bluuebunny/crossref_metadata_2025 huggingface dataset:
Treatment of 46 patients with Turner's syndrome with recombinant human growth hormone (YM-17798) for three years: a multicentre study
Authors: Takano Kazue , Shizume Kazuo , Hibi Itsuro , syndrome Turner's
Published: June 2009

A total of 46 patients with Turner's syndrome were treated for three years with recombinant hGH. Nineteen patients received hGH at a weekly dosage of 0.5 IU·kg−1·week−1, while 27 received 1.0 IU·kg−1·week−1 by daily sc injection. Both treatment groups showed a statistically significant growth increase during treatment. The increase in height over three years' treatment, as expressed by sd score (sds) for chronological age, did not differ significantly between patients treated with 0.5 IU and those with 1.0 IU hGH. Seventeen of 22 patients over the age of 14 had exceeded their expected adult height. Plasma IGF-1 levels were elevated and no remarkable advances in bone age were observed during the treatment in either treatment group. There were no other significant changes in physical or laboratory examinations. No glucose intolerance was observed. These results indicate that hGH treatment is useful for accelerating growth velocity in patients with Turner's syndrome. However, further study will be required to find the best treatment dosage.
Biogenic amines and thyrotoxicosis
Authors: Upadhyaya L , Agrawal JK , Dubey GP , Udupa KN
Published: June 2009

Circulating levels of T3, T4, γ-amino-butyric acid, glutamate, 5-hydroxytryptamine, histamine, monoamine oxidase and histaminase were studied in 45 (2 5M, 20F) hyperthyroid patients and 46 (2 5M, 21F) normal healthy volunteers. Increased levels of blood 5-hydroxytryptamine, histamine and glutamic acid were observed along with elevated T3 and T4, whereas plasma γ-aminobutyric acid, monoamine oxidase and histaminase activities were found to be low in both male and female patients. After three months of treatment, circulating levels of 5-hydroxytryptamine, histamine and glutamic acid decreased significantly along with normalization of thyroid hormones and with an increase in the concentrations of γ-aminobutyric acid, monoamine oxidase and histaminase. There was a positive correlation between these amines and thyroid hormone levels. The findings thus suggest that alterations in the metabolism of biogenic amines may be related to an altered metabolism in thyrotoxicosis, and these parameters may prove to be useful markers for diagnosis and follow-up of these patients.
Calcitonin release from medullary thyroid carcinoma by thyrotropin-releasing hormone: comparison with calcium injection
Authors: Oishi Seiichi , Yamauchi Jouji , Fujimoto Yasuko , Hamasaki Shinichiro , Umeda Teruhisa , Sato Tatsuo
Published: June 2009

The effects of thyrotropin-releasing hormone on the release of calcitonin were investigated in 15 normal subjects and 12 patients with medullary thyroid carcinoma. The present study also compared the effect of TRH stimulation with calcium infusion test on calcitonin release in patients with medullary thyroid carcinoma. In normal subjects, calcitonin increased from a basal value of 7.5±2.5 pmol/l to a peak value of 9.4±3.0 pmol/l (p<0.01) after iv injection of synthetic TRH (500 μg). Basal calcitonin values in patients with medullary thyroid carcinoma were high (1216±2230 pmol/l, p<0.05), and TRH induced a further increase in calcitonin to 1 842±3149 pmol/l in all the patients (p< 0.05). They had a peak value of 7891±13 528 pmol/l after the calcium infusion, which was significantly higher than the basal value of 1463±2630 pmol/l (p<0.05). All medullary thyroid carcinoma patients displayed a marked calcitonin increase after TRH and calcium stimulation. Although the increase in serum calcitonin after TRH injection was lower than that after calcium injection (1.6-fold vs 5.4-fold, p <0.05), there was no significant difference in mean peak calcitonin value following TRH and calcium injection in patients with medullary thyroid carcinoma. These results indicated that TRH could stimulate calcitonin release from the thyroid C-cells in both normal subjects and patients with medullary thyroid carcinoma.
Progesterone, testosterone and estradiol-17β inhibit gonadotropin-releasing hormone stimulation of G protein GTPase activity in plasma membranes from rat anterior pituitary lobe
Authors: Ravindra Rudravajhala , Aronstam Robert S
Published: June 2009

In order to understand the biochemical mechanisms underlying the rapid, non-genomic effects of gonadal steroids on gonadotropin secretion, we examined the effects of progesterone, testosterone and estradiol-17β on the low Km GTPase activity associated with transducer G proteins coupled to gonadotropin-releasing hormone (GnRH) receptors. Homogenates of anterior pituitary lobes from adult male rats were processed by discontinuous sucrose gradient centrifugation to isolate plasma membranes. The low Km GTPase activity (EC 3.6.1.-) was assayed in 5 μg membrane protein using [γ-32P]GTP at 37°C in an ATP-regenerating buffer containing 1 μmol/l unlabeled GTP. One hundred nmol/l each of progesterone, testosterone and estradiol-17β maximally stimulated low Km GTPase activity by 61%, 59% and 45%, respectively (p<0.05). Time course studies revealed that 100 nmol/l progesterone stimulated the enzyme activity by 93% and 62% at 5 and 30 min, respectively; 100 nmol/l testosterone stimulated GTPase activity by 100% and 72% at 5 and 30 min, respectively: 100 nmol/l estradiol-17β stimulated GTPase activity by 80% and 70% at 5 and 30 min, respectively. GnRH stimulated the low Km GTPase activity by about 60% in a concentration-dependent manner. In the presence of the gonadal steroids, the ability of GnRH to stimulate the GTPase activity was inhibited. For example, stimulation ranged from 36% to 60% with 0.1–100 nmol/l GnRH alone, but only from 7% to 20% in the presence of GnRH and 100 nmol/l progesterone (p<0.05). Similarly, in the presence of 100 nmol/l estradiol-17β, GnRH stimulation of the enzymatic activity ranged from 12% to 19%. It appeared that testosterone was less effective in inhibiting GnRH-stimulated GTPase activity; stimulation ranged from 15% to 32% in the presence of GnRH and 100 nmol/l testosterone (p<0.05). These results, while suggesting that the gonadal steroids disrupt GnRH receptor-G protein interactions, are consistent with the notion that steroids have a profound effect at the membrane level prior to their interaction with the cytosolic receptors.
Changes in plasma vasopressin concentration and plasma osmolality in relation to age and time of day in the male Wistar rat
Authors: Terwel Dirk , ten Haaf Jeroen A , Markerink Marjanne , Jolles Jellemer
Published: June 2009

The influence of age on several parameters related to water balance was studied in Wistar rats. Plasma AVP concentration and plasma osmolality were increased at midday in 21-month-old rats as compared with 3- and 4-month-old rats. Daily water intake per 100 g body weight was reduced in 14- and 21-month-old rats as compared with 3- and 4-month-old rats, but total water intake was unaltered. These results suggest that there is a change in water balance in Wistar rats with age. In order to obtain information about the influence of age on daily fluctuations in plasma AVP concentration and osmolality these parameters were determined in 4-month-old Wistar rats sacrificed at 2 h intervals during the day and in 20- and 31-month-old rats sacrificed at 8 h intervals. Plasma AVP concentrations were low during the light period and high during the dark period in 4-month-old rats. The relationship between plasma osmolality and plasma AVP concentration was dependent on the time of day in 4-month-old-rats, Plasma AVP concentrations were higher at 16.00 than at 08.00 and 24.00 in 20-month-old rats, and higher at 24.00 than at 08.00 and 16.00 in 31-month-old rats. In contrast to the plasma AVP concentration during the light period, the average daily AVP concentration (average of plasma AVP concentrations at 08.00, 16.00 and 24.00) was increased in 31-month-old rats only. The relationship between plasma osmolality and plasma AVP concentration was not age-related. The results of the present study suggest that there is a circadian rhythm of plasma AVP concentration in Wistar rats which is age-related but which does not fully correlate with plasma osmolality.
Evidence for the presence of endogenous 19-nortestosterone in the cow peripartum and in the neonatal calf
Authors: Meyer Heinrich HD , Falckenberg Daniela , Janowski Tomasz , Rapp Martin , Rösel Elisabeth F , van Look Lieve , Karg Heinrich
Published: June 2009

Urine samples were collected from five Brown Swiss cows during the 18 days prior to and 11 days after parturition and were analysed for 19-nortestosterone using an enzyme immunoassay. Nortestosterone concentrations ranged from 70 to 130 nmol/l in all samples taken before parturition. The levels declined within two days, and 11 days post partum no nortestosterone was detectable. In urine from newborn calves, maximal nortestosterone concentrations were determined during the first day of life (10.9–120 nmol/l), declining below 7.3 nmol/l until day 3 in most animals and remaining below the detection limit (<3.6 nmol/l) after day 8 in all animals. There was no obvious difference between cows carrying a male or a female calf nor between newborn male or female calves. Using the combined methods high performance liquid chromatography/enzyme immunoassay and high performance liquid chromatography/gas chromatography-mass spectrometry, the immunoreactivity in urine was identified to be 19-nortestosterone-1 7α. Although there is unequivocal evidence for the endogenous production of nortestosterone in pregnant cows, its function for placenta physiology, pregnancy anabolism and parturition remains unclear. However, new threshold levels for residue control of nortestosterone need to be fixed in accordance with the endocrine status of the animals.
Lipid peroxidation in early experimental diabetes in rats: effects of diabetes and insulin
Authors: Rungby Jørgen , Flyvbjerg Allan , Andersen Herdis B , Nyborg Kirsten
Published: June 2009

The degree of lipid peroxidation was measured in organs from diabetic rats receiving no treatment, and in those from insulin-treated diabetic rats and controls. Lipid peroxidation was measured as organ content of malondialdehyde, a degradation product of polyunsaturated fatty acids. In the kidney, lipid peroxidation was increased after one week of diabetes; insulin treatment reduced the level of lipid peroxidation to levels lower than seen in controls. In the liver, diabetes caused an increased lipid peroxidation, which could be reversed by insulin; no additional effect of insulin was found. In heart and pancreas no effects of diabetes or insulin were demonstrated. The present paper provides evidence that lipid peroxidation is increased in the early stages of experimental diabetes and is reversible by insulin treatment. Hyperinsulinaemia may, in itself, counteract lipid peroxidation in kidney.
Arginine-vasopressin and endothelium-associated proteins in thyroid disease
Authors: Arnaout MA , Awidi AS , El-Najdawi AM , Khateeb MS , Ajlouni KM
Published: June 2009

Plasma concentrations of endothelium-derived proteins (fibronectin and von Willebrand factor), liver synthesized proteins (haptoglobin, transferrin, ceruloplasmin, α1-antitrypsin, antithrombin III and factor VIII-coagulant) and plasma arginine-vasopressin (AVP) were measured in 12 hyperthyroid, 9 hypothyroid and 1 5 age- and sex-matched normal controls. In hyperthyroid patients the plasma concentrations of AVP and endothelium-associated proteins (EAP) were significantly higher than in the control group (p <0.05 and p <0.01 respectively). Rendering hyperthyroid patients into the euthyroid state significantly lowered AVP (p<0.01), fibronectin (p<0.05) and von Willebrand factor (p<0.01) compared with pretreatment levels. Hypothyroid patients were studied at diagnosis and after replacement therapy with levothyroxine. Compared with pretreatment values, significant increases were noted in plasma concentrations of von Willebrand factor, fibronectin and AVP (p<0.01). With the exception of factor VIII-coagulant, the concentrations of hepatic synthesized proteins did not deviate from normal values in hyperthyroid and hypothyroid patients. Significant correlations were found beween serum-free thyroxine on the one hand and the plasma concentrations of fibronectin (p<0.005), von Willebrand factor (p<0.001) and AVP (p<0.0001). Similarly, there was significant correlation between the plasma concentrations of AVP on the one hand and fibronectin (p <0.002) and von Willebrand factor (p<0.01). The results demonstrate elevated plasma levels of AVP in hyperthyroid patients and an increase during levothyroxine treatment of hypothyroid patients. The increase in EAP (fibronectin and von Willebrand factor) was dependent on thyroid hormone, and correlated with the increase in the plasma AVP concentrations. The mechanism(s) underlying the interrelation between AVP, EAP and thyroid hormones is (are) yet to be defined.
Ovulation induction with a single-blind treatment regimen comparing naltrexone, placebo and clomiphene citrate in women with secondary amenorrhea
Authors: Armeanu Magda C , Moss Robert J , Schoemaker Joop
Published: June 2009

Secondary amenorrhea is often associated with emotional stress, weight loss, eating disorders or polycystic ovary-like disease. Involvement of the endogenous opioids in the pathophysiology of hypothalamic amenorrhea, by inhibition of hypothalamic GnRH secretion, has been demonstrated in some cases. Chronic blockade of the endogenous opioids with the long-acting opioid antagonist naltrexone could result in increased gonadotropin secretion and ovulation induction in these cases. A single-blind ovulation induction protocol comparing naltrexone, placebo and clomiphene citrate was evaluated in eight patients with secondary amenorrhea. Naltrexone proved not to be more effective than placebo in our study. Only one patient ovulated on naltrexone, one on placebo and four on clomiphene citrate. The latter therapy caused a better endocrine response. In conclusion, although ovulation could be incidentally induced by naltrexone, this drug did not appear to be more successful than placebo and clomiphene citrate for ovulation induction in this population of patients.
Hormonal gradients between inferior petrosal sinuses in various pituitary diseases
Authors: Merola Bartolomeo , Colao Annamaria , Rossi Emanuela , La Tessa Giuseppe , Spaziante Renato , Lombardi Gaetano
Published: June 2009

The aim of this retrospective study was to evaluate the existence of a multihormonal gradient between the inferior petrosal sinuses in various pituitary diseases: Cushing's disease (8 cases), acromegaly (4 cases), prolactinomas (7 cases), GH, PRL-secreting adenoma (1 case), functionless adenoma (2 cases), empty sella (3 cases) and in non-tumoral hyperprolactinemia (5 cases). A significant intersinus gradient (more than 1.4:1) was recorded for GH, ACTH and PRL in 16 patients (80%), but in only 9 patients (45%) out of the 20 with hormone-secreting tumors for TSH, FSH and LH. Moreover, of the 10 patients in the remaining groups, only in two cases was a significant intersinus gradient present: one for GH and one for LH. In conclusion, the finding of a multihormonal release in the inferior petrosal sinus ipsilateral to the adenoma is reported, for the first time, in patients with GH- and PRL-secreting adenomas. The possible explanation for such a finding may be either an increased blood flow in this site of sampling or a pituitary multihormone release through a paracrine mechanism primed by the tumoral hypersecreted hormone. In addition, the pulsatile secretory pattern and the short half-life of polypeptide hormones may contribute to better demonstrate this phenomenon in respect to glycoprotein hormones.
Plasma oxytocin during the first and second stages of spontaneous human labour
Authors: Thornton Steven , Davison John M , Baylis Peter H
Published: June 2009

A technique for complete oxytocinase inhibition has been combined with a rapid serial sampling strategy to determine plasma oxytocin concentrations in twelve women during the early and late first stage and in eight women throughout the second stage of labour. The progress of labour is not related to an increase in oxytocin concentration, uterine contractions are not associated with changes in plasma oxytocin concentration and hypocontractile labour does not appear to be the result of a deficit of oxytocin. The majority of patients do not demonstrate an increase in plasma oxytocin concentration during the second stage of labour; however, a minority produce a large surge immediately before delivery. The results do not support a role for oxytocin during spontaneous labour unless uterine activity is controlled by extremely low plasma hormone concentrations or the uterus becomes sensitive to a constant oxytocin concentration.
Dose-dependent stimulatory effect of human growth hormone on the strength and collagen deposition of colonic anastomoses in the rat
Authors: Christensen Henrik , Flyvbjerg Allan
Published: June 2009

The effects of treatment with four different doses of biosynthetic human growth hormone (b-hGH; 0.125mg kg−1 d−1, 0.5mg kg−1 d−1, 2.0 mg kg−1 d−1, 8.0 mg kg−1 d−1) on the bursting strength and collagen deposition of rat colonic anastomoses were studied. Rats receiving 2.0mg and 8.0 mg b-hGH demonstrated increases in the pre- and postoperative body weights, and the bursting strength and hydroxyproline content of the anastomotic segments in these groups were significantly higher than controls on day 4 postoperatively. The serum levels of insulin-like growth factor I (IGF-I) were significantly higher than the controls after four days of preoperative treatment in the groups receiving 2.0 mg and 8.0 mg b-hGH, and postoperatively the IGF-I levels were significantly higher than those of the controls in the groups receiving 0.5 mg, 2.0 mg and 8.0 mg b-hGH per kg. Consequently, positive correlations were found between treatment doses of b-hGH and anastomotic defatted dry weight, hydroxyproline content and bursting strength of colonic anastomoses.
Fetal resorption in rats treated with an antiestrogen in relation to luteal phase nidatory estrogen secretion
Authors: Singh MM , Kamboj VP
Published: June 2009

Centchroman was administered to rats in relation to luteal phase nidatory estrogen secreted between 21.00 on day 4 and 10.00 on day 5 of pregnancy. A single oral dose of 1.25 mg/kg before the secretion of nidatory estrogen, i.e. until 21.00 on day 4, prevented implantation in 100% of the rats without altering plasma estradiol or progesterone concentration. Administration of a dose of up to 62.5 mg/kg at 10.00 on day 5 even failed to inhibit implantation, but caused dose-dependent resorption of implantations. Resorption of all implantations at a dose of 62.5 mg/kg was associated with a decrease in circulating progesterone levels, but was only partially reversed by progesterone or progesterone + estrone supplementation. Apparently normal morulae and blastocysts recovered between days 4 and 10 from rats treated with anti-implantation doses before release of nidatory estrogen, when transferred to the uteri of control rats exhibited lower pregnancy, implantation and development rates with increasing confinement in the genital tract of treated donors. None of the embryos recovered from control or centchroman treated females implanted in the uteri of treated rats. Centchroman administration on day 1, but not on day 5, abolished endometrial receptivity to an artificial stimulus for decidualization. All term fetuses were apparently normal and their weight comparable to that of control fetuses. The study provides evidence of post-implantation fetal resorption, occurring primarily between days 10 and 19 post-coitum, in rats treated with a potent antiestrogen before or immediately after the prenidatory estrogen secretion. This was not related to altered ovarian function and the decreased plasma progesterone concentration on day 19 after a higher dose of the compound was secondary to resorption of all implantations.
Effects of wheat bran and energy restriction on onset of puberty, cell proliferation and development of mammary tissue in female rats
Authors: Arts Cor JM , Govers Carin ARL , van den Berg Henk , Thijssen Jos HH
Published: June 2009

Delayed onset of puberty and mammary development is assumed to reduce the risk of mammary cancer. An animal experiment was performed to investigate the influence of dietary fiber, which is known to affect hormonal balance, on these characteristics. Forty-five immature female rats were randomized into three groups, which were fed ad libitum a low-fiber diet ( <0.5% dietary fiber based on white wheat flour), a high-fiber diet (9.2% dietary fiber based on wheat bran), or an energy-restricted low-fiber diet providing 90% of the energy of the ad libitum low-fiber diet. Energy intake in the second and third groups was similar. Wheat bran slightly delayed onset of puberty, whereas restricted energy intake delayed onset of puberty by about six days. At 48–58 days of age, 14 rats of the low-fiber group, 10 of the high-fiber group and 7 of the restricted group were in cycle. Development of mammary tissue was rudimentary in rats of the energy-restricted low-fiber group, stronger in the high-fiber group and strongest in the ad libitum low-fiber group. Cell proliferation in mammary tissue was similar for both groups fed ad libitum, but significantly lower in the restricted group. Peroxidase activity, a biomarker for estrogenicity, was lower in the high-fiber group than in the two low-fiber groups. It is concluded that wheat bran and, even more effectively, an imposed restricted energy intake delays onset of puberty and mammary development. This shortens the time for mammary cells to be initiated to tumor cells and hence reduces the risk of mammary cancer development. It seems that wheat bran acts via a reduced energy intake. However, that wheat bran plays a role in the delay of mammary development due to a reduced exposure to estrogen cannot be excluded.
Effect of serum thyrotropin levels on the concentration of messenger RNA for thyroid peroxidase in the rat
Authors: Magnusson Ronald P , Yu Bo , Brennan Veronica
Published: June 2009

The effect of serum TSH on rat thyroid peroxidase mRNA levels was studied in order to investigate the regulation of thyroid peroxidase gene expression in vivo. A nearly full-length rat thyroid peroxidase cDNA clone was isolated from a bacteriophage cDNA library synthesized using poly A+ RNA isolated from the thyroids of propylthiouracil-treated rats. cDNA probes derived from this clone were used to study rat thyroid peroxidase mRNA levels in response to the level of serum TSH. Two major rat thyroid peroxidase mRNA bands were detected on Northern blots of total cellular RNA (at 3.2 kb and at 3.7kb). Injection of thyroxine, which lowered the levels of serum TSH, also lowered the steady-state levels of both rat thyroid peroxidase mRNAs, whereas treatment with methimazole, which increased serum TSH, increased both rat thyroid peroxidase mRNA levels. In hypophysectomized rats 10 days postoperative, very low levels of thyroid peroxidase mRNA were observed. Injection of bovine TSH (1 IU/day) increased rat thyroid peroxidase mRNA expression, preferentially in the 3.2 kb band. These results clearly demonstrate that TSH regulates rat thyroid peroxidase mRNA levels in vivo.
Cabergoline in the long-term therapy of hyperprolactinemic disorders
Authors: Ferrari Carlo , Paracchi Alessandra , Mattei Anna M , de Vincentiis Sangrila , D'Alberton Alberto , Crosignani PierGiorgio
Published: June 2009

The efficacy and safety of the new long-acting dopamine agonist cabergoline were evaluated in 127 hyperprolactinemic patients (124F and 3M; 71 with microprolactinoma, 14 with macroprolactinoma, 5 with operated macroprolactinoma and 37 with idiopathic disorder) who were treated with the drug for from 3 to 52 months (median, 14 months). Cabergoline was administered orally at dose levels ranging between 0.2 and 3.5mg per week, given once weekly in 92 patients, twice weekly in 22, thrice weekly in 9 and daily in 4. Serum prolactin and progesterone levels, hematology, blood chemistry and electrocardiograms were frequently evaluated throughout treatment. CT or MR imaging of the pituitary was repeated during treatment in patients with macroprolactinoma and in 38 with microprolactinoma. After drug discontinuation, serum prolactin and gonadal function were evaluated monthly for three months in 65 patients and for up to two years in 12. Serum prolactin levels were normalized in 114 patients (90%). Of 56 women with amenorrhea, 52 resumed menses (with presumptive evidence of ovulation in 49); 17 women became pregnant; and sexual potency was restored in the 3 men. Evidence of tumor shrinkage was obtained in 13 of the 14 patients with macroprolactinoma and in 28 of 38 with microprolactinoma; complete disappearance of the tumor image was achieved in 2 macro and 14 microprolactinomas. A total of 48 adverse events was reported by 29 patients (2 3%), almost all typical of the pharmacological class and mild to moderate; no patient withdrew from treatment due to adverse events. Safety parameters did not change. Following cabergoline discontinuation, prolactin levels increased slowly, being still markedly lower than pretreatment values after three months; 10 patients out of 32 had persistently normal prolactin levels during one year of follow-up. Of 28 previously amenorrheic women who resumed menses during treatment and were followed for at least six months after cabergoline withdrawal, 23 continued to have cyclic ovulatory menses. These efficacy and safety data, including those obtained on drug withdrawal, compare favorably with those reported for bromocriptine and other prolactin-lowering drugs. Because of its very simple administration schedule, which should increase patient compliance, cabergoline may become the drug of choice for hyperprolactinemic disorders.
Presence of aldosterone-like immunoreactivity in cerebrospinal fluid in normotensive subjects
Authors: Kageyama Yo , Suzuki Hiromichi , Saruta Takao
Published: June 2009

Accumulating evidence, including a wide distribution of specific receptors for aldosterone in the brain, has revealed a potential role of aldosterone in the central nervous system. However, whether or not aldosterone is present in cerebrospinal fluid remains unclear. We attempted to detect aldosterone in cerebrospinal fluid in 14 normotensive subjects. Cerebrospinal fluid was obtained by lumbar puncture. Aldosterone-like immunoreactivity was detected in cerebrospinal fluid (163±5 pmol/l, range 139-211 pmol/l) and was found to significantly correlate to both plasma aldosterone (r = 0.70, p<0.01) and plasma renin activity (r=0.68, p<0.01). However, no significant relationship was found between aldosterone-like immunoreactivity in cerebrospinal fluid and the level of sodium or potassium in cerebrospinal fluid or mean blood pressure. Although we confirmed the presence of aldosterone-like immunoreactivity in cerebrospinal fluid of normotensive subjects, the physiological role of aldosterone in cerebrospinal fluid has yet to be elucidated. Further study will thus be needed to determine the role of cerebrospinal fluid aldosterone.
Regulation of parathyroid hormone release in normal and pathological parathyroid cells exposed to modulators of protein kinase C
Authors: Ridefelt Peter , Nygren Peter , Hellman Per , Larsson Rolf , Rastad Jonas , Åkerström Göran , Gylfe Erik
Published: June 2009

Effects of the protein kinase C activating phorbol ester 12-O-tetradecanoyl phorbol 13-acetate and the inhibitor 1-(5-isoquinolinyl-sulfonyl)-2-methylpiperazine (H-7) on parathyroid hormone (PTH) release were studied in normal bovine and pathological human parathyroid cells. An increase of extracellular Ca2+ from 0.5 to 3.0 mmol/l inhibited PTH release by 60% in the bovine cells with half maximal effect (ED50) at 1.31 mmol/l. This inhibition reached less than 50% in the cells from patients with primary and uremic hyperparathyroidism, and the ED50 values were 1.49 and 1.42 mmol/l, respectively. The phorbol ester (0.1 μmol/l) made secretion insensitive to changes of extracellular Ca2+, an action counteracted by H-7 (50 μmol/l) in the bovine cells, whereas H-7 alone had no effects. The phorbol ester and H-7 had opposite actions on regulation of PTH release also from cells from patients with hyperparathyroidism. However, in pathological cells H-7 alone improved Ca2+ inhibition of secretion by stimulating release in low Ca2+ concentrations and decreasing the ED50 values. The magnitude of changes in ED50 values by H-7 increased with the severity of the secretory disturbance of the pathological cells. The results indicate that increased protein kinase C activity may be a factor of importance in the pathophysiology of hyperparathyroidism.
The effects of goitrogenesis, involution, and goitrogenic rechallenge on the clonogenic cell content of the rat thyroid
Authors: Groch Kevin M , Clifton Kelly H
Published: June 2009

A fraction of enzymatically monodispersed rat thyrocytes from untreated animals clonally proliferate into thyroid follicular units following transplantation into the subcutaneous fat pads of syngeneic recipients. During the induction of experimental goiters in rats either with 3-amino-1,2,4-triazole/iodine sufficient diet or KClO4/Remington low iodine diet, the clonogenic fractions of cells from aminotriazole goiters decreased to 1.9×10−4 and KClO4 goiters to 9.8×10−5 as compared to 5.8× 10−3 for cells from age-matched controls during the growth phase of goitrogenesis. With continued aminotriazole treatment after thyroid hyperplasia had ceased, the clonogenic fraction increased to 2.0×10−3 while continued KClO4 treatment had little further effect. The changes in the clonogenic fraction induced by both regimens were reversed during involution; goitrogenic rechallenge of involuted glands led to changes in the clonogenic fraction similar to that noted during the initial challenge. The clonogenic fractions of cells from aminotriazole goiters were greater than that of cells from KClO4 goiters at all time points examined despite similar TSH levels in situ. We conclude that the rat thyroid contains a hierarchy of cells with different proliferative capacities and that the clonogenic thyrocytes possess many of the attributes of a stem-cell.
Recombinant human growth hormone stimulates B cell immunoglobulin synthesis and proliferation in serum-free medium
Authors: Yoshida Akira , Ishioka Chihiro , Kimata Hajime , Mikawa Haruki
Published: June 2009

In order to investigate the effects of growth hormone on human B cells, we studied immunoglobulin synthesis and [3H]-thymidine uptake by B cell lines, IM-9, GM-1056 and CBL, and purified tonsil B cells. Cells were cultured in a serum- and albumin-free medium, Cosmedium-001 to exclude interaction between a certain growth-promoting substance and any unknown substances that serum may contain. GH enhanced IgG synthesis and [3H]-thymidine uptake by IM-9 cells, IgA synthesis by GM-1056 cells and IgM synthesis by CBL cells in a dose-dependent fashion. This was not a non-specific effect of protein in GH, since equivalent or higher concentrations of proteins such as bovine serum albumin, interleuki-2, interleukin-5, granulocyte/macrophage colony-stimulating factor, or erythropoietin did not stimulate B cell lines. Moreover, the rabbit anti-GH antibody blocked the enhancing effect of GH, while normal rabbit antibody failed to do so. GH also enhanced immunoglobulin synthesis (IgG and IgM) and thymidine uptake by Staphylococcus aureus Cowan strain I-activated tonsil B cells. These results indicate that GH has a direct stimulating effect on B cells, and, in addition to its endocrinological function, GH may also act as an immunoregulatory cytokine.
Effect of growth factors on hyaluronan and proteoglycan synthesis by retroocular tissue fibroblasts of Graves' ophthalmopathy in culture
Authors: Imai Yumi , Odajima Ritsuko , Inoue Yoichi , Shishiba Yoshimasa
Published: June 2009

One of the pathological changes seen in Graves' ophthalmopathy is the deposition of glycosaminoglycans such as hyaluronan and proteoglycan in retroocular connective tissue. We analyzed glycosaminoglycans synthesized by retroocular tissue fibroblasts in culture derived from an individual not suffering from thyroid disease and from three patients with Graves' ophthalmopathy. Retroocular tissue fibroblasts synthesized both hyaluronan and proteoglycan, the latter composed mainly of chondroitin sulfate. This contrasts with the proteoglycan synthesized by adult skin fibroblasts which was composed of dermatan sulfate and heparan sulfate proteoglycan. Chondroitin sulfate proteoglycan secreted by retroocular tissue fibroblasts consisted of large and small chondroitin sulfate proteoglycans (CS-PG), their size being determined by the Sepharose CL-6B column. The effects of IGF-1 and PDGF on hyaluronan and proteoglycan synthesis were studied separately and in combination. Both IGF-1 and PDGF increased the synthesis of hyaluronan and proteoglycan in a dose-dependent manner. IGF-1 predominantly stimulated secretion of small CS-PG, while PDGF increased large CS-PG markedly when studied in retroocular tissue fibroblasts. In contrast, IGF-1 stimulated secretion of small proteoglycan while PDGF had little effect on proteoglycan synthesis in skin fibroblasts. Thus, glycosaminoglycan synthesized by retroocular tissue fibroblasts has a unique composition and each component is regulated independently, at least in part.
Immunoreactive somatostatin in the rat ovary
Authors: McIntyre H David , Maréchal Daniel J , Déby Ginette P , Mathieu Anne G , Hézée-Hagelstein M-T , Franchimont Paul P
Published: June 2009

Immunoreactive SRIH was detected in the rat ovary (15.6 pg/mg wet weight, 520 pg/mg protein) and was localized to the granulosa cells (168±6 pg/106 cells). Serial dilution studies showed parallelism of the inhibition curve for synthetic SRIH-14 and those of extracts of whole ovary and media conditioned by granulosa cells. The quantity of immunoreactive SRIH released into granulosa cell conditioned media decreased with time, while the intracellular content remained relatively constant. Gel chromatography showed peaks of immunoreactivity co-eluting with SRIH-14 (38%), SRIH-28 (31%) and a high molecular weight component. The addition of synthetic SRIH-14 stimulated meiotic maturation in cumulus-enclosed rat oocytes, with dose dependency being observed at SRIH-14 concentrations between 1 and 1000 pmol/l. No evidence of pre-pro-SRIH gene expression could be demonstrated in either rat ovary or testis using both Northern analysis and reverse transcriptase/polymerase chain reaction amplification of polyadenylated RNA. SRIH may be produced in the ovary during a specific stage of ontogeny or by an alternative gene. It is also possible that SRIH is actively taken up and stored by granulosa cells without being produced locally.
Alterations in circadian rhythm of serum thyrotropin in critically ill patients
Authors: Custro Nicola , Scafidi Vincenza , Notarbartolo Alberto
Published: June 2009

To evaluate the 24-h pattern of serum thyrotropin (TSH) in critically ill patients, we measured serum concentrations of TSH in blood samples collected every 2 h for 24 h from nine patients (six with malignancy, two with liver cirrhosis, one with chronic renal failure), who had subnormal levels of both triiodothyronine (T3) and thyroxine (T4), in the absence of history, symptoms or signs of thyroid disease. Analysis of the data, performed using a second-order inferential statistical methodology for rhythmometry (cosinor method), demonstrated that critically ill patients still had daily oscillations of serum TSH which significantly adapted to the function approximating the circadian rhythms (R2 = 74.3%). However, the mean level (mesor) in the rhythm of the patients was found to be significantly lower than that of healthy subjects (0.96 vs 2.18 mU/l); the amplitude of rhythmical daily variations also was lower in patients than in healthy subjects (0.23 vs 0.56 mU/l), even though the amplitude/mesor ratio was similar (23% vs 26%). Lastly, the highest level in the TSH rhythm of the patients was found to be in the late afternoon, in contrast to healthy subjects, who had a TSH surge after midnight. Although these alterations are consistent with the existence of a dysregulation at suprahypophyseal level in critically ill patients, it remains to be established whether the state of low T3 and T4 may be ascribed to anomalous circadian rhythm of TSH.
Evaluation of the degradation of desamino1,D-arginine8-vasopressin by nasal mucosa
Authors: Jönsson Karin , Alfredsson Karin , Söderberg-Ahlm Christina , Critchley Helen , Broeders Anja , Ohlin Mats
Published: June 2009

The nasal route is a convenient and simple way to administer peptides to humans. Absorption of the drug, however, requires passage of the substance through the nasal mucosa. This is a possible site of enzymatic degradation of the peptide. It is shown that rabbit nasal mucosa homogenates rapidly degrade the synthetic anti-diuretic hormone analogue desamino1,D-arginine8-vasopressin in vitro. The metabolite formed has been identified as des-(amino,arginine8,glycineamide9)-vasopressin, which is stable under the prevalent in vitro incubation conditions. It is proposed that this process is catalyzed by intracellular post-proline cleavage enzyme. Reversed phase chromatography in combination with immunological detection has been used to study the possible presence of this metabolite in the circulation after intranasal administration to humans. The metabolite des-(amino,arginine8,glycineamide9)-vasopressin could not be detected in plasma following intranasal administration, possibly indicating a paracellular absorption of desamino1,D-arginine8-vasopressin or absence of this enzymatic activity in humans.
Long-term stability of low insulin responses to glucose in non-diabetic subjects
Authors: Alvarsson Michael , Grill Valdemar E , Wajngot Alexandre , Cerasi Erol , Efendic Suad
Published: June 2009

We investigated the stability of the insulin response to glucose in healthy subjects by making retrospective comparisons of insulin responses after two 60 min glucose infusion tests performed many years apart. The subjects (N =49) were divided into two lower and two higher quartiles as assessed by the incremental 0–10 min insulin area during the initial glucose infusion test. Ages were initially 32.3±2.8 years in lower quartiles and 26.6±1.1 in higher quartiles and body mass indexes 21.6±0.6 kg/m2 and 21.8±0.5, respectively. The interval between the first and second glucose infusion tests was 8.1±2.8 years for lower quartiles and 10.4±1.3 for higher quartiles. In lower quartiles, the 0–10 min insulin area at first testing was 157.1±15.9 mU/l × 10 min and at follow-up 202.2±26.6 (+ 29%, NS). In higher quartiles, the insulin area decreased from 654.8±70.6 mU/l × 10 min at first testing to 489.8±53.6 at follow-up (−25%, p<0.05). The 0–60 min glucose area did not change significantly between glucose infusion tests in lower quartiles (+ 5%), but did increase by 12% (p<0.005) in higher quartiles. Only one subject of the lowest quartile at first testing changed to higher quartiles at follow-up. Predictable "regression toward the mean" at follow-up was moderate, hence the individual insulin response to glucose was relatively stable with time. This finding is compatible with the hypothesis that genetic factors are of major importance for the insulin response to glucose.
Serum and plasma epidermal growth factor in thyroid disorders
Authors: Kung Annie WC , Hui WM , Ng Eddie SK
Published: June 2009

Epidermal growth factor (EGF) is an important mitogen and its secretion in neonatal animals has been shown to be affected by thyroid hormone levels. EGF in blood of humans is found in both platelets (as reflected in its serum level) and in plasma; its origin in plasma remains unclear. Serum and plasma EGF were studied in a group of patients with thyroid disorders. Twenty hyperthyroid subjects (3M, 1 7F) aged 37.3±14.9 years and 10 hypothyroid patients (3M, 7F) aged 58.3±18.6 years were studied before and after euthyroidism was restored. Before treatment, serum EGF in the hyperthyroid patients was elevated compared to normal controls (501±376 vs 270±154 pmol/l, p<0.001). After treatment of hyperthyroidism, serum EGF returned to the normal levels (232±176 pmol/l). In contrast, serum EGF was not significantly different in the hypothyroid subjects either before or after treatment (151±194 and 237±153 pmol/l respectively). A significant correlation (r = 0.461, p < 0.001) between serum EGF and serum-free thyroxine index (FTI) was found when all samples from both untreated and treated hyper- and hypothyroid patients were examined. Multiple regression analysis revealed that both serum FTI and platelet count independently affected the serum EGF levels. Similarly, plasma EGF was also elevated in untreated hyperthyroid patients with a median of 26.4 pmol/l (range < 16.6–88.0), whereas all normal controls and hypothyroid subjects had unmeasurable levels. It is concluded that thyroid hormones affect EGF levels in plasma and serum. The physiological significance of this finding is unclear and needs further elucidation.
Cerebrospinal fluid and blood concentrations of luteinizing hormone, follicle stimulating hormone and prolactin following castration of adult male rats
Authors: Balasinor Nafisa , Gill-Sharma Manjit K , Parte Priyanka , Juneja HS
Published: June 2009

Comparative levels of LH, FSH and PRL in the serum and cerebrospinal fluid (CSF) of adult male rats were studied at different periods following castration. Intact and sham-operated animals served as controls. Blood and CSF were collected at 1, 3, 7, 14, 21, 28, 35 and 46 days following castration. The CSF was collected via cisterna-magna puncture, while the blood was collected from abdominal aorta. Serum gonadotropins increased progressively beginning day 1 post-castration to reach maximum by day 35 or 46 post-castration. Sham operation and castration did not affect mean CSF, LH and FSH levels compared to intact controls. Analysis of the temporal pattern of serum and CSF gonadotropin levels following castration revealed significant positive correlation between CSF and serum LH (r=0.58) and FSH (r=0.64) levels respectively. The data suggest that CSF gonadotropins may be derived from systemic circulation. Serum PRL levels were not affected by castration, but CSF PRL levels were significantly reduced at days 28, 35 and 46 post-castration compared to intact controls. CSF PRL levels showed negative correlation with serum LH and FSH levels but failed to show a correlation with serum PRL levels. Hypothalamic norepinephrine turnover rate increased at days 28, 35 and 46 post-castration. Hypothalamic dopamine contents and turnover rates were reduced at days 21 and 28 post-castration. It is suggested that CSF PRL may have a role in the regulation of serum gonadotropins.
Primary culture of prepubertal human testicular cells isolated from testes collected at necropsy
Authors: Berensztein Esperanza B , Belgorosky Alicia , Rivarola Marco A
Published: June 2009

The aim of the present work was to develop a method for maintaining prepubertal human testicular cells in culture. Seven pairs of testes of boys who died of causes unrelated to endocrine or metabolic diseases were obtained at necropsy. Histology of the testes was normal. Testes were digested with collagenase and dispersed cells were seeded in multi-well dishes in the presence of 5% bovine fetal serum. After the first day, cells were cultured for five days in serum-free medium in the presence or absence of 918 pmol/l insulin. At the end of culture, microscopic examination showed healthy looking cells with characteristics compatible with pre-Sertoli cells; peritubular cells were identified by immunocytochemistry. In the presence of insulin, cells were able to secrete either testosterone or estradiol into the medium, as well as to reveal aromatase activity. In order to study the effect of the time elapsed between death and beginning of cultures, steroidogenic activity was related to this post mortem time. It was found that, in the presence of insulin, cells obtained from testes with less than 24 h of post mortem time secreted testosterone (64±7.2 pmol/106 cells·24 h, mean±sd) while cells obtained from testes with more than 24 h of post mortem time did not secrete testosterone. With long post mortem times, aromatase activity under insulin increased from non-detectable to 35 pmol/106 cells·24 h. Time course studies showed that cells with capacity to secrete testosterone increase this secretion gradually up to day 10 of culture, while those with detectable aromatase activity showed increments in this activity during the first week of culture. It is concluded that it is possible to maintain cultures of prepubertal human testicular cells obtained at necropsy. In order to maintain testosterone secretion capacity, the time between death and initiation of culture should not exceed 24 h.
Degradation of oxytocin by the human placenta: effect of selective inhibitors
Authors: Mizutani S , Yokosawa H , Tomoda Y
Published: June 2009

The hydrolysis of oxytocin by human placental subcellular fractions was studied in the presence of selective inhibitors by measuring liberated amino acids by high performance liquid chromatography (HPLC). Oxytocin degradation by microsomal and lysosomal fractions was inhibited by bestatin, amastatin and puromycin. The IC50 values of these inhibitors on oxytocin degradation by both fractions were similar to those of these inhibitors on the human placental aminopeptidase M measured by L-Leu-p-nitroanilide as a substrate (LAP activity), which we reported previously. However, purified aminopeptidase M from human placental microsomal fractions could not liberate any amino acid from oxytocin. Since phosphoramidon (1 μmol/l), a putative metalloendopeptidase inhibitor, and N-benzylcarbonyl-valyl-prolinal (Z-Val-prolinal) (14 μmol/l), a selective inhibitor of post-proline endopeptidase, could not significantly influence the degradation of oxytocin by either subcellular fractions, neither enzyme seems to be actively involved in oxytocin degradation. These results strongly suggested the existence of oxytocinase(s) other than the above three enzymes in microsomal and/or lysosomal fractions of human placenta.
Decrease of testosterone level during an experimental African trypanosomiasis: involvement of a testicular LH receptor desensitization
Authors: Soudan Benoit , Tetaert Daniel , Racadot André , Degand Pierre , Boersma Arnold
Published: June 2009

To investigate gonadal disorders and changes of the testicular receptors occurring during the sleeping sickness disease (African trypanosomiasis), an experimental model was developed with 10-month-old rats infested by bloodstream forms of two variants of Trypanosoma brucei brucei (AnTat 1.1 A and AnTat 1.8). At the acute phase, three days after inoculation, the animals were sacrificed for estimating the serum levels of LH and testosterone and the number of testicular LH receptors. Considering a possible intervention of the stress during the infestation and to improve our investigations on gonadal imbalance related to trypanosomasis, levels of additional parameters [corticosterone, glucose and transaminases (glutamic-oxaloacetic transaminase and glutamic-pyruvic transaminase)] were determined. Stimulation testing with hCG was likewise assessed in infested rats to analyse the testicular testosterone response to gonadotropin. A significant decrease was demonstrated for serum LH and testosterone levels in the infested rats, as well as the loss of: (i) the testicular responsiveness to exogenous gonadotropin; (ii) the number of testicular LH receptors. Moreover, the remaining testicular receptors of infested rats showed an increase in their equilibrium association constant (Ka). Our study suggests that dysfunction of Leydig cells occurring during African trypanosomiasis is in part related to stress induced by the presence of the parasites.