bluuebunny/crossref_metadata_2025_split huggingface dataset:
INTERRELATIONSHIP BETWEEN CALCITONIN AND PARATHYROID HORMONE IN INTACT, THYROIDECTOMIZED, PARATHYROIDECTOMIZED, AND THYROPARATHYROIDECTOMIZED RATS
Authors: Sørensen O. Helmer 
Published: December 2008

ABSTRACT
Calcitonin is capable of completely suppressing the hypercalcaemic effect of parathyroid hormone but not irreversibly. The parathyroid hormone extract used was the commercial preparation Para-Thor-Mone® (Lilly). When injected simultaneously, the parathyroid hormone had no influence on the hypocalcaemia induced by calcitonin one hour after the injection. The parathyroid hormone produced a hypercalcaemia of up to 42 h duration in rats without thyroids. If the thyroid gland was present the serum calcium did not exceed 5.5 mEq./l, probably because of an increased secretion of calcitonin. A transitory hypercalcaemia followed by a hypocalcaemia was seen in intact rats after an intraperitoneal calcium load. The hypocalcaemia could be explained by the counteracting secretion of calcitonin.
EXTRA-THYROIDAL EFFECT OF THYROTROPHIN ON SERUM THYROXINE
Authors: Sisson James C. 
Published: December 2008

ABSTRACT
Injections of bovine thyrotrophin (TSH) into thyroidectomized guinea pigs which were receiving maintenance doses of thyroxine (T4) reduced the PBI levels. The phenomenon was demonstrated only with relatively large quantities (0.8-6 U per day) of TSH, but the response was dosedependent. The quality to affect the PBI remained associated with the thyroid-stimulating activity of TSH when partial purification of the trophic hormone was achieved.
Multiple effects of TSH on T4 economy were found in these animals. Diminished binding affinity for T4 by serum proteins and enhanced deiodination of T4 by hepatic tissue could be demonstrated. The depression of the PBI by TSH appeared to be related to a redistribution of T4 which may, in part, have resulted from changes in the serum binding proteins. A relationship of increased hepatic deiodination of T4 to the decrement in PBI could not be established with certainty.
In doses that could be reasonably administered, bovine TSH had no effect on the thyroid hormone economy in an athyreotic man.
KINETICS OF DOUBLE-ANTIBODY RADIOIMMUNOASSAY SYSTEMS FOR HUMAN GONADOTROPHINS
Authors: Borth Rudi 
Published: December 2008

ABSTRACT
Incubation time curves were investigated in double-antibody radioimmunoassay systems. It was confirmed that the first reaction is not always halted on addition of the second antiserum; depending on the condition of the system at the time of adding the second antiserum, the first reaction may continue slowly, come to a standstill, or be reversed. A kinetic interpretation is discussed. Under the experimental conditions employed, the distortion of incubation time curves produced by disregarding the observed phenomena was found to be slight.
NORMAL VALUES OF SERUM PROTEIN BOUND IODINE IN HEALTHY CHILDREN AGED BETWEEN 4 AND 13 YEARS; BIOCHEMICAL EVIDENCE FOR THE EXISTENCE OF THE JUVENILE OR MID-GROWTH SPURT
Authors: van Stekelenburg G. J. , Stoop J. W. , van der Stam P. J. 
Published: December 2008

ABSTRACT
Protein bound iodine (PBI) was determined in 379 serum specimens of boys and girls, aged between 4 and 13 years. From this investigation it can be seen that: (a) there is no significant difference in the PBI concentration between boys and girls of the same age group, (b) in general the PBI concentration decreases with increasing age (1.4 μ/l/year), (c) both for boys and for girls there is a significant increase in the PBI concentration from the sixth year to the seventh year of age, a result which coincides with the juvenile or mid-growth spurt, and (d) the normal range, calculated from all data, amounts to 40.7–71.1 μg/l (mean value ± 2x standard deviation).
EFFECT OF SYNTHETIC HUMAN 1,39-CORTICOTROPHIN ON BLOOD GLUCOSE LEVEL IN MICE
Authors: László F. A. , Szijj I. , Durszt F. , Kovács K. 
Published: December 2008

ABSTRACT
The hypoglycaemic action of synthetic human 1,39-corticotrophin was determined in mice and its effectiveness compared with highly purified porcine corticotrophin.
Synthetic human 1,39-corticotrophin (0.01 mg = 1.0 IU) and porcine corticotrophin (1.0 IU) induced a transient hypoglycaemia. After the administration of the porcine corticotrophin the decrease in the blood glucose concentration was somewhat more marked and prolonged. Adrenocortical activity was not necessary for the development of hypoglycaemia. In adrenalectomized mice, dexamethasone substitution by increasing the initial blood glucose content, made the effect more pronounced. Pretreatment with corticotrophin reduced the extent of the alloxan-induced transitory hyperglycaemia. On the other hand, it did not influence the high blood glucose values in manifest alloxan diabetic animals.
It is possible that corticotrophin induces hypoglycaemia through insulin release. This is an extra-adrenal effect of corticotrophin as it is also observed in adrenalectomized mice.
PARTIAL SEPARATION OF A 3α-KETOSTEROID OXIDOREDUCTASE AND AN ANDROGEN BINDING SUBSTANCE PRESENT IN RAT VENTRAL PROSTATE CYTOPLASM
Authors: Unhjem Olav 
Published: December 2008

ABSTRACT
The presence of a 3α-ketosteroid oxidoreductase in the rat ventral prostate cytoplasm has been demonstrated. The enzyme was confined to the 105 000 × g supernatant fraction with very little activity in the mitochondrial-microsomal fraction. Addition of NADPH2 was necessary for the enzymatic reaction to proceed. The enzymatic activity was lost when supernatant fractions were dialysed against 0.1 m Tris-HCl buffer, pH 7.4 or when chromatographed by gel filtration using the same buffer. When either L-cysteine, reduced glutathione, 2-mercaptoethanol or EDTA was added to the buffer, the enzymatic activity was preserved. The molecular weight of the enzyme was calculated to be 40 000–50 000. 3H-5α-dihydrotestosterone associates with macromolecules in the 105 000 × g supernatant fraction which are of two molecular sizes (60 000–70 000 and ∼ 200 000). These complexes could not be demonstrated by gel filtration using buffers containing either reduced glutathione, 2-mercaptoethanol or EDTA. By using L-cysteine, the small molecular complex was preserved.
EFFECTS OF OESTROGEN ON SERUM LEVELS OF LH AND FSH
Authors: Nillius Sven Johan , Wide Leif 
Published: December 2008

ABSTRACT
The acute effects on the serum levels of LH and FSH after the administration of some oestrogen preparations were investigated in oligoamenorrhoeic women, in postmenopausal women and in men. Immunoreactive LH and immunoreactive FSH in the serum were assayed by a radioimmunosorbent technique.
The diurnal rhythm in the secretion of the gonadotrophins was first studied. No significant circadian variation in either LH or FSH levels in the serum of hospitalized women or healthy men was found with this radioimmunoassay procedure.
The intravenous or intramuscular administration of 17β-oestradiol in doses from 5 μg to 5 mg resulted in a decrease in the serum levels of LH in 14 of 15 women studied and in the serum levels of FSH in 10 of 12 women. This can be explained by a negative feedback effect on the hypothalamic-pituitary system during the period of observation. The decrease in the serum gonadotrophin levels was as a rule more pronounced for LH than for FSH. No positive feedback effect on the hypothalamic-pituitary system following oestrogen treatment was observed. In men insignificant and variable changes in the serum gonadotrophin levels were found. This could possibly be explained by the low oestrogen doses used.
CIRCADIAN VARIATIONS IN ADRENAL SECRETION OF LEMMINGS, VOLES AND MICE
Authors: Andrews Richard V. 
Published: December 2008

ABSTRACT
Daily variations in adrenal secretion by glands from arctic rodents were measured in vitro. Serial-sacrifice, short-term incubation studies yield similar results to those data obtained through organ-culture methods. Adrenal secretory rates display some desynchronization from locomotor activity during the summer solstice, although circadian variation persists during all seasons of the arctic year.
IN VITRO OESTROGEN BIOSYNTHESIS IN FOETAL ORGANS OF MIDPREGNANCY
Authors: Wu Chung-Hsiu , Archer David F. , Flickinger George L. , Touchstone Joseph C. 
Published: December 2008

ABSTRACT
Foetal organs; namely adrenal, gastrointestinal tract, kidney, liver, lung, skin and testis of midpregnancy were incubated individually with radio-active dehydroepiandrosterone (DHA) and the free and conjugated oestrogens were analyzed. Free oestriol was isolated in the gastrointestinal tract, liver and skin incubates. Oestrone and oestriol glucuronides were found in the gastrointestinal tract and liver incubates respectively. In the gastrointestinal tract incubate oestrone sulphate was found in the highest concentration while sulphates of oestradiol and oestriol were shown in the liver incubate. Conversion rates were small, ranging from 0.009% to 0.121%. These studies suggest that although certain foetal organs are able to aromatize steroids, their contribution to the high levels of oestrogen produced by the foeto-placental unit may be negligible.
WEIGHT LOSS IN OBESE-HYPERGLYCAEMIC AND NORMAL MICE FOLLOWING TRANSAURICULAR HYPOPHYSECTOMY BY A MODIFIED TECHNIQUE
Authors: Herbai Georg 
Published: December 2008

ABSTRACT
Hypophysectomy was performed by a modified transauricular procedure in normal (N. M. R. I.-strain), obese-hyperglycaemic mice and their lean litter mates. In order to obtain a high percentage of operation success the dimensions of the cannula were carefully adapted to the cranium sizes of the mice of both strains and the cannula fitted with a stop-disc. Abrupt post-operative growth arrest was shown to be a rapid in vivo indicator of the completeness of the operation. In obese-hyperglycaemic mice hypophysectomy caused a rapid decrease of the body weights by disappearance of large amounts of fat. Fourteen days after the operation successfully hypophysectomized obese mice became apparently normal. It is suggested that the pituitary plays a role in the maintenance of the syndrome.
EFFECTS OF PORCINE CALCITONIN ON SOME URINE ELECTROLYTES IN THE RAT
Authors: Aldred J. P. , Stubbs R. K. , Hermann W. R. , Zeedyk R. A. , Bastian J. W. 
Published: December 2008

ABSTRACT
Bidaily (b. i. d.) subcutaneous administration of porcine calcitonin (CT) to intact rats resulted in dose-related increases in urinary excretion of water, calcium, phosphorus and magnesium. The effects required several days of treatment to reach maximum levels and persisted for several days after treatment ceased.
Although hypocalcaemia occurred immediately following CT injections in chronically treated rats, animals treated for 8 days were significantly hypercalcaemic 18 hours later.
Bidaily administration of CT (9 a. m. and 3 p. m.) induced a distinct 24 hour periodicity in urinary excretion patterns of calcium, magnesium and urine volume, with maximal excretion at night. In the case of magnesium, this represented a direct reversal of the diurnal excretion pattern seen in control rats.
Urine volume and urine calcium were increased in parathyroidectomized (PTX) and thyroparathyroidectomized (TPTX) rats treated daily with CT. Surprisingly, the initial low blood calcium levels of these rats were elevated toward normal with daily CT treatment and returned to pretreatment levels following cessation of CT injections.
PTX rats treated with parathyroid extract (PTE) exhibited hypercalcaemia and hypercalciuria. Hypercalcaemia was only partially prevented by simultaneous treatment with high doses of CT and hypercalciuria was essentially unaltered.
A GRAPHICAL METHOD FOR THE COMPONENT ANALYSIS OF BINARY HORMONE MIXTURES: DISSIMILARITY OF PITUITARY AND URINARY GONADOTROPHINS IN RADIOIMMUNOASSAY
Authors: Borth Rudi 
Published: December 2008

ABSTRACT
A graphical method using Loewe's isobols is described for the characterization of assay systems in which two agents produce a response, and for the component analysis of binary mixtures. The method is illustrated by describing the response surface of two radioimmunoassay systems for human gonadotrophins (tracer-FSH – anti-FSH and tracer-LH – anti-HCG) in terms of an FSH and an LH standard of pituitary origin. An attempt to assay the immunoreactivity of the second International Reference Preparation of Human Menopausal Gonadotrophins (HMG-IRP-2) produced strong evidence of dissimilarity, supporting the conclusion that HMG-IRP-2 is not a suitable reference standard for the radioimmunoassay of pituitary materials. The need for separate international research standards of human FSH and ICSH (LH) is emphasized.
PITUITARY LH CONTENT DURING DELAYED IMPLANTATION INDUCED BY DIFFERENT TREATMENTS IN RATS
Authors: Labhsetwar Anant P. 
Published: December 2008

ABSTRACT
The capacity of oestrogens to induce nidation during delayed implantation and the known dependence of oestrogen secretion on LH prompted a detailed study of the pituitary LH content of rats in which implantation of blastocysts was delayed by various procedures. Implantation was delayed by Provera (2 mg), reserpine (200 μg), oral dosing with the antioestrogen I.C.I. 46,474 (40 μg) or clomiphene (100 μg), ovariectomy followed by progesterone treatment and finally by permitting mothers mated postpartum to suckle a large litter (10 pups). The pituitary LH stores (OAAD method) of such animals were compared with those of rats killed in prooestrus and oestrus and on day 9 of pseudopregnancy, pregnancy or lactation.
Hypophyseal LH levels were very low during delayed implantation induced by Provera or suckling and very high during that induced by ovariectomy followed by progesterone treatment compared with those in prooestrous, pseudopregnant or pregnant controls. By contrast, no significant change in LH stores was observed when nidation was delayed by single injections of I.C.I. 46,474 or clomiphene. Delayed implantation could not be induced in intact rats with chlormadinone or norgestrel even when given in large doses (2–8 mg/day). It is postulated that to delay implantation in the presence of the ovaries, a centrally acting agent must be capable of decreasing synthesis of LH in the pituitary.
THE EFFECT ON BONE OF LONG-TERM TREATMENT OF INTACT, PARATHYROIDECTOMIZED AND THYROPARATHYROIDECTOMIZED RATS WITH CALCITONIN
Authors: Hindberg Inge , Sørensen O. Helmer 
Published: December 2008

ABSTRACT
Intact, parathyroidectomized, and thyroparathyroidectomized young, male Wistar rats were treated with sc injections of 80 MRC mU of calcitonin twice daily for three weeks and compared with similar controls receiving the vehicle for calcitonin. The serum calcium responses to single injections of calcitonin on the 10th and the 21st experimental days were found to be identical in the calcitonin-treated animals and their corresponding controls.
The results of calcium and magnesium determinations in the sternal manubria and in the left clavicles showed no evidence of an increased mineral deposition in the bones of calcitonin-treated rats, nor did isotope studies with 45Ca or survey X-rays and microdensitometer scannings of two caudal vertebrae.
The results in the intact rats can be explained by an increased parathyroid function as a counteraction to calcitonin. Rats with no parathyroid glands will have a greatly reduced bone resorption and will therefore show a diminished response to calcitonin. This can explain the observation that mineral deposition in bone is not increased in thyroparathyroidectomized and parathyroidectomized rats after long-term treatment.
COMPARATIVE BIOLOGICAL EFFECTS OF 125I AND 131I ON THE RAT THYROID
Authors: Vickery Austin L. , Williams E. Dillwyn 
Published: December 2008

ABSTRACT
125I emits no β rays but part of its soft γ radiation is transformed into low energy electrons. Considering the short tissue path length (2-5 μm) of these electrons, it was postulated that its radiation effect on the thyroid might be different from that of 131I (path length 2000 μm). An experiment was designed to compare the biological effect of several dose levels of radiation from 125I on the rat thyroid gland with that from 131I. The effect of varying doses of each isotope on goitrogenesis (methylthiouracil induced) and on thyroid/serum radioiodide concentration (T/S) ratio was measured in animals radiated while on either a normal or a low iodide diet.
In relation to 131I, the effect of 125I on goitrogenesis generally was much less than its effect on function. The low iodide diet group given 125I, surprisingly, showed markedly less inhibition of goitrogenesis than the normal diet group, an opposite effect to that attained with 131I. We suggest that the observed differences are due to the gradient of energy absorption in the follicular cell from irradiation from 125I stored in the colloid. The apical cytoplasm would absorb much more energy than the basal cytoplasm and the nucleus, in contrast to the uniform absorption of energy from 131I across the cell. The comparatively lower effect of 125I on goitrogenesis, and the paradoxical reduction in its effect in the low iodide diet groups, may be due to the low energy absorption by the nucleus, especially when, in a taller cell, the nucleus is farther from the colloid.
ANALYSIS OF RADIOIMMUNOASSAY BY DISC ELECTROPHORESIS AND SUCROSE GRADIENT CENTRIFUGATION
Authors: Valenta Lubomir , Aubert Michel L. 
Published: December 2008

ABSTRACT
Radioiodine-labelled synthetic adrenocorticotrophic hormone (ACTH), human growth hormone (HGH), human chorionic somato-mammotrophin (HCS), and human (HTSH) and bovine (BTSH) thyroid stimulating hormones were studied by disc-electrophoresis and sucrose gradient centrifugation before and after incubation with corresponding antisera. All antisera contained 7 S antibodies. After incubation, soluble antigenantibody complexes besides a small amount of precipitate were observed in the incubation mixture, characteristic of each hormone. The complexes migrated like gamma globulins or more slowly on disc-electrophoresis. and on sucrose gradient centrifugation showed patterns dependent on the time of incubation. Light 7 or 9 S, or < 12 S complexes occurred mostly after incubation for several minutes (up to 30 min) before analysis. When incubation was prolonged to 24 h and more, these relatively light complexes disappeared or diminished in favour of heavier soluble or precipitating complexes. Reproducibly obtainable sedimentation patterns of the soluble complexes suggested some definite recombination of antigen molecules with 7 S antibodies. The complexes did not occur on incubation with other sera than an antiserum to a given hormone. They were not influenced by EDTA. Displacement of the radioactivity of the complexes into the free hormone peak was obtained by addition of a non-labelled hormone identical with the labelled one. Sucrose gradient centrifugation and disc-electrophoresis are recommended for the study of immunoreaction of diluted materials and for a separate analysis of different steps of the radioimmunoassay.
Radioimmunoassay was introduced for the measurement of protein hormones by Yalow & Berson (1960). The method, described originally for insulin, was later adapted to the detection of a number of protein and polypeptide hormones. On incubation of the hormone with its antiserum, a soluble antigenantibody complex is formed, which is separated from an excess of the free hormone by various methods, e. g. chromatoelectrophoresis, precipitation with a second antibody, adsorption on a solid phase etc. (Hunter 1967).
Sucrose gradient centrifugation and disc-electrophoresis were occasionally used to follow some isolated aspect of radioimmunoassay (Fitschen 1965; Monjardino et al. 1968).
We are demonstrating that these methods made it possible to analyze the radioimmunoassay step by step and thus may be useful for practical purposes as well as in a study of the immunoreaction of diluted materials.
ELIMINATION AND METABOLISM OF 6-CHLORO-17α-HYDROXY-16-METHYLENE-4,6-PREGNADIENE-3,20-DIONE ACETATE AND ITS ANALOGUES IN RATS
Authors: Čekan Z. , Horešovský O. 
Published: December 2008

ABSTRACT
The recovery of radioactivity in the urine, faeces and carcasses following single oral doses of [4-14C] progesterone, 17α-hydroxyprogesterone [2-14C] acetate (14C-AP), 16-methylene-6-dehydro-17α-hydroxyprogesterone [2-14C] acetate (14C-MAP), 6-bromo-16-methylene-6-dehydro17α-hydroxyprogesterone [2-14C] acetate (14C-BrMAP), 6-[36Cl] chloro-16-methylene-6-dehydro-17α-hydroxyprogesterone acetate (36Cl-ClMAP) and 6-chloro-16-methylene-6-dehydro-17α-hydroxyprogesterone [2-14C]-acetate (14C-ClMAP), respectively, was followed during 4–11 days. The total recovery was almost 100 per cent in all the compounds bearing the 17α-[14C] acetoxy group (AP, MAP, ClMAP, BrMAP). Comparison of 14C-ClMAP and 36Cl-ClMAP revealed that about 25 per cent of the administered radioactivity is eliminated in the urine in the form of desacetylated metabolites. However, most of the liberated acetic acid is not exspired, but is probably bound in an unknown form in the organism and excreted in the faeces.
The half-life of 36Cl-ClMAP is longer than that of the steroids labelled with 14C in the 17α-acetoxy group (14C-ClMAP, 14C-BrMAP, 14C-MAP, 14C-AP). This fact can be accounted for by a prolonged elimination of desacetylated metabolites.
The elimination in the urine of individual compounds was studied with ClMAP, AP, and MAP, the former two compounds being analyzed by double isotope analysis, the last one by single-label technique. The half-life of the individual compounds is shorter than that of the total radioactivity. This indicates that the individual compounds are eliminated faster than most of their metabolites. From the amount of unchanged steroids in the urine (related to the total radioactivity) it is apparent that ClMAP is metabolized less than AP, with MAP probably in an intermediate position. This correlates well with the biological activity of the compounds studied.
A preliminary study showed that following the administration of 14C-ClMAP a major portion of the radioactivity was found in both the urine and faeces in a non-conjugated, mostly neutral form. The majority of the neutral metabolites consisted of highly polar compounds. None of the metabolites separated by thin-layer chromatography, however, could be identified.