bluuebunny/crossref_metadata_2025_split huggingface dataset:
RADIOIMMUNOASSAY FOR PORCINE PROLACTIN: PLASMA LEVELS DURING LACTATION, SUCKLING AND WEANING AND AFTER TRH ADMINISTRATION
Authors: van Landeghem A. A. J. , van de Wiel D. F. M. 
Published: December 2008

ABSTRACT
A sensitive heterologous radioimmunoassay for porcine prolactin (pPRL) has been developed. Anti-ovine prolactin antibody was raised in rabbits which allowed a final dilution of 1:500 000. The separation of free and antibody bound [125I]pPRL is based on the double antibody solid phase system. The assay is specific for pPRL. There is no cross-reaction with pLH, pFSH and pTSH; little cross-reaction (1.35 %) was found with pGH. The smallest detectable amount was 0.08 ng per tube. During lactation high plasma levels are found with great fluctuations. After weaning the plasma PRL levels fall to basal levels within a few hours. After thyrotrophin-releasing hormone (TRH) administration plasma concentrations increase within a few minutes.
THE RELATIONSHIP BETWEEN LEVELS OF THYROID STIMULATING HORMONE AND OF THYROXINE AND TRIIODOTHYRONINE IN BLOOD OF HYPOTHYROID PATIENTS
Authors: Johansen Klaus , Hansen Jens Mølholm , Skovsted Lis 
Published: December 2008

ABSTRACT
Serum TSH values and the free concentration of T4 and T3 in serum expressed as the free T4- and T3-indices showed a curvilinear relationship in 24 patients with manifest hypothyroidism mainly due to extremely elevated serum TSH levels associated with very low thyroid hormone levels.
The same degree of negative correlation was found between the log serum TSH concentration and serum free T4-index (r = −0.51, P < 0.05) and between log serum TSH concentration and serum free T3-index (r = −0.47, P < 0.05). The correlation coefficients dropped to non-significant levels when the interdependence between the free T3- and T4-indices was taken into account and eliminated by partial correlation analysis.
The degree of negative correlation between serum TSH and the thyroid hormones was also of the same order of magnitude in 5 hypothyroid patients studied prospectively during treatment with L-thyroxine (TSH vs. T4: mean r = −0.71; TSH vs T3: mean r = −0.79).
A CASE OF HASHIMOTO'S THYROIDITIS WITH THYROID IMMUNOLOGICAL ABNORMALITY MANIFESTED AFTER HABITUAL INGESTION OF SEAWEED
Authors: Okamura Ken , Inoue Kenjiro , Omae Teruo 
Published: December 2008

ABSTRACT
An interesting case of iodide induced goitre with immunological abnormalities is described. The patient who was sensitive to synthetic penicillin had previously been treated for exudative pleuritis, congestive heart failure and acute renal failure. Following recovery, he began to ingest large amounts of seaweed after which he developed goitrous hypothyroidism. It was of interest that the serum level of gamma-globulin increased, and subsequently the antithyroid microsomal antibody became strongly positive, suggesting that thyroidal autoimmune processes had been precipitated. Biopsy of the thyroid gland revealed chronic thyroiditis, with evidence suggesting extreme stimulation by TSH. High thyroidal uptake of 131I, positive perchlorate discharge test and biochemical analysis of the thyroidal soluble protein showed severe impairment of hormone synthesis following continuous accumulation of excess iodide. While there is evidence suggesting that increased iodide may be an important factor in the initiation of Hashimoto's thyroiditis, this may result from the marked increased sensitivity of Hashimoto's gland to the effects of iodine. Thus an occult lesion could be unmasked in this manner. The mechanism by which iodide mediates this effect is not clear.
SEX DIFFERENCES IN CATECHOLAMINE CONTENT IN DISCRETE BRAIN NUCLEI OF THE RAT: EFFECTS OF NEONATAL CASTRATION OR TESTOSTERONE TREATMENT
Authors: Crowley W. R. , O'Donohue T. L. , Jacobowitz D. M. 
Published: December 2008

ABSTRACT
Dopamine and norepinephrine levels were measured in individual brain nuclei in normal adult male and female rats and in adult male rats castrated on day 1 of life and in adult female rats given 1.25 mg testosterone propionate on day 4 of life. Normal adult males showed higher concentrations of dopamine than females in the caudate, tractus diagonalis and arcuate nuclei and in the median eminence. Day 1 castration of males reduced the dopamine levels of the arcuate nucleus and nucleus of the tractus diagonalis, while neonatal administration of testosterone to females elevated the dopamine concentration of the arcuate nucleus and nucleus of the tractus diagonalis. Normal adult males had higher concentrations of norepinephrine than females in the preoptic-suprachiasmatic, paraventricular, periventricular, and arcuate nuclei and in the median eminence. Neonatal endocrine manipulations (neonatal male castration and female testosterone treatment) failed to alter significantly these sex differences. The results suggest a sexual dimorphism in the catecholamine innervation of certain discrete areas of the brain and that the dopamine concentration in the arcuate and tractus diagonalis nuclei is influenced by perinatal androgen.
EFFECTS OF TWO SUBSTITUTED BENZAMIDES, TIAPRIDE AND SULTOPRIDE, ON GONADOTROPHINS AND PROLACTIN
Authors: L'Hermite M. , MacLeod R. M. , Robyn C. 
Published: December 2008

ABSTRACT
The acute effects in the human of tiapride and sultopride, two new substituted benzamides related to sulpiride, were studied with respect to gonadotrophins (LH and FSH) and prolactin (PRL) secretion. Two different groups of 3 normal men and 3 normally cycling women received im injections of either 100 mg sultopride or 200 mg tiapride. Five min after the injection of either psychotropic drug, the serum PRL concentration increased significantly (P < 0.001 by variance analysis) and reached maximal values by 30 min and remained elevated for at least 6 h; women tended to release more prolactin than men.
Although tiapride (500 nm) had no direct effect on the in vitro synthesis or secretion of prolactin, the drug blocked the inhibitory action of dopamine (500 nm) on the secretion of prolactin. Rats bearing a transplantable prolactin-secreting pituitary tumour MtTW15 have extremely high serum prolactin and through an autofeed mechanism the host's pituitary gland is suppressed. The in vitro synthesis and secretion of prolactin by these rats' pituitary gland is decreased. The in vivo administration of tiapride to these tumour-bearing rats restored the in vitro secretion of prolactin to control values. The in vitro data support the concept that tiapride increases prolactin secretion directly at the pituitary level by blocking the inhibitory activity of dopamine; an additional effect at a higher level can not, however, be ruled out.
In vivo in the human, no significant modification of LH and FSH occurred after either drug, suggesting that the menstrual cycle disturbances observed during chronic treatment with tiapride might be related to hyperprolactinaemia or be the result of a mechanism similar to that inducing hyperprolactinaemia.
CALCITONIN HETEROGENEITY IN LUNG CANCER AND MEDULLARY THYROID CANCER
Authors: Becker Kenneth L. , Snider Richard H. , Silva Omega L. , Moore Charles F. 
Published: December 2008

ABSTRACT
An investigation was made of the increased serum calcitonin in patients with medullary thyroid cancer and bronchogenic carcinoma in order to determine whether these conditions can be differentiated immunochemically. Endogenous fractions of immunoreactive calcitonin were separated by gel filtration and radioimmunoassayed with calcitonin antibodies having different region specificities. The pattern of serum heterogeneity of patients with medullary thyroid cancer was characterized by the presence of at least seven different fractions of immunoreactive calcitonin, ranging from fraction I (≧ 30 000 molecular weight (MW)) to fraction V (~ 2500 MW). In contrast, most patients with bronchogenic cancer had a predominance of high MW fractions (i. e. fractions I and II A). Following in vitro incubation of the serum, the typical large MW pattern of bronchogenic cancer serum could be converted to the more diffuse pattern seen in the serum of medullary thyroid cancer. We were able to differentiate, pre-operatively, the hypercalcitonaemia serum of medullary thyroid cancer patients from that of bronchogenic cancer patients by determination of the ratio of calcitonin as radioimmunoassayed with midportion versus carboxyl terminal antibody.
BINDING OF GONADOTROPHIN RELEASING HORMONE (GnRH) BY BOVINE ANTERIOR PITUITARY PLASMA MEMBRANES AND PURIFIED GnRH RECEPTOR PROTEIN (GnRH.R)
Authors: Zolman Joseph C. , Valenta Lubomir J. 
Published: December 2008

ABSTRACT
[125I]-(GnRH) concentration dependence binding curves using isolated bovine anterior pituitary plasma membranes, intact and solubilized, and purified GnRH receptor protein, are compared. In all instances the concentration dependence binding curves had a stepwise character here interpreted as multisigmoid, with several steep increases and plateaus. These curves are compatible with the existence of several binding sites for GnRH. Purification of the GnRH receptor protein (GnRH.R) resulted in about 500 000-fold increase of binding activity and yielded a single protein species on polyacrylamide gel electrophoresis in SDS, of estimated molecular weight 60 000. Similarity of GnRH binding by the purified protein with that of intact and solubilized plasma membranes suggested that a single protein was responsible for the binding in each instance. Thus heterogeneity of GnRH binding is likely attributable to phase transitions of a single receptor protein into different allosteric forms. The data suggest that positive cooperativity is involved in the studied system.
TIME-DEPENDENT DECREASE OF PITUITARY RESPONSE TO LH-RH AFTER CHRONIC TREATMENT OF INTACT FEMALE RATS WITH ETHINYLOESTRADIOL AND NORETHINDRONE
Authors: Kuhl Herbert , Sachs Angelika , Rosniatowski Christian , Taubert Hans-Dieter 
Published: December 2008

ABSTRACT
The effect of daily injections of 50 μg ethinyloestradiol and 1 mg norethindrone upon basal and LH-RH-stimulated LH release was investigated in intact adult female rats during a period of 30 days. Basal plasma LH was depressed by about 30 % during the whole time of steroid treatment, and returned to the level of the control values two weeks after discontinuation. The injection of 30 ng and 150 ng LH-RH into untreated rats resulted in a significant increase of plasma LH which was, however, not dose-dependent. After the treatment with ethinyloestradiol and norethindrone for 5 days, the pituitary response to 150 ng was approximately four times higher than that to 30 ng. The LH release after injection of 150 ng LH-RH decreased significantly with the duration of steroid treatment, and was totally abolished by 30 days; whereas two weeks after the termination of steroid application the pituitary responded to LH-RH in the same manner as in control rats. When 30 ng LH-RH were injected into oestrogen/norethindrone treated rats, no decrease in LH release was found until day 20 of the experiment. By 30 days of treatment no rise in plasma LH could be elicited.
The activity of the LH-RH-degrading enzyme L-cystine arylamidase was stimulated during the treatment with ethinyloestradiol and norethindrone in the pituitary by approximately 100 %, whereas almost no effect on this enzyme was seen in the hypothalamus.
It is concluded that the chronic treatment of intact female rats with ethinyloestradiol and norethindrone causes time-dependent and reversible alterations in the storage of LH in the pituitary. The elevated activity of the LH-RH-degrading enzyme in the pituitary is possibly involved in these processes and/or in the mechanism responsible for the depression of basal LH.
URINARY EXCRETION OF THYROXINE, TRIIODOTHYRONINE, 3,3′,5′-TRIIODOTHYRONINE (REVERSE T3) AND RENAL FUNCTION IN HUMAN NEWBORNS
Authors: Rogowski Preben , Faber Jens , Kirkegaard Carsten , Lundsteen Merete , Poulsen Dorte Loldrup , Siersbæ-Nielsen Kaj 
Published: December 2008

ABSTRACT
The urinary excretion and serum levels of thyroxine (T4), triiodothyronine (T3) and 3,3′,5′-triiodothyronine (reverse T3) was estimated in a longitudinal study of human newborns. The maternal and cord blood was also studied. Neonatal renal function was evaluated using endogenous creatinine clearance. In cord blood serum T3 was found to be lower than in maternal blood, but reverse T3 highly elevated. During the first 5 days of life serum T4 and T3 increased with maximum at 48 and 24 h in contrast to reverse T3 which remained high and then declined rapidly after 4 days.
Creatinine clearance during the first 3 days of life increased from 5.3 to 21.9 ml/min/1.73 m2. In the same period the urinary T4 excretion increased from 79 to 281 ng/24 h, urinary T3 excretion from 16 to 44 ng/24 h and urinary reverse T3 from 4 to 15 ng/24 h. The renal excretion of thyroid hormones, corrected for body surface, was decreased compared to adult controls, corresponding to an immature renal function. The lack of ability to excrete thyroid hormones involved primary T3 and reverse T3 suggesting particular immaturity of tubular secretion of these hormones during the neonatal period.
EFFECTS OF SUBSTITUTION WITH THYROXINE ON THE THYROTROPHIN (TSH) RESPONSE TO THYROTROPHIN-RELEASING HORMONE (TRH) IN SEVERE PRIMARY MYXOEDEMA AND IN MILD HYPOTHYROIDISM FOLLOWING PROLONGED THYROSTATIC THERAPY
Authors: Fischer H. R. A. , Hackeng W. H. L. , Schopman W. , Silberbusch J. 
Published: December 2008

ABSTRACT
The evolution of the thyrotrophin (TSH) response after 400 μg thyrotrophin-releasing hormone (TRH) was investigated during recovery of hypothyroidism.
In 14 myxoedematous patients, replacement therapy with thyroxine (T4) caused characteristic changes. Before treatment a relatively blunted pattern with mΔTSH1) of 51.2 ± 30.6 mU/1 was found. Two and 4 weeks after treatment an enhanced response was evolved with values for mΔTSH of 87.7 ± 43.4 and 96.0 ± 48.0 mU/1 (P < 0.02 respectively < 0.01). Comparison of the TSH curve showed significant increases in ΔTSH during the first 4 weeks of treatment at 20, 40 and 60 min compared to corresponding measurements in the basal state.
In 17 overtreated hyperthyroid patients with mild, mostly chemical hypothyroidism the influence of T4 replacement on TSH responses at different TSH levels was studied. At the stage of mild TSH elevation (3–10 mU/1) mΔTSH before and during substitution were 12.6 ± 6.7 and 25.9 ± 15.3 mU/1, respectively (P < 0.01). Moderate TSH elevation (10–25 mU/1) was accompanied by mΔTSH of 25.4 ± 13.4, respectively 44.5 ± 22.9 mU/1 (P < 0.01) while high TSH values (> 26 mU/1) had responses of 39.1 ± 16.0 and 92.5 ± 22.0 mU/1 (P < 0.001). In these patients the initial blunting of TSH responses could not be attributed to the foregoing toxicosis, since follow up during 6–15 weeks of protracted hypothyroidism did not show any tendency to enhancement of relative release (% mΔTSH).
These findings suggest that in the early stage of replacement therapy of hypothyroidism, either pituitary TSH is accumulating or that endogenous TRH is declining.
REGULATION OF PANCREATIC GLUCAGON SECRETION DURING A CONTINUOUS GLUCOSE INFUSION IN EARLY AND OVERT DIABETICS
Authors: Schulz B. , Ziegler M. , Witt S. , Rjasanowski I. , Heinke P. , Bibergeil H. 
Published: December 2008

ABSTRACT
The pancreatic glucagon (IRG) secretion pattern was studied during a 2 h glucose infusion test (12 mg/kg/min) in 21 controls as well as in 44 subjects showing different degrees of carbohydrate intolerance.
The fasting IRG levels increased significantly from controls (98 ± 7.6 pg/ml) to chemical (144 ± 9 pg/ml) and mild maturity-onset-type diabetics (166 ± 12.2 pg/ml).
During artificial hyperglycaemia the glucagon concentrations decreased slightly in all groups, but they remained at a higher level in early and overt diabetics1). The molar IRI-IRG ratios have been found to be diminished in patients displaying a disturbed carbohydrate tolerance. There was not any correlation between insulin and glucagon concentrations in the blood.
The findings suggest that abnormalities of alpha cell function may be present in early and overt diabetes independent of beta cell responsiveness. The causal relationship of A and B cell function in glucose intolerant subjects has to be cleared in follow-up studies.
IN VITRO AND IN VIVO STUDIES ON LEYDIG CELL FUNCTION IN OLD RATS
Authors: Pirke Karl M. , Vogt Hermann-J. , Geiss Michael 
Published: December 2008

ABSTRACT
Young adult (3 months old) and old (26–28 months old) male Wistar rats were studied. Testicular weight was 1.66 g (range: 1.33 – 2.86) in the younger group and 1.62 g (range: 1.04 – 1.90) in the older group. The total Leydig cell volume as measured by a quantitative histometric method was significantly larger in the old animals (x̄ = 0.153 ml vs. x̄ = 0.089 ml). The testicular HCG binding capacity was 2.54 ng HCG per 100 mg tissue (range: 1.88 – 3.77) in the younger animals and 1.83 ng HCG per 100 mg tissue (range: 0.80 – 3.02) in the older ones (P < 0.01). Plasma testosterone was on an average 242 ng/100 ml (range: 72 – 1162) in the young adult rats and 91 ng/100 ml (range: 23 – 277) in the older rats. Plasma LH was only slightly (P < 0.05) decreased and was 49 ng LH–RP–1/ml (range: 14 – 120) in the younger group and 40 ng LH–RP–1 ng/ml (range: 5 – 98) in the older.
When the testicular tissue pieces were incubated with different doses of HCG or dibutyryl cAMP and testosterone production was measured, identical dose-response curves for old and young tissue were obtained. After in vitro incubation with a NADPH generating system, which under the conditions used was a much stronger stimulus for steroid biosynthesis than HCG or dibutyryl cAMP, the tissue of young rats produced about twice the amount of testosterone and testosterone precursors (pregnenolone, progesterone, 17α-hydroxyprogesterone and androstenedione) than old tissue.
EFFECTS OF MEDIAL HYPOTHALAMIC DEAFFERENTATION ON PROLACTIN SECRETION IN PSEUDOPREGNANT RATS
Authors: Kato H. , Velasco M. E. , Rothchild I. 
Published: December 2008

ABSTRACT
Frontal hypothalamic deafferentation (FHD), which disconnects the anterior hypothalamus from the preoptic area, stops the twice daily surges of prolactin secretion of pregnancy or pseudopregnancy in the rat, and causes rapid luteolysis. Medial hypothalamic deafferentation (MHD), which separates the anterior from the posterior half of the hypothalamus, does not interrupt pregnancy and causes a significant increase in the size of the corpora lutea. To see whether MHD induces an increase in the basal level of prolactin secretion and/or a change in the pattern of prolactin surges, pseudopregnant rats were subjected to MHD or a sham operation on day 3 (day 1 = day of oestrus) and their bloods assayed for prolactin on either day 5 or days 7–8.
MHD caused a specific disappearance of the day-time prolactin surge and a diminution in the height of the night-time surge, but no change from the controls in the basal prolactin level. In spite of what thus appears to be a lesser secretion of prolactin than in the controls, the corpora lutea of the MHD rats were larger, and progesterone was secreted at a higher rate and for a longer time, than in the controls. The relation of these findings to the existence of a "surge centre" in the hypothalamus was discussed.
INFLUENCE OF THE PURITY OF THE IODINATED TRACER ON THE SPECIFICITY OF THE RADIOIMMUNOASSAY OF HUMAN LUTEINIZING HORMONE
Authors: Suginami H. , Robertson D. M. , Diczfalusy E. 
Published: December 2008

ABSTRACT
Human luteinizing hormone (HLH) iodinated with 125I by the use of a lactoperoxidase method, was fractionated by either cellulose adsorption, gel filtration or by the combination of these methods. The products of iodination were characterized by their in vitro biological LH activity and by their binding profiles with antisera to HLH, HLHα and HLHβ subunits. Several radioactive components were obtained after gel filtration with or without an initial cellulose adsorption step. One of these fractions was identified as biologically active HLH and another as the HLHα subunit.
Radioimmunoassay studies were conducted with different iodinated fractions as tracers, using three well defined and widely available antisera to HLH. The standard used was the HLH International Reference Preparation for immunoassay (68/40). Cross-reactivity was examined with several purified pituitary preparations, such as HFSH, HTSH, HLHα and HLHβ subunit. A significantly higher cross-reactivity with HLHα, HFSH and HTSH was obtained with the [125I]HLHα fraction as tracer than with biologically active [125I]HLH. Furthermore, in the radioimmunoassay of HLH preparations of varying purity, significantly higher estimates of immunological activity were obtained with the [125I]HLHα tracer than with the biologically active [125I]HLH.
It is concluded that the presence of [125I]HLHα in the [125I]HLH tracer can result in serious overestimates of the immunological activity in the measurement of LH. Therefore [125I]HLHα should be separated from [125I]HLH prior to radioimmunoassay. Many of the fractionation methods commonly used (cellulose adsorption and short column gel filtration systems) are inadequate for this purpose. However, an adequate separation can be achieved by the use of high resolution gel filtration systems.
ADRENAL INVOLVEMENT IN THE TIMING OF PUBERTY IN FEMALE RATS: INTERACTION WITH SERUM PROLACTIN LEVELS
Authors: Gelato Marie C. , Meites J. , Wuttke W. 
Published: December 2008

ABSTRACT
Female Sprague-Dawley derived rats were either sham-operated or adrenalectomized at 20 days of age. Treatment of separate groups of rats with progesterone, corticosterone or prolactin was started at 21 days of age, and was continued until the day of vaginal opening. Similarly treated rats were decapitated at 25, 29 and 33 days of age and at the day of vaginal opening and the sera were collected from each animal and assayed for prolactin, LH and FSH. All rats were decapitated between 4–6 p. m. Adrenalectomy, as previously reported, significantly delayed the day of vaginal opening. Prolactin treatment advanced the day of vaginal opening in intact rats and it restored the day of vaginal opening in adrenalectomized rats to that of intact control rats. Progesterone treatment always delayed the day of vaginal opening in intact rats. It caused an even greater delay in vaginal opening than adrenalectomy alone. Corticosterone treatment, on the other hand, was able to reverse the effect of adrenalectomy but had no effect on vaginal opening in intact rats. In intact rats serum prolactin levels rose steadily until the day of vaginal opening. Adrenalectomized and intact rats treated with progesterone had significantly decreased serum prolactin levels. However, in adrenalectomized corticosterone treated rats serum prolactin levels were significantly increased at all ages measured when compared to the untreated rats. The FSH and LH levels showed no significant changes during any of these experimental procedures. Approximately 50 % of the rats showed LH peaks on the day of vaginal opening as well as an increase in FSH. The data indicate a prolactin-adrenal interaction for the timing of the onset of puberty in immature rats, assuming that the day of vaginal opening in association with increased gonadotrophin levels is an indicator for the occurrence of puberty.