bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of treatment of neonatal rats with highly purified FSH alone and in combination with LH on testicular function and endogenous hormone levels at various ages
Authors: Ultee-van Gessel A. M. , Timmerman M. A. , de Jong F. H. 
Published: December 2008

ABSTRACT
Factors which play a role in the regulation of testicular size in rats were investigated using neonatal animals treated with exogenous gonadotrophins for 2 or 3 weeks, starting on the day after birth. Effects on testis weight and various aspects of the pituitary-testicular axis were evaluated up to the age of 9 weeks.
Daily treatment with human FSH (Metrodin; 0·15 U/g body wt) for 2 or 3 weeks, starting on the first day or 1 week after birth, resulted in enlargement of the testes, increased testicular content of inhibin and a suppression of pituitary and plasma FSH. The relative increase of testis weight decreased after cessation of treatment. Injections of human FSH combined with administration of human LH (Pergonal) for 3 weeks, starting on the first day after birth, resulted in larger testes immediately after treatment. In addition, an increased amount of interstitial tissue was observed in these animals. Pituitary and plasma FSH and LH were suppressed after this treatment, while the growth of the accessory sex organs was significantly stimulated.
In animals treated with human FSH during the first 2 or 3 weeks of life, levels of rat FSH in blood samples collected at weekly intervals were significantly suppressed until the animals were killed at the age of 9 weeks. In the animals treated with human FSH and human LH, both FSH and testosterone concentrations were significantly lower than those in control animals between the ages of 4 and 9 weeks. At the age of 9 weeks testicular weights were still higher than those in control animals after these treatments. In the treated animals, no histological abnormalities of spermatogenesis were observed.
We conclude that the first 3 weeks after birth are important for the establishment of testis size in the rat because during this period it is possible to stimulate mitoses of Sertoli cells with FSH. To obtain a permanent increase in testis size a longer period of treatment with exogenous gonadotrophins is needed. A possible feedback suppression of endogenous gonadotrophins by inhibin in FSH-treated rats and by inhibin and testosterone in the FSH- and LH-treated 3-week-old animals could be the reason for the relative delay of testicular development after the end of the treatments. The low endogenous level of LH which was observed caused impaired Leydig cell function in animals which were treated with FSH and LH.
J. Endocr. (1988) 116, 413–420
Radioimmunoassay of progesterone receptor in human tissues: application to breast cancer
Authors: Brailly S. , Lorenzo F. , Jolivet A. , Logeat F. , Pallud C. , Milgrom E. 
Published: December 2008

ABSTRACT
A radioimmunoassay method to measure progesterone receptor in rabbit and human tissues was devised and applied to human breast cancer. A specific progesterone receptor antibody was prepared by purifying rabbit receptor by immunoaffinity chromatography, sodium dodecylsulphate-polyacrylamide gel electrophoresis and injection of the isolated 110 000 dalton receptor band into a goat. Immunoblot studies of progesterone target and non-target tissues showed the specificity of the antibody, which was used at a dilution of 1/45 000. The tracer consisted of 125I-labelled electroeluted 110 000 dalton receptor.
The sensitivity of the method was 1 fmol/tube for the rabbit receptor and 3 fmol/tube for the human receptor. The intra-assay coefficient of variation was 11% for tumours positive for the progesterone receptor and 9·9% for those on the borderline (10–30 fmol receptor/mg protein). The interassay coefficients of variation were 20 and 19% respectively. The correlation between the radioimmunoassay and a steroid-binding assay was studied in 40 tumour biopsies. In 39 cases, very good correlation was found (r = 0·99); in a single case an immunoreactive protein was detected which apparently bound steroid poorly.
One important feature of this method was that receptor immunoreactivity remained unchanged when either the tissue or the cytosol was exposed to a temperature of 20 °C for relatively long periods of time. Under the same conditions the steroid-binding capacity declined rapidly. This characteristic of the radioimmunoassay may prevent errors due to improper handling of tissue samples. Such stability was not observed for oestrogen receptors when measured by a sandwich immunoenzymatic method after incubation of tissue at 20 °C.
J. Endocr. (1988) 116, 427–434
Plasma LH and testosterone responses to gonadotrophin-releasing hormone in adult red deer (Cervus elaphus) stags during the annual antler cycle
Authors: Fennessy P. F. , Suttie J. M. , Crosbie S. F. , Corson I. D. , Elgar H. J. , Lapwood K. R. 
Published: December 2008

ABSTRACT
Eight adult red deer stags were given an i.v. injection of synthetic gonadotrophin-releasing hormone (GnRH) on seven occasions at various stages of the antler cycle, namely hard antler in late winter, casting, mid-velvet growth, full velvet growth, antler cleaning and hard antler both during the rut and in mid-winter. The stags were allocated at random on each occasion to one of four doses, i.e. 1, 3, 10 or 95 μg GnRH. Blood samples were taken before GnRH injection and for up to 2 h after injection. Pituitary and testicular responses were recorded in terms of plasma LH and testosterone concentrations.
There was an increase in plasma concentration of LH after the GnRH injection in all stags at all stages of the antler cycle. Dose-dependent responses of LH to GnRH in terms of area under the curve were apparent at all stages of the antler cycle. The lowest responses were recorded at casting, during velvet antler growth and at the rut sampling.
The pattern of testosterone response reflected the inter-relationship of the antler and sexual cycles with very low testosterone responses occurring at casting and during velvet antler growth. The responses were higher at antler cleaning and then increased to a maximum at the rut before declining to reach their nadir at casting. The results are consistent with a hypothesis that the antler cycle, as a male secondary sexual characteristic, is closely linked to the sexual cycle and its timing is controlled by reproductive hormones. Low plasma concentrations of testosterone, even after LH stimulation, are consistent with the hypothesis that testosterone is unnecessary as an antler growth stimulant during growth.
J. Endocr. (1988) 117, 35–41
Monoclonal antibody enhancement of the effects of human growth hormone on growth and body composition in mice
Authors: Holder A. T. , Blows J. A. , Aston R. , Bates P. C. 
Published: December 2008

ABSTRACT
Dwarf mice were treated for 10 days with phosphate-buffered saline (PBS), human growth hormone (hGH) or hGH with monoclonal antibody EB1 (hGH/MAB-EB1); for each treatment there were three groups which received 50, 75 or 100% of the amount of food eaten when available ad libitum.
The PBS control groups lost more or gained less weight than equivalent groups receiving hGH alone, and mice given hGH/MAB-EB1 showed a greater weight gain than those in comparable groups receiving hGH alone. When weight gain or loss was expressed as g/g food eaten, groups treated with hGH gained more or lost less than the PBS groups. Similarly, weight gain/g food was significantly greater in hGH/MAB-EB1 animals than in the comparable groups given hGH alone. A similar pattern of response was observed for increases in tail length and uptake of 35SO42− into costal cartilage in vivo. For mice given hGH alone, fat content was decreased compared with that in the equivalent group given PBS, and mice treated with hGH/MAB-EB1 had less fat than the equivalent group given hGH alone. Administration of hGH alone caused a concomitant increase in protein content and body weight such that, compared with mice given PBS, there was no significant increase in protein as a proportion of body weight. However, hGH/MAB-EB1 caused an increase in whole body protein which was significantly greater than that for the equivalent group given hGH alone, when expressed as per cent body weight.
Monoclonal antibody EB1 has been shown to enhance the actions of hGH on growth and body composition in Snell dwarf mice and to increase food conversion efficiency.
J. Endocr. (1988) 117,85–90
Differential secretion of pro-opiomelanocortin peptides by the pars distalis and pars intermedia of beagle dogs
Authors: Kemppainen R. J. , Sartin J. L. 
Published: December 2008

ABSTRACT
Beagle dogs were given saline, insulin or the dopamine antagonist, haloperidol, to examine peripheral concentrations of immunoreactive (ir)-pro-opiomelanocortin (POMC) peptides resulting from pars distalis or pars intermedia stimulation. Six beagles were given each test substance on separate occasions with and without dexamethasone pretreatment. Plasma was assayed directly for glucose, ir-ACTH, ir-α-MSH, cortisol and, after Sephadex G-50 Fine gel filtration chromatography, for ir-β-lipotrophin (ir-β-LPH) and ir-β-endorphin (ir-β-END) content. Injection of 0·5 units insulin/kg lowered (P < 0·001) plasma glucose from 4·9 ± 0·3 mmol/l (mean ± s.d., saline controls) to 2·3 ± 0·5 mmol/l, coincident with increasing ir-ACTH (9·5 ± 3·1 to 106 ± 54 pmol/l), cortisol (52 ± 27 to 221± 27 nmol/l), ir-β-LPH (not detectable to 34 ± 18 pmol/l) and ir-β-END (not detectable to 52 ± 22 pmol/l). Plasma ir-α-MSH concentrations were not affected by insulin. Pretreatment with dexamethasone abolished the ir-ACTH, cortisol, ir-β-LPH and ir-β-END increases in response to 0·75 units insulin/kg. Haloperidol (1 mg/kg) increased (P < 0·01) plasma ir-ACTH (to 103 ± 63 pmol/l), cortisol (to 243 ± 11 nmol/l), ir-β-LPH (to 16 ± 6 pmol/l), ir-β-END (to 136 ± 73 pmol/l) and additionally raised ir-α-MSH (7 ± 8 pmol/l in saline controls to 131 ± 80 pmol/l after haloperidol). Pretreatment with dexamethasone significantly (P < 0·01 ) reduced the plasma ir-ACTH (96%), cortisol (93%), ir-β-LPH (100%) and ir-β-END (55%) response to haloperidol, but the ir-α-MSH increase (117 ± 81 pmol/l) was not affected.
The pituitary distribution of ir-β-END-like peptides was determined in tissue obtained from one healthy mongrel dog. Following G-50 gel filtration chromatography of HCl extracts, 40% of the total immunoreactivity determined in an extract of pars distalis eluted near the position of human β-LPH while 60% eluted near human β-END(1–31). In contrast, over 95% of ir-β-END eluted near β-END(1–31) in the tissue extract prepared from the neurointermediate lobe.
From the in-vivo data, it appears that insulin-induced hypoglycaemia selectively activates POMC peptide secretion by the pars distalis in dogs and that this effect is totally suppressible by dexamethasone. In contrast, haloperidol appears to activate secretion of POMC peptide from both the pars distalis and pars intermedia. The dog pars distalis secretes a mixture of ir-β-LPH and ir-β-END while the pars intermedia preferentially secretes ir-β-END.
J. Endocr. (1988) 117, 91–96
β-Core fragments are contaminants of the World Health Organization Reference Preparations of human choriogonadotrophin and its α-subunit
Authors: Wehmann R. E. , Blithe D. L. , Akar A. H. , Nisula B. C. 
Published: December 2008

ABSTRACT
Highly purified preparations of human choriogonadotrophin (hCG), hCGα and hCGβ, including those preparations which are being distributed by the World Health Organization as International Standards, cross-reacted in a new radioimmunoassay with increased relative specificity for the β-core fragment of hCG. A major portion of the β-core immunoreactivity in the hCG and hCGα preparations eluted from Sephadex G-100 in a position (approximate apparent molecular size 15 000–18 000) corresponding to that of purified β-core fragment prepared from pregnancy urine. However, in the case of hCGβ-subunit preparations, virtually all of the β-core cross-reacting material eluted from Sephadex G-100 in the same fractions as the native hCGβ-subunit. Quantitatively, the cross-reacting β-core material accounts for less than 1% (w/w) of the total hCG or subunit immunoreactivity, as measured by conventional radioimmunoassays. The presence of the β-core fragments as discrete molecular components of the hCG and hCGα preparations should be borne in mind when these preparations are used to calibrate new radioimmunoassays for hCG-related molecules.
J. Endocr. (1988) 117, 147–152
Inadequate function of corpora lutea following the induction of ovulation with monensin and FSH in seasonally anoestrous ewes
Authors: Atkinson S. 
Published: December 2008

ABSTRACT
Sixteen ewes in mid-seasonal anoestrus were stimulated to ovulate using sequential injections of FSH (total dose 10 mg) over a 4-day period. Half of the ewes received a dietary growth promotant (monensin) known to enhance the ovarian response to exogenous gonadotrophins. The ewes were ovariectomized on day 5 or 11 (day 0 = the initiation of FSH treatment). Serial blood samples were taken in half of the ewes to determine peripheral concentrations of LH and a single sample of ovarian venous blood was collected before ovariectomy. All luteal structures were dissected from the ovaries, counted and incubated in vitro to determine progesterone production. The luteal structures were then examined histologically for the abundance of luteal cells.
The physical appearance of the ovary, along with plasma concentrations of LH and ovarian venous oestradiol indicated that the monensin-treated ewes ovulated before control ewes. The corpora lutea from control ewes produced significantly (P <0·05) more progesterone than did the corpora lutea from the monensin-treated group. Furthermore, only 7% of the remaining luteal structures in the monensin-treated group produced significant amounts of progesterone on day 11, whereas 61% of the luteal structures in the control group were actively secreting progesterone. The mean number of granulosa cells in the follicles was similar at ovulation in the two groups, but the mean numbers of large and small luteal cells were significantly (P <0·05) lower in luteal structures from the monensin-treated ewes than in those from the control ewes. It is therefore postulated that inadequate corpora lutea function following precocious ovulation is due to a lack of luteal cell development formed after premature luteinization.
J. Endocr. (1988) 117, 167–172
Induction of LH hypersecretion in cyclic rats during the afternoon of oestrus by oestrogen in conjunction with progesterone antagonism or opioidergic blockade
Authors: Lustig R. H. , Pfaff D. W. , Fishman J. 
Published: December 2008

ABSTRACT
The pro-oestrous secretion of progesterone that follows the LH surge in the rat limits the expression of the daily signal for LH surge initiation until the following oestrous cycle. This study explored the role of endogenous opioid peptides in the extinction by progesterone of the signal for the LH surge induced by oestrogen. Intact cyclic rats underwent external jugular venous cannulation on dioestrus, and were allowed to elicit a spontaneous pro-oestrous LH surge. On the afternoon of pro-oestrus, rats received an s.c. injection of oestradiol and an s.c. injection of either oil, 17β-hydroxy-11β-(4-dimethylaminophenyl)17α-(prop-1-ynyl)oestra-4,9,dien-3-one (RU 486; a synthetic anti-progestin), or N-cyclopropylmethyl-6-desoxy-6-methylene-noroxy-morphone (nalmefene; a long-acting opiate antagonist). Repeat doses of each were administered on the morning of oestrus to maintain increased oestrogen levels, and either progesterone or opioidergic blockade. Plasma was obtained from 13.00 to 19.00 h on oestrus for determination of the concentration of rat LH.
Rats treated with oestradiol alone demonstrated consistently low concentrations of LH throughout the afternoon of oestrus. Rats treated with both oestradiol and either RU 486 or nalmefene demonstrated spontaneous augmentations of rat LH concentration during the afternoon of oestrus, which, although of diminished amplitude as compared with that seen in pro-oestrus, were consistent with a reactivation of the LH surge-generating mechanism. Rats treated with nalmefene in the absence of oestradiol were unable to augment LH secretion spontaneously.
These experiments suggest that antagonism of progesterone action at the time of the LH surge prevents the extinction of the LH surge signal, so that it may be reactivated the next day by exogenous oestrogen. They similarly demonstrate that persistent opioidergic antagonism will permit oestrogen to reactivate the daily LH surge signal. The similar properties of an anti-progestin and an anti-opiate in this study suggest that the pro-oestrous progesterone rise extinguishes consecutive daily LH surges, in part, through increases in opioidergic tone.
J. Endocr. (1988) 117, 229–235
Vitamin D-induction of secretory responses in rat pituitary tumour (GH4C1) cells
Authors: Wark J. D. , Gurtler V. 
Published: December 2008

ABSTRACT
1,25-Dihydroxyvitamin D3(1,25-(OH)2D3) selectively enhances prolactin gene expression in GH4C1 clonal rat pituitary tumour cells. Because this effect requires extracellular Ca2+, we studied the effect of 1,25-(OH)2D3 on another Ca2+-dependent process, agonist-induced hormone secretion. Pretreatment with 1,25-(OH)2D3 (1 nmol/l) caused at least 25-fold sensitization of GH4C1 cells to the voltage-sensitive Ca2+ channel agonist BAY K 8644 (methyl-1,4-dihydro-2,6-dimethyl-3-nitro-4-(2-trifluoromethylphenyl)-pyridine-5-carboxylate) as a prolactin secretagogue. This inductive effect of 1,25-(OH)2D3 followed a similar time-course to the enhancement of prolactin production. 1,25-(OH)2D3 had no effect on basal or BAY K 8644-induced 45Ca2+ uptake. The Ca2+-selective divalent cation ionophore 11,19,21-trihydroxy-4,6,8,12,14,18,20-heptamethyl-9-oxo-22-(tetrahydro-5 methyl-5-tetra hydro-5-(1-hydroxyethyl)-5-methyl-2-furanyl)-10,16-docosadienoic acid (ionomycin; 12 nmol/l–1·2 μmol/l) caused no significant increase in prolactin secretion in the absence of 1,25-(OH)2D3, but in cells treated with 1,25-(OH)2D3-(1 nmol/l), it increased prolactin secretion by 73% at 12 nmol/l and by a maximum of 98% at 0·12 μmol/l. These data demonstrate that vitamin D markedly enhances the responsiveness of GH4C1 functional pituitary tumour cells to two secretagogues which acts primarily through Ca2+-dependent mechanisms. They support the proposal that 1,25-(OH)2D3 acts in this cultured cell model either by effecting a redistribution of intracellular Ca2+ or by increasing the response of a Ca2+ -sensitive effector system, but not by enhancing agonist-induced Ca2+ uptake.
J. Endocr. (1988) 117, 293–298
Expression of androgen receptors and prostatic steroid-binding protein during development of the rat ventral prostate
Authors: Zhang Y. L. , Zhou Z. X. , Zhang Y. D. , Parker M. G. 
Published: December 2008

ABSTRACT
Prostatic steroid-binding protein (PSBP) mRNAs transcribed from the three genes C1, C2 and C3 were quantitated in neonatal rat ventral prostate by Northern blot analysis. Transcription was initiated at day 14 for C1 and C2 and day 10 for C3, and reached mature levels by day 21 for C1 and C2 and day 28 for C3. The changes of both cytoplasmic and nuclear prostatic androgen receptors in 10- to 150-day-old rats were investigated by radioligand assay and showed a fivefold transient increase between days 10 and 28. Thus there was a good correlation between the onset of PSBP gene expression and the transient increase in androgen receptors; increases in receptor concentration may be a prerequisite for changes in gene expression.
J. Endocr. (1988) 117, 361–366
Aldosterone in colonic potassium adaptation in rats
Authors: Edmonds C. J. , Willis C. L. 
Published: December 2008

ABSTRACT
The influence of adrenalectomy and administration of aldosterone on potassium secretion by colonic epithelium was studied in vivo in rats, particularly in relation to potassium adaptation (induced by feeding a potassium-rich diet) and the response to acute i.v. administration of a potassium load. Adrenalectomy (rats maintained on dexamethasone and saline) impaired the development of potassium adaptation or considerably reduced it if the rats had been previously adapted. The partial adaptation observed in the adrenalectomized rats may be related to the increased plasma potassium concentration developed when these rats received the potassium-rich diet.
Within 2 h of acute aldosterone administration, the response of the potassium secretion rate to acute potassium loading in adrenalectomized rats was significantly improved. When aldosterone (2 μg/day per 100 g body weight, given by osmotic minipump) was added to the replacement treatment, the plasma concentration of potassium was similar to that of the intact rats, and both potassium adaptation and the response to the acute potassium load were completely restored. Transepithelial potential difference and sodium transport were not stimulated, being similar to the values in intact rats. Considerable changes in potassium secretion induced by acute potassium loading did not significantly affect sodium transport.
The findings suggest that the sodium and potassium epithelial pathways are, to a large extent, independently influenced by aldosterone. Aldosterone appears to be essential for complete adaptation and, in a relatively low dose, can completely restore potassium adaptation and the response to acute potassium loads in adrenalectomized rats.
J. Endocr. (1988) 117, 379–386