bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plasma aldosterone response to acute stimulation in panhypopituitarism
Authors: Birkhäuser M. , Rionde A. M. , Gaillard R. , Mantero F. , Vallotton M. B. 
Published: December 2008

Abstract.
The influence of acute stimulation by ACTH, upright posture and angiotensin II on plasma aldosterone levels was assessed in human panhypopituitarism.
While stimulation by ACTH in hypopituitary patients induced a plasma aldosterone increase similar to that observed in healthy controls, stimulation by upright posture or by infusion of angiotensin II resulted in a lower plasma aldosterone response than in controls in most of the patients.
These results suggest that the presence of an anterior pituitary hormone, most likely ACTH, directly or indirectly exerts a permissive action on aldosterone secretion in man.
Inhibitory effect of potassium on blood pressure in DOCA salt hypertension in rats
Authors: Suzuki Hiromichi , Kondo Kazuoki , Saruta Takao 
Published: December 2008

Abstract.
The present study was performed to assess the influence of potassium on blood pressure in deoxycorticosterone (DOCA) salt hypertensive rats. The effects of potassium administration on the systolic blood pressure, fluid intake, urine volume, excretion of sodium and potassium, serum sodium and potassium, plasma renin activity (PRA) and plasma aldosterone concentration (PAC) were investigated both during the first 2 weeks of development of DOCA salt hypertension and during the next 2 weeks of established DOCA salt hypertension. Potassium administration prevented the development of DOCA salt hypertension and reduced the blood pressure in established DOCA salt hypertension. Fluid intake, urine volume, and excretion of sodium and potassium appeared to be markedly increased in rats treated with potassium. The levels of serum sodium and potassium were unchanged by potassium loading. Both the PRA and PAC which were suppressed in DOCA salt hypertensive rats, were reversed in rats treated by potassium loading. It is suggested that the elevation of blood pressure may be prevented and the increased blood pressure reduced mainly by the diuresis and natriuresis caused by potassium loading.
Effects of prolonged ACTH treatment on adrenal steroidogenesis and blood pressure in rats
Authors: Vazir H. , Whitehouse B.J. , Vinson G. P. , McCredie E. 
Published: December 2008

Abstract.
The effects of long-term (8–16 days) treatment of rats with synthetic 1–24 ACTH (100 μg/day) on adrenocortical function and blood pressure have been investigated. After 16 days, treated animals had considerably enlarged adrenals, a reduced body weight and systolic blood pressures of 169 ± 3 mmHg compared with 117 ± 4 mmHg in untreated controls. Corticosterone and 18-hydroxydeoxycorticosterone (18-OH-DOC) production in vitro from endogenous precursors was increased 3–4-fold in capsules and 1.5-fold in inner zones, whereas production of aldosterone and 18-hydroxycorticosterone was reduced. Similar increases in corticosterone and 18-OH-DOC production by capsules and inner zones were found with 12 days' treatment, during which blood pressure increased to a constant level after 8 days. Secretion of 18-OH-DOC and corticosterone by the left adrenal gland in anaesthetised rats was significantly higher in the ACTH treated group while the secretion of aldosterone was more than 80% lower. The aldosterone response of dispersed capsule cells to stimulation by potassium (8.4 mmol/l) and ACTH (10−8 mol/l) was lost following ACTH treatment. The responses of inner zone and capsule dispersed cell preparations to ACTH (10−8 mol/l) were reduced compared with controls. Restriction of the rats' sodium intake (to less than 20 μmol/day) during ACTH treatment did not prevent the decrease in aldosterone production in vitro, nor the increase in blood pressure. Overall chronic ACTH treatment resulted in a marked inhibition of aldosterone production and response to stimulation coupled with an increase in corticosterone and 18-OH-DOC production. The results are consistent with the hypothesis that ACTH induces functional transformation of the glomerulosa cell to a fasciculata-like cell. It appears that the hypertension in ACTH treated rats should be related to the increased secretion of corticosterone and 18-OH-DOC, and that aldosterone and 18-hydroxycorticosterone are not involved.
Effect of oestradiol-17ß on the metabolism of noradrenaline in brain slices of ovariectomized rats
Authors: Köster G. , Breuer H. 
Published: December 2008

Abstract.
Ovariectomized rats received a single injection of 10 μg oestradiol-17β 3-benzoate; 90 min or 19 h after injection, slices of various brain areas were prepared and incubated with tritiated noradrenaline for 30 min. Methylated and non-methylated metabolites of tritiated noradrenaline were determined after chromatographic separation. Nineteen h after administration of oestradiol-17β 3-benzoate, the formation of normetanephrine, 3-methoxy 4-hydroxy phenylglycol and 3-methoxy 4-hydroxy mandelic acid was decreased (P < 0.05) in hypothalamic tissue, whereas that of 3,4-dihydroxy mandelic acid was increased (P < 0.001). In thalamus tissue a decrease of normetanephrine (P < 0.05) and an increase of 3,4-dihydroxy mandelic acid (P < 0.01) were also observed. No conclusive results were obtained with hypophyseal tissue. The present findings suggest that oestrogens reduce the methylation of noradrenaline, probably through a competitive inhibition of the catechol-O-methyl-transferase by 2-hydroxylated oestrogens.
Somatomedin activity measured as sulphation factor in culture media from normal human liver and connective tissues explants. Effects of human growth hormone
Authors: Schimpff R. M. , Donnadieu M. , Gautier M. , Polini G. , Repellin A. M. 
Published: December 2008

Abstract.
Normal human explants from liver and from connective tissues (aponeurosis or skin) incubated in vitro released sulphation activity measurable in chick embryo cartilage. Addition of human Growth Hormone (hGH) at physiological levels (10 ng/ml) increased the sulphation activity after 6 hours incubation time. Higher doses failed to increase the sulphation activity produced by connective tissues and decreased the sulphation activity produced by the liver.
Sensitivity of insulin secretion to feedback inhibition by hyperinsulinaemia
Authors: DeFronzo Ralph A. , Binder Christian , Wahren John , Felig Philip , Ferrannini Eleuterio , Faber Ole K. 
Published: December 2008

Abstract.
The ability of insulin to inhibit its own secretion was examined in 15 normal subjects given an intravenous infusion of insulin in a dose of 0.25, 0.50, 1.0, 5.0 or 10.0 mU/kg/min for two hours. Arterial plasma insulin concentration achieved during the infusion segregated into three levels of hyperinsulinaemia: 35 ± 1 (mean ± sem), 87 ± 15 and 828 ± 210 μU/ml. Plasma glucose concentration was kept constant at the basal level by a variable glucose infusion. Fasting C-peptide (0.29 ± 0.02 pmol/ml) fell significantly in all subjects during hyperinsulinaemia and reached a concentration of 0.19 ± 0.03 pmol/ml at 60 min and 0.14 ± 0.03 at 120 min after the start of the insulin infusion. The C-peptide response was not related to the infusion dose nor to the steady state plasma insulin concentration.
It is concluded that (a) basal insulin secretion as evaluated from C-peptide measurements is inhibited by small (24 ± 3 μU/ml) physiological elevations in plasma insulin concentration independent of changes in plasma glucose, and (b) supraphysiological or even pharmacological elevations in plasma insulin do not result in a further decrease in endogenous insulin secretion above that achieved with mild hyperinsulinaemia.
Mineralocorticoid and metabolic response to metyrapone in normotensive children and children with dexamethasone-suppressible and primary hyperaldosteronism
Authors: Sonino Nicoletta , Levine Lenore S. , New Maria I. 
Published: December 2008

Abstract.
The effect of 5 to 9 days of metyrapone administration (400 mg/m2 every 4 h) on aldosterone, deoxycorticosterone, plasma renin activity, electrolyte balance, and blood pressure was investigated in 2 normotensive siblings (one of whom showed limited ACTH reserve), in 3 patients with hypertension and dexamethasone-suppressible hyperaldosteronism, and in a hypertensive patient with primary hyperaldosteronism due to bilateral adrenal hyperplasia.

Results:
1. Plasma and urinary aldosterone levels were steadily suppressed by metyrapone in all cases, except in the oldest patient studied who had dexamethasonesuppressible hyperaldosteronism and in whom, after a few days, aldosterone gradually rose to normal levels. 2. Mild mineralocorticoid effect occurred only in the normal subject. In all other patients there was no apparent mineralocorticoid effect despite deoxycorticosterone hypersecretion. 3. There was no significant change in blood pressure with metyrapone administration in any patient.
Isolated growth hormone deficiency, ovarian dysgenesis and Turner stigmata with normal chromosomal complement
Authors: McNeil Larry W. , Daniel James F. , Russell Marcia H. , Rabin David 
Published: December 2008

Abstract.
An 18 year old white female presented with short stature and amenorrhoea. Her height was 135 cm, weight 46.6 kg; she had a broad neck, a high arched palate, short fifth metacarpals bilaterally, short third, fourth and fifth metatarsals bilaterally and minimal breast development. Although the clinical picture strongly suggested Turner's syndrome, investigations revealed: (a) normal female 46,XX chromosomal pattern on analyses of skin, lymphocytes and ovarian tissue; (b) undetectable serum growth hormone levels; (c) pre-pubertal oestradiol-17β levels; (d) only very occasional primordial follicles on ovarian biopsy with a thickened capsule; and (e) basal LH and FSH levels of 6.8 and 9.6 mIU/ml which rose after LRH injection to 90 and 26 mIU/ml, respectively. The patient has the unusual combination of growth hormone deficiency, gonadal dysgenesis and Turner stigmata with a normal chromosomal complement.
Luteal blood flow and plasma steroids in rats with corpora lutea of different ages
Authors: Damber Jan-Erik , Janson Per Olof , Axén Claes , Selstam Gunnar , Cederblad Åke , Ahrén Kurt 
Published: December 2008

Abstract.
Ovarian and luteal blood flow rates were measured at different stages of luteal development in anaesthetized rats using 15 ± 5 μm radioactive microspheres. Ovulations were induced by injection of 8 IU of PMSG at 28 days of age. Steroid concentrations in peripheral plasma were determined using radioimmunoassays. The highest luteal blood flow was found in the youngest corpora lutea and decreased gradually with luteal age. Luteal flow on days 13 and 14 was significantly lower than that of days 2,4, and 6. Ovarian stromal blood flow remained unchanged throughout the lifespan of the corpus luteum. Peripheral progesterone concentrations rose significantly on days 4, 6, and 8 with a maximum on day 8, as compared to day 2, and fell significantly after day 8. The levels of 20α-OH-progesterone increased sharply on day 10, indicating functional luteolysis. The progesterone levels fell significantly between day 8 and 10 without a concomitant significant decline in luteal blood flow. Since a fall in progesterone production seems to precede a drop in luteal blood flow, the initiation of luteolysis does not appear to be caused by a vascular mechanism.
Possible circadian periodicity of foetal prolactin secretion late in gestation
Authors: Yaginuma Tsutomu 
Published: December 2008

Abstract.
Prolactin levels were determined in samples of umbilical venous blood at vaginal delivery after 38–42 weeks of uncomplicated gestation. The mean level of prolactin for all samples was 328.4 ± 7.4 (se) ng/ml. The levels did not vary significantly during these weeks of gestation, nor correlate with the duration of labour. The means of levels combined every 2 h varied significantly throughout the 24 h period with a maximum value of 460.3 ± 85.1 ng/ml at 2–4 a.m. and a minimum value of 241.4 ± 27.2 ng/ml at 6–8 a.m. and remained relatively constant between 2–4 and 10–12 p.m. These results suggest that a circadian periodicity may exist in the secretion of prolactin by the human foetus, and that this is not affected by labour and delivery.
Comparative response to oestradiol in the synthesis of the progesterone receptor in the maternal and foetal uterus of guinea pig and rabbit at the end of gestation
Authors: Laure Francoise , Pasqualini Jorge Raul 
Published: December 2008

Abstract.
In the present paper the stimulatory effect of oestradiol on the progesterone receptor (PR) in two species: rabbit and guinea pig, is studied in both the maternal and foetal uterine tissues. Oestradiol (1 mg/kg/day) in saline solution was injected sc into the maternal compartment of pregnant guinea pig and rabbit at the end of gestation for 3 consecutive days and the PR evaluated 24 h after the last injection; control animals received the vehicle alone. In the maternal uterus the number of specific binding sites in the cytosol fraction for the synthetic progestagen R-5020 (17α,21-dimethyl-19-nor-pregna-4,9-diene-3,20-dione) in the non-treated animals was, for the rabbit 117 ± 25 (sd) fmol/mg protein and for the guinea pig 325 ± 62 (sd) fmol/mg protein. In the treated animals a stimulation is observed of 2.5–3 times, 315 ± 85 (sd) fmol/mg protein for the maternal uterus of rabbit and 865 ± 100 (sd) fmol/mg protein for the maternal uterus of guinea pig. In the foetal uterus it is a very different picture, while in the foetal uterus of guinea pig a great stimulatory effect is observed on the PR; from 267 ± 53 (sd) fmol/mg protein in the nontreated animals to 1984 ± 357 (sd) in the oestradiolprimed animals; in the foetal uterus of rabbit very little or no PR is detectable in the non-treated animals while in the treated animals with the same or 1/20 of the dose of oestradiol for only 1 day, the death of the foetus was provoked.
In summary, the effect of oestradiol on the stimulation of PR in maternal uterine tissue is similar in these two species. In the foetal uterus of guinea pig the response to the action of oestradiol on the PR is very significant but this hormone is of great toxicity for the rabbit foetus. It is concluded that the oestradiol response of the foetus is related to the maturity of the foetus.
The relationship of plasma gonadotrophins and androgen concentrations to body growth in boys
Authors: Parra Adalberto , Cervantes Carlos , Sánchez Martha , Fletes Ladislao , García-Bulnes Guadalupe , Argote Rosa Ma. , Carranco Armando , Sojo Isaura , Arias Raúl , Cortés-Gallegos Vicente 
Published: December 2008

Abstract.
Plasma concentrations of luteinizing hormone (LH), follicle-stimulating hormone (FSH), 17 alpha-hydroxyprogesterone (17α-OPH), androstenedione (Δ4) and testosterone (T) were measured in 543 healthy boys aged 6.0 to 15.9 years (with weight and height between the 3rd and 97th percentile for Mexican standards) as a function of chronologic age (CA), weight, height, surface area (SA) and calculated lean body mass (LBM) and total body fat (TBF).
The earliest hormonal event was a clear rise in plasma 17α-OHP, either prior or simultaneously to at steady increase in plasma FSH, far ahead of any sign of puberty. These changes were closely followed by a continuous rise in plasma Δ4. Thereafter, there was a prolonged period of low but progressively increasing plasma FSH levels in the face of constantly low LH levels. However, a brisk rise in plasma LH and FSH occurred at a mean weight of 35.4 kg, at a height of 144.5 cm and when LBM was 32.0 kg. Simultaneously, plasma 17α-OHP began to fall, Δ4 reached a plateau and soon after, a marked rise in plasma T was documented. When plasma LH and FSH concentrations were plotted against CA, weight, height, SA and LBM a significant quadratic equation was disclosed in each case. Both gonadotrophins did not correlate with TBF. Multiple variance analysis demonstrated that LBM and SA had the most marked effect on LH, while LBM was the most important variable affecting plasma FSH concentrations. The present data suggest the association between a "critical level" of body composition and the major hormonal events in boys, regardless of a cause-effect relationship. A critical level of LBM (20–23 kg) and not of TBF was attained at time of the initial hormonal changes, as well as at the time of the major changes in plasma gonadotrophins (32–35 kg).
Hyperprolactinaemia does not affect the development of the stimulatory mechanism of oestrogen-progesterone on LH secretion
Authors: Moguilevsky Jamie A. , Faigón María R. , Scacchi Pablo , Scwarcfarb Berta 
Published: December 2008

Abstract.
Previous reports indicate that prolactin induces precocious puberty in the female rat. The present investigation was designed to determine if hyperprolactinaemia affects the development of the stimulatory effect of oestrogen-progesterone on LH secretion in prepubertal rats. Hyperprolactinaemia was induced by the administration of sulpiride at the dose of 7 mg/100 g body weight/day for 6 days. The rats were sacridied 6 to 9 h after the last injection. Normal sulpiride-treated rats were injected 76 h before sacrifice with 10 μg of oestradiol benzoate and with 1 mg of progesterone on the day of sacrifice. The animals were killed at 14, 22, 24, 28 and 32 days of age.
The sulpiride treatment induced a significant increase in serum prolactin levels (P < 0.01) at all ages studied. The treatment of oestrogen-progesterone induced prolactin release in controls and in the sulpiride-hyperprolactinaemic rats of 24, 28 and 32 day old but not in younger rats. The administration of oestrogen-progesterone alone in normal and in sulpiride hyperprolactinaemic rats produced a negative feed-back effect on LH secretion at 14 and 22 days of age and a significant stimulatory action at 24, 28 and 32 days. No differences were observed in the basal LH serum concentration between control and hyperprolactinaemic rats at the different ages studied. Our findings suggest that the modifications in the onset of puberty induced by hyperprolactinaemia are not connected with alterations in the maturation of the hypothalamic-pituitary mechanism involved in the positive feed-back effect of ovarian steroids on LH secretion.
The TRH-metabolite histidyl-proline-diketopiperazine (DKP) inhibits prolactin secretion in male rhesus monkeys
Authors: Brabant Georg , Wickings E. Jean , Nieschlag Eberhard 
Published: December 2008

Abstract.
Histidyl-proline-diketopiperazine (DKP) - a stable degradation product of TRH - has been shown to selectively inhibit prolactin secretion in vitro in rat pituitary tissue. In this study the effects of DKP on serum prolactin in intact and anaesthetized male rhesus monkeys and on TRH-stimulated prolactin levels have been investigated.
In conscious monkeys 400 μg DKP significantly suppressed prolactin levels by 27%, and under ketamine anaesthesia, serum prolactin was suppressed in a dose-dependent manner by 150 and 400 μg DKP. The maximum prolactin response and the cumulative response to TRH (20 μg) was significantly and specifically inhibited by 400 μg DKP, while the lower dose was without effect. TSH levels were not affected by DKP in any instance.
Hence DKP can specifically inhibit prolactin release in the rhesus monkey, and may be discussed as a possible regulatory factor in prolactin secretion.
Thyroglobulin assay in the follow-up of patients with differentiated thyroid carcinomas: comparison of its value in patients with or without normal residual tissue
Authors: Schlumberger M. , Fragu P. , Parmentier C. , Tubiana M. 
Published: December 2008

Abstract.
The usefulness of serum thyroglobulin (Tg) assay in the follow-up of differentiated thyroid carcinomas has been evaluated in 109 subjects divided into two groups.
Group 1 included 64 patients who had undergone total thyroid ablation. In 40 of the 41 patients in complete remission serum Tg was undetectable during replacement therapy (TSH below 5 μU/ml). In 18 out of the 40 patients serum TG was detectable following endogenous TSH stimulation. As 83% of these patients had ectopic uptake prior to the last radioiodine treatment, this release of Tg under TSH stimulation suggests the persistence of occult neoplastic tissue. Of the other 23 patients, 20 had bone or lung metastases and 3 patients had lymph node recurrences: in all these patients, serum Tg was detectable during replacement therapy and increased after TSH stimulation.
Group 2 included 45 patients in whom normal residual thyroid tissue was present at the time of the investigation. Of these, 35 patients were in apparent remission and 19 of them had detectable Tg level within the normal range. The other 10 patients had detectable metastases and in 4 of these the Tg level was also within the normal range. Thus, no conclusion can be drawn from a normal Tg level in the presence of residual thyroid tissue. Bovine TSH stimulation did not improve significantly the diagnostic value of Tg assay in this group of patients.
hCG and hCG subunits as tumour markers in patients with endocrine pancreatic tumours and carcinoids
Authors: Öberg Kjell , Wide Leif 
Published: December 2008

Abstract.
Serum levels of hCG, hCG-α- and hCG-βsubunits were measured in 29 patients with APUD-tumours, 16 patients with endocrine pancreatic tumours (EPT) and 13 patients with carcinoids. Twenty out of 29 patients (69%) had elevated level of hCG and its subunits. Among patients with EPT, 11 out of 16 (69%) had rised levels of these peptides. Three patients with benign tumours had normal concentrations, thus giving a frequency of 85% in the group of malignant EPT. In patients with carcinoids 9 out of 13 (69%) had elevated serum levels of at least one of the components. A discordance in secretion pattern between the two types of APUD-tumours was noticed. Only one patient, a case with a carcinoid had rised levels of the complete hCG molecule. The levels of hCG-α were elevated in 23% of the patients with malignant EPT and 69% of the patients with carcinoids while the corresponding frequencies of raised hCG-β levels were 69% and 8%, respectively. Three out of 4 patients with so-called non-functioning islet cell tumours had rised levels of the subunits. These results indicate that hCG subunits are valuable tumour markers in both of these APUD-tumours, and that malignant EPT predominantly secrete hCG-β- and carcinoids hCG-α-subunits.
Characterization of cytoplasmic progesterone receptors in rat granulosa cells. Evidence for nuclear translocation
Authors: Naess Oddvar 
Published: December 2008

Abstract.
The granulosa cells from immature rats were found to possess binding components for progestins. The physicochemical properties were determined. By sucrose gradient centrifugation, binding of [3H]R-5020 was observed in the 7S and 4S region of the gradient. Isoelectric focusing, however, revealed only one binding component (pH 5.9). The component was of protein nature and was destroyed by heating the cytosol fraction to 37°C for 30 min. Scatchard analysis of the data showed one single binding component with high affinity (KD ∼ 1.5 × 10−9 mol/l). The binding capacity was 50 fmol/mg protein in unprimed animals and 193 fmol/mg protein in animals treated with oestrogen. Studies on the steroid specificity revealed that R-5020 had the highest affinity for the receptors, followed by progesterone and the synthetic progestin, cyproterone acetate. Corticosterone, oestradiol-17β and testosterone had low affinity, whereas cortisol had no significant affinity for the receptor.
Using exchange assay, it was demonstrated that the cytoplasmic receptors translocated to the nucleus after administration of unlabelled progesterone to the animals.
The presence of cytoplasmic and nuclear progestin receptors, strongly indicates that progesterone may have a direct effect on granulosa cell function.