bluuebunny/crossref_metadata_2025_split huggingface dataset:
EFFECT OF LOCALLY IMPLANTED OESTROGEN ON THE RESPONSE OF THE RAT'S LACTATING MAMMARY GLAND TO OXYTOCIN
Authors: Bruce J. D. , Cofre X. , Ramirez V. D. 
Published: December 2008

ABSTRACT
On the day following delivery (day 1 of lactation) one abdominal mammary gland was implanted with oestrogen and the contralateral gland received an empty needle. At 2, 5 or 10 days of lactation the rats were anaesthetized with pentobarbital and the nipples of both abdominal glands were cannulated and their pressures recorded by means of transducers coupled to an amplifier and recording system. The normal mammary glands of 5-day lactating rats responded to very low doses of oxytocin (Syntocinon®, Sandoz) (5× 10−8 mU) with a rhythmic elevation in pressure.
However, saline infusion also evoked a small rise in intra-mammary pressure. Earlier (2 days) and later (10 days) in lactation the responses were smaller. Oestrogen decreases significantly the milk ejection response to oxytocin, and the effect was maximal at day 10 of lactation. Histological observations confirmed the diminished reaction of the gland to oxytocin, since the milk was retained in the alveoli of rats bearing a mammary-oestrogen implant. A paradoxical rise in pressure was detected in normal as well as in oestrogen-implanted glands when the lowest dose of oxytocin was injected in lactating rats which had previously received a high dose of oxytocin (50 mU or 500 mU). These results reinforce the hypothesis that oestrogen alters the milk ejection response to oxytocin and that the mechanism is probably related to changes in the contractility of the myoepithelial cells.
CHANGES IN HYPOTHALAMIC PEPTIDASE ACTIVITY DURING THE OESTROUS CYCLE IN THE ADULT FEMALE RAT
Authors: Griffiths E. C. , Hooper K. C. 
Published: December 2008

ABSTRACT
The activity of peptidases in the rat hypothalamus which are capable of inactivating oxytocin has previously been found to vary with stimuli known to influence gonadotrophin release and may be related to both luteinizing hormone (LH) and luteinizing hormone releasing factor (LH-RF) release (Griffith & Hooper 1972a,b). In the present study, enzyme activity was determined in normal female rats during the morning and afternoon of each stage of the oestrous cycle, in normal rats, and in female rats injected neonatally with testosterone. The activity of the supernatant fraction was found to be not significantly different during the morning of each stage, but was greatly decreased on the afternoon of pro-oestrus; particulate activity did not vary during the oestrous cycle. Supernatant and particulate activities were found to be the same in normal male rats and testosterone-treated females, as previously shown. Both fractions' activities were significantly less than those found in the oestrous cycle, other than on the afternoon of pro-oestrus. These results indicate changes in hypothalamic peptidase activity during the oestrous cycle which may be inversely related to LH and LH-RF release; they also confirm the masculinizing effect of neonatal testosterone on the hypothalamus.
PLASMA GROWTH HORMONE LEVELS AFTER LUNCH IN DIABETIC AND NON-DIABETIC SUBJECTS
Authors: Tchobroutsky Georges 
Published: December 2008

ABSTRACT
Plasma growth hormone (HGH) was serially assayed for 2 h after a midday meal in 56 non-diabetic subjects and in 55 diabetic patients, including obese and non-obese, insulin treated and non-insulin treated subjects.
The post-prandial mean HGH values during the 2 h of observation were very low. A very small but significant increase in the mean plasma HGH levels (up to 2 ng/ml) was observed 90 min after the beginning of the meal in non-diabetic non-obese women and in insulin treated diabetics of both sexes. Intergroup comparisons did not show any differences at any time except at the 90 min point between non-diabetic non-obese women and non-diabetic non-obese men.
There were no differences between non-diabetic and diabetic subjects. A few individuals in some groups showed elevated HGH values but there were no differences between the frequency of HGH responders among diabetic and non-diabetic subjects. Thus during the two hours after a midday meal there is no hypersecretion of HGH in diabetic subjects whatever the kind of treatment and the level of blood sugar.
INDUCTION OF GOITRE BY PTU OR KClO4 IN MALE AND FEMALE RATS. EFFECT OF GONADECTOMY
Authors: Jolín T. , Tarin M. J. , Garcia M. D. 
Published: December 2008

ABSTRACT
Male and female rats of varying ages were placad on a low iodine diet (LID) plus KClO4 or 6-propyl-2-thiouracil (PTU) or on the same diet supplemented with I (control rats). Goitrogenesis was also induced with LID plus PTU in gonadectomized animals of both sexes. The weight of the control and goitrogen treated animals, and the weight and iodine content of their thyroids were determined, as well as the plasma PBI, TSH, insulin and glucose levels. The pituitary GH-like protein content was assessed by disc electrophoresis on polyacrylamide gels.
If goitrogenesis was induced in young rats of both sexes starting with rats of the same age, body weight (B.W.) and pituitary growth hormone (GH) content, it was found that both the males and females developed goitres of the same size. On the contrary, when goitrogenesis was induced in adult animals, it was found that male rats, that had larger B.W. and pituitary GH content than age-paired females, developed larger goitres. However, both male and female rats were in a hypothyroid condition of comparable degree as judged by the thyroidal iodine content and the plasma PBI and TSH levels.
When all the data on the PTU or KClO4-treated male and female rats of varying age and B.W. were considered together, it was observed that the weights of the thyroids increased proportionally to B.W. However, a difference in the slope of the regression of the thyroid weight over B.W. was found between male and female rats, due to the fact that adult male rats develop larger goitres than female animals. In addition, in the male rats treated with PTU, gonadectomy decreased the B.W., pituitary content of GH-like protein and, concomitantly, the size of the goitre decreased; an opposite effect was induced by ovariectomy on the female animals. However, when goitrogenesis was induced in weight-paired adult rats of both sexes, the male animals still developed larger goitres than the females.
Among all the parameters studied here, the only ones which appeared to bear a consistent relationship with the size of the goitres in rats of different sexes, treated with a given goitrogen, were the rate of body growth and the amount of a pituitary GH-like protein found before the onset of the goitrogen treatment. Moreover, though the pituitary content of the GH-like protein decreased as a consequence of goitrogen treatment, it was still somewhat higher in male that in female animals.
The present results suggest that GH may somehow be involved in the mechanism by which male and female rats on goitrogens develop goitres of different sizes, despite equally high plasma TSH levels.
THE FORMATION OF THYROGLOBULIN IN HUMAN THYROID MEDULLARY CARCINOMA
Authors: Ljunggren J.-G. , Löwhagen T. , Hjern B. 
Published: December 2008

ABSTRACT
The biosynthesis of thyroglobulin has been investigated in five welldemarcated thyroid medullary carcinomas. The biochemical methods used allowed the study to be performed on small amounts of tissue, about 2–4 mg. The biochemical results were compared with the morphological structure.
A normal biosynthesis was obtained in three of the five investigated tumours. No indication of a biosynthesis was obtained in the remaining two tumours. The morphological investigation revealed that normal thyroid follicles were found in the tumour tissue close to the pieces with a normal biosynthesis. Normal thyroid follicles could not be found in the tumour tissue with no sign of biosynthesis. Metastases from two medullary carcinomas were also investigated. No indication for a biosynthesis of thyroxine or thyroglobulin was found. Normal thyroid follicles could not be demonstrated.
It is concluded that the biosynthesis of thyroglobulin in well-demarcated medullary carcinomas occurs in normal thyroid tissue present within the tumour. It is also concluded that all studies on the function of thyroid carcinomas must involve studies on very small pieces of fresh tissue in order to avoid heterogeneity and must involve a morphological examination of the surrounding tissue.
METABOLISM OF 6-CHLORO-9α,10α-PREGNA-1,4,6-TRIENE-3,20-DIONE IN RAT, RABBIT, MONKEY AND MAN
Authors: Breuer H. , Kime D. E. , Knuppen R. 
Published: December 2008

ABSTRACT
When 6-chloro-9β,10α-pregna-1,4,6-triene-3,20-dione (trengestone) was incubated with liver slices of male rats, the substrate was rapidly transformed to a polar metabolite; in contrast, liver slices of female rats metabolised trengestone much more slowly, and only traces of a polar metabolite could be detected. After paper and thin layer chromatography in various systems, the polar metabolite was obtained in crystalline form and identified as 6-chloro-16α-hydroxy-9β,10α-pregna-1,4,6-treiene-3,20-dione (16α-hydroxytreengestone) by its infrared spectrum and by gas chromatography-mass spectrometry. After administration of trengestone to male or female rats, the main metabolite in the urine was again a6α-hydroxytrengestone.
When trengestone was incubated with liver slices of male or female human subjects, two metabolites were detected, one of which was formed in large amounts. By comparison with the authentic compound, the major metabolite proved to be identical with (20S)-6-chloro-20-hydroxy-9β,10α-pregna-1,4,6-triene-3-one (20α-hydroxytrengestone). After oral administration of radioactive trengestone to man, the amount of total radioactivity in the urine was considerably greater in a human female (50 %) than in two human males (6–8 %). The main metabolite of trengestone was identified as 20α-hydroxytrengestone.
When trengestone was given orally to a female rabbit, and to a female Rhesus monkey, both the 20α-hydroxy and the 2β-hydroxy derivatives of trengestone were detected in the urine. These experiments demonstrate considerable differences in the metabolism of the rat, rabbit, monkey, and man.
ADRENERGIC CONTROL MECHANISM FOR ACTH SECRETION IN MAN
Authors: Nakai Yoshikatsu , Imura Hiroo , Yoshimi Teruya , Matsukura Shigeru 
Published: December 2008

ABSTRACT
In order to determine if an adrenergic mechanism is involved in the secretion of corticotrophin (ACTH), the effect of adrenergic-blocking or -stimulating agent on plasma ACTH, cortisol and glucose levels was studied in normal human subjects.
The intravenous infusion of methoxamine, an alpha adrenergic-stimulating agent, caused a rise in plasma ACTH and cortisol. This increase in plasma ACTH and cortisol was significantly inhibited by the simultaneous administration of phentolamine, an alpha adrenergic-blocking agent, in combination with methoxamine. The intravenous infusion of propranolol, a beta adrenergic-blocking agent, caused no significant change in plasma ACTH and cortisol, although it enhanced the plasma ACTH response to insulin-induced hypoglycaemia. On the other hand, alpha adrenergicblockade by intravenous infusion of phentolamine significantly suppressed the plasma ACTH response to insulin-induced hypoglycaemia. These studies suggest a stimulatory effect of alpha receptors and a possible inhibitory effect of beta receptors on ACTH secretion in man.
FACTORS AFFECTING PERIPHERAL CORTISOL LEVELS IN UNRESTRICTED EWES
Authors: Thurley D. C. , McNatty K. P. 
Published: December 2008

ABSTRACT
Sheep were bled at frequent intervals over a period including cyclical oestrus activity, pregnancy and lactation. The changes in peripheral plasma cortisol levels in response to herding by better or less well trained dogs or by people were compared. In all cases the cortisol response took the form of a hump-backed curve. The height of this hump was lower when people drove the sheep than when dogs were used, and was lower during lactation than in late pregnancy.
PERIPHERAL PLASMA LEVELS OF OESTROGENS, PROGESTERONE AND 17α-HYDROXYPROGESTERONE DURING GESTATION IN THE RHESUS MONKEY
Authors: Bosu William T. K. , Johansson Elof D. B. , Gemzell Carl 
Published: December 2008

ABSTRACT
Peripheral plasma levels of oestrogens1), progesterone and 17α-hydroxyprogesterone were measured during normal pregnancy in seven rhesus monkeys. The plasma concentrations of oestrogens ranged between 200 and 1300 pg/ml throughout the gestation period. Increases in the levels of oestrogens in plasma occurred several days before parturition. The plasma concentrations of progesterone ranged between 0.5 and 22 ng/ml during pregnancy. The concentrations of oestrogens decreased dramatically after parturition and remained low during the post-partum period. The concentration of progesterone decreased after parturition, but did not reach follicular phase levels during the period observed. The plasma levels of 17α-hydroxyprogesterone were low throughout the gestation period and during the post-partum period.
SUBCELLULAR DISTRIBUTION AND FATE OF RADIOACTIVITY IN OVARIES OF PSEUDO-PREGNANT RATS AFTER IN VIVO ADMINISTRATION OF [131I]HCG
Authors: Braendle Wilhelm , Breckwoldt Meinert , Graesslin Dieter , Weise Hans-Christoph 
Published: December 2008

ABSTRACT
After in vivo application of [131I]HCG to pseudo-pregnant rats most of the radioactivity is found in the ovaries. Ovarian homogenate contains per mg protein 50 times as much radioactivity as the liver and 7 times as much as the kidney. The relatively high amount of radioactivity in the kidney possibly reflects a rapid excretion of metabolized or damaged hormone. The subcellular distribution of radioactivity after in vivo application of the labelled hormone indicates a biologically occurring process which cannot be studied by in vitro experiments. Various binding components are shown to exist in the individual subcellular compartments of ovaries which diverge in their binding affinity and capacity for HCG. Binding sites in the nuclear fraction are already saturated when injecting 10 μg HCG together with the label. The uptake of radioactivity in the cytosol, however, is only inhibited when using higher doses of HCG. 1 μg LH-RH provokes maximum release of endogenous LH, inhibits radioactivity uptake by the corpuscular subcellular compartments and does not affect the binding components in the cytosol. It may be concluded that the hormone itself penetrates the cell membrane to reach its target site within the cell or that the recovered radioactivity in the different fractions is due to plasma membrane contamination which may represent the actual hormone binding sites.
RADIOIMMUNOASSAY FOR ALDOSTERONE WITHOUT CHROMATOGRAPHY
Authors: Vetter Wilhelm , Vetter Hans , Siegenthaler Walter 
Published: December 2008

ABSTRACT
A radioimmunoassay for the determination of plasma aldosterone has been developed suitable for the clinical laboratory.
Two ml of plasma is extracted with methylene chloride and the aldosterone concentration is determined in these extracts with two different antisera obtained from rabbits immunized with an aldosterone-oxime bovine gamma globulin conjugate. In view of the high recovery of [1,2-3H] aldosterone no internal standards are needed.
The coefficient of variation within a single assay was 9.0 and 10.6 % respectively. The coefficient of variation for inter-assay determinations was 13.5 and 15.0 %
The validity of the method was tested by the determination of plasma aldosterone concentration in normal subjects during postural changes and salt restriction and in patients suffering from primary hyperaldosteronism.
Both antisera gave almost identical values in 161 out of 170 plasma specimens. Since both antisera differed considerably in their degree of cross-reaction with various steroid hormones, the identical values obtained with the two antisera seem to provide a good indication that no cross-reaction with substances other than aldosterone had occurred in the assay systems.
IN VITRO BIOSYNTHESIS OF ANDROGENS IN CANINE TESTES
Authors: Oh Ran , Tamaoki Bun-ichi 
Published: December 2008

ABSTRACT
In the cell-free homogenates (supernatant fluid at 800× g) of canine testes, the following Δ5-pathway was suggested as the major biosynthetic route of testosterone in vitro: Pregnenolone → 17α-hydroxypregnenolone → dehydroepiandrosterone → 5-androstenediol → testosterone. This pathway was found to be partly dependent on a predominant cofactor present in the medium. In addition to the androgen formation, 17α,20α-dihydroxy-4-pregnen-3-one and 11 -deoxycortisol were produced in significant yields from 17α-hydroxyprogesterone by the cell-free homogenates. The activities of 17α-hydroxylase, 21-hydroxylase, C17—C20 lyase and 17β-hydroxysteroid dehydrogenase were concentrated in the microsomal fraction (10 000-105 000× g precipitate) of the testicular homogenates. By a time-course study on the metabolism of 17α-hydroxypregnenolone and dehydroepiandrosterone with the testicular microsomal fraction in the presence of NAD and NADPH, testosterone was formed from 17α-hydroxypregnenolone via dehydroepiandrosterone and subsequently 5-androstenediol or androstenedione. The biosynthetic pathways of androgens among vertebrates are discussed from the comparative endocrinological point of view.
URINARY FOLLICLE STIMULATING HORMONE AND LUTEINIZING HORMONE IN SIX MALES WITH THE XYY SYNDROME
Authors: Christiansen Peter , Nielsen Johannes 
Published: December 2008

ABSTRACT
Urinary follicle stimulating hormone (FSH) and luteinizing hormone (LH) were studied in 6 males with karyotype 47, XYY and compared to FSH and LH in 14 normal males of the same age. FSH was within the normal range in all 6 subjects, LH however was markedly elevated in one case. The FSH/LH ratio was thus decreased in one case but normal in the remaining 5 cases. The mean excretion of FSH and LH did not differ significantly from that of normal males.
DEMONSTRATION OF THYROGLOBULIN IN LYMPH VESSELS OF TSH STIMULATED GUINEA PIGS BY THE INDIRECT IMMUNOFLUORESCENCE TECHNIQUE
Authors: Böcker W. , Lietz H. 
Published: December 2008

ABSTRACT
The presence of thyroglobulin in intra- and extrathyroidal lymph vessels of TSH-stimulated guinea pigs was demonstrated immunohistochemically. Guinea pig thyroglobulin was purified by gel filtration on Sephadex G-200 and tested by the double diffusion method and by polyacrylamide gel electrophoresis. Antibodies to guinea pig thyroglobulin were obtained in rabbits by immunisation of the animals with this antigen.
Indirect fluorescence staining was performed on formol fixed paraffin embedded tissue with rabbit anti-guinea pig thyroglobulin serum in the first step and fluorescein-labelled antirabbit IgG from the goat in the second step of the incubation process.
ENDOCRINE CHANGES BEFORE AND AFTER THE MENARCHE
Authors: Lamberg B.-A. , Kantero R.-L. , Saarinen P. , Widholm O. 
Published: December 2008

ABSTRACT
In an endocrine survey of healthy girls aged 8 to 20 years before and after the menarche, the serum thyroxine (T4), uptake of triiodothyronine by Sephadex (T3U), and the binding capacities of thyroxine binding globulin (TBG) and pre-albumin (TBPA) were measured, and a free thyroxine index (FTI = T4 × T3U) was calculated. The subjects were grouped according to skeletal age (SA) until the menarche and after this in the post-menarcheal age (PMA), expressed in years.
T4 and FTI increased concomitantly and reached peak values of 8.40 μg/100 ml and 8.40, respectively, at 2–3 years PMA. The corresponding mean values for post-menarcheal girls (7.74 μg/100 ml and 7.51) differed statistically significantly from the means before the menarche (7.03 μg/ 100 ml and 6.75). The TBG remained virtually unchanged during the whole period, whereas the TBPA showed a continuous increase and reached a maximal level 1–2 years after the menarche.
The maturation process in girls in some way involves an increase in the total and free T4 level which is not dependent on hormone binding proteins.
ENDOCRINE CHANGES BEFORE AND AFTER THE MENARCHE
Authors: Lamberg B.-A. , Kantero R.-L. , Saarinen P. , Widholm O. 
Published: December 2008

ABSTRACT
In an endocrine survey of healthy girls aged 8 to 20 years before and after the menarche the serum TSH was measured by radioimmunoassay along with some parameters of thyroid function which are described separately. The subjects were grouped according to the skeletal age (SA) until the menarche and after this in the post-menarcheal age (PMA) expressed in years.
The TSH value was highest in the youngest age group and from then on decreased. However, within 0.5 years after the menarche another significantly elevated TSH peak occurred. There was no significant difference between the means for TSH before (5.4 μU/ml) and after the menarche (5.7 μU/ml). Both values, however, as well as the means for almost all the individual age groups, were significantly higher than the mean for 13 boys aged 12 to 16 years (3.9 μU/ml) and that for normal adults (3.6 μU/ml). When the girls were grouped according to the stage of puberty, the TSH peak at the time of menarche disappeared. When they were grouped according to SA, a gradual declining trend was seen from age 8 to 16 years.
It is concluded that the maturation process in girls in some way involves a significant elevation of serum TSH and an increase in the total and free T4 level which is not dependent on binding proteins.
ACTION OF POTASSIUM IODIDE ON THYROID ACID PROTEASE
Authors: Pisarev M. A. , Altschuler N. 
Published: December 2008

ABSTRACT
Potassium iodide (KI) is known to inhibit thyroid hormone secretion. In the present studies its action on the proteolytic step of this process was investigated. Rats were treated with KI (200 μg/ml in the drinking water) for 30 days. This treatment caused a decrease of protease activity in total homogenate and in the specific activity of a 15 000 × g pellet. No alteration in the pattern of subcellular distribution was observed. In order to rule out an action of KI on enzyme activity its in vitro action was studied. KI concentrations around 103-–10−4 m were without effect, though 10−2 caused a stimulation of activity. Similar results were observed when a liver enzyme preparation was checked under the same conditions. Neither CL− nor F− had an effect on thyroid or liver protease at concentrations between 10−2 to 10−4 m. The present results suggest that KI inhibition of thyroid hormone secretion can be explained at least in part by its action on acid protease. Moreover, the lack of an in vitro inhibitory affect of KI would suggests that this drug affects enzyme synthesis and/or breakdown.