bluuebunny/crossref_metadata_2025_split huggingface dataset:
A somatostatin analogue inhibits chondrosarcoma and insulinoma tumour growth
Authors: Reubi J. C. 
Published: December 2008

Abstract. The in vivo effects on tumour growth of a potent somatostatin analogue, SMS 201-995 [H-(D)Phe-Cys-Phe-(D)Trp-Lys-Thr-Cys-Thr-(ol)], were measured in two characterised transplantable tumours:
the Swarm rat chondrosarcoma, known to be insulin-, growth hormone (GH)-, somatomedin- and corticosteroid-dependent, a hamster insulinoma, bearing specific high affinity somatostatin receptors.
SMS 201-995 (1.25 mg/kg/day) given for 25 days to rats bearing freshly transplanted chondrosarcomas inhibited tumour volume by 48%. A significant tumour growth inhibition was measured also in well developed tumours treated with high doses of SMS 201-995 (1.25 mg/kg/day) for 7 days. In the treated animals, GH was significantly inhibited.
In hamsters bearing a freshly transplanted insulinoma, the daily application of SMS 201-995 (200 μg/kg/day, sc) for 33 days could significantly inhibit the growth (as measured by tumour volume) of the tumour. A moderate inhibitory effect of SMS 201-995 on the growth of well grown insulinomas could also be observed.
This study shows that SMS 201-995 under the present experimental conditions has a moderate but significant growth inhibitory effect in two different transplantable tumour models. In the rat chondrosarcoma, the effect of SMS 201-995 is probably indirect, due to inhibition of GH, somatomedin and insulin. In the hamster insulinoma, the effect is possibly due to a more direct action of SMS 201-995 on specific somatostatin receptors present in this tumor.
Relaxin-induced changes in adenosine 3',5'-monophosphate levels in the human cervix
Authors: Norström Anders , Wiqvist Ingrid 
Published: December 2008

Abstract. The effects of porcine relaxin on the levels of cAMP in human cervical tissue were studied in vitro. The specimens were obtained by needle biopsy from women undergoing hysterectomy, legal abortion in the first trimester or elective Casearean section at term, and were incubated in Krebs-Ringer buffer for 15 min in the presence of porcine relaxin (5 μg/ml, 3000 GPU/mg). cAMP was determined using a modified protein binding assay. The concentration of cAMP was higher in pregnant than in non-pregnant women. Relaxin stimulated the production of cAMP in the 7th–8th week of gestation and at term but did not significantly alter the cervical cAMP levels in neither non-pregnant women nor in women in the 10th–12th week of pregnancy.
Previous studies have shown that porcine relaxin reduces collagen synthesis in tissue from the human cervix and lower uterine segment. The present observations indicate that these effects can be mediated by cAMP.
Naloxone administration does not affect gonadotrophin secretion in male patients with isolated hypogonadotrophic hypogonadism
Authors: Maggi Mario , De Feo Maria Laura , Mannelli Massimo , Delitala Giuseppe , Forti Gianni 
Published: December 2008

Abstract. We evaluated the gonadotrophin response to acute naloxone administration (10 mg iv) in 4 male patients with isolated hypogonadotrophic hypogonadism (age range 18.5–26 years) before and after pituitary priming with daily infusions of GnRH (25 μg/h for 4 h) for 4 days.
A blunted gonadotrophin response to acute GnRH administration (100 μg iv) and a lack of response to naloxone was observed before pituitary priming. After repeated infusions of GnRH, pituitary gonadotrophin responsiveness to GnRH was restored, whilst naloxone still did not affect gonadotrophin levels.
Our data suggest that in male isolated hypogonadotrophic hypogonadism 1) the lack of pituitary response to naloxone is not due to pituitary hyporesponsiveness to GnRH; 2) endogenous opioids do not exert any inhibitory influence on GnRH secreting neurons and thus are not involved in the pathogenesis of this disease.
Catch-up growth following transfer from three times weekly im to daily sc administration of hGH in GH deficient patients, monitored by knemometry
Authors: Hermanussen M. , Geiger-Benoit Karin , Sippell W. G. 
Published: December 2008

Abstract. A novel and non-invasive technique of growth measurement is introduced. By this method the length of the human lower leg is measured with an accuracy of 0.1 mm. Thus, growth velocities can be estimated within a few weeks. In the present study the immediate changes of growth velocity are demonstrated, following the transfer of growth hormone administration from three times weekly im to daily sc in 9 growth hormone deficient children, age 7.4 to 20.5 years. The first observation period (3 times weekly im administration) ranged from 32 to 72 days, the second observation period (daily sc administration) ranged from 160 to 267 days). During the study, the total weekly dosage of growth hormone remained unchanged (12 IU/m2/week).
In all 9 patients growth velocity increased significantly after the transfer of application. Mean growth velocity of the lower leg rose from 0.04 mm/day up to 0.065 mm/day. Mean growth velocity of total body height rose form 4.8 cm/year up to 6.9 cm/year.
In addition, differential lower leg growth rates of 3 to 4 week periods were established in all 9 patients, revealing a significant catch-up growth spurt immediately following the transfer of application. During this spurt mean lower leg growth velocity rose form 0.04 mm/day up to 0.091 mm/day. This marked increase of lower leg growth rates lasted for only a few weeks and was followed by a period of decreased growth velocity. On the long run, growth velocity shifted upward in a wave-like pattern, stabilizing on a significantly higher level than before the transfer of application.
Prolactinoma of the pituitary containing amyloid
Authors: Paetau A. , Partanen S. , Mustajoki P. , Valtonen S. , Pelkonen R. , Wahlström T. 
Published: December 2008

Abstract. A transsphenoidal operation was performed in a 27 year old man because of a large intrasellar expansion and marked hyperprolactinaemia (33 000 mU/l). The tumour found in the operation bulged into the sphenoidal sinus and was extirpated.
On histopathological examination the tumour consisted mainly of congophilic amyloid spherules with intermingled sparse adenoma cells. The adenoma cells were strongly positive for prolactin in immunoperoxidase staining, and in electron microscopy they contained secretory granules. Ultrastructurally the amyloid spherules consisted of masses of concentrical extracellular amyloid filament bundles.
Sequential changes in the pituitary thyroid axis after chronic TRH administration: effects on euthyroid and thyroxine treated female rats
Authors: Iglesias R. , Llobera M. , Montoya E. 
Published: December 2008

Abstract. The effect of chronic oral thyrotrophin-releasing hormone (TRH) administration on thyrotrophin (TSH), l-triiodothyronine (T3) and l-thyroxine (T4) serum levels, pituitary TSH concentration and serum response to acute TRH injection, has been studied in female rats under different thyroidal conditions: shamoperated control animals, and thyroidectomized animals receiving 25 μg l-T4/100 g body weight/day. After 30 days, these groups were divided into two subgroups (6–10 animals per group), one receiving the aforementioned treatment and the other the same plus 2 mg TRH/10 ml distilled water (DW), as drinking water.
TRH-treated sham-operated animals showed significantly reduced serum and pituitary TSH levels and inceased serum T3 levels at most of the times studied (1, 6, 10, 18 and 34 days of oral TRH or DW administration), and a transient elevation in serum T4 between day 1 and 6. Thyroidectomized-l-T4-treated animals showed increased serum and pituitary TSH levels throughout the treatment and reduced T3 and T4 serum levels at the beginning, as compared to thyroidectomized-l-T4-treated animals.
TSH response to iv TRH administration on the 10th day of oral TRH administration was reduced in controls chronically treated with oral TRH as compared to nontreated controls, and was increased in thyroidectomizedl-T4-treated animals on chronic TRH vs the same group on oral DW.
These results suggest that chronic TRH administration can stimulate TRH synthesis in vivo, bypassing the inhibitory effects of thyroid hormones, the increased pituitary TSH reserve being responsible for the partial restoration of a response to acute TRH injection in the thyroidectomized-l-T4-treated animals.
Effects of FSH and LH on adenylate cyclase activity in rat granulosa cell membranes during follicular maturation
Authors: Nordenström K. , Rosberg S. , Roos P. 
Published: December 2008

Abstract. Adenylate cyclase activity was measured in membranes prepared of granulosa cells isolated from PMSG-treated immature rats and the effects of ovine, highly purified human and rat gonadotrophins were compared. Furthermore, a comparison of the effects of the human preparations (hLH, hFSH) on the adenylate cyclase activity in membranes prepared from granulosa cells isolated at different stages of follicular maturation, was performed.
The adenylate cyclase in membranes of immature granulosa cells was stimulable with FSH but not with LH, while in pre-ovulatory granulosa cell membranes, both gonadotrophins were stimulatory with FSH generally being more effective than LH. Surprisingly, the dose-response curve for ovine LH (oLH) was biphasic with a plateau at a level of adenylate cyclase activity corresponding to the maximal stimulatory effect of hCG. With increasing oLH concentrations the response resumed and the maximal stimulation corresponded to that of oFSH. With highly purified rat gonadotrophins the FSH response was significantly higher than the response to LH at all concentrations tested. Using highly purified human gonadotrophins the maximal FSH response was 50% higher than the maximal LH response and by adding increasing concentrations of hFSH to a maximally stimulatory concentration of hLH it was possible to mimic the biphasic dose-response curve for oLH. When the membranes were prepared from ganulosa cells isolated after the pro-oestrus LH/FSH surge there was clear increase in the sensitivity of the adenylate cyclase to stimulation with LH although the maximal response was unaffected. The sensitivity to FSH was not altered.
These data indicate that FSH gives a higher maximal stimulation of the adenylate cyclase in rat granulosa cells than does LH, and the biphasic dose-response curve seen with oLH most probably is due to a FSH contamination in the LH preparation used. After in vivo exposure to the pro-oestrus LH/FSH surge no desensitization was observed but instead a clear increase in LH sensitivity. It thus seems as if the primary FSH sensitive cell under the influence of the LH/FSH surge turns to a primary LH sensitive one.
Circannual concentrations of melatonin, gonadotrophins, prolactin and gonadal steroids in males in a geographical area with a large annual variation in daylight
Authors: Martikainen Hannu , Tapanainen Juha , Vakkuri Olli , Leppäluoto Juhani , Huhtaniemi Ilpo 
Published: December 2008

Abstract. This study was aimed at elucidating the possible effects of a large annual variation in photoperiodicity on the secretory activities of the pineal gland, pituitary and testes. Serum daytime melatonin, FSH, LH, prolactin (Prl), testosterone and oestradiol concentrations were determined monthly over a year in 24 healthy young adult men (except for melatonin which was analysed only in 11 subjects) in northern Finland, where the day length is 22 h in mid-summer and 3.5 h in midwinter.
Serum daytime melatonin levels showed two annual peak values, in December and May, and a nadir was observed in August. The absolute values of the other hormones measured did not show significant month to month variation over the observation period. When hormone levels were calculated as percentages of the individual annual means, several significant differences were found between monthly levels. The melatonin peak in May (133 ±20%, se, of the annual mean) was associated with significant increases in LH (110 ±4%) and FSH (107 ± 3%). Prl levels (115 ± 9%) reached a maximum in January. The nadirs of melatonin and the pituitary hormones measured were seen in August. Oestradiol showed the highest values in April-June, but no significant variation was found in serum testosterone levels. Positive correlations were observed between FSH and LH (r = 0.41, P <0.01), and Prl and LH (r = 0.26, P< 0.01), whereas Prl and testosterone (r = −0.17, P< 0.01) were inversely correlated.
This study indicates circannual rhythmicity of peripheral serum daytime melatonin, gonadotrophin, Prl and oestradiol levels, but this variation was not related to extremes in daylight and therefore seasonal factors other than light may regulate this circannual variation.
Serum reduces the TSH content in rat pituitary cells in culture
Authors: Spira O. , Halabi A. , Vlodavsky I. , Atzmon R. , Gross J. , Gordon A. 
Published: December 2008

Abstract. Euthyroid rat pituitary cells were plated on a natural extracellular matrix (ECM) and cultured in either a medium supplemented with hormones and growth factors (SM) or in an unsupplemented medium (USM). Hormone supplementation resulted in a marked increase in the number of cells and in a less pronounced increase in the TSH content. Addition of 10% dehormonized serum (DHS) to the medium caused a further increase in the cell number as well as a significant elevation in the GH content but, surprisingly, it caused also a dramatic decrease in the TSH content. Time course experiments revealed that the serum doubled the rate of suppression of the TSH. DHS prepared from rat serum was as effective as that prepared from foetal calf serum and heat-inactivation of the serum did not change its suppressive effect on the production of TSH. This effect was confined to the serum fraction which was precipitable with 45% ammonium sulphate but did not bind to Con-A.
It is suggested that a high molecular weight protein fraction of serum reduces the number of thyrotrophs in the culture and/or decreases the rate of TSH production by these cells.
Increased peripheral venous somatostatin concentration and decreased glucagon response to arginine in patients with insulin dependent diabetes mellitus without residual B-cell function Increased plasma SRIF in IDDM
Authors: Skare S. , Dahl-Jørgensen K. , Hanssen K. F. , Norman N. 
Published: December 2008

Abstract. The glucagon response to insulin hypoglycaemia is frequently reduced in patients with IDDM. In the present study arginine infusion, thought to act directly on the islet cells, was used to stimulate somatostatin (SRIF) and glucagon in IDDM without residual B-cell function.
Thirteen IDDM patients' were compared with 13 sex-and age matched normal controls following an arginine infusion. The plasma SRIF concentrations in the 'IDDM group' and normal controls increased from 24.2 ± 2.5 to 31.1 ± 3.9 pmol/l (P <0.01) and 19.7 ± 1.7 to 23.9 ± 3.4 pmol/l respectively after 10 min (P < 0.01). The plasma glucagon concentrations increased from 27 ± 4.7 to 176 ±23.1 pmol/l (P < 0.01) and 36 ± 5.0 to 302 ± 31.9 pmol/l (P <0.01) respectively after 20 min.
Thus, in long standing IDDM without residual B-cell function, increased plasma SRIF concentrations are found and the glucagon response to arginine is reduced. The last observation further explains why these patients are especially vulnerable to hypoglycaemia.
Prolactin dynamics in patients with non-secreting tumours of the hypothalamic-pituitary region
Authors: Barbarino Antonino , De Marinis Laura , Mancini Antonio , Menini Edoardo , D'Amico Colomba , Passeri Marina , Sambo Paola , Anile Carmelo , Maira Giulio 
Published: December 2008

Abstract. Twenty-four patients with non-secreting tumours of the hypothalamic-pituitary region, diagnosed by radiographic procedures and confirmed at surgery, were examined before and after the surgical treatment to establish a correlation between Prl responsiveness to dynamic tests and the location of pathological tissue. Three groups of patients were identified. In 10 patients with an intrasellar tumour (group I), Prl had a positive response to TRH, metoclopramide (MCP), and nomifensine (NOM), both pre- and postoperatively. In 4 patients with tumours located entirely in the hypothalamus (group II), Prl responded to TRH, but remained unresponsive to MCP and NOM. Only a partial normalization of the Prl responses was obtained after surgery. Finally, 10 patients had an intra- and extrasellar tumour (group III). In 8 of them Prl responded to TRH, but the increment was lesser than that observed in hypothalmic tumours. Prl did not respond to MCP and NOM. After surgery, Prl responsiveness reappeared in some patients (6 after TRH, 4 after MCP, 3 after NOM). In 2 patients with extensive pituitary damage, Prl did not respond to all dynamic tests pre- or postoperatively.
In conclusion, Prl dynamic tests are a reliable tool for studying the altered control of Prl secretion in these patients, since plasma Prl stems from only normal lactotropes surrounding the tumoural tissue. The location of the tumour has a key role in influencing the pattern of Prl response to direct and indirect dynamic tests.
Evidence that a 'memory' for glucose metabolism desensitizes A-cell responsiveness in the perfused pancreas of the rat
Authors: Grill V. , Rundfeldt M. , Efendić S. 
Published: December 2008

Abstract. The effects of prior exposure to glucose or an inhibitor of glycolysis (iodoacetate) on A-cell sensitivity to glucose in the perfused pancreas of the rat was investigated. Inhibition of glucagon secretion by a high glucose concentration (22 mm) was attenuated and delayed when tested 20 min after a previous infusion with the same glucose concentration. Previously elevated glucose also delayed for 2 min a glucagon response to glucose omission whereas the total response was not significantly affected. During a 20 min perfusion with 1 mm iodoacetate, glucagon secretion increased and rates of secretion were further augmented after withdrawal of iodoacetate. When introduced 10 min after cessation of the iodoacetate pulse, 22 mm glucose failed to affect insulin or somatostatin release but, conversely, induced a profound decrease in glucagon secretion which was more marked than during control conditions.
Conclusions: A-cell sensitivity to glucose is diminished and enhanced by prior fuel abundance and deprivation, respectively. Such effects could be due to persisting changes in A-cell energy availability rather than to pertubations in insulin or somatostatin secretion.
Somatomedin synthesis by a subclone of Buffalo rat liver cells. Influence of divalent cations on rIGF-II release
Authors: Mayer Peter W. , Schalch Don S. 
Published: December 2008

Abstract. Previous studies have provided evidence that biosynthesis and secretion of somatomedin (SM) is not only hormone dependent, but also modulated by nutritional factors. Little is known, however, about the role of divalent cations in these processes. A subclone of Buffalo rat liver (BRL) cells, known to secrete rat insulin-like growth factor-II (rIGF-II) into serum-free medium, was used to define the influence of Ca2+, Mg2+ and Zn2+ on this function.
The secretion of rIGF-II by subclone BRL-3SC appears to be quite stable in minimal essential medium (MEM) over a wide range in Ca2+ concentrations (0.18–3.0 mm) but is reduced to only 8% of controls in the absence of Ca2+ (P <0.01). Reducing, and even eliminating, the extracellular concentration of Mg2+ alone caused no change in basal rIGF-II release, while simultaneously decreasing Mg2+ and Ca2+ results in a marked drop in the secretion of this SM, reaching a nadir of 38% of controls in the absence of Mg2+ (P <0.001). A Mg2+ concentration of 10 mm, or 25 times 'normal', did not alter the basal secretion of rIGF-II. Eliminating the trace amount (0.8 nm) of Zn2+ in MEM by chelation with EDTA decreased rIGF-II secretion to 62% of control levels (P<0.01), while increasing the concentration of this cation to 3 mm did not alter the basal release of this SM. Decreased rIGF-II release in the presence of EGTA and EDTA is not due to irreversible cell damage since the secretion of this SM was restored to normal during subsequent reincubation in MEM alone.
These studies indicate that normal rIGF-II secretion by BRL-3SC cells occurs only at concentrations of Ca2+, Mg2+ (in the presence of reduced Ca2+) and Zn2+ above certain threshold levels. Moreover, reduced Mg2+ alone, without a concomitant reduction in Ca2+, does not decrease rIGF-II release, attesting to the known interaction of these cations in a variety of intracellular processes. Concentrations of these three cations considerably higher than 'normal' appear to have no significant effect on basal rIGF-II secretion.
Effects of oxytocin and vasopressin on the ovarian blood flow, progesterone and oestradiol-17β secretion in oestrous rats
Authors: Varga Bertalan , Horváth Edit , Zsolnai Béla 
Published: December 2008

Abstract. Oestrous rats were anaesthetized with pentobarbital, one of the femoral arteries and veins and one of the ovarian veins were cannulated, and a thin polyethylene cannula was fixed in the ovarian bursa. Five-min blood fractions were collected from the ovary for 50 min. Following the control fractions 15 mU of oxytocin, 15 mU of vasopressin or 50 μl of 0.9% NaCl solution was given into the ovarian bursa over 10 min. Blood pressure and ovarian blood flow were continuously recorded. Progesterone (P) and oestradiol-17β (E2) were determined from the blood samples by RIA. Oxytocin did not alter the blood pressure, whereas the ovarian blood flow showed a short increasing tendency. Later, however, it started to decrease in parallel with the decrease in blood pressure owing to blood loss. The secretion of P and E2 remained unchanged. No changes in blood pressure were observed after vasopressin administration, although the ovarian blood flow quickly decreased in parallel with the secretion of P and E2.
It is suggested that oxytocin has no direct effect on ovarian blood flow and hormone secretion in the rat. Vasopressin, however, is an effective vasoconstrictor in the rat ovary and may in this way reduce hormone synthesis.
Alterations of adrenergic systems in thyroid slices from patients with Graves' disease
Authors: Yamashita Kamejiro , Aiyoshi Yuji , Kuzuya Nobuaki , Koide Yoshinobu 
Published: December 2008

Abstract. The responses to TSH of tissue cAMP levels in thyroid slices from patients with Graves' disease were significantly lower than those in normal thyroid slices. Conversely, tissue cAMP levels in thyroid slices from these patients were greatly increased by β-adrenergic agonists, either isoproterenol or norepinephrine compared with those in normal thyroid slices.
The elevation of cAMP levels induced by TSH in normal thyroid slices was significantly reduced by norepinephrine via α-adrenergic action as reported previously in canine thyroid slices, while such an elevation by TSH of cAMP levels in slices of Graves' disease thyroids was not inhibited, or rather increased by norepinephrine.
These results indicate that, in addition to low responses to TSH, α- and β-adrenergic systems were functionally altered in thyroid tissues of patients with Graves' disease.