presence of oxytocin despite earlier reports that this principle occurs in Protopterus and in the South American lungfish, Lepidosiren. From these studies it appears that Polypterus has neurohypophysial principles (arginine vasotocin and isotocin) identical with those found among higher actinopterygians, the Holostei and Teleostei. On the other hand, Protopterus principles resemble those found among Amphibia (arginine vasotocin, mesotocin, and possibly oxytocin).
THE EFFECT OF EXOGENOUS GONADOTROPHINS ON THE CONCEPTUS AND CORPUS LUTEUM IN PREGNANT SHEEP
Authors: MOOR R. M. , ROWSON L. E. A. , HAY MARY F. , CALDWELL B. V.
Published: December 2008

Interruption of pregnancy occurred in 25 out of 57 unilaterally pregnant sheep after gonadotrophins (pregnant mare serum and human chorionic gonadotrophin) had been injected at various times, ranging from day 17 to 70, in order to induce additional corpora lutea. The conceptus became moribund before luteal regression occurred. The same gonadotrophins administered on day 50 to hysterectomized sheep did not affect the corpora lutea. It would therefore appear that the primary action of the gonadotrophins is on the conceptus and that luteal regression is a secondary response.
SYNTHESIS OF CORTICOTROPHIN-LIKE POLYPEPTIDES AND PROTEIN BY BOVINE HYPOTHALAMUS, MEDIAN EMINENCE AND PITUITARY TISSUE SLICES
Authors: WINNICK M. , HUSSA R. O. , WINNICK T.
Published: December 2008

The biosynthetic activity of several bovine tissues was compared in slice incubation experiments based on the incorporation of 3H-labelled amino acids. An approximate parallelism was observed between general protein and peptide synthesis in each case. The highest activity was observed in hypothalamus and median eminence, followed by adeno- and neurohypophysis, while liver cells were least potent in these processes. A radioactive polypeptide preparation, isolated from hypothalamus and median eminence experiments, was found to resemble adrenocorticotrophin in certain physico—chemical properties, including molecular size and pattern of isotopic leucine incorporation.
THE DESIGN AND PRECISION OF PIGEON CROP SAC ASSAYS FOR PROLACTIN
Authors: FORSYTH ISABEL A. , HOSKING ZENA D.
Published: December 2008

The 'local' method of pigeon crop assay, involving injection of prolactin into the skin overlying the crop, was found to be much more sensitive than the systemic method. It suffers, however, from two drawbacks: first, the problem of finding a suitable method to measure the response; and secondly, the considerable variation in response between birds, especially when pigeons of unknown origin and age must be used. The results of measuring the response by cutting out and weighing the stimulated area are described, together with the use of a balanced incomplete block design which, using 30 pigeons in a (2+2) dose assay, gave an index of precision (λ) of 0·2 or less.
UROTERPENOL, A PETTENKOFER CHROMOGEN OF DIETARY ORIGIN AND A COMMON CONSTITUENT OF HUMAN URINE
Authors: SMITH OLIVE W. , WADE A. P. , DEAN F. M.
Published: December 2008

A Pettenkofer and sulphuric acid chromogen, excreted as a glucuronide and found in the fractions of urine that also contain hydroxylated Δ5-3β-hydroxysteroids and pregnanediol, was identified as p-menth-1-ene-8,9-diol (uroterpenol). Pettenkofer chromogenicity in a compound of this nature has not previously been reported. The recovery of uroterpenol in urine after ingestion of limonene showed that it was a metabolic product of this unhydroxylated monoterpene. Although experiments on its excretion by normal subjects indicated that it was largely, if not entirely, of dietary origin, there was evidence that its rate of excretion in women was influenced by endocrine factors. Hormonal effects on the formation and/or excretion of glucuronides in general are suggested. Care is needed to ensure that dietary constituents and their metabolites, which are excreted as glucuronides and exhibit colour reactions commonly used in the estimation of urinary steroids, are not confused with hormonal metabolites.
INCREASED PRODUCTION OF FOLLICLE-STIMULATING HORMONE IN IMMATURE FEMALE RATS BY A SINGLE INJECTION OF ANDROGEN OR OESTROGEN
Authors: NAQVI R. H. , JOHNSON D. C.
Published: December 2008

An increase in ovarian weight in immature rats after the injection of chorionic gonadotrophin (HCG) was used to measure variations in endogenous follicle-stimulating hormone (FSH) after steroid treatment. A single injection of several steroids (testosterone, androstenediol, androstenedione, oestradiol benzoate) given 12–96 hr. before treatment with HCG caused a 30–200% increase in ovarian weight. This was not a direct effect of the steroids since hypophysectomy abolished the response, and administration of the compounds concurrently with HCG was ineffective. Within certain limits an increase in the duration of pretreatment enhanced the ovarian response while an increase in the dose of steroid had little effect.

Pretreatment with testosterone propionate did not change pituitary FSH activity, indicating that the increase in circulating FSH was due to an increased production of hormone. On the other hand, pituitary FSH in animals treated with oestradiol benzoate was significantly lowered within 72 hr. suggesting an increased release of FSH.
OESTROGEN-PROGESTERONE RELATIONSHIPS IN THE INDUCTION OF OESTRUS IN SPAYED HEIFERS
Authors: CARRICK M. J. , SHELTON J. N.
Published: December 2008

Experiments were conducted to examine the behavioural response of spayed heifers to oestrogen, and its modification by progesterone.

In two groups of heifers, the median effective doses (MED) of oestradiol benzoate (ODB) were 121 and 132 μg. Repeated doses of ODB at physiological levels did not induce a state of refractoriness; in this respect the heifer is dissimilar to the ewe. However, repeated doses of 10 mg. ODB induced refractoriness to 400 μg. ODB. When such refractory heifers were treated with 10 mg. progesterone/day for 5 days, they showed a normal response to 400 μg. ODB given 3 days later. This return to normal sensitivity was not sustained, and pretreatment with progesterone was necessary for a normal response to subsequent small doses of ODB. The transient removal of the refractory state appears not to be due to a simple synergistic effect of residual progesterone, but to an effect of preconditioning a neural centre to respond to oestrogen. Increasing the duration of pretreatment with progesterone beyond 5 days did not result in a greater sensitivity to ODB.

Pretreatment with progesterone in heifers not made refractory to ODB did not result in an increased sensitivity to ODB. Moreover, up to 7 days after termination of the progesterone treatment, the response to ODB was reduced and the slope of the dose-response line was less steep than when ODB was injected alone. The reduction of the response was more pronounced with 40 mg. progesterone/day than with 10 mg.

The possible significance of these results in intact animals is discussed.
THE INFLUENCE OF THE PITUITARY ON THE RESPONSE OF THE SEBACEOUS AND PREPUTIAL GLANDS OF THE RAT TO PROGESTERONE
Authors: EBLING F. J. , EBLING ERIKA , SKINNER J.
Published: December 2008

Progesterone, given as an implant releasing 0·1–0·2 mg./day for 24 days, failed to increase sebum production or preputial gland weight in castrated or hypophysectomized-castrated male rats. A dose of 10 mg./day in arachis oil also failed to increase sebum production or mitoses in the sebaceous glands, though it increased by 70% preputial gland weight in the presence of the pituitary.

Hypophysectomy greatly reduced preputial gland wt, and the response of hypophysectomized rats to 10mg. progesterone/day was much less than when the pituitary was present. A porcine growth hormone preparation, known to facilitate the response of the sebaceous gland to testosterone in the hypophysectomized rat, failed to facilitate the response of the preputial gland to progesterone.

It is concluded that 'sebum-permissive' activity (the facilitation of the response of the sebaceous gland to testosterone) may be distinct from ' sebotropic' activity (facilitation of the response of the preputial gland to progesterone), and it is argued that each of these activities may prove to be separable from somatotrophic activity.
EVALUATION OF HUMAN FOLLICLE-STIMULATING HORMONE PREPARATIONS
Authors: BARKER S. A. , GRAY C. J. , KENNEDY J. F. , BUTT W. R.
Published: December 2008

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

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

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

Dexamethasone caused premature delivery when infused into foetal lambs at rates of 0·06–4·0 mg./24 hr. but it had no effect when administered to pregnant ewes at the rate of 4·0 mg./24 hr. Infusions into the foetus of deoxycorticosterone or corticosterone were ineffective; mixtures of dexamethasone and deoxycorticosterone did not cause parturition more rapidly than dexamethasone alone. Thus, the ability of corticosteroids to cause premature parturition appears to depend on glucocorticoid rather than mineralocorticoid activity.

Parturition induced by dexamethasone was not delayed by administration of 100 mg. progesterone/24 hr. to the ewe or to the foetus. This suggests either that withdrawal of inhibitory effects of progesterone on the myometrium can occur independently of the progesterone concentration in peripheral plasma, or that the mechanism of parturition provoked by corticosteroids in the foetus can override any regulatory influence of progesterone on myometrial contractility.

Partial aeration of the lungs was observed in lambs born vaginally at 117–123 days of gestation after receiving dexamethasone. It is suggested that this may be the result of accelerated appearance of surfactant activity.
INTERACTION BETWEEN PROLACTIN AND THYROXINE IN MOUSE MAMMARY GLAND LOBULO-ALVEOLAR DEVELOPMENT IN VITRO
Authors: SINGH D. V. , BERN H. A.
Published: December 2008

Intact female BALB/cCrgl mice, 3–4 weeks old, were pretreated with oestrogen and progesterone for 9 days. Whole mammary glands from these mice were cultivated for 5 days in a synthetic medium supplemented with aldosterone (A), prolactin (MH) and insulin (I), with and without thyroxine (T4) at concentrations ranging from 0·01 to 5 μg./ml.

A medium containing 1 μg. A +5 μg.MH +5 μg.I/ml. was generally optimal for lobulo-alveolar development. Addition of thyroxine to this combination resulted in a decrease in development which was highly significant at higher concentrations. However, when cultures were maintained in media containing suboptimal or low amounts of prolactin (1 μg. A + 3 μg. MH +5 μg. I/ml. and 1 μg. A + 1 μg. MH +5 μg. I/ml., respectively), the results indicate two possible effects of thyroxine: lower amounts of thyroxine had synergistic effects, whereas greater amounts had antagonistic effects on lobulo-alveolar development.
EFFECT OF HYPOTHALAMIC DEAFFERENTATION ON THE CONTROL OF LUTEINIZING HORMONE SECRETION
Authors: TALEISNIK S. , VELASCO M. E. , ASTRADA J. J.
Published: December 2008

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

The quantitative changes in glycogen content of the hamster uterus, cervix, upper and lower vagina during the first 8 days of pregnancy were measured. The amount of glycogen in the conceptual sites on days 6, 7 and 8 was determined and compared with that of artificially induced deciduomata. The greatest concentration of glycogen was demonstrated in the tissue of the upper portion of the vagina. While no significant differences were found in the uterus, cervix and lower vagina during the time-interval investigated, significant increases in glycogen in upper vaginal tissue occurred on the 6th, 7th and 8th day of pregnancy.

Uterine glycogen during the first 5 days, or the interdecidual sites on days 6, 7 and 8, did not differ significantly in their glycogen content. On day 6, when the conceptual site becomes discernible, the glycogen values were increased by 370% over the uterine levels of day 5 followed by a 28- and 31-fold increase on days 7 and 8.

The glycogen content of deciduomata induced non-mechanically (saline, oil, air) or by trauma (scratching) did not differ significantly from that of the conceptual sites of normal pregnancy.

These findings demonstrate that on day 6 a glycogenic stimulus is evoked which results in local stimulation of glycogen production in the decidual sites and the upper vagina. Induction of deciduomata by different procedures results in quantitatively similar amounts of the polysaccharide. The glycogenic factor, therefore (a) stimulates localized glycogen synthesis and (b) can be evoked by either natural or artificial means.
EFFECT OF HUMAN CHORIONIC GONADOTROPHIN ON THE UTERUS AND OVARIES OF HYPOPHYSECTOMIZED RATS
Authors: STOLZENBERG S. J. , WILBUR R. D.
Published: December 2008

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

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

The capacity of the interrenal tissue of the elasmobranch fish Squalus acanthias L., Scyliorhinus canicula L. and Galeus melastomus Rafinesque to synthesize corticosteroids in vitro has been examined and found to be augmented by the presence of NADPH or its generating system.

Homogenates of cold-stored interrenal tissue from all three species converted [4-14C]pregnenolone to labelled progesterone, corticosterone and 11-deoxycorticosterone. Homogenates from freshly killed S. canicula formed, additionally, 1α-hydroxycorticosterone. No indication of the synthesis of aldosterone, of 17α-hydroxycorticosteroids or of C19 steroids was obtained.
INFLUENCE OF PROLACTIN AND PITUITARY ISOGRAFTS ON SPERMATOGENESIS IN DWARF MICE AND HYPOPHYSECTOMIZED RATS
Authors: BARTKE A. , LLOYD C. W.
Published: December 2008

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

The rate of thyroxine utilization has been measured from the rate of degradation of [125I]thyroxine and the concentration of plasma proteinbound iodine in ewe lambs. Repeated measurements were made between 10 and 60 weeks of age in two groups of lambs, one in conditions including temporarily inadequate nutrition and outdoor ambient temperatures, and the other in a controlled environment with free access to food.

The lambs in the controlled environment showed an increase in thyroxine utilization with increasing age throughout the experiment, whereas the 'outdoor lambs' showed a decrease in hormone utilization until after 34 weeks of age. The 'outdoor lambs' also lost bodyweight between the 20th and 26th week of age due to the poor quality of the pasture, and this undernutrition is considered to have caused the lowered rate of thyroxine utilization. After 26 weeks of age the nutrition of these lambs was adequate but thyroxine utilization did not increase until after 34 weeks of age, when the mean environmental temperature was about 5°. It was concluded that undernutrition caused a marked depression in thyroxine utilization of young lambs.
EFFECTS OF CYPROTERONE ACETATE ON AGGRESSIVE BEHAVIOUR AND THE SEMINAL VESICLES OF MALE MICE
Authors: EDWARDS D. A.
Published: December 2008

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

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

Plasma growth hormone (GH) concentrations in adult sheep and lambs were measured by radioimmunoassay. Mean values before feeding were 3·1 (s.e. − 0·4, + 0·5) ng./ml. in lactating ewes and 3·9 (− 0·5, + 0·7) ng./ml. in their lambs. In adult wethers the mean GH concentration before feeding was 2·3 (−0·2, + 0·3) ng./ml.

After one i.v. injection of 400 μg. ovine GH, the hormone disappeared from the plasma of adult sheep with a half-time of 7–8 min. Plasma GH concentrations decreased at a similar rate after the establishment of high concentrations of endogenously secreted GH. The results suggest a shorter half-life than has been reported for human GH in man. GH could not be recovered in an immunologically recognizable form in urine. Fasting for 4 days led to no systematic change in plasma GH concentrations. Feeding did not increase plasma GH. Intravenous injection of saline resulted in some increase in plasma GH in both ewes and lambs. In adult sheep intravenous glucose (0·25 g./kg.) did not cause any greater change than that seen after saline, but in lambs an increase occurred. Intravenous injection of insulin (0·25 unit/kg.) resulted in an increase in plasma GH at 15–30 min. and this effect was found in both lambs and ewes. Infusion of adrenaline at either 25 μg. or 50 μg./min. into adult wethers (average body wt 51 kg.) caused a decrease in plasma GH concentration. It was concluded that the changes in plasma GH concentration of sheep in a number of physiological situations differ from those reported to occur in man.
LOCATION OF l-IDITOL: NAD OXIDOREDUCTASE (d-SORBITOL TETRAZOLIUM REDUCTASE OR KETOSE-REDUCTASE) IN THE GENITAL TRACT OF THE BULL
Authors: GERMINO N. I. , MICUCCI M. , GRAU V. , RAMA F. , CASTELLANO M. A.
Published: December 2008

The histochemical technique for the demonstration of the d-sorbitol dehydrogenase activity gave intensely positive results in the epithelium of the seminal vesicles and the glands of the ampulla of the ductus deferens of the bull. The enzymic activity was lower in the prostatic epithelium of the ductus deferens and the epididymis. The reaction was negative in the epithelium of the bulbo-urethral glands of Cowper.

The enzymic activity detected is connected with the synthesis of fructose, but in organs with a low concentration of fructose, such as the prostate gland and the ductus epididymidis the presence of the enzyme may be connected with the synthesis of sorbitol, also present in the semen.

In the seminal vesicles d-sorbitol dehydrogenase activity was found in the epithelium of the glandular tubules and in the material contained in those tubules. Using this technique, we have observed in the epithelium different types of cells which may correspond to different stages of a secretory cycle. The cells with greater deposits of diformazan appear to be related to the secretion of a product with enzymic activity.
OESTROGEN AND PROGESTERONE AND THE FUNCTION OF THE CORPORA LUTEA IN THE GUINEA-PIG
Authors: BLAND K. P. , DONOVAN B. T.
Published: December 2008

Regression of the corpora lutea in the guinea-pig could be accelerated by treatment with 10 μg. oestradiol benzoate daily over days 3–11 of the oestrous cycle. A single injection of 10 μg. oestradiol benzoate on day 3 was also effective. The luteolytic effect of oestrogen was abolished by hysterectomy, indicating that the uterus is involved in the mediation of the response. Progesterone (5 mg. daily over days 3–11) enhanced the luteal regression brought about by the presence of two glass beads in one horn of the uterus, but did not affect luteal size in otherwise intact females. Treatment of guinea-pigs with 5 mg. progesterone daily over days 2–5 or 4–7 failed to alter the length of the oestrous cycle.
THE IDENTIFICATION OF STEROIDS
Authors: BROOKS C. J. W. , BROOKS R. V. , FOTHERBY K. , GRANT J. K. , KLOPPER A. , KLYNE W.
Published: December 2008

In this paper the problems of establishing the identity of a compound isolated from biological material with a steroid are outlined and discussed. The nature of evidence required for identification and some techniques for obtaining this are briefly considered. The importance of establishing the specificity of a method for the quantitative measurement of a steroid in a biological extract is emphasized.
PATHWAYS OF DEHYDROEPIANDROSTERONE SULPHATE BIOSYNTHESIS IN THE HUMAN FOETAL ADRENAL GLAND
Authors: COOKE B. A. , COWAN R. A. , TAYLOR PATRICIA D.
Published: December 2008

The pathways of dehydroepiandrosterone sulphate (DHAS) biosynthesis in adrenal glands from the human previable foetus have been investigated by incubating pregnenolone, 17 α-hydroxypregnenolone and pregnenolone sulphate with homogenates of this tissue for different periods of time. The steroids formed were identified and measured by reverse isotope dilution or by gas—liquid chromatography and mass spectrometry of their derivatives. The results obtained are consistent with a main pathway from pregnenolone to DHAS via non-sulphated intermediates, i.e. 17 α-hydroxypregnenolone and DHA. The rate of pregnenolone sulphate metabolism to DHAS via 17 α-hydroxypregnenolone sulphate was found to be very slow compared with the rapid metabolism of pregnenolone to DHAS. These results are discussed in relation to the availability and nature of DHAS precursors in vivo.
THE STIMULATION OF INSULIN RELEASE BY ESSENTIAL AMINO ACIDS FROM RABBIT PANCREAS IN VITRO
Authors: MILNER R. D. G.
Published: December 2008

Pieces of rabbit pancreas were incubated in vitro in an incubation medium containing no glucose or 1·5 mg. glucose/ml. In each of these conditions the effect on insulin release of each of the essential amino acids at 5 mm concentration was studied. Leucine was the only essential amino acid that stimulated insulin release to a level which reached statistical significance in an incubation medium containing no glucose. In medium containing 1·5 mg. glucose/ml., arginine, isoleucine, leucine and lysine stimulated insulin release and phenylalanine inhibited insulin release. Glucagon, theophylline or dibutyryl cyclic adenosine monophosphate stimulated insulin release significantly in the presence of leucine but not in the presence of arginine. Arginine stimulated insulin release in the presence of leucine. The results of these experiments characterize further the difference in the mechanism of action of leucine and arginine on the pancreatic β-cell and indicate possible explanations for results obtained in other species in vivo.
STEROID BIOSYNTHESIS BY HUMAN FOETAL ADRENALS INCUBATED IN VITRO WITH [4-14C]PROGESTERONE: CHANGES WITH GESTATIONAL AGE
Authors: MILNER A. JOSEPHINE , MILLS I. H.
Published: December 2008

Adrenals from foetuses of 13 to 27 weeks gestation were sliced and incubated with 5 μC of [4-14C]progesterone for 2 hr. The biosynthesis of cortisol, 11-deoxycortisol, androstenedione and 11β-hydroxyandrostenedione was estimated by reverse isotope dilution. Cortisol was the major product identified and the production of both cortisol and 11β-hydroxyandrostenedione increased with gestational age in approximate proportion to the increasing adrenal weight. The ratio of (cortisol plus 11-deoxycortisol) to (androstenedione plus 11β-hydroxyandrostenedione) was constant at 13, 16 and 27 weeks gestation. The production of cortisol and androstenedione from progesterone and from pregnenolone by adrenal tissue from a 27-week-old foetus is compared.
PIGEON CROP SAC-STIMULATING ACTIVITY IN THE PITUITARY OF THE FLOUNDER (PLEURONECTES FLESUS)
Authors: CHADWICK A.
Published: December 2008

The examination of a pigeon crop sac-stimulating hormone from flounder pituitaries by polyacrylamide gel electrophoresis is described. Elution of the proteins after electrophoretic separation permitted both the identification of the protein bands responsible for stimulating the crop and a comparison with the prolactin bands from rat and toad pituitaries, as well as from the pituitaries of several other species of fish. The nature of the crop-sac response is discussed and it is suggested that certain features, in particular the absence of fatty granules, indicate a difference between fish and tetrapod prolactin sufficient to warrant the adoption of an alternative name for the fish hormone.
THE EFFECT OF ANGIOTENSIN ON RAT INTESTINAL FLUID TRANSFER
Authors: DAVIES N. T. , MUNDAY K. A. , PARSONS B. J.
Published: December 2008

Fluid transfer by isolated everted sacs of rat jejunum, ileum and intact colon prepared from adrenalectomized-nephrectomized rats 48 h after operation was reduced when compared with that of sacs prepared from untreated controls (P < 0·001). Angiotensin at 10−10 g/ml significantly (P < 0·01) stimulated fluid transfer by intestinal sacs prepared from the adrenalectomized-nephrectomized rats; all three regions of gut were equally sensitive.

Fluid transfer was similarly reduced in stripped colon sacs prepared from adrenalectomized-nephrectomized rats. Angiotensin had a dose-dependent biphasic action on fluid transfer by stripped colon sacs: low concentrations (10−11 and 10−12 g/ml) stimulated (P < 0·05), whilst high concentrations (10−9 and 10−8 g/ml) inhibited fluid transfer (P < 0·01). Histological examination of the colon preparations showed that the stripping procedure removed the ganglia, indicating that both angiotensin effects were due to direct action on the colon mucosa.

The significance of these results is discussed in relation to the role of angiotensin in the control of salt and fluid transport by the mammalian kidney and other epithelial tissues.
DEMONSTRATION OF MAMMOTROPHIC ACTIVITY OF THE MOUSE PLACENTA IN ORGAN CULTURE AND BY TRANSPLANTATION
Authors: KOHMOTO K. , BERN H. A.
Published: December 2008

Mammotrophic (i.e. mammogenic and/or lactogenic) activity of mouse placentae of different stages (4–19 days of pregnancy) was examined using organ co-culture of placental explants with mammary tissue. The test mammary tissues were taken from midpregnant (11–12 days) nulliparous A/Crgl mice and cultured in a synthetic medium (Waymouth's) supplemented with insulin (5 μg/ml) and aldosterone (1 μg/ml). The responses of mammary gland to placental explants were judged histologically, and were compared with those seen after the addition of ovine prolactin (5 μg/ml). With placentae from 6- to 19-day pregnant animals, distinct mammotrophic activity was seen, with the appearance of eosinophilic secretion in the mammary alveolar lumina, whereas with 4- or 5-day-old 'placentae', no mammotrophic activity was detected. Inasmuch as growth hormone does not substitute for prolactin in mammary gland development and function in the A/Crgl mouse, it can be concluded that a prolactin-like factor is present in the mouse placenta. The influence of placentae on mammary gland was further analysed by transplantation of placental fragments to mammary fat pads. Local lobuloalveolar development was prominent in some instances in the area around the placental transplants.