bluuebunny/crossref_metadata_2025_split huggingface dataset:
ALDOSTERONE SECRETION DURING HIGH SODIUM CEREBROSPINAL FLUID PERFUSION OF THE BRAIN VENTRICLES
Authors: Abraham Suzanne F. , Blair-West John R. , Coghlan John P. , Denton Derek A. , Mouw David R. , Scoggins Bruce A. 
Published: December 2008

ABSTRACT
Conscious sheep with permanent indwelling cannulae in the lateral ventricles and the cisterna magna were Na depleted and then perfused for 9 h with an artificial CSF solution. There were 3 experimental groups: Group I (n = 5) received perfusion with artificial CSF containing Na 170 mEq./l, Group II (n=7) received perfusion with artificial CSF containing Na 145 mEq./l, Group III (n = 7) received no perfusion. In Group I the blood aldosterone level fell from 26.4 ± 7.4 to 8.6 ± 2.3 ng/100 ml by 9 h after perfusion. There was no significant change in plasma [Na] or [K], blood angiotensin II or plasma renin concentration. Blood cortisol and corticosterone levels rose. There was also a fall in blood aldosterone in Group II but this was not significant until 4 h post-perfusion. Group III showed no significant change in blood aldosterone concentration. Multivariate statistical analysis showed that the fall in aldosterone levels during 170 mEq./l Na perfusion could not be accounted for by changes, either alone or together, of ACTH as evidenced by alteration in blood cortisol or corticosterone, or by change of plasma [Na], [K] or renin concentrations. This data supports the hypothesis of an additional factor which may be of CNS origin being involved in the control of aldosterone secretion.
PATHWAYS OF TESTOSTERONE SYNTHESIS IN DECAPSULATED TESTES OF MICE
Authors: de la Torre B. , Benagiano G. , Diczfalusy E. 
Published: December 2008

ABSTRACT
In order to study the temporal relations in the biogenesis of testosterone, decapsulated testes of adult mice were incubated with carbon-14-labelled sodium acetate and attempts were made to isolate the most likely intermediates.
Considerable quantities of radiochemically homogeneous squalene, lanosterol, cholesterol, testosterone and androstenedione, but no pregnenolone, progesterone, 17-hydroxypregnenolone, 17-hydroxyprogesterone, dehydroepiandrosterone, pregnenolone sulphate or dehydroepiandrosterone sulphate were isolated. The same pattern of incorporation was found when gradually increasing amounts of non-labelled pregnenolone, progesterone, 17-hydroxypregnenolone, 17-hydroxyprogesterone, dehydroepiandrosterone, dehydroepiandrosterone sulphate or testosterone were added to the system as "trapping agents" or when Leydig cell preparations rather than decapsulated testes were used.
The presence of 10 mIU of HCG greatly enhanced the de novo formation of testosterone, androstenedione and 5α-dihydrotestosterone but did not change the pattern of acetate incorporation.
Radioimmunoassays of the incubation medium with or without added HCG, and carried out at different periods of time indicated the presence of gradually increasing amounts of testosterone and androstenedione together with some 5α-dihydrotestosterone, whereas only trace amounts of pregnenolone, progesterone, 17-hydroxypregnenolone, 17-hydroxyprogesterone and dehydroepiandrosterone were present.
An analysis of the incubated testes revealed that the addition of HCG significantly enhanced the content of testosterone, androstenedione and 5α-dihydrotestosterone. Little or no increase was observed as far as pregnenolone, progesterone, 17-hydroxypregnenolone, 17-hydroxyprogesterone or dehydroepiandrosterone were concerned.
It is concluded that decapsulated testes of mice synthesize de novo testosterone from sodium acetate under conditions in which the formation of pregnenolone, progesterone, 17-hydroxypregnenolone, 17-hydroxyprogesterone, pregnenolone sulphate and 17-hydroxypregnenolone sulphate cannot be demonstrated.
A HISTOCHEMICAL APPROACH TO THE STUDY OF HUMAN CHORIONIC GONADOTROPHIN RECEPTORS IN THE RAT TESTIS
Authors: Lago A. Dal , Rolandi M. T. , Galli S. , Bortolussi M. 
Published: December 2008

ABSTRACT
Standard suspensions of interstitial cells in PBS were exposed to the action of various fixatives, solvents (clearing agents), temperatures and U. V. light, in order to establish the effects of such chemical and physical agents on the HCG receptors. After exposure to the various agents, the interstitial cells were incubated with [125I]HCG for 2 h at 37°C. To check the specificity of the reaction, competitive tests were performed with added excess non-iodinated HCG.
Only formaldehyde fixation for short periods of time, preserved satisfactorily the specific binding activity of the receptors.
A different degree of thermolability of the receptors was demonstrated, in relation to 37, 45, 54 and 60°C, while freezing in liquid nitrogen had no effect on the receptors binding activity.
After the binding reaction, solvents had a significant solubilizing effect on the HCG-receptor complexes.
U. V. light had no significant damaging effect on the receptors.
The application of the results for a histochemical approach to the study of the HCG receptors is discussed.
A SIMPLE COMPETITIVE PROTEIN-BINDING ASSAY FOR ADENOSINE-3′,5′-MONOPHOSPHATE IN PLASMA AND URINE
Authors: Madsen S. Nistrup , Badawi I. , Skovsted L. 
Published: December 2008

ABSTRACT
A modified competitive protein-binding assay for the measurement of adenosine-3′,5′-monophosphate is desribed. The procedure allows measurement of adenosine-3′,5′-monophosphate in unextracted plasma samples. The mean plasma values in 25 normal, fasting and ambulatory subjects were 22.7 ± 4.7 pmol/ml (mean ± sd) (range 13–31 pmol/ml. The mean urinary content was 3.2 ± 1.0 μmol per g creatinine (mean ± sd) (n=24).
EFFECT OF α-MSH ON PLASMA LEVELS OF LH, FSH, PROGESTERONE AND CORTISOL DURING THE CORPUS LUTEUM PHASE OF THE MENSTRUAL CYCLE
Authors: Runnebaum B. , Heep J. , Geiger W. , Vecsei P. , Andor J. 
Published: December 2008

ABSTRACT
In healthy women (21–28 years) the influence of synthetic α-MSH upon the peripheral plasma levels of LH, FSH, progesterone and cortisol was determined during the corpus luteum phase of the menstrual cycle. As controls 3 women were given 6 intravenous infusions of 250 ml NaCl; 4 women received a total of 18 intravenous infusions of 5–20 mg α-MSH from 9.00 to 11.00 a. m. on the 5th and 7th hyperthermic day of the menstrual cycle. The blood levels of the hormones were usually followed for 24 h, and in two cases for 48 h. During and after the control as well as the experimental infusions with 5–20 mg α-MSH, no significant changes in the plasma concentrations of LH, FSH and progesterone were found. The cortisol concentrations, however, showed on the average a 2-fold increase over the initial values during the infusion of 5 mg and 10 mg α-MSH. During the control infusions they were not enhanced. One experiment was conducted with 20 mg α-MSH. The increase in the plasma cortisol levels following α-MSH administration generally seemed to be dose dependent, but statistically no significant differences regarding the increase in cortisol level could be detected between the 5 mg and 10 mg doses.
SOME ASPECTS OF HYPOTHALAMIC-PITUITARY FUNCTION IN PATIENTS WITH ANOREXIA NERVOSA
Authors: Travaglini P. , Beck-Peccoz P. , Ferrari C. , Ambrosi B. , Paracchi A. , Severgnini A. , Spada A. , Faglia G. 
Published: December 2008

ABSTRACT
The secretion of luteinizing hormone (LH), follicle-stimulating hormone (FSH), thyrotrophin (TSH) and prolactin (PRL, was studied in 17 women suffering from anorexia nervosa. The mean basal serum LH was reduced (8.4 ± 0.8 se mIU/ml; P < 0.001 vs normal controls), while LH increase after gonadotrophin-releasing hormone (LH-RH) appeared to be normal in 9 cases and impaired in 6 cases. The mean basal FSH did not significantly differ from normal subjects (3.9 ± 0.5 mIU/ml), while LH-RH administration elicited an exaggerated increase in 7 cases and a normal increase in 8 cases: the mean FSH response was significantly higher than in controls (P < 0.02). Plasma oestradiol-17β was reduced (20.4 ± 0.4 pg/ml; P < 0.001) while the serum testosterone levels were normal (0.73 ± 0.09 ng/ml). Clomiphene administration induced an increase in gonadotrophins in only 1 out of 7 patients. The mean serum TSH concentration was normal (2.3 ± 0.4 μU/ml), while serum thyroxine and triiodothyronine and free thyroxine index, though generally in the normal range, were significantly lower than values obtained in a control group (6.1 ± 0.4 μg/100 ml, P< 0.005; 102.3±7.7 ng/100 ml, P <0.005; 3.8±0.3, P < 0.05). Though the mean serum TSH increase after thyrotrophin-releasing hormone (TRH) was normal (12.0 ± 2.3 μU/ml), there were 4 impaired and 1 exaggerated increases, and 8 patients showed a delayed and frequently prolonged response.
The increase in serum T3 after TRH appeared lower than in normal subjects (36.3 ± 1.8 ng/100 ml, P < 0.001). Serum PRL levels in basal conditions were higher than in the controls (19.4 ± 4.1 ng/ml, P < 0.001) while the increase in PRL after TRH was exaggerated in only 2 patients. The present data suggest that the primary failure in gonadotrophin secretion in anorexia nervosa occurs at hypothalamic level; moreover the data on TSH and PRL secretion also point to the existence of a hypothalamic disorder in this disease.
THE EFFECT OF ACTH ON PLASMA TESTOSTERONE AND ANDROSTENEDIONE CONCENTRATIONS IN PATIENTS WITH PROSTATIC CARCINOMA
Authors: Cowley Teresa H. , Brownsey B. G. , Harper M. E. , Peeling W. B. , Griffiths K. 
Published: December 2008

ABSTRACT
The effect of Synacthen (β1–24-corticotrophin) on plasma testosterone and 4-androstene-3,17-dione concentrations in untreated patients with prostatic carcinoma, and in patients receiving endocrine therapy is described. An established specific radioimmunoassay was used for the measurement of testosterone, and a radioimmunoassay for 3-androstene-3,17-dione using thin layer chromatography has been developed. Administration of Synacthen resulted in a fall in testosterone in untreated patients, but a rise in 4-androstene-3,17-dione was observed. The plasma concentration of testosterone in all treated patients increased after administration of Synacthen. An increased concentration of plasma 4-androstene-3,17-dione was also observed in these treated patients after Synacthen, but the magnitude of the response was not significantly different from that of untreated patients.
The work provides further evidence that in the patient being treated with oestrogen for carcinoma of the prostate a rise in plasma testosterone concentration will result from an increased secretion of ACTH.
PLASMA CONCENTRATION OF OESTRADIOL-17β IN PREMATURE THELARCHE AND IN DIFFERENT TYPES OF SEXUAL PRECOCITY
Authors: Escobar Maria Eugenia , Rivarola Marco A. , Bergadá César 
Published: December 2008

ABSTRACT
Plasma Oe2 concentration was measured by radioimmunoassay in patients with premature thelarche, with precocious puberty and in 29 normal controls. The mean plasma Oe2 was 1.5 pg/ml (0–7.2) in normal prepubertal girls, 23.8 ± 17.8 (sd) in pubertal girls, 50.2 (± 19.4) in the follicular phase, and 94.2 (± 19.5) in the luteal phase of normal adult females. Ten girls with premature thelarche had a mean of 7.7 ± 6.6 pg/ml. Three of them showed higher values than the other 7, suggesting that in these cases, elevated levels of plasma Oe2 might have played a role in the development of breast tissue. Ten untreated girls with idiopathic precocious sexual development had a mean of 51.6 ± 42.9 pg/ml while 6 patients treated with 150 mg per week of medroxyprogesterone acetate had a mean of 11.4 ± 2.5 pg/ml. Two patients with Down's syndrome, hypothyroidism and sexual precocity had plasma Oe2 of 144 and 31.5 which fell to 24.7 and 8 pg/ml, respectively, after thyroid replacement. One girl with a granulosa cell tumour had a basal value of 304 pg/ml and a concentration of 27 pg/ml after surgery.
DISSOCIATION BETWEEN LH-INDUCED AEROBIC GLYCOLYSIS AND OOCYTE MATURATION IN CULTURED GRAAFIAN FOLLICLES OF THE RAT
Authors: Tsafriri A. , Lieberman M. E. , Ahrén K. , Lindner H. R. 
Published: December 2008

ABSTRACT
Luteinizing hormone (NIH-LH-S18; 5 μg/ml) stimulated aerobic glycolysis in cultured Graafian follicles explanted from pro-oestrous rats before the preovulatory gonadotrophin surge: lactate accumulation in the medium was 70 % above control levels during 6 h incubations. Iodoacetate (2.5× 10-5 m) prevented this effect, without impairing the ability of LH to induce resumption of oocytic meiosis. Enrichment of the medium with pyruvate (3.3 × 10-4 m) or lactate (2.5 × 10-2 m) did not in itself cause ovum maturation. The results do not support the hypothesis that termination of meiotic arrest by LH is due to stimulation of glycolytic activity in the follicle cells, resulting in increased availability of an energy source readily utilizable by the oocyte.
BOVINE PLASMA OESTROGENS, PROGESTERONE AND GLUCOCORTICOIDS DURING DEXAMETHASONE INDUCED PARTURITION
Authors: Evans L. E. , Wagner W. C. 
Published: December 2008

ABSTRACT
Plasma samples were collected from jugular, uterine and utero-ovarian veins during glucocorticoid induced parturition. Plasma oestrogens, corticosteroids and progesterone were determined by competitive protein binding methods.
Corticosteroids and progesterone began to decline within 8 to 10 h following DXMS treatment. Corticoids were only temporarily suppressed, while progesterone fell to minimum levels and remained low through calving.
At this stage of gestation (270 days) peripheral plasma progesterone was primarily of ovarian origin. Pre-treatment with HCG appeared to support progesterone production by the CL despite DXMS treatment in 2 of 6 cows. These 2 cows failed to calve within the expected 96 h after DXMS. Plasma oestrogens did not show significant increases until 24 h after DXMS treatment. Cows which responded to DXMS treatment (calved) had significantly higher oestrogen levels than those which did not respond. It was concluded that oestrogens probably play a permissive rather than an initiating role in parturition.
EFFECT OF SOME SYNANDROGENS AND ANTIANDROGENS ON THE CONVERSION OF TESTOSTERONE TO DIHYDROTESTOSTERONE IN THE CULTURED RAT VENTRAL PROSTATE
Authors: Johansson Risto 
Published: December 2008

ABSTRACT
The actions of prolactin, insulin and cortisol on the conversion of testosterone to dihydrotestosterone in the cultured rat ventral prostate were examined in conditions in which they have been demonstrated to act synergistically with testosterone on the macromolecule synthesis of the prostate. On the other hand oestradiol, progesterone and cyproterone were tested similarly in conditions where they have been shown to be effective antiandrogens.
The metabolism of testosterone to dihydrotestosterone was found to be extremely rapid and approximately 70 % of the radioactive steroids in the tissue was dihydrotestosterone from 5 min onwards, but only insignificant amounts of dihydrotestosterone were found in the culture medium during the first hour. Physiological concentrations of the synandrogens did not alter the metabolism of testosterone or the accumulation of the steroids into the tissue. Oestradiol, progesterone and unlabelled testosterone in a 500-fold concentration markedly reduced the conversion of tritiated testosterone to dihydrotestosterone while cyproterone and dihydrotestosterone had no effect. The possible role of other hormones in the alteration of testosterone metabolism in the target organs as the mechanism of synandrogenic or antiandrogenic action is discussed.
THE MELANOGENIC RESPONSE TO TESTOSTERONE IN SCROTAL EPIDERMIS: EFFECTS ON TYROSINASE ACTIVITY AND PROTEIN SYNTHESIS
Authors: Wilson Michael J. , Spaziani Eugene 
Published: December 2008

ABSTRACT
Pigmentation of the scrotum of the black-pelted rat, as expressed through melanocyte melanogenic activity, is controlled by androgens. Castration decreased in vitro incorporation of [14C] tyrosine into melanin. Testosterone pre-treatment for 4 days increased melanin radioactivity over castrate controls; the increment in vitro was prevented by an inhibitor of protein synthesis (cycloheximide) added to the incubation. However, cycloheximide only partially blocked melanin synthesis when added to tissue from animals hormone treated for 6 days in vivo, and was ineffective in tissue from intacts. Bulk protein synthesis in vitro (incorporation of [14C] tyrosine or -leucine) was not affected by castration or testosterone treatment but was uniformly inhibited by cycloheximide. The data suggest that new synthesis of specific protein in vitro was necessary for initial hormone-stimulation of melanogenesis, but with longer exposure to hormone sufficient protein was pre-synthetized in vivo to permit melanogenesis during incubation with the inhibitor.
Radioautographs of epidermis incubated with [14C] tyrosine showed grains concentrated over macromolecular aggregates in melanocytes, a pattern not altered by cycloheximide. Though available for incorporation into general tissue protein. [14C] tyrosine was apparently incorporated preferentially into melanin by melanocytes. DOPA (3,4-dihydroxyphenylalanine) added to incubations in cofactor amounts did not affect decreased melanin synthesis after castration and appears, therefore, not to be rate limiting in that decrease. Tissue uptake of free [14C] tyrosine or — leucine during incubation was lower than normal in castrate epidermis; uptake was elevated by testosterone treatment. Concentrations appeared sufficient in all preparations to suggest that availability is not rate limiting for synthesis of melanin or protein; however, a possible influence on amino acid permeability for melanocytes remains undetermined.
Tyrosinase activity was present in both particulate and cytosol fractions of epidermis but decreased significantly after castration only in the cytosol. Testosterone increased particulate activity after 4 days and soluble activity after 9 days of treatment. These and findings above are consistent with a model that tyrosinase is synthesized and incorporated into melanosome structure within 4 days testosterone treatment; with longer treatment synthesis may then exceed that required for melanosome assembly and tyrosinase appears in the soluble milieu.
IN VIVO ACTIVATION OF SYNTHETIC HORMONOGENS OF LYSINE VASOPRESSIN: Nα-GLYCYL-GLYCYL-GLYCYL-[8-LYSINE]VASOPRESSIN IN THE CAT
Authors: Pliška V. , Chard T. , Rudinger J. , Forsling Mary L. 
Published: December 2008

ABSTRACT
The urine and plasma levels of vasopressin-like immunological activity and of antidiuretic activity were examined following injection of Nα-glycyl-glycyl-glycyl-[8-lysine] vasopressin (triglycylvasopressin, TGLVP) in 3 cats. The plasma levels of immunoreactive material were initially high, and fell rapidly. The levels of antidiuretic activity showed considerable variation; the overall pattern was strikingly different from that demonstrated by radioimmunoassay, and all 3 animals showed a rise in plasma antidiuretic activity in the early part of the experiment. Following injection of lysine vasopressin (LVP) the pattern of disappearance of both biological and immunological activity was similar. The total amount of immunoreactive material found in the urine was greater than the amount of antidiuretically active material. These results clearly demonstrate that the antidiuretic activity of TGLVP is mainly due to its conversion to LVP in vivo.
ACUTE REDISTRIBUTION OF THYROXINE AFTER THE ADMINISTRATION OF UNIVALENT ANIONS, SALICYLATE, THEOPHYLLINE AND BARBITURATES IN RATS
Authors: Langer Pavel , Kokešová Hana , Gschwendtová Klaudia 
Published: December 2008

ABSTRACT
Rats were injected with [125I]L-thyroxine (T4) ip 16 h before the experiment and samples of blood were frequently taken from polyethylene tubing inserted into the femoral artery in anaesthetized and heparin injected animals, isovolaemia being maintained. In each sample of plasma T4 counts per ml were estimated with the aid of paper chromatography. Rapid decrease of circulating T4 level was found at 20 min after iv injection of various compounds (thiocyanate, iodide, fluoroborate, theophylline and salicylate) and a dose-response relationship was established between such a decrease and the administered dose of salicylate (5–160 mg/400 g b. w.). A similar decrease was observed at 60 min after ip injection of some general anaesthetics (thio-, pento- and allo-barbiturate, urethane) or tranquilizers (Innovar-Vet®). Finally, an increase of T4 fractional disposal rate was found between 120 and 480 min after the administration of some of the above mentioned anaesthetics and this effect was abolished by the administration of thiocyanate.
It was concluded that there are two different effects of drugs on the circulating T4 level: 1. the immediate effect resulting apparently from a decreased plasma protein binding; 2. the prolonged effect which presumably results from the increased turnover of T4 by peripheral tissues, the metabolic basis of which remains unexplained.
SERUM LEVELS OF UNCONJUGATED AETIOCHOLANOLONE, ANDROSTENEDIONE, TESTOSTERONE, DEHYDROEPIANDROSTERONE, ALDOSTERONE, PROGESTERONE AND OESTROGENS DURING THE NORMAL MENSTRUAL CYCLE
Authors: Frölich Marijke , Brand Egenius C. , van Hall Eylard V. 
Published: December 2008

ABSTRACT
The results of daily determination of the levels of gonadotrophins, oestradiol, oestrone, progesterone, aldosterone, dehydroepiandrosterone, androstenedione, testosterone, and aetiocholanolone in the serum of 6 normal, ovulating women are reported and discussed. A pre-ovulatory aldosterone peak and rising values in the luteal phase of the cycle were found. Androstenedione, testosterone, and aetiocholanolone levels were significantly elevated from 3 days before until 3 days after ovulation. Since the mean androstenedione/aetiocholanolone ratio in the individual cycles in this period was similar to the ratio found during the rest of the cycle, we think it unlikely that aetiocholanolone is produced by the ovaries. No correlation was found between the aetiocholanolone patterns and the basal body temperature. In a case of conception followed for 20 days after ovulation, the steroid patterns remained unchanged until the presumed day of implantation, after which the aldosterone, androstenedione, testosterone, and aetiocholanolone levels started to rise. The mean androstenedione/aetiocholanolone ratio during the 10 days after implantation did not differ from the values obtained in the foregoing periods, so direct aetiocholanolone production by the ovaries after implantation seems unlikely.
COMPARISON OF THE METHODS FOR MEASURING HUMAN CHORIONIC GONADOTROPHIN AFTER HYDATIDIFORM MOLE
Authors: Salmon John A. , Peh K. L. , Ratnam S. S. 
Published: December 2008

ABSTRACT
Six patients who had hydatidiform mole and who subsequently developed clinical choriocarcinomas were studied. Serial plasma samples were assayed for HCG content by (i) haemagglutination-inhibition test (HI test), (ii) a non-specific radioimmunoassay and (iii) a specific radioimmunoassay developed against the β-sub unit of HCG. When levels of HCG were high all three assays gave results which parallelled each other. However, the radioimmunoassays were able to detect the presence of HCG several weeks after the HI test became negative.
Luteinizing hormone cross-reacted in the non-specific radioimmunoassay of HCG and may lead to false positive results. The present study indicated that it is important to employ the radioimmunoassay against the β-sub unit of HCG to permit a specific assessment of HCG activity and thereby provide a reliable monitoring of patients following hydatidiform mole or with choriocarcinoma.