bluuebunny/crossref_metadata_2025 huggingface dataset:
Receptor mediated gonadotropin action in the ovary
Authors: Azhar Salman , Menon Mangaladevi , Menon K. M. J.
Published: December 2008

The role of macromolecular synthesis in gonadotrophin, cholera enterotoxin and cAMP stimulated progesterone production by rat ovarian cells has been investigated. Both progesterone and cAMP accumulation were increased by cholera enterotoxin in a concentration dependent manner. Incubation of cells with cholera enterotoxin resulted in a 10–20-fold increase in cAMP levels. The effect was observed 15–20 min after addition of toxin. In contrast, stimulation of cAMP levels by hCG was immediate. Cyclic AMP production in response to trophic hormone reached a maximum at 60 min, while maximum stimulation in response to toxin was attained after 2–3 h of incubation. Activation of steroidogenesis in response to both cholera enterotoxin and gonadotrophin showed a lag period. hCG and cholera enterotoxin stimulated a maximum amount of progesterone production after 2 and 3 h of incubation, respectively. With the maximum effective concentration of hCG, addition of choleragen did not result in any further increase in steroidogenesis. Similarly 8 Br-cAMP and Bt2-cAMP also stimulated steroidogenesis.

Progesterone response to cholera enterotoxin, hCG, LH, 8 Br-cAMP and Bt2-cAMP was completely blocked by incubation of cells with cordycepin, actinomycin D, emetine and cycloheximide. That the specific effect of these inhibitors was on macromolecular synthesis rather than a general non-specific toxic effect was demonstrated by inhibition of [3H]proline incorporation and the lack of effect of these inhibitors on cAMP production in response to hCG, LH and cholera enterotoxin. Emetine (10 μm) and cycloheximide (50 μm) inhibited cholera enterotoxin and hCG stimulated progesterone production when added at different time points during the incubation. Cordycepin (250 μm) also blocked toxin and hCG induced steroidogenesis in a similar manner. The concentrations of cordycepin, cycloheximide and emetine required to completely block hCG stimulated progesterone production were 250, 50, and 5 μm, respectively. Similar concentrations of these inhibitors also maximally inhibited 8 Br-cAMP and cholera enterotoxin stimulated steroidogenesis. No effect of these inhibitors on basal production of progesterone was observed. These results suggest that gonadotrophin induced progesterone synthesis is dependent upon the continued synthesis of short lived mRNA and protein(s).
Adrenal corticosteroids and immunoreactive ACTH in chronically cannulated ovine foetuses with bilateral adrenalectomy
Authors: Wintour E. Marelyn , Coghlan J. P. , Hardy K. H. , Hennessy D. P. , Lingwood Barbara E. , Scoggins B. A.
Published: December 2008

The adrenal fails to develop in the hypophysectomised ovine foetus but adrenal growth, maturation and increased cortisol secretion occur in the intact foetus whilst plasma immunoreactive ACTH remains at a constant value. The presence of a feedback relationship between foetal adrenal and pituitary was examined in 8 ovine foetuses which were bilaterally adrenalectomised (adrx.) at the time of implantation of catheters in the carotid artery and jugular vein (90–127 days of gestation). Ten chronically cannulated foetuses served as controls. Gestation length in these sheep was 147 ± 5 days. Plasma immunoreactive (IR) ACTH (IR.ACTH) was measured with a Sorin Biomedica kit. The antibody cross-reacts with ACTH1–39, and ACTH1–24, but not with ACTH1–13, ACTH18–39, β-LPH or β-endorphin. Cortisol (F) and corticosterone (B) were measured by a double isotope dilution derivative assay. In intact foetuses the IR.ACTH was 69.6 ± 7.1 pg/ml (mean ± sem, n = 37) until the day before parturition when values increased to 326 ± 60 pg/ml (n = 6). In adrx. foetuses of 91–121. 122–135 and > 136 days gestation the IR.ACTH values were 50.3 ± 4 (n = 14), 444 ± 46 (n = 26) and 1155 ± 175 (n = 6) pg/ml, respectively. The foetal F and B concentrations were 0.12 ± 0.027 μg/100 ml and 40 ± 6 ng/100 ml (n = 14), respectively, in adrx. foetuses. These values are not significantly different from those in intact foetuses younger than 135 days. The mean F and B concentrations in adrx. foetuses were 22 ± 4.3% (n = 14) and 49 ± 5.4% (n = 14) of the respective maternal values. In summary prior to 120 days the IR.ACTH, F and B concentrations are similar in intact and adrx. foetuses. After 122 days the IR.ACTH secretion by the foetal pituitary first begins to exhibit a feedback relationship with some adrenal secretion (?not F or B) and after 130–135 days some subtle change in pituitary sensitivity to F and/or B may operate. It is suggested that about 120 days a significant alteration in the foetal pituitary capacity for ACTH synthesis occurs.
Pituitary and gonadal function in prepubertal and pubertal cryptorchidism
Authors: Okuyama A. , Itatani H. , Mizutani S. , Sonoda T. , Aono T. , Matsumoto K.
Published: December 2008

LRH and hCG tests were performed in 35 prepubertal and 35 pubertal boys with unilateral or bilateral cryptorchidism to examine the pituitary and gonadal function. Twenty-one normal boys were also examined as controls. In the prepubertal group, distinct increases in serum LH, FSH and testosterone levels by LRH and hCG tests were found in all of the normal and unilateral cryptorchid boys. However, no or very little response was observed in 4 out of 17 boys with bilateral cryptorchidism.

In the pubertal group, serum levels of LH, FSH and testosterone in normal boys, in unilateral and in bilateral cryptorchid boys were evidently higher than those in the prepubertal group, and distinct or moderate responses by the LRH and hCG tests were found in all boys examined. Although serum testosterone levels were similar in all groups, serum basal and peak gonadotrophin levels by the LRH test were significantly higher in bilateral cryptorchid boys than in normal and unilateral cryptorchid boys. The difference was more marked in FSH than in LH level. An elevated level of serum LH is suggestive of the hypofunction of not only the seminiferous tubules but also of the Leydig cells in cryptorchid testes.
Morning and evening human Leydig cell responses to hCG
Authors: Nankin H. R. , Murono E. , Lin T. , Osterman J.
Published: December 2008

The present 72 h study compares the patterns of 17α-hydroxyprogesterone (17OHP) and testosterone responses to im hCG (40 IU/kg) injected at 09.00 h and on different occasions at 17.00 h in eight normal men. Basal a.m. steroid concentrations were significantly higher for both steroids (15% for testosterone and 52% for 17OHP). A peak (at 2 h and 3 h) and statistically significant nadir (at 5 h, 5.5 h and 6 h) response was found for each steroid in the a.m. studies, but in the p.m. studies the two steroids rose significantly at 2 h and remained plateaued through 6 h. Between 5 h and 6 h, and for the remainder of the morning and evening studies, the respective steroid concentrations and the patterns to the changes were the same. Between 6 h and 24 h both steroids rose further. 17OHP peaked at 24 h and 48 h, 3.2 times basal and declined at 72 h. Testosterone rose further between 24 h and 48 h, and was unchanged at 72 h. At the latter two times it averaged 2.2 fold basal values. hCG was detectable at 1 h, rose progressively to highest levels at 24 h, and declined thereafter — in similar fashion in the a.m. and p.m. studies.

The 'peak and nadir' responses occur within the first few hours of gonadotrophin stimulation begun in the morning and appear to be related to the time of day and do not appear to be the result of a biosynthetic block. This suggests a diurnal variation of human Leydig cell response. With intense, probably maximal, testis stimulation each steroid shows the same respective pattern and circulating concentrations between 5 h and 72 h in both the a.m. and p.m. studies.
The influence of sexual hormones on lipogenesis and lipolysis in rat fat cells
Authors: Hansen Finn Mølgaard , Fahmy Nibal , Nielsen Jens Høiriis
Published: December 2008

The insulin-stimulated conversion of glucose to fatty acids (fatty acid synthesis) and the maximally norepinephrine-stimulated lipolysis were studied in isolated fat cells from normal male and female rats, ovariectomized rats and sexual hormone-treated normal and ovariectomized rats. The fatty acid synthesis and the lipolysis oscillated considerably more in fat cells from female rats than in fat cells from male rats. This was found to be due to the oestrous cycle, since the fatty acid synthesis was high in prooestrus and low in both oestrus and dioestrus, while the lipolysis was higher in oestrus and prooestrus than in dioestrus. Oestradiol treatment of both female and male rats and testosterone treatment of male rats for three days lowered the fatty acid synthesis and increased the lipolysis. The metabolic oscillation disappeared in ovariectomized rats, and the fat cells from these animals showed a metabolic pattern comparable with that found in prooestrus. Even when ovariectomized rats were treated with oestradiol or progesterone only three hours before the examination a significant lower fatty acid synthesis was found in oestradiol-treated animals compared with the progesterone-treated animals. Since these rats were fasted three hours before the experiments, the results were not due to differences in food intake. It is concluded that fat cell metabolism is influenced by sexual hormones. The results are compatible with the hypothesis that the variation in food intake due to sexual hormones is secondary to the metabolic changes.
Plasma pattern of immunoreactive ACTH in normal man and in patients with Nelson's syndrome
Authors: Thorén M. , Ajne M. , Hall K.
Published: December 2008

A radioimmunoassay for ACTH determinations in human plasma was developed using an N-terminal antiserum. Plasma ACTH levels at 6 a.m. in 39 patients with normal pituitary-adrenal function were below 4 pmol/l in two individuals. The remaining had a mean of 32.7 ± 4 pmol/l (n = 37). Gel filtration on Sephadex G-50 medium and G-75 revealed that a high molecular weight immunoreactive ACTH was found in plasma from both normal individuals and patients with Nelson's syndrome. The stimulation of ACTH secretion with metyrapone (750 mg perorally) significantly increased the mean plasma levels of 1–39 ACTH after 3 h (from 0.9 to 6.6 pmol/l) in 10 healthy individuals. The level of the high molecular weight form remained constant. In one patient with Nelson's syndrome hydrocortisone iv (100 mg/h for 3 h) suppressed the total ACTH levels from 360 to 83 pmol/l following corticoid withdrawal on the previous evening, but did not affect the high molecular weight form of ACTH. The difference between the amounts of immunoreactive ACTH found in plasma from normal individuals and from patients with Nelson's syndrome was attributed to 1–39 ACTH.
Effect of treatment with bromocriptine on the size and activity of prolactin producing pituitary tumours
Authors: Sobrinho L. G. , Nunes M. C. , Calhaz-Jorge C. , Maurício J. C. , Santos M. A.
Published: December 2008

Eleven consecutive patients with large prolactinomas were treated for 6 months with bromocriptine, (7.5 mg/day). Nine had invasion of the sphenoidal sinus, one a visual field defect and one a secondary trigeminal neuralgia. At the end of the treatment period 8 of the first 9 patients showed radiographical signs of bone remodelling and/or actual reduction of the tumour size. The last 2 patients had complete disappearance of their symptoms.

The remissions could be observed as early as 3 weeks after the start of the treatment. Two patients suffered acute, reversible (partial in one case) episodes of loss of vision during the study. During the treatment the prolactin values decreased in all patients to an average of 1.7% of the baseline levels. There was a steep rise in the serum prolactin concentrations after withdrawal of the drug. After one month there was a plateauing at a high level, although lower than basal level.

Libido and potency were restored in all 3 males studied. Two of the females experienced orgasm for the first time in their lives after some years of primary frigidity. It is concluded that bromocriptine reproducibly reduces the size of prolactinomas. This effect can be observed shortly after the beginning of the treatment and is at least partially reversible. Episodes of pituitary apoplexy may occur during the treatment of large tumours despite an otherwise favourable response.
Hypernatraemia, diabetes mellitus, hyperprolactinaemia, retarded growth and delayed puberty in a 14 year old girl. Effect of bromocriptine treatment
Authors: Christensen Niels Christian , Hagen Claus , Nielsen Meta Damkjær , Petersen Sten
Published: December 2008

Investigations in a 14 year old girl with arrested growth for 2 years, delayed pubertal development, hypernatraemia without thirst, diabetes mellitus and hyperlipaemia are reported. The hypernatraemia was accompanied by a low vasopressin concentration with an abnormal response to thirst, high plasma renin but normal plasma aldosterone concentrations. Treatment with vasopressin and increased fluid intake decreased serum sodium levels. Serum gonadotrophins were low; GH response during an insulin tolerance test was subnormal and basal serum Prl concentration was elevated. Bone age, thyroid function and adrenal function were normal. After initiation of bromocriptine treatment her growth accelerated and regular menstruations commenced. The serum gonadotrophin levels increased and showed pulsatile release. A hypothalamic disorder is suggested, but no cerebral lesion could be demonstrated.
Pituitary-thyroidal function in children with β-thalassaemia major
Authors: Cavallo L. , Mautone A. , Altomare M. , Licciulli M. , Pascazio A. , Schettini F.
Published: December 2008

Thyroid function was investigated in eleven β-thalassaemia major prepubertal children, 3–15 years old.

Basal serum levels and the levels during a TRH-test of TSH, T4, T3, and rT3 were determined. The data were correlated with age and with serum ferritin levels.

Although the patients were euthyroid clinically, the mean serum T3 and rT3 levels were significantly lower than the values in normal control children. Basal serum T4 and TSH values were similar to those of normal controls.

In thalassaemic children, during the TRH-test, the increases in serum TSH at 20, 30, and 45 min, the peak and the maximum ΔTSH were higher than those normally found.

Basal T3 and the 60 min value during the TRH-test were lower than normal, and the peak was delayed to 120 min. No statistically significant correlation was found between the hormonal parameters studied, and either chronological age or serum ferritin levels.

That there is a slight impairment of thyroid secretion in thalassaemia major children is suggested only by the differences in response during the TRH-test (peak and maximum ΔTSH is increased, T3 increase delayed, the negative linear correlation between basal TSH values and per cent increase in T3 and maximum ΔT3, and the positive linear correlation between per cent increase in TSH and in T3).

The low basal T3 and rT3 values might be explained by a decrease in the monodeiodinating enzymatic systems for T4, although other interpretations, e.g., increased clearance of T3 and rT3, cannot be excluded. The absence of clinical signs of hypothyroidism in thalassaemia major children might be due to the normal circulating levels of T4 if we accept that T4 has hormonal activity at least when T3 is low.
Thyroid hormone regulation of the catecholamine effects in human adipose tissue
Authors: Arner Peter , Wennlund Anders , Östman Jan
Published: December 2008

The possibility of a relationship between the thyroid hormone level and the peripheral action of catecholamines was examined in 4 normal-weight and 19 obese euthyroid subjects as well as in 27 hyperthyroid subjects by comparing the serum thyroid hormone level and the in vitro effect of catecholamines on lipolysis and cyclic AMP accumulation in adipose tissue incubated with and without isopropyl noradrenaline (ISNA) or noradrenaline (NA). ISNA- and NA-induced rates of lipolysis and cyclic AMP production were significantly correlated with free thyroxine index (r = 0.63–0.74) and with the serum triiodothyronine level (r = 0.83–0.87). The thyroid hormone level was neither correlated with basal rate of lipolysis nor with basal cyclic AMP production (r < 0.2). These results suggest that the magnitude of catecholamine-induced cyclic AMP production by peripheral cells may be regulated by the level of circulating thyroid hormones. The effect of thyroid hormones on lipolysis appears to be specifically linked to the action of catecholamines.
DNA synthesis and secretory activity in parathyroid adenomas
Authors: Lloyd H. M. , Jacobi J. M. , Willgoss D. , Kearney J. , Ward P.
Published: December 2008

DNA synthesis was measured in vitro by incorporation of [3H]thymidine into DNA in 42 parathyroid chief cell adenomas immediately after surgical removal. The results ranged from 18 to 185 dpm/μg DNA and showed a positive correlation with pre-operative values for serum immunoreactive parathyroid hormone (r = + 0.47; P < 0.001) and plasma calcium (r = + 0.35; P < 0.05). There was no correlation between DNA synthesis and tumour weight or mean diameter of tumour cell nuclei. The results suggest that DNA synthesis and cell division in parathyroid adenomas are determined in part by the secretory activity of the tumour. DNA synthesis measured on one occasion is not necessarily an overall index of tumour growth.
Calcium and pancreatic β-cell function. 12. Modification of 45Ca fluxes by excess of K+
Authors: Andersson T. , Betsholtz C. , Hellman B.
Published: December 2008

Glucose stimulation of insulin release is supposed to result from depolarization of the pancreatic β-cells with subsequent influx of Ca2+. Isolated islets from non-inbred ob/ob-mice were employed for elucidating whether the glucose effects on the β-cell handling of Ca2+ could be simulated by the depolarization evoked by excess of K+. Addition of 25 mm K+ was as effective as 20 mm glucose in stimulating the intracellular uptake of 45Ca. In both instances the additional amounts of incorporated 45Ca appeared in the mitochondria and the secretory granules. When analysing the washout pattern for 45Ca it was evident that the effects of raising K+ differed from those evoked by glucose. Whereas glucose inhibited 45Ca efflux during perifusion with Ca2+-deficient medium the addition of K+ resulted in a slight stimulation. Furthermore, the 45Ca incorporated in response to K+ was more readily mobilised.
Determinations of redox states in A2 and B-cell rich islet specimens from guinea pigs, using bioluminescence assay of NAD+ and NADH
Authors: Brolin S. E. , Ågren A. , Petersson B.
Published: December 2008

The ability of the pancreatic islets to form ATP is often studied and this naturally draws attention to the oxidation of NADH in the respiratory chain. It is therefore essential to obtain data on nicotinamide-adenine dinucleotide phosphates in the islet cells. In order to provide such information the concentrations of NAD+ and NADH were determined in collagenase isolated B-and A2-cell rich pancreatic islets from normal and streptozotocin-injected guinea pigs. In this way new data about the physiology of the A2-cells were obtained. The measurements were performed either in islets freshly isolated or cultured after isolation. Application of recent improvements in bioluminescence assay made it possible to carry out a sufficient number of determinations for calculating total nucleotide concentrations and their redox states.

In both kinds of islet specimens the total nucleotide concentrations were significantly higher when the cells had been cultured for 7 days after isolation. After culture the redox state as reflected by the ratio [NAD+]/[NADH] reached high values in both the A2- and B-cell rich specimens which may signify a strong capacity for drawing energy from NADH in the oxidative phosphorylation. Low values were found soon after isolation, probably indicating a state of hypoxia. The ratio [NAD+]/ [NADH] appears to be a sensitive measure of the metabolic state of the cells. The two kinds of islet specimens diplayed remarkable similarities, but it remains to be clarified whether the B-cells can change their redox state faster than the A2-cells. The bioluminescence techniques should provide the analytical facilities required for further studies of this kind.
Effect of cyproterone acetate on pituitary-adrenocortical function in man
Authors: van Wayjen R. G. A. , van den Ende A.
Published: December 2008

Recent literature (1973–1976) suggests suppression of pituitary-adrenal function in patients (eg with pubertas praecox) who are treated with cyproterone acetate in high doses for prolonged periods. Therefore we investigated in our metabolic ward the effects of administration of 200 mg cyproterone acetate per day during 20 days to 4 healthy male volunteers.

Baseline plasma cortisol and ACTH levels, repeated diurnal plasma cortisol and ACTH profiles and the results of tetracosactide (Synacthen) stimulation tests and single-dose metyrapone (Metopiron) tests proved to be comparable before, during and after treatment. Moreover, a slight gradual increase in urinary cortisol excretion during the observation period indicated that cyproterone acetate in the given dose during 20 days certainly does not reduce the pituitary-adrenal function of 4 healthy male volunteers.

Long-term administration (during 1 to 7 years) of the combination of cyproterone acetate and ethinyloestradiol did not suppress serum levels of cortisol, prolactin, thyroxine and TSH in 18 female patients with hirsutism and/or acne.
The prolactin response to thyrotrophin-releasing hormone is intact in the human male castrate
Authors: LeRoith Derek , Lie Yair , Caine Marco , Spitz Irving M.
Published: December 2008

This study has evaluated the role of the testis in the modulation of Prl secretion in the male. Six elderly male castrates aged 58–69 years, who had undergone bilateral orchidectomy for prostatic carcinoma, were challenged with LRH (100 μg) and TRH (200 μg) administered together as a bolus. Their response was compared to 8 elderly males aged 65–75 years. One additional male aged 26 years, who had lost both his testes following a war injury was also challenged with bolus LRH and TRH; in addition, he was given LRH, TRH and the dopaminergic antagonist, metoclopramide (MET) sequentially at 30 min intervals. On a subsequent occasion, MET was given also. The responses in this young castrate were compared to 24 young males who received the sequential protocol and 12 who received a solitary bolus of MET. In the castrate subjects, gonadotrophins were markedly elevated, whereas testosterone and oestradiol levels were significantly decreased as compared to the controls. The castrate subjects also had exaggerated LH and FSH responses to LRH. In contrast, basal Prl levels and the responses to TRH in the castrates were similar to the controls. In addition, the young male castrate showed a normal Prl response to metoclopramide, when this was given alone, or 30 min after TRH. The intact Prl profile in the castrate subjects should be contrasted to the exaggerated Prl response to TRH which has been described in patients with primary testicular failure and elevated LH and FSH levels. These results indicate that the presence of the testis is obligatory for the exaggerated Prl response to TRH observed in patients with primary testicular failure.
Serum thyroglobulin, its autoantibody and thyroid stimulating antibodies in the endocrine exophthalmos
Authors: Rasmussen Ulla Feldt , Kemp Axel , Bech Karine , Madsen Stig Nistrup , Date John
Published: December 2008

Serum concentrations of thyroglobulin, its antibody, and thyroid stimulating antibodies were studied in 32 patients referred to a department of eye-diseases for exophthalmos. Twenty-three of the patients were or had been medically treated for Graves' disease, one had toxic nodular goitre, one subclinical myxoedema, three euthyroid exophthalmos and four were shown to have non-endocrine eye-disease.

In patients with medically treated Graves' disease serum thyroglobulin was significantly elevated (P < 0.02), the still toxic patients accounting for the highest values. Both thyroid stimulating and thyroglobulin antibodies were detectable in 4 of 18 patients. The rest of the patients had normal concentrations of thyroglobulin and undetectable thyroid stimulating antibodies, but 3 patients had measurable thyroglobulin antibodies. In Graves' patients there was no correlation between serum concentrations of thyroid stimulating antibodies and thyroglobulin, and no clear difference between the frequency of thyroid stimulating or thyroglobulin antibodies in the patients with persistent elevation of circulating thyroid hormones and those remaining euthyroid.

A relation between the thyroid autoantibodies, thyroglobulin and the thyroid hormonal level or severity of the exophthalmic state could not be demonstrated.

It is suggested that hyperthyroidism and exophthalmos are separate disorders, and immunological phenomena probably involved in the pathogenesis of exophthalmos associated with Graves' disease appear to be reflected only locally.
Altered serum levels of thyroxine, triiodothyronines and diiodothyronines in endogenous depression
Authors: Kirkegaard C. , Faber J.
Published: December 2008

Serum levels of thyroxine (T4), 3,3',5-triiodothyronine (T3), 3,3',5'-triiodothyronine (rT3), 3,5-diiodothyronine (3,5-T2), 3,3'-diiodothyronine (3,3'-T2) and 3',5'-diiodothyronine (3',5'-T2) were studied in 80 patients with endogenous depression before and after electroconvulsive treatment (ECT). Compared to the values found after recovery, the patients when depressed had significant increased serum levels of T4, rT3, 3,3'-T2 and 3',5'-T2. Serum concentrations of T3 and 3,5-T2 were not significantly altered. Similarly the free T4 index (FT4I) was increased, while the free T3 index (FT3I) was unaffected. Previous studies have shown a reduced TSH response to TRH in patients with endogenous depression and that the long-term outcome after ECT is strongly related to changes in the TSH response. However, patients with increased TSH response to TRH (n = 23) had a pattern of serum iodothyronine concentrations similar to those (n = 57) with an unchanged TSH response. A similar pattern was also found in 7 patients with non-endogenous psychosis, in whom the TSH response to TRH was unchanged after recovery. It is concluded that the alterations of the TSH response to TRH found in endogenous depression cannot be explained by changes of FT4I or FT3I.
Gastric peroxidase — localization, catalytic properties and possible role in extrathyroidal thyroid hormone formation
Authors: Banerjee Ranajit K. , Datta Asoke G.
Published: December 2008

A highly active peroxidase (EC 1.11.1.7) has been found to be localized in the mitochondria isolated from the fundic region of mouse stomach. The stomach has also the property of concentrating iodide significantly. Evidence has been presented to show that the peroxidase is orientated outside the mitochondrial membrane. The enzyme is strongly inhibited by antithyroid drugs like methimazole and thiouracil. Azide and cyanide completely inactivate the enzyme. The activity is inhibited by SH-blocking reagents like mersalyl or pchloromercuribenzene sulphonate, but not by N-ethylmaleimide. The enzyme is also sensitive to the action of some proteolytic enzymes. It can catalyse the formation of mono- or diiodotyrosine from tyrosine or monoiodotyrosine as substrate, respectively. The enzyme is capable of synthesizing thyroxine and triiodothyronine on the backbone of a protein, such as thyroglobulin or albumin.
Effects of caerulein and trypsin inhibitors on the endocrine mouse pancreas
Authors: Bonnevie-Nielsen Vagn
Published: December 2008

Oral administration to mice with soybean trypsin inhibitor (SBTI) (27–30 mg/mouse/day) or aprotinin (5500–6000 KIU/mouse/day) for six weeks increased the total pancreatic insulin (IRI). The pancreatic IRI was also increased after sc injections of synthetic caerulein (0.05 μg/mouse/day divided into 3 daily doses), being 82% above the control levels when expressed per g pancreas. Aprotinin (6000 KIU/mouse/day divided into 3 daily doses) injected sc had no effect on the insulin content. The total glucagon did not change significantly in any of the groups, but the molar ratio of insulin to glucagon was increased in the caerulein- and SBTI-treated mice. Caerulein-treatment led to an increased disappearance rate of glucose with k-values being 7.1 ± 0.3 compared to 6.0 ± 0.1 (mean ± sem) in the controls (P < 0.02). In islets isolated by collagenase-digestion of the pancreas and subjected to an overnight incubation, the content of insulin and glucagon was increased in islets from caerulein-treated animals. This corresponded to the results observed in the whole pancreas. The present study suggests that oral administration of proteolytic enzyme inhibitors or treatment with caerulein has a trophic effect on the endocrine pancreas. A difference in specificity seems to exist as SBTI affected both the pancreatic weight and IRI, and aprotinin orally did not influence the pancreatic weight, but increased the total content of IRI. Caerulein led to an increase in IRI, but did not affect the weight of pancreas.
Modification of pituitary-adrenal feedback sensitivity in young rats by neonatal treatment with cortisol
Authors: Erskine M. S. , Geller Edward , Yuwiler Arthur
Published: December 2008

Neonatal exposure of rats to cortisol acetate was found to alter pituitary-adrenal feedback regulation at 20–25 days of age. Plasma levels of adrenocorticotrophin (ACTH) after ether stress were reduced in cortisol-treated rats pre-treated with 100 μg corticosterone/100 g body weight, while rats given vehicle neonatally did not show suppression of the ACTH response below levels in animals given saline only or not injected as pre-treatments. Neonatal cortisol increased sensitivity to dexamethasone in inhibition of the stress response; cortisol-treated animals had a reduced plasma corticosterone response to stress 3 h after pre-treatment with 1.25, 2.5, 25, or 250 μg dexamethasone/100 g body weight, while the stress response in animals given vehicle neonatally was not inhibited by the lowest dosage of dexamethasone. Neonatal cortisol treatment did not affect corticosteroidbinding globulin (CBG) binding capacity in plasma of 25-day-old animals. Thus, neonatal treatment with cortisol appears to increase feedback sensitivity to circulating corticosteroids at 20–25 days of age.
Study on immunoreactive prolactin of decidua in early pregnancy
Authors: Kubota Toshiro , Kumasaka Takahiro , Yaoi Yoshimasa , Suzuki Akira , Saito Motoi
Published: December 2008

In order to investigate the source of prolactin in amniotic fluid, immunoreactive-prolactin (IR-Prl) of decidua and villi was measured in 40 cases of early pregnancy, and analyzed by gel filtration. The IR-Prl release from these tissues was also observed in an incubation experiment.

The decidua of 8 weeks of gestation contained the highest amount of IR-Prl, 81.06 ± 2.13 ng/0.1 g dry weight. In the incubation experiment, the decidua of 12 weeks of gestation released 360.35 ± 10.54 ng/0.1 g wet weight in 120 min. In regard to the villi, the IR-Prl concentration was low.

In the profile of column chromatogram of decidua, a peak of small-Prl was observed, and the pattern of IR-Prl was similar to that of pituitary Prl. Furthermore, the IR-Prl profile was not distinguishable from the hPL fraction, but the IR-Prl and hCG profile were different from each other in the chromatogram of the extracted samples of decidua. So we concluded that the source of the Prl was decidua at least in early gestational stage.
In vitro effects of various metabolic inhibitors on the formation of inactive renin and the loss of renin in rabbit uterine tissue
Authors: Jørgensen Jørgen
Published: December 2008

A pronounced formation of renin occurs during incubation of non-pregnant uterine tissue slices in vitro. The synthesized renin appears in an enzymatically inactive form, which can be activated by acidification. Prior to incubation only a small fraction of inactive renin is present. The formation of inactive renin is blocked by puromycin and by inhibition of energy metabolism, indicating a de novo synthesis. A similar pattern of inhibition prevails the modest formation of inactive renin in post-partum uterus.

The marked loss of active renin seen during incubation of post-partum uterine tissue is partly prevented by an inhibition of energy metabolism. Potent inhibitors are iodoacetate and chloroquine. These findings are in accordance with lysosomal engagement in the inactivation of renin. Incubated kidney cortex tissue shows only a minor loss of renin during incubation. This loss is uninfluenced by attempts to block it.
Interstitial pituitary irradiation with 90Y for the treatment of acromegaly. A reappraisal
Authors: Cassar J. , Doyle F. H. , Banks Linda M. , Jadresic A. , Mashiter K. , Joplin G. F.
Published: December 2008

The management of 54 acromegalics referred to us between 1974 and 1978 has been analysed. Twenty-two patients were treated with pituitary implants of yttrium-90 (90Y). Eleven are in complete remission (mean growth hormone (GH) < 11 mIU/l), 8 had improved (mean GH 11–20 mIU/l or 50% less than pre-operatively) and 3 were poor responders. Two patients had temporary 6th nerve paresis. Seven patients are on replacement therapy. Thirty-one patients were not implanted for the following reasons with a number of patients having more than one: extension of the tumour into the sphenoid sinus 10, or above the sella 3, partially empty sella 9, internal carotids too close to midline 2, invisible landmarks 1, mild acromegaly 6, poor general health 3, declined investigations or operation 6.

It is concluded that pituitary implant of yttrium is an effective and safe form of treatment in carefully selected patients.
Protein composition in single follicles, homogenates and fine-needle aspiration biopsies from normal and diseased human thyroid
Authors: Anderberg B. , Eneström S. , Gillquist J. , Kägedal B. , Månsson J. C. , Smeds S.
Published: December 2008

The protein composition of the thyroid colloid was analysed by microgel electrophoresis and densitometry in 41 euthyroid patients. The colloid samples were obtained from single follicles by micropuncture, from homogenates of microbiopsies or from aspiration biopsies. Fourteen of the patients had morphologically normal thyroid tissue, 18 had atoxic nodular goitre and 9 of the patients had atoxic adenoma. Ten of the patients with nodular goitre had prior to the investigation recieved lithium therapy for psychiatric disorders.

The main component of the thyroid colloid was 19S thyroglobulin (TG), but larger iodoproteins (S-TG) and smaller protein fractions, an albumin-like protein and a pre-albumin fraction, were also present in varying relative amounts. Analyses of homogenates of microbiopsies from normal thyroid tissue demonstrated the same protein composition as observed in single follicles.

In colloid samples from atoxic nodular goitre the lighter protein fractions were absent in most of the samples. Analyses of homogenates or aspiration biopsies could not demonstrate this alteration in the protein composition in nodular goitre. Lithium therapy resulted in a significantly lower amount of the lighter protein fractions but unchanged amounts of the globulin fractions in atoxic nodular goitre.

In the atoxic adenomas the protein composition was heterogeneous. The major globulin fractions as well as the lighter protein fractions were present in the analyses of colloids and homogenates of microbiopsies. Aspiration biopsies from atoxic adenomas could not be used for analyses of the protein composition due to contamination with serum proteins.
Biochemical changes in rat endometrium induced by oestrogens
Authors: Jelínková Marta , Jelínek J. , van der Vies J.
Published: December 2008

The effect of oestradiol (Oe2) or ethinyloestradiol (EOe) on several enzymes, soluble protein and DNA in the endometrium was studied in ovariectomized adult rats. The most marked effect of Oe2 was the increase in the activity of lactate dehydrogenase (LDH). If the treatment was started on the day of ovariectomy, it took approximately 8 days to reach a constant elevation. If the administration of Oe2 was started one week after castration, the maximum response was seen after 4 days of treatment. Using the latter schedule a linear dose-reponse regression curve of LDH/DNA was obtained with λ = 0.086. This parameter is considered suitable for the comparison of the effects of different oestrogens. Administration of Oe2 for 8 days beginning on the day of ovariectomy gave no linear dose-response curve of LDH/DNA.

Administration of EOe caused a very marked increase of the specific activity of pyruvate kinase, LDH, M-type LDH and some slight, but significant decreases in isocitrate dehydrogenase, glutamate dehydrogenase, acid phosphatase and alkaline phosphatase. The changes of β-glucuronidase were only slight. The content of DNA per wet weight of endometrium decreased after oestrogen treatment, the protein content remained reasonably constant. It is concluded that, after stimulation with oestrogen, the rat endometrium produces the energy needed for its own growth mainly via anaerobic glycolysis and that the Krebs cycle plays a relatively small role.
Induction of anovulatory sterility by neonatal treatment with 5β-dihydrotestosterone in female rats
Authors: Arai Y. , Yamanouchi K. , Mizukami S. , Yanai R. , Shibata K. , Nagasawa H.
Published: December 2008

Wistar female rats were injected with testosterone (T) or 5β-dihydrotestosterone (5β-DHT) for the first 5 days of life. Neonatal treatment with 1 mg of T resulted in anovulatory persistent oestrous syndrome in 100% of the animals. In the females injected with 1 mg of 5β-DHT, 74% of the treated rats became sterile at 120 days of age. In addition, 0.5 mg 5β-DHT was also effective in inducing anovulatory persistent oestrus; the incidence of sterility was 10 and 80% at 60 and 120 days of age, respectively. When daily dose of 5β-DHT was reduced to 0.1 mg, however, only 33% of the rats resulted in sterility. These results suggest that the free form of T and non-aromatizable androgen, 5β-DHT, can permanently suppress the development of female type of neuroendocrine regulation. The possible participation of the process other than the central aromatization in androgenization will be discussed.
Calcium and vitamin D metabolism in acromegaly
Authors: Lund Bjarne , Eskildsen Peter Claes , Lund Birger , Norman Anthony W. , Sørensen Ole Helmer
Published: December 2008

Acromegalic subjects were found to have elevated serum levels of both 1,25-dihydroxyvitamin D (1,25-(OH)2D), (67 ± 22 (sd) pg/ml) and 24,25-dihydroxyvitamin D (24,25-(OH)2D), (6.9 ± 1.5 (sd) ng/ml). The serum concentration of 1,25-(OH)2D correlated positively (P < 0.02, R = 0.56) to the 24 h urinary excretion of growth hormone, but not to the serum levels of parathyroid hormone, prolactin, thyroid hormones or the urinary excretion of free cortisol. Fourteen patients were treated with bromocriptine at doses from 15–45 mg/day for a period of about 6 months. This was accompanied by a significant decrease in the urinary excretion of growth hormone and calcium and in the serum concentrations of 1,25-(OH)2D and 24,25-(OH)2D. A relationship was demonstrated between the decrease in urinary calcium excretion and the decrease in serum 1,25-(OH)2D (P < 0.02, R = 0.64). It is concluded that the serum concentration of 1,25-(OH)2D is elevated in acromegaly, perhaps as a consequence of a direct action of growth hormone on the renal lα-hydroxylase activity.
Total and non-dialyzable urinary hydroxyproline in acromegalics and control subjects
Authors: Halse Johan , Gordeladze Jan O.
Published: December 2008

The urinary excretion of total and non-dialyzable hydroxyproline (HYP) containing peptides has been studied in 25 patients with active acromegaly and 44 control subjects — all kept on a collagen free diet.

Acromegalics had a greater excretion of both total and non-dialyzable HYP than controls, indicating an increased turn-over of collagen/bone matrix. The amounts of total and non-dialyzable HYP excreted in acromegalics were significantly correlated to mean fasting growth hormone levels. Both acromegalics and controls exhibited a significant coupling between the excretion of total and non-dialyzable HYP.

Female control subjects demonstrated an age-dependent decrease in the excretion of both total and non-dialyzable HYP, whereas no such age-dependence could be observed in males. Age seemed to have a greater effect on the non-dialyzable fraction than on the total HYP excretion. These results may imply that collagen/bone matrix turn-over declines with age and that bone formation declines at a more rapid rate than resorption.

In acromegalics the ratio of non-dialyzable to dialyzable HYP was not significantly different from control values, indicating that although turn-over is increased the actual matrix formation rate is normal in acromegaly.

No correlation was found between serum or urinary parameters of calcium/phosphate metabolism or the urinary excretion of 3',5'-cyclic adenosine monophosphate and total or non-dialyzable HYP in acromegalics or controls.
Effect of low doses of continuously administered catecholoestrogens on peripheral and central target organs
Authors: Ball Peter , Emons Günter , Gethmann Ulrich
Published: December 2008

Osmotic minipumps containing low doses of either 4-hydroxyoestradiol or 2-hydroxyoestradiol2) were sc implanted for 152 h (6⅓ day) into immature male and female rats. At the end of the test period the animals were killed and the uterine weight, the vaginal opening, the gonadotrophin serum levels and the gonadal weight monitored.

The following results were obtained: 1) a significant increase in the uterine weight and a consistent vaginal opening were observed after 4-hydroxyoestradiol but not after 2-hydroxyoestradiol treatment, 2) LH-levels increased after 2-hydroxyoestradiol but not after 4-hydroxyoestradiol; the increase was, however, not significant, 3) FSH-levels and gonadal weights were lowered by 4-hydroxyoestradiol treatment in male animals only; 2-hydroxyoestradiol had no effect on FSH-levels in both sexes, 4) in no instance an antioestrogenic effect of either catecholoestrogen was observed.

It is concluded that 4-hydroxyoestrogens — using the above paradigm — have a significant importance on uterine growth and vaginal opening but (on day 6) no role on LH-release, whereas 2-hydroxyoestrogens may increase LH levels (on day 6) but are nearly ineffective with respect to peripheral parameters.
The effect of growth hormone on the plasma levels of T4, free-T4, T3, reverse T3 and TBG in hypopituitary patients
Authors: Gács G. , Bános Cs.
Published: December 2008

The plasma concentrations of thyroxine (T4), free thyroxine (free-T4), triiodothyronine (T3), reverse triiodothyronine (rT3), TSH and thyroxine-binding globulin (TBG) were measured in 19 children suffering from idiopathic growth hormone deficiency. Blood was taken before and one month after growth hormone treatment. Ten patients were hypothyroid (group 1) and 9 were euthyroid (group 2). The basal T3 and rT3 levels correlated well with the T4 concentrations. Free-T4 levels were very low in all the hypothyroid patients and proved to be the most reliable index of TSH deficiency. TBG concentration was high in the hypopituitary patients regardless of their thyroid function.

Following growth hormone treatment T4, free-T4 and rT3 levels fell in both groups. The T3 concentration rose in group 1 but no change was seen in group 2. There was a significant correlation between the changes of T4 and T3, such that the increase in T3 level was greatest in those with only a slight reduction of T4 concentration and no T3 increase was seen with more marked T4 decreases.

The plasma TBG concentration is enhanced in growth hormone deficiency causing relatively high T4 values. Growth hormone treatment reduces T4 secretion and affects the peripheral metabolism of thyroid hormones resulting in an increase of T3 and a reduction of rT3 concentration.
Regulation of TSH secretion and thyroid function in Cushing's disease
Authors: Visser TheoJ. , Lamberts Steven W. J.
Published: December 2008

In 15 untreated patients with Cushing's disease the regulation of TSH secretion and thyroid function were evaluated. The maximal increment of plasma TSH to TRH was 3.8 ± 2.2 vs 8.7 ± 2.9 μU/ml (patients with Cushing's disease vs controls; mean ± sd; P < 0.001). Free thyroxine-index was 21.8 ± 5.2 vs 27.7 ± 5.0 (P < 0.001). Plasma T3 1.45 ± 0.24 vs 1.96 ± 0.32 nmol/1 (P < 0.001) and reverse T3 0.22 ± 0.05 vs 0.20 ± 0.08 nmol/l (N.S.). The maximal TSH increase in response to TRH was inversely correlated with plasma cortisol (P < 0.05).

The maximal increment of TSH to TRH and plasma T4, free T4 index and T3 are reduced in patients with Cushing's disease due to an impaired thyrotroph function. Plasma reverse T3, however, is normal which may be due to a simultaneous decrease in production and degradation.
Direct long-term effect of hydrocortisone on insulin and glucagon release from mouse pancreatic islets in tissue culture
Authors: Brunstedt J. , Nielsen J. Høiriis
Published: December 2008

The effects of glucocorticoids on the pancreatic endocrine function was studied in isolated mouse pancreatic islets maintained in tissue culture for 1 to 3 weeks. Following culture for 1 week without corticoid supplement acute experiments with hydrocortisone showed no significant effect on the glucose-induced insulin release at 10−8 to 10−5 mol/l hydrocortisone. When, however, the islets were cultured in the presence of hvdrocortisone, there was an increased insulin release to the medium in a dose-dependent manner, with the maximal effect at 10−7 mol/l hydrocortisone. The release of glucagon to the medium was not affected to the same degree, but showed a slight inhibition at increasing concentrations of hydrocortisone.

Short-term experiments after the culture period showed that islets cultured for 3 weeks in the presence of 10−7 to 10−5 mol/l hydrocortisone had an enhanced insulin secretion in response to glucose. The islets did not show any statistically significant change in their insulin- and DNA-content after 3 weeks of culture with hydrocortisone, but a marked reduction in the content of glucagon was found with increasing concentrations of hydrocortisone.

The present results suggest that physiological concentrations of hydrocortisone are of importance for mouse islets to maintain their insulin production in tissue culture.