bluuebunny/crossref_metadata_2025_split huggingface dataset:
BIOGENESIS OF CORTICOSTEROIDS IN MONOLAYER CULTURES OF HUMAN FOETAL ADRENAL CELLS
Authors: Goodyer Cynthia G. , Torday John S. , Hall C. St. George , Smith Barry T. , Giroud C. J. P. 
Published: December 2008

ABSTRACT
Human foetal adrenal cells were grown in monolayer culture and their steroidogenic capacity observed for up to a month. The cells produced a complex array of steroids and some of their ester sulphates from endogenous as well as from [14C] and [3H] precursors.
ACTH stimulated corticoidogenesis, particularly cortisol secretion, and markedly enhanced the incorporation of progesterone and pregnenolone into cortisol. Following incubation with the same precursors, large amounts of radioactivity remained water soluble. From the butanol extractable material of this fraction, dehydroepiandrosterone sulphate was characterized as the main metabolite of pregnenolone and corticosterone and 11-deoxycorticosterone sulphates as the main metabolites of progesterone. With time in culture there was a decrease in steroidogenesis as well as a steady decline in responsiveness to ACTH, mainly manifested by cortisol secretion. The medium from homologous foetal pituitary cultures stimulated cortisol production by the human adrenal cell monolayer.
EFFECT OF PROLACTIN, GROWTH HORMONE AND INSULIN ON THE UPTAKE AND BINDING OF DIHYDROTESTOSTERONE TO THE CULTURED RAT VENTRAL PROSTATE
Authors: Johansson Risto 
Published: December 2008

ABSTRACT
The effects of prolactin, growth hormone and insulin on the total uptake and specific binding of tritiated dihydrotestosterone in the cultured rat ventral prostate were examined. In similar conditions prolactin and insulin act synergistically with testosterone on the macromolecule synthesis of the prostate, but have no effect on the conversion of testosterone to dihydrotestosterone.
The total uptake of tritiated dihydrotestosterone to the tissues was slightly, but not statistically significantly, increased by prolactin, insulin and growth hormone. The majority of the radioactive dihydrotestosterone in the tissue was in free form or very loosely bound. None of these three hormones altered the binding of tritiated dihydrotestosterone to the cytoplasmic receptors.
Non-radioactive dihydrotestosterone, cyproterone and cyproterone acetate in 1000 foid excess strongly decreased the binding of tritiated dihydrotestosterone to the cytoplasmic reseptors and to the nuclei. That part of the binding, which was inhibited by the hormones was considered to represent the specific binding to the receptors. Insulin stimulated both the specific and the unspecific uptake of dihydrotestosterone to the nuclei. Prolactin only stimulated the specific uptake to the nuclei while growth hormone had no effect.
Autoradiography of the nuclear fraction indicated a firm binding of tritiated dihydrotestosterone to the nuclei. The radioactivity of the other contaminating cell components in this fraction appeared to be negligible.
PROLACTIN AND THE PITUITARY-GONADAL AXIS IN MALE URAEMIC PATIENTS ON REGULAR DIALYSIS
Authors: Hagen C. , Ølgaard K. , McNeilly A. S. , Fisher R. 
Published: December 2008

ABSTRACT
In 21 consecutive adult male patients with chronic renal failure on regular haemo- or peritoneal dialysis, the plasma levels of prolactin (hPr), growth hormone (HGH), thyrotrophin (TSH), luteinizing hormone (LH), follicle stimulating hormone (FSH), testosterone (T) and sex hormone binding globulin (SHBG) were measured.
Elevated levels of hPr were found in 16 of the patients and could not only be explained by the medicamentation. All the patients studied showed an inverse ratio of LH to FSH with higher levels of FSH than LH and 15 of the 21 patients had elevated plasma concentrations of FSH, while only 4 had elevated LH.
No significant difference in any of the hormone levels could be demonstrated before and after dialysis, and no significant correlation between the hormone levels and the time of dialysis, the type of dialysis or the age of the patient was found. However, 8 of the 21 patients showed higher levels of HGH before than after dialysis.
Impotency was found in 11 of the patients, but was not related to abnormal levels of hPr, LH, FSH, T or SHBG.
INHIBITION OF INSULIN RELEASE BY CYPROHEPTADINE: EFFECTS ON 3′,5′-CYCLIC-AMP-CONTENT AND 45Ca-ACCUMULATION OF INCUBATED MOUSE ISLETS
Authors: Joost H. G. , Beckmann J. , Lenzen S. , Hasselblatt A. 
Published: December 2008

ABSTRACT
Cyproheptadine (1, 10 and 100 μm) significantly reduced insulin release from isolated mouse islets in response to glucose. In contrast, 1 mm cyproheptadine induced a large release of insulin into the incubation medium probably due to islet cell damage, since the islets had lost a considerable amount of their protein content. 3′,5′-cyclic-AMP-levels of the islets were not significantly affected by 10 μm cyproheptadine in the presence as well as in the absence of theophylline (10 mμ). As the inhibitory effect of cyproheptadine on insulin release was correlated with reduced accumulation of calcium-45, the agent may inhibit insulin release by interfering with the calcium handling of the β-cell.
THE EFFECT OF CYPROTERONE ACETATE ON THE ADRENAL OF THE MALE HAMSTER
Authors: Zieger G. , Lux B. , Kubatsch B. 
Published: December 2008

ABSTRACT
Administration of different doses of cyproterone acetate (CPA) to male hamsters for 5 weeks slows down the growth of the adrenals and the increase in body weight. This effect is still present 4 weeks after cessation of CPA treatment, though some recovery can be seen. Histological and histometrical evaluations confirm an atrophy of the adrenal, particularly in the zona fasciculata and in higher doses also in the zona reticularis. After operative castration it is the zona reticularis which shows the most marked atrophic changes. It is therefore concluded, that CPA possesses besides its anti-androgenic properties an inhibiting corticoid-like effect on the adreno-pituitary feed-back mechanism.
LIGAND-BINDING CHARACTERISTICS OF RAT TESTIS RECEPTORS FOR LUTEINIZING HORMONE
Authors: Esfahani Mojtaba , Schlamowitz Max , Cronquist Jacqueline , Ward Darrell N. 
Published: December 2008

ABSTRACT
Ligand-binding activity of rat testis homogenate increases during storage for 24 h at 4°C, and rapidly deteriorates after 48 h at the same temperature. Inhibition of cellular proteases with phenylmethanesulphonylfluoride (PMSF) preserves the activity for 7 days, and, lyophilized preparations of the tissue homogenate retain their ligand-binding activity for prolonged periods of time during storage at 4°C. The rate of increase in ligand-binding capacity is temperature-dependent. Enhancement of activity is also noted in the purified membrane fraction and appears to be due to unmasking of receptor molecules in the membrane. Even in the presence of PMSF, there is a rapid and irreversible loss of ligand-binding activity when either fresh or reconstituted freeze-dried receptor preparations are pre-incubated at 37°C, although in the former case this is preceeded by a brief period of activation. The destabilization of the reconstituted lyophilized preparation at 37°C is induced by the dehydration step in the freeze-drying process and not by freezing alone. It is therefore unlikely that the rapid inactivation at 37°C is enzymatically induced; rather it is due to destabilization of membrane architecture and/or receptor accessibility. The inherent inaccuracies of measurements of kinetic parameters and assessments of the number of receptor sites in such unstable systems by Scatchard plots of binding data are pointed out.
Evidence is presented which indicates that in the presence of luteinizing hormone the spontaneous inactivation of receptors is inhibited and that there is an apparent "conservation" of receptor sites. A mechanism whereby this is accomplished is proposed, on the basis of the kinetics of inactivation.
SECRETIN-INDUCED INSULIN RESPONSE
Authors: Enk B. , Lund B. , Schmidt A. , Deckert T. 
Published: December 2008

ABSTRACT
Intravenous injection of the gastro-intestinal hormone secretin elicits an increase in the insulin concentration in the cubital vein.
In 10 normal weight non-diabetics and 10 obese non-diabetics the latter group gave a hypernormal insulin response.
By the simultaneous determination of the insulin concentration in the cubital and portal veins and also by an investigation of 2 pancreatectomized patients, it was demonstrated that an increase in the cubital insulin concentration following intravenous injection of secretin was due to an altered secretion from the pancreas and not to an altered elimination of insulin.
PLASMA INSULIN AND GROWTH HORMONE CONCENTRATIONS IN PREGNANT SHEEP II:
Authors: Blom Anne Kristine , Hove Knut , Nedkvitne Jon J. 
Published: December 2008

ABSTRACT
The pregnant ewe compensates the reduced carbohydrate availability in late pregnancy by increased fat combustion. The purpose of the present study was to examine the adaptation of plasma growth hormone (GH) and insulin levels to this change in energy substrate metabolism. Two groups of ewes were bled in the post-absorptive state at different stages of pregnancy. One group (7 animals) was fed adequately throughout pregnancy, while the other received a maintenance ration for non-pregnant sheep (28 animals).
Plasma GH increased from averages from 2–3 to 8–14 ng/ml during the last month before lambing. Shearing of the wool combined with a cold stress resulted in a clearly detectable peak in plasma GH in the underfed sheep. No significant difference in plasma GH attributable to differences in diet could be detected in late pregnancy.
Plasma insulin decreased steadily the last 5 weeks towards lambing, most in mothers with 3 lambs. Plasma free fatty acid levels (FFA) increased the last 2 months of pregnancy, most in the underfed sheep. GH and FFA were positively correlated (r = 0.50 and 0.30 in the two groups).
It is concluded that the adaptation of the maternal metabolism to reduced carbohydrate - and eventually energy-availability in late pregnancy included lowering of insulin and enhancement of plasma GH levels. These adaptations were detectable under the present conditions the last 5–6 weeks before term.
STUDIES ON THE PATTERN OF CIRCULATING STEROIDS IN THE NORMAL MENSTRUAL CYCLE
Authors: Aedo A.-R. , Landgren B.-M. , Cekan Z. , Diczfalusy E. 
Published: December 2008

ABSTRACT
Plasma levels of 20α-dihydroprogesterone, 17-hydroxyprogesterone and 17-hydroxypregnenolone were assayed daily in 15 normally menstruating women during a complete menstrual cycle. In order to ascertain the normalcy of the cycles studied, LH, progesterone and oestradiol were also determined daily.
The pattern of 20α-dihydroprogesterone was very similar to that of progesterone. The levels found during the proliferative phase (around 240 pg/ml) increased significantly on the day of the LH-surge and reached values of approximately 3.7 ng/ml at the peak period of luteal activity.
The plasma levels of 17-hydroxyprogesterone in the proliferative phase were around 380 pg/ml. The first significant increase occurred one day before the LH-surge and was followed by a sharp peak (approximately 1.5 ng/ml) which coincided with the LH peak. A significant decrease occurred after this first peak, which reached a nadir two days after the LH-surge. This was followed by a second rise with a rather broad peak (about 1.8 ng/ml) around the 5th to 7th days after the LH-surge.
The levels of 17-hydroxypregnenolone did not show any cyclic variation: from all figures a geometric mean value of 1.62 ng/ml was calculated with tolerance limits at 0.241 and 10.8 ng/ml.
Individual day-to-day changes in steroid levels were assessed with regard to their potential for the early identification of the day of the LH-surge. A 17-hydroxyprogesterone value of 1.0 ng/ml, or more, was seen for the first time in the cycle on the day of the LH peak in 13 cycles and a progesterone + 17-hydroxyprogesterone level of at least 1.8 ng/ml in 14 of the 15 cycles studied. These data seem to warrant a study of the predictive value of progesterone and 17-hydroxyprogesterone assays in a much larger population.
STUDIES ON THE CONVERSION OF OESTRADIOL LINKED TO A CYTOSTATIC AGENT (ESTRACYT®) IN VARIOUS RAT TISSUES
Authors: Høisaeter Per Aage 
Published: December 2008

ABSTRACT
Estracyt®, a compound of nitrogen-mustard linked to oestradiol phosphate, is used in the treatment of human prostatic cancer. The metabolism of this compound has been studied in different tissues of the rat both in vivo and in vitro.
The phosphate group in position 17 of the oestradiol moiety is rapidly split off from the compound. An oestrone-cytostatic compound was extractable from the liver half an hour after the injection of Estracyt®. In addition the in vitro results showed that only the liver was able to convert the oestradiol-cytostatic compound to an oestrone-cytostatic one. When animals were killed 24 h after a 3-day period of Estracyt® treatment, the dominating metabolite in the ventral prostate was an oestrone-cytostatic compound, but traces of free oestrone could also be demonstrated. No such compound, however, was found in liver, diaphragm or blood at this time.
It is concluded that in vivo an oestrone-cytostatic compound seems to be preferentially retained in the ventral prostate after Estracyt® injection whilst the metabolic conversion of the oestradiol-cytostatic compound into an oestrone-cytostatic one possibly occurs in the liver.
ISOLATION OF CANINE PROLACTIN BY POLYACRYLAMIDE GEL ELECTROPHORESIS
Authors: Jones G. E. , Brownstone A. D. , Boyns A. R. 
Published: December 2008

ABSTRACT
The electrophoretic mobility of prolactin obtained from canine pituitary extract was studied with the aid of polyacrylamide disc electrophoresis. Using a preparative gel electrophoretic system the immunoreactive material was purified on a quantitative scale which was then used to develop a homologous radioimmunoassay for canine prolactin.
The radioimmunoassay system was able to detect prolactin in the plasma of dogs after the administration of agents which would be expected to affect prolactin secretion.
AUGMENTED SECRETION OF TSH IN RESPONSE TO TRH AFTER PRE-TREATMENT WITH DEXAMETHASONE FOR SIX DAYS IN RATS
Authors: Ranta Tapio 
Published: December 2008

ABSTRACT
Serum TSH and corticosterone concentrations were measured in rats given TRH or exposed to short-term cold, as well as in intact rats, after pretreatment with dexamethasone for six days at two different dose levels (25 and 250 μg/100 g body weight). Both doses increased the secretion of TSH in response to TRH whereas cold-induced TSH secretion was not modified by pre-treatment with dexamethasone. In intact rats serum TSH levels did not differ significantly from controls. In all experiments the steroid blocked ACTH secretion. It was also found that administration of TRH produced a rise in serum corticosterone concentrations.
Our results support the view that dexamethasone given for six days facilitates TRH stimulation of the pituitary whilst simultaneously inhibiting the secretion of TRH in response to cold.
CHANGES IN PLASMA RENIN ACTIVITY AND PLASMA ALDOSTERONE IN THE INDUCED PARALYTIC ATTACK OF THYROTOXIC PERIODIC PARALYSIS
Authors: Takeda Ryoyu , Morimoto Shinpei , Uchida Kenzo , Miyamori Isamu 
Published: December 2008

ABSTRACT
Changes in serum electrolytes, haematocrit, plasma renin activity and plasma aldosterone induced by glucose and insulin (GI) infusion were serially investigated in seven patients with periodic thyrotoxic paralysis. An attack which developed into complete quadriplegia was induced within 90 min after the beginning of the GI infusion in four out of seven patients. Only a slight paralysis of the legs was produced in another two patients and induction of an attack did not materialize in one. In four patients with complete quadriplegia, the mean values of serum sodium and potassium concentrations, haematocrit, plasma renin activity and plasma aldosterone slightly decreased immediately after the beginning of the GI infusion. Induction of a paralytic attack was not accompanied by any significant changes in serum sodium concentration, haematocrit, plasma renin activity and plasma aldosterone either 15 min before or after the onset of attack, while the serum potassium concentration progressively decreased, and an increase in plasma aldosterone associated with an increase of haematocrit and plasma renin activity reached a peak level at the stage of complete quadriplegia. On the other hand, in the three patients in whom an infusion produced slight or no paralysis of the legs, changes in the serum sodium concentration, haematocrit, plasma renin activity and plasma aldosterone were insignificant and the serum potassium concentration was slightly but insignificantly decreased.
These results suggest that hyperaldosteronism may not be a trigger for the induced paralytic attack but a phenomenon secondary to volume depletion and a change in potassium homoeostasis induced by GI infusion.
ADRENALINE IN THE HUMAN PANCREAS
Authors: Christensen N. J. , Neubauer B. 
Published: December 2008

ABSTRACT
The present study describes the results of examinations of the noradrenaline and adrenaline concentrations in the human pancreas as well as in a number of other organs. Tissue specimens were obtained at postmortem examination.
Adrenaline was present in small amounts in the cardiovascular system, the liver and the spleen in comparison with the noradrenaline concentration. The pancreas, especially the body of the pancreas, contained, however, considerable amounts of adrenaline. The average adrenaline concentration was approximately 20 times higher in the pancreas than in the other organs examined. The greatest concentration of adrenaline was found in the posterior and superior parts of the body of the pancreas. There was no relationship between the cause of death in the human subjects and the adrenaline concentration in the pancreas and large amounts of adrenaline were also found in tissue specimens of pancreas obtained from long-term diabetic patients.
Adrenaline was present in the pancreas of the rat, dog and rabbit but in small amounts in comparison with the noradrenaline concentration.
GROWTH HORMONE RELATED TO INSULIN AND SUGAR IN NOCTURNAL BLOOD PLASMA OF LACTATING COWS
Authors: Halse K. , Blom Anne Kristine , Hove K. 
Published: December 2008

ABSTRACT
Nocturnal blood plasma samples from about 190 indoor-fed cows at varying stages of the lactation cycle showed wide variations in the concentrations of sugar (43–88 mg/100 ml) and acetoacetate (0.12–8.7 mg/100 ml). Plasma immunoreactive insulin decreased and acetoacetate increased with decreasing sugar.
Plasma growth hormone (GH) was significantly correlated to insulin (r = −0.24, P < 0.001) and to sugar (r = −0.15, P < 0.05), but not to acetoacetate (r = +0.13).
Since the plasma level of GH in bovines is known to vary widely from hour to hour, individual cows are poorly represented by single determinations of the hormone. However, in accordance with the results from the correlation tests, different GH averages, about 11 and 9 ng/ml, were found for groups of animals with plasma sugar respectively below and above 70 mg/100 ml. By subgrouping according to insulin levels within sugar ranges, categories could be singled out with GH averages as different as 12.7 ng/ml (low sugar - low insulin) and 8.3 ng/ml (high sugar - high insulin).
The findings are consistent with the view that GH is involved in the regulation of energy metabolism in bovines. But no support has been provided for the hypothesis of GH hypersecretion as a cause of ketosis in cows.
STUDIES OF HUMAN CHORIONIC GONADOTROPHIN IN STEROID-PRIMED HYPOPHYSECTOMIZED RATS
Authors: Mizejewski Gerald J. 
Published: December 2008

ABSTRACT
The uptake of [125I]HCG was studied in the ovaries of intact and hypophysectomized (Hypox) Sprague-Dawley rats. The [125I]HCG localized specifically in the ovary of the intact rat, and to a lesser extent, in the ovary of the hypox rat. The concentration of HCG in all other tissues and organs of either sex was negligible. However, the localization of [125I]HCG in the hypox rat was enhanced by the presence of exogenous steroids. The greatest increase in HCG uptake was observed in the rats primed with androgen; while a lesser enhancement was demonstrated in the oestrogen treated rats. Comparison of the ovary-to-body weight ratios revealed that a greater amount of HCG localized in the androgen-primed rats than in the oestrogen treated animals even though the ovaries of the former were smaller. These findings suggest that the hypox rat ovary primed with androgen could provide a highly sensitive animal model for further studies of the HCG cell receptor site in animals free of pituitary influence.
COMPARISON OF CIRCULATING GLYCOPROTEIN HORMONES AND THEIR SUBUNITS IN PATIENTS WITH OAT CELL CARCINOMA OF THE LUNG AND URAEMIC PATIENTS ON CHRONIC DIALYSIS
Authors: Hagen C. , Gilby E. D. , McNeilly A. S. , Ølgaard K. , Bondy P. K. , Rees Lesley H. 
Published: December 2008

ABSTRACT
It has recently been suggested that the measurement of the glycoprotein hormones and their subunits in human serum may serve as biochemical markers of non-endocrine tumours. Using radioimmunoassays for LH, FSH, HCGβ-, LHβ- and the common α-subunit, significant differences in the levels of these substances could not be detected between patients with oat cell lung tumours and patients with chronic renal failure.
However, compared to normal subjects the α-subunit levels in serum were elevated in 12% of the male and 30% of the female patients with oat cell carcinoma of the lung and in 80 and 50% of the male and female patients, respectively, with chronic renal failure. The LHβ-subunit concentration was normal in all tumour patients and none of these patients had detectable (< 4 ng/ml) levels of HCGβ-subunit. While such measurements may be of value in relationship to particular neoplasms, it appears that raised levels of glycoproteins and their subunits may be found in other disease states.
CALCIUM AND STIMULUS SECRETION COUPLING IN THE NEUROHYPOPHYSIS
Authors: Robinson I. C. A. F. , Russell J. T. , Thorn N. A. 
Published: December 2008

ABSTRACT
Slices from ox neurohypophyses were incubated in a calcium-free medium with the ionophores A23187 or X537A. X537A (5 × 10−5 mol/l) caused a marked release of vasopressin, neurophysin and protein to the medium. A23187 (2 × 10−5 mol/l) did not cause any release by itself, but when Ca2+ was added to the medium in the presence of the ionophore, an increase in the release of vasopressin, neurophysin and protein occurred. Release of lactate dehydrogenase and peptidase were not affected by the ionophores. The secretion caused by A23187 was abolished by D600 (a verapamil analogue) (2 × 10−5 mol/l) whereas the effect of X537A was unchanged.
The effects of X537A were strongly inhibited by removal of sodium from the medium. Re-addition of sodium to the medium caused a marked release. Gramicidin (10−6 or 5 × 10−5 mol/l) had no effect on secretion.
Efflux of 45Ca2+ from pre-loaded slices was drastically reduced in a sodium-free medium. X537A caused an increase in the efflux rate of 45Ca2+ both in medium with a normal concentration of sodium and when slices had been incubated in a sodium-free medium.
A23187 and X537A both released 45Ca2+ from a neurohypophyseal mitochondrial fraction. When sodium in a concentration of 20 mmol/l was added to this fraction, the Ca2+ accumulation was inhibited. This effect was reduced by inorganic phosphate up to a concentration of 2 mmol/l.