bluuebunny/crossref_metadata_2025_split huggingface dataset:
INCREASED SENSITIVITY OF SEMINAL VESICLES TO TESTOSTERONE IN A MOUSE STRAIN WITH LOW PLASMA TESTOSTERONE LEVELS
Authors: BARTKE A. 
Published: December 2008

SUMMARY
In male mice of the C57BL/10J (C57) strain the testicular weight, sex drive and aggression are low compared with a number of other strains, indicating androgen deficiency. In contrast, DBA/2J (DBA) males were 'normal' in all studied parameters of testicular function. The weight of the seminal vesicles is similar in both strains.
Plasma testosterone levels, and the responsiveness of the seminal vesicles to injected testosterone propionate in C57 and DBA animals were compared. Plasma testosterone levels were 1·3 ± 0·4 ng/ml in C57 and 4·6 ± 1·0 ng/ml in DBA mice. The increase in weight of the seminal vesicles after administration of testosterone propionate to castrated male mice was, however, considerably greater in C57 than in DBA mice. In order to restore the weight of the seminal vesicles to normal it was necessary to administer twice as much testosterone propionate to DBA than to C57 males.
HISTOLOGICAL AND ULTRASTRUCTURAL CHANGES IN THE PARS DISTALIS OF THE RABBIT PITUITARY IN ORGAN CULTURE
Authors: PATHAK S. , FISK A. 
Published: December 2008

SUMMARY
Typical histological and ultrastructural changes that occur in the pars distalis of the rabbit pituitary after different periods of organ culture are described. The best technique for the maintenance of the maximum proportion of the explant was assessed by comparing cultures grown under different conditions. Explants in air with a medium buffered with N-2-hydroxyethylpiperazine-N1-2-ethanesulphonic acid (HEPES), not previously used in organ culture, proved more satisfactory than explants in carbogen with bicarbonate-buffered 199, and cultures were maintained for more than 3 weeks.
The survival of cells was assessed on the basis of their cytological integrity; DNA- and RNA-fluorescence with acridine orange was a valuable indicator. Prolactin cells, which were few in uncultured controls, became the most common type of granular cell in long-term cultures.
Cell modifications during culture included the development of a peripheral epithelioid layer and the appearance of numerous microvilli. Microfibrils, coated or smooth vesicles, lytic bodies, desmosomes and intranuclear rods became more common and intranuclear rodlets (fibrous or membranous structures) were identified. Cells often became more electron dense during long-term culture.
Though there was an increase in the number of agranular cells during culture, identifiable granules were retained by many cells throughout culture.
CHANGES IN LEYDIG CELL HYDROXYSTEROID DEHYDROGENASES INDUCED BY ADMINISTRATION OF TESTOSTERONE PROPIONATE TO NORMAL MEN
Authors: MORSE H. C. , HELLER C. G. 
Published: December 2008

SUMMARY
By the employment of an improved histochemical technique, frozen sections from human testicular biopsy specimens were examined for 3β-and 17β-hydroxysteroid dehydrogenase (HSD) activity, before, during, and after administration of 25 or 50 mg testosterone propionate per day to normal men. This administration strongly suppressed Leydig cell HSD activity and caused these cells to be transformed into fibroblast-like cells. After cessation of administration, the Leydig cells recovered morphologically and so did, simultaneously their 3β- and 17β-HSD activity. It is concluded that histochemically detectable 3β- and 17β-HSD are under gonadotrophin control and change with alterations in Leydig cell function. The morphology or 3β- and 17β-HSD are therefore probably acceptable as indicators of Leydig cell function in reproductively normal men.
OESTROGEN AND PROGESTERONE INFLUENCE ON THE RELEASE OF PROLACTIN IN OVARIECTOMIZED RATS
Authors: CALIGARIS L. , ASTRADA J. J. , TALEISNIK S. 
Published: December 2008

SUMMARY
The concentration of prolactin in serum after oestrogen and progesterone injection into spayed rats was measured by radioimmunoassay.
After a single injection of 5 μg oestradiol benzoate (OB) into long-term ovariectomized rats, serum prolactin concentrations showed a circadian rhythm with high levels in the afternoon and almost no changes in the morning. Peaks of prolactin occurred 2, 3 and 4 days after the injection. Below a dose of 1 μg OB, the response was dose-dependent, but the response was then maximal.
In spayed rats primed with 5 μg OB, the injection of 2 mg progesterone 2, 3 or 4 days later resulted in a significant increase in serum prolactin. This response, in contrast to that of oestrogen, occurred in the morning and in the evening and was found to be dose-dependent. The rise in serum prolactin after injection of 1 mg progesterone also showed a close relationship to the priming dose of OB. Progesterone had no effect in spayed, untreated animals. Maximal levels of prolactin were attained 3–4 h after the s.c. injection of progesterone. The release of prolactin which can be induced either by OB or by progesterone was blocked by the administration of progesterone injected 1 day before the expected release would occur. These results indicate that progesterone exerts both facilitatory and inhibitory effects on prolactin secretion. Male rats were found to be less sensitive to the ovarian steroid treatment.
It is suggested that oestrogen could be responsible for the rise in prolactin observed at pro-oestrus and progesterone for the increase in prolactin in pseudopregnancy and pregnancy.
OESTRONE, OESTRADIOL-17β AND OESTRIOL LEVELS IN HUMAN FOETAL PLASMA DURING GESTATION AND AT TERM
Authors: SHUTT D. A. , SMITH I. D. , SHEARMAN R. P. 
Published: December 2008

SUMMARY
Marked rises in both unconjugated and sulphoconjugated oestrone, oestradiol-17β and oestriol were observed in human foetal plasma between mid-gestation and term. Significant arterio-venous differences for the individual oestrogens in the unconjugated form were found in the umbilical cord plasma. No consistent arterio-venous differences were found for the oestrogen sulphates. This indicates that all three oestrogens are secreted from the placenta into the foetal circulation in the unconjugated form. Mean unconjugated oestrogen (oestrone + oestradiol-17β + oestriol) levels rose from 22·7 ng/ml at 17–20 weeks of gestation to 108·9 ng/ml at term in umbilical venous plasma and from 4·3 ng/ml to 23·3 ng/ml in umbilical arterial plasma. This represents a secretion rate of approximately 30 mg oestrogen/day into the umbilical vein at term. Mean oestrogen sulphate levels rose from 128 ng/ml to 313 ng/ml in the cord plasma during the same period. Of the three oestrogens measured, oestriol was quantitatively the major oestrogen in foetal plasma. It consistently represented about 78% of the unconjugated fraction and 95% of the sulphate fraction at all stages of gestation.
The method of delivery did not have a significant effect on the oestrogen levels in uncomplicated pregnancies. Similar oestrogen levels were found in foetal heart blood after either hysterotomy or spontaneous abortion at 16–20 weeks of gestation, and no significant differences were found for oestrogen levels in cord plasma after elective Caesarean section at 38–39 weeks when compared with oestrogen levels after normal delivery at term.
A significant rise in foetal unconjugated oestrogens at a time when foetal corticosteroids are increasing may be of physiological importance for foetal maturation in women.
THE INFLUENCE OF OVARIAN HORMONES UPON THE MOTILITY AND PROSTAGLANDIN PRODUCTION OF THE PREGNANT RAT UTERUS IN VITRO
Authors: HARNEY P. J. , SNEDDON J. M. , WILLIAMS K. I. 
Published: December 2008

SUMMARY
The output of prostaglandin-like material and the spontaneous contractions of the pregnant rat uterus in vitro have been studied during the last 6 days of pregnancy and for 3 days post partum. Both prostaglandin release and uterine activity were minimal on days 17–18 of pregnancy but both parameters gradually increased, reaching a peak on day 22, the expected day of delivery. Post partum both uterine prostaglandin release and spontaneous activity declined. Progesterone (25 mg, i.m.) given to rats from days 16–21 of pregnancy did not alter uterine activity or prostaglandin output when compared with uteri taken on day 22 from animals which had received ethyl oleate over the same period. On day 22 the spontaneous activity of uteri in vitro taken from animals ovariectomized on day 17 was very low compared with that seen in preparations from sham-operated controls, although prostaglandin release in these groups was not significantly different. Oestrogen (1 μg, i.m.) was given to one group of ovariectomized animals on days 19 and 20; uterine activity was determined on day 21 of pregnancy and found to be of greater intensity and amplitude than that seen in an ovariectomized control group. Prostaglandin output was similar in these groups. Thus although exogenous progesterone and oestrogen do not influence uterine prostaglandin release at term, oestrogen appears essential for the occurrence of spontaneous contractions. It is concluded that, in the pregnant rat uterus in vitro, prostaglandin release may contribute to uterine activity but oestrogen is essential for this to become apparent.
EFFECTS OF MICROQUANTITIES OF TESTOSTERONE ON THE EPIDIDYMIS AND ACCESSORY GLANDS OF THE CASTRATED RHESUS MONKEY, MACACA MULATTA
Authors: DINAKAR N. , ARORA RENU , PRASAD M. R. N. 
Published: December 2008

SUMMARY
Release of testosterone from silastic implants over a period of 90 days resulted in variable stimulation of the epididymis and accessory glands of reproduction in the castrated rhesus monkey. While the weights of the seminal vesicles, prostate gland and bulbo-urethral glands were maintained at the same level as the intact control animals by four or eight implants of testosterone, those of the epididymis and ductus deferens were not affected by either dose of testosterone.
Fructose in the seminal vesicles was stimulated significantly above intact control levels by eight implants of testosterone.
There was no regional variation in the levels of sialic acid in the caput, corpus and cauda epididymides, but the concentrations of phospholipid and total lipid were significantly higher in the caput epididymidis.
Our observations suggest there may be differential threshold requirements of androgens for the maintenance of the epididymis and accessory glands in the male rhesus monkey.
EFFECT OF ANGIOTENSIN II ON ALDOSTERONE SECRETION IN THE CONSCIOUS RAT
Authors: COLEMAN T. G. , McCAA R. E. , McCAA CONNIE S. 
Published: December 2008

SUMMARY
Aldosterone secretion has been shown to increase in response to exogenous angiotensin II in man and many experimental animals. However, the rat adrenal has traditionally shown little or no response to angiotensin in experimental protocols using either angiotensin added to incubating adrenal tissue or angiotensin infused into anaesthetized rats. In this study, changes in plasma aldosterone concentration in response to a 20 min infusion of small amounts of angiotensin II into conscious rats were compared with the changes produced in sodium pentobarbitone anaesthetized rats. Both groups showed typical arterial pressure increases in response to infusion: 5 ng angiotensin/kg/min producing approximately a 12 mmHg pressure increase and 20 ng angiotensin/kg/min producing approximately a 25 mmHg increase. Plasma aldosterone concentration increased in anaesthetized rats only at the higher infusion rate, reaching a value 37 ± 6v. 17 ± 2 (s.e.m.) ng/100 ml (n = 5) in anaesthetized control animals. In contrast, plasma aldosterone concentration in conscious rats increased to 69 ± 24 and 106 ± 43 ng/100 ml at the two infusion rates, respectively, v. 13 ± 5ng/100ml in conscious controls. This marked sensitivity indicates that the acute response of the rat to angiotensin infusion is similar to that of other experimental animals and man; however, the response is severely attenuated by anaesthesia and surgical preparation.
ALTERATION OF 3β-HYDROXYSTEROID DEHYDROGENASE ACTIVITY IN RAT OVARIES DURING THE OESTROUS CYCLE
Authors: GAWIENOWSKI A. M. , CLARK J. N. , SRINIVASAN C. N. 
Published: December 2008

SUMMARY
The activity of 3β-hydroxysteroid dehydrogenase has been determined during various stages of the oestrous cycle in rats. The enzyme activity was high during pro-oestrus and oestrus but low during dioestrus I and II.
PLACENTAL TRANSFER OF OXYTOCIN IN THE GUINEA-PIG AND ITS RELEASE DURING PARTURITION
Authors: BURTON A. M. , ILLINGWORTH D. V. , CHALLIS J. R. G. , McNEILLY A. S. 
Published: December 2008

SUMMARY
Oxytocin levels in pregnant and parturient guinea-pigs were studied by means of a sensitive and specific radioimmunoassay. Oxytocin was released from the maternal pituitary in substantial amount only during the expulsive phase of labour, when the mean concentration in carotid arterial blood in five animals was 503 pg/ml plasma (range 96–2900 pg/ml). Oxytocin was not found in the plasma of the first born at the moment of birth, but was usually detected in amounts ranging from 96 to 455 pg/ml in those born subsequently. The mean half-time of oxytocin in the maternal circulation during late pregnancy was 62 ± 7·5 (s.e.m., n = 5) s. In-vivo experiments showed that the placenta was permeable to oxytocin in both directions.
MODIFICATIONS IN OVARIAN AND PITUITARY FUNCTION IN THE HYSTERECTOMIZED PREGNANT HAMSTER
Authors: GREENWALD G. S. 
Published: December 2008

SUMMARY
When hamsters were hysterectomized on day 1 of pregnancy, ovulation occurred 17 days later. On day 12 of this prolonged pseudopregnancy, plasma levels of progesterone were approximately half of those of intact animals on the same day of pregnancy. The concentration of follicle-stimulating hormone in the pituitary of the hysterectomized animals was only half that of the pregnant group, but luteinizing hormone concentrations were similar. The massive proliferation of antral follicles characteristic of pregnant hamsters on day 12 was not found in the hysterectomized animals; injection of 20 i.u. human chorionic gonadotrophin (HCG) on day 12 resulted in the ovulation of 31 and 6 ova respectively, but priming the hysterectomized hamsters with pregnant mare serum gonadotrophin (before HCG) resulted in superovulation.
After hysterectomy on day 9 of pregnancy, by day 12 there was a rapid decline in luteal activity as shown histologically by the onset of structural luteolysis and a concomitant fall in luteal weight, and luteal and plasma levels of progesterone. These effects were partially or completely reversed by daily injection of 1 mg prolactin on days 9–11.
The results indicate that hysterectomy before the establishment of the placenta results in the sustained release by the pituitary of prolactin and gonadotrophins, but most likely at lower levels than in pregnant animals. However, hysterectomy on day 9 abruptly removes the placental source of a prolactin-like hormone and the pituitary cannot respond in time to prevent luteolysis.
CHANGES IN CELL PROLIFERATION RATE IN MOUSE UTERINE EPITHELIUM DURING CONTINUOUS OESTROGEN TREATMENT
Authors: LEE AUDREY E. , ROGERS L. A. , TRINDER GAIL 
Published: December 2008

SUMMARY
Fraction of labelled mitoses (FLM) curves were constructed for mouse uterine luminal epithelium during oestradiol treatment; on day 2 when mitosis was high, and on days 4 and 9 when mitosis was low. No difference was found between the duration of DNA synthesis on these 3 days. The distance between the first and second peaks, usually taken as an estimate of the mean cell cycle time, did not change significantly between days 2 and 4, although the labelling index fell from 38 to 8%. The second peaks of the FLM curves became progressively lower on the three days examined, which was consistent with the interpretation that there was a reduction in the probability of transition of cells from G1 (the post-mitotic period) into the replicative phase of the cell cycle, resulting in the observed fall in mitotic index.
THE INHIBITION OF FERTILIZING ABILITY OF EPIDIDYMAL SPERMATOZOA BY THE ADMINISTRATION OF OESTRADIOL BENZOATE TO TESTOSTERONE-MAINTAINED HYPOPHYSECTOMIZED OR CASTRATED HAMSTERS
Authors: LUBICZ-NAWROCKI C. M. 
Published: December 2008

SUMMARY
Experiments were designed to discover if oestradiol benzoate induces loss of fertilizing ability of hamster epididymal spermatozoa by acting directly on the cauda epididymidis. Spermatozoa were retained in the cauda epididymidis by ligating the distal corpus epididymidis and proximal ductus deferens and fertilizing ability was compared in oestrogen-treated, intact hamsters and in castrated or hypophysectomized animals maintained with testosterone. Fertility tests showed that 12 daily s.c. injections of 3·5 or 5 μg oestradiol benzoate reduced fertilizing ability to 35·2 and 0%, respectively; supplementary testosterone did not prevent the adverse effect of oestrogen and reduced fertilizing ability was shown not to be related to a deficiency of circulating testosterone as judged by fructose concentration in the seminal vesicles. Daily treatment of androgen-maintained castrated or hypophysectomized hamsters with 3·5 μg oestradiol benzoate for 12 days reduced fertilizing ability to 43·7 and 31·3%, respectively. The results suggest that oestradiol benzoate reduces fertilizing ability in hamsters by acting directly on the cauda epididymidis and inhibiting the effect of testosterone.
RADIOIMMUNOASSAY OF ENDOGENOUS AND EXOGENOUS PROLACTIN IN MILK OF RATS
Authors: McMURTRY J. P. , MALVEN P. V. 
Published: December 2008

SUMMARY
Immunoreactive rat prolactin was detected in rat milk. Increasing volumes of milk decreased the percentage of 131I-labelled rat prolactin bound to antiserum in a manner parallel to the decreases produced by increasing log doses of standard hormone and blood serum. Rats suckling litters of 4, 8 or 12 pups were milked at various stages of lactation and prolactin concentrations (ng/ml) in milk varied significantly both with stage of lactation and with litter size. Mean prolactin levels were maximal on day 4 to day 15 and they decreased sharply near the end of lactation. At every stage of lactation litter size tended to influence prolactin concentrations with larger litters always being associated with more prolactin per millilitre of milk. Intraperitoneal injection of 1 mg bovine prolactin into lactating rats promptly caused the appearance of high levels of this foreign hormone in rat milk without significantly affecting the concentration of the native hormone.
PROGESTERONE CONCENTRATION, INTRALUMINAL PRESSURE AND ELECTRICAL ACTIVITY OF THE GUINEA-PIG UTERUS
Authors: PORTER D. G. , YOSHINAGA K. , FORD J. 
Published: December 2008

SUMMARY
The electrical activity of the myometrium and the intra-uterine pressure were recorded by means of suction electrodes and intraluminal balloons respectively from anaesthetized, oestrogen-primed, ovariectomized guinea-pigs treated with progesterone (25 mg, s.c. twice, 16 h apart). No loss of intra-uterine pressure occurred after progesterone treatment and electrical activities in the balloon-containing and intact horns were indistinguishable. Furthermore, the concentration of progesterone in the uteri of these animals was 0·32 ± 0·05 (S.E.M.) μg (balloon-containing horn) and 0·43 ± 0·06 μ/g wet tissue (intact horn). These values greatly exceed the levels found in uteri of pregnant animals (0·07 ± 0·03 μ/g wet tissue). Thus the failure of progesterone to reduce myometrial activity in the guinea-pig is real and is not due to interference from the balloon, or to failure of the steroid to reach the uterine muscle or to lack of oestrogen priming.
PRODUCTION OF PROSTAGLANDINS BY THE EARLY PREGNANT GUINEA-PIG UTERUS IN VITRO
Authors: WALKER FELICITY M. MAULE , POYSER N. L. 
Published: December 2008

SUMMARY
The amounts of prostaglandins F2α (PGF2α) and E2 (PGE2) produced by homogenized, incubated, pregnant and non-pregnant guinea-pig uteri were compared. The sizes of the corpora lutea from these animals were considered in relation to the amounts of prostaglandins produced by their uteri.
The amount of PGF2α produced by the uteri from day-15 bilaterally pregnant guinea-pigs was significantly less than that produced by uteri from guinea-pigs on day 15 of the oestrous cycle. Corpora lutea from the pregnant animals were maintained but those from the day 15 non-pregnant animals had regressed. There was no significant difference between the results obtained for PGE2. Results from day 15 unilaterally pregnant animals and day 25 bilaterally pregnant animals are also presented and their implications discussed. The findings reported here may well explain how, in the guinea-pig, the conceptus is able to neutralize the luteolytic effects of the uterus.
A COMPARATIVE STUDY OF PROGESTERONE- AND CORTISOL-BINDING ACTIVITY IN THE UTERUS AND SERUM OF PREGNANT AND NON-PREGNANT WOMEN
Authors: GUÉRIGUIAN J. L. , SAWYER M. E. , PEARLMAN W. H. 
Published: December 2008

SUMMARY
The 105000 g supernatant fraction (soluble proteins) of homogenates of human uterine tissue, essentially myometrium, and peripheral blood serum, were assayed for progesterone- and cortisol-binding activity by batchwise use of Sephadex G-25 in test tubes (not gel filtration) under equilibrium conditions; the results were expressed empirically as the reciprocal of the protein concentration, 1/P, at 50% steroid binding. The steroid-binding activity of the uterine soluble proteins was due apparently to a single component closely resembling corticosteroid-binding globulin (CBG) with respect to equilibrium association constants, steroid ligand specificity, and elution behaviour on hydroxylapatite chromatography and Sephadex G-100 filtration. Therefore, the mean 1/P values for steroid-binding activity were converted to the apparent CBG content (nmol/g total soluble protein). Comparison of the mean ratio (about 0·2) of the respective total binding activity, uterus (g): serum (ml), with the mean ratio (0·03) of the total iron content, uterus:serum, indicated that the high CBG content of the uterus could not be attributed to retention of blood; the apparent CBG levels in skeletal muscle (pectoral) were very low. The mean values for the apparent CBG content of uterine soluble protein were almost as high as those for the CBG content of serum protein; the mean value for the apparent CBG content of uterine soluble protein was slightly higher for pregnant women (mostly in early pregnancy) than that for non-pregnant women with various gynaecological complications. On polyacrylamide gel electrophoresis, soluble protein from the uterus resembled that of serum in the areas corresponding to serum albumin and transferrin; the electrophoretic patterns were distinctly different, however, in the area between the origin and the transferrin band.
It is suggested that CBG may accumulate in interstitial fluid of the myometrium, thereby regulating the local concentration of bound and unbound progesterone and cortisol, and influencing hormone action on the respective target cells, muscle and fibroblast. A more extensive study of levels of progesterone- and cortisol-binding activity in serum was carried out also. It was concluded that the progesterone-binding activity of human serum, as in the case of human myometrium, is due largely to CBG.