bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effects of forskolin and LH on cAMP changes and maturation in the follicle-enclosed oocytes of hamsters
Authors: Hubbard C.J. 
Published: December 2008

Abstract. Graafian follicles from mature pro-oestrous hamsters were incubated with LH, various concentrations of forskolin, or forskolin plus LH. The incubations were either terminated at different time periods for analysis of follicular or oocyte cAMP levels or incubated for the entire 6 h and the oocytes examined to determine maturational status. Incubations with LH (1 μg/ml) produced a short transient rise in follicular and oocyte cAMP concentrations, while forskolin (60 μm, 20 μm and 10 μm) produced cAMP values which remained elevated for longer periods of time. The 1 μm concentration of forskolin initiated oocyte maturation (28%) but at a level which was significantly below that stimulated by LH (74%). When LH was included with forskolin, a dramatic rise in follicular cAMP occurred which was approximately 2 times greater than levels seen with LH alone. A significant percentage of oocytes matured when 100 nm forskolin (45%) was included with LH (I μg/ml) but not with any other concentration of forskolin tested. Maturation percentages for follicle-enclosed oocytes exposed to 1 μm forskolin plus 1 μ/ml of LH (3.8%) were not different from the controls (7%). However, when 1 μm forskolin was combined with 100 ng/ml of LH a significant percentage of oocytes matured (47%). While continuous incubations with forskolin did not stimulate a high percentage of oocytes to mature, oocytes from follicles exposed to forskolin (60 μm and 20 μm) for short periods (5 min–30 min) with a change to plain medium did mature.
The results of these studies indicate that, in the hamster, long term exposure to forskolin inhibits maturation in follicle-enclosed oocytes. This appears to be the result of persistently elevated cAMP levels in both the follicle and the oocyte. By contrast, short-term incubations initiate maturation. In these groups, cAMP presumably undergoes a transient increase similar to that which is initiated by LH. Maturation in the follicle-enclosed oocytes of hamsters appears to require both a rise and decline in cAMP.
The bioavailability of thyroxine and 3,5,3′-triiodothyronine in normal subjects and in hyper- and hypothyroid patients
Authors: Hasselström Kjeld , Siersbæk-Nielsen Kaj , Lumholtz lb Bo , Faber Jens , Kirkegaard Carsten , Friis Thorkild 
Published: December 2008

Abstract. A new method for the estimation of the bioavailability of thyroxine (T4) and 3,5,3′-triiodothyronine (T3) is described based on gel separation followed by antibody extraction of labelled T4 and T3 from serum, and using the area under the curve of disappearance of the tracer (AUC) for the calculations. The peak serum concentrations of radioactive labelled T4 and T3 were reached approximately 90 min after oral administration of both tracers. The relative difference of duplicate estimations was below 10% (n = 3). The bioavailability of T4 in 6 euthyroid controls was in median 65% (range 64–75%), and it was significantly increased both in hyperthyroidism (88% (75–99%), n = 6, P < 0.01) and hypothyroidism (84% (67–100%), n = 6, P<0.02).
The bioavailability of T3 in 6 euthyroid controls was in median 78% (69–99%) and significantly greater than that of T4 (P < 0.02). The bioavailability was unaffected by hyperthyroidism (79% (61–98%), n = 9) and hypothyroidism (77% (66–97%), n = 7). No significant difference between T4 and T3 bioavailabilities was found in hyper- or hypothyroidism.
The clinical implication of the present study is that the bioavailability of T4 and T3 is almost identical and approximately 80% in patients with severe hypothyroidism.
Homeorhesis during early lactation. Euthyroid sick-like syndrome in lactating cows
Authors: Aceves C. , Ruiz-J. A. , Romero C. , Valverde-R. C. 
Published: December 2008

Abstract. Serum levels of thyroxine (T4), triiodothyronine (T3) and reverse T3 (rT3) were studied in dry, early (first trimester) and middle (second trimester) lactating purebred Holstein cows. The study encompassed three different seasons: autumn, winter and spring. Under comfortable weather conditions (temperature 22°C; relative humidity, 40%) or moderately hot (28°C; 60%), January and October, respectively, cows in early lactation exhibited significantly lower levels of T4 and T3, and higher values of rT3 than dry or middle lactating animals. In contrast, during May, when environmental temperature increased (34°C; 40%), a clear-cut shift in T3/rT3ratio occurred, and animals in early lactation exhibited the highest T3 and the lowest rT3 concentrations.
These findings suggest that in dairy cattle, peripheral thyroid hormone metabolism plays a major role in regulating the homeorhetic responses involved in the maintenance of high priority functions.
Ablation of serotonergic nerves in the rat pancreas. Lack of effects on hormone secretion and intrinsic blood flow
Authors: Jansson Leif , Leung Pearl E. , McEvoy Robert C. 
Published: December 2008

Abstract. The aim of the present study was to evaluate the physiological role of intrapancreatic serotonergic nerves for endocrine pancreatic function.
The specific uptake of [3H]5-hydroxytryptamine (5-HT) into pancreatic slices from the rat was completely abolished after an intrapancreatic injection of 5,7-di-hydroxytryptamine (5,7-DHT). Since also high-affinity uptake of [3H]5-HT was absent it was concluded that intrapancreatic serotonergic nerves were destroyed.
The effects of this selective denervation on glucose-stimulated insulin and somatostatin secretion were investigated with the aid of perfused rat pancreatic glands removed 3, 7 or 14 days after the injection of 5,7-DHT. Neither the basal release of these hormones nor their response to a glucose challenge was significantly altered by the ablation of the intrapancreatic serotonergic nerves.
The microsphere technique was used to investigate the blood flow through the pancreatic islets in rats injected intrapencreatically with 5,7-DHT 4 days previously. No significant changes in either the whole pancreatic blood flow or the islet blood flow could be demonstrated.
These result show that in normal physiological conditions the intrapancreatic serotonergic nerves do not affect the hormonal release from or the blood flow through the endocrine pancreas.
Autoradiographic binding studies with [3H]oestradiol and [3H]dihydrotestosterone in the autonomic genital ganglion (plexus of Frankenhäuser) of the mouse
Authors: Schleicher G. , Stumpf W. E. , Thiedemann K.-U. , Drews U. 
Published: December 2008

Abstract. Male, female and Tfm mice (testicular feminization) were injected with [3H]oestradiol or [3H]dihydrotestosterone, and autoradiograms prepared of male accessory sex organs and of the cervico-vaginal portion of the female reproductive tract.
After injection of [3H]oestradiol in male, female and Tfm animals a nuclear concentration of radioactivity was found in a subpopulation – about 20–30% – of the neurons of the genital ganglion. No such concentration was seen after [3H]dihydrotestosterone. The results suggest a direct genomic effect of oestradiol on certain neurons of the autonomic genital ganglion in both sexes.
Congenital hypothyroidism in a Turkish family: the role of immunoglobulins blocking the trophic effects of TSH and maternal-foetal relationship
Authors: van der Gaag R. D. , Frisch H. , Weissel M. , Wick G. , Drexhage H. A. 
Published: December 2008

Abstract. A Turkish family with frequent intermarriages is described, in which two siblings were born with persistent forms of congenital hypothyroidism, in the elder child concomitant with absent radioactive thyroid imaging. The mother was clinically euthyroid throughout the period of observation, but showed in addition to thyroid microsomal antibodies, high levels of immunoglobulins blocking the trophic action of TSH. These maternal growth blocking antibodies were transiently present in the youngest of the siblings (from birth to 2 months of age). She had a relatively mild form of congenital hypothyroidism (T3: 33 μg/100 ml; T4: 3.9 μg/100 ml). The older sibling, with proven non-functioning thyroid tissue (negative thyroidscan, T4: 0.4 μg/100 ml) produced the growth-blocking immunoglobulins herself and may thus represent a juvenile form of thyroid autoimmunity with a very early onset.
An aunt and uncle of the children, both hypothyroid since birth, were at the age of 19 and 18 years weakly positive for growth blocking immunoglobulins.
This study indicates that familial forms of congenital hypothyroidism are probably complex and may be brought about by maternal to foetal passage of thyroid reactive autoantibodies, but also by the inheritance of a trait for thyroid autoimmunity. In some cases these two mechanisms might act in conjunction.
Evaluation of sodium and potassium pump activity and number in diabetic erythrocytes
Authors: Nagamatsu Shinya , Inoue Nobuo , Murakawa Shoichiro , Matsui Hideo 
Published: December 2008

Abstract. The Na+,K+-ATPase (= Na pump), which produces the concentration gradient of Na+ and K+ across the cell membrane, was studied in diabetic erythrocytes. The activity and number of Na pumps, which are functional and quantitative expression of the Na+, K+-ATPase in erythrocytes, were measured by ouabainsensitive 42K or 43K influx and by [3H]ouabain binding, respectively. The turnover rate of the pumps was calculated from the two measurements to evaluate in situ activity of the pump.
The Na pump activity was found to be higher in the diabetic (193 ± 12 nmol K+/h · 109 cells) than in the normal group (164 ± 6) (P < 0.05), though the affinities of the pump for extracellular K+ were not different. The number of Na pumps and the Kd of the pumps for ouabain in the diabetic group were not significantly different from those in the normal group (354 ± 12 site/cell and 4.33 ± 0.20 nm). The turnover rate of the diabetic group tended to be higher than that of the normal group. The rate was about one third of the molecular activity reported for Na+,K+-ATPase under optimum conditions. These results indicate that the enzymatic properties as well as the number of Na pumps were not altered in diabetic erythrocytes despite the increased Na pump activity. Therefore the increased activity of the erythrocyte Na pump in diabetes mellitus suggests an increase of cation permeability associated with a possible disorder in the diabetic membrane.
Concentrations of immunoreactive tonin in submandibular glands and saliva of the rat
Authors: Hirata Yukio , Tomita Masahiro , Fujita Takuo , Ikeda Masao 
Published: December 2008

Abstract. The submandibular gland (SMG) of the rat contains tonin, an enzyme of serine proteases, which specifically cleaves angiotensinogen and angiotensin I to yield angiotensin II directly. Using a specific RIA for rat tonin, the present study was performed to examine the concentrations of immunoreactive (IR) tonin in SMG of normal Wistar male rats with various ages, those in SMG and saliva of normal adult males and females, and also its SMG levels of castrated males and testosterone-treated females.
The concentrations of IR-tonin in SMG of immature 4 week old male rats were very low but rose exponentially with increasing age to reach adult levels (3–6 μg/mg wet tissue) in male rats after 6 week old or more. SMG of the adult male rat contained 10-fold more IR-tonin than that of the female rat and male saliva contained 5-fold more IR-tonin than that of females. The concentrations of SMG IR-tonin in the castrated males fell to about one-tenth the levels of normal males, whereas SMG IR-tonin levels in the testosterone-treated females increased about ten times more than those of normal females.
These data confirm the sexual dimorphism of rat SMG with respect to the concentrations of tonin and indicate that androgens play an important role in regulating the synthesis and/or storage of tonin in rat SMG. It is also suggested that tonin is secreted into saliva in concentrations reflecting its SMG levels. However, biological significance of tonin in SMG and saliva remains obscure.
Effect of gonadotrophin-releasing hormone analogue (GnRH-A) administration on serum gonadotrophin and steroid levels in patients with polycystic ovarian disease
Authors: Mongioi Alessandro , Maugeri Grazia , Macchi Maria , Calogero Aldo , Vicari Enzo , Coniglione Francesca , Aliffi Antonia , Sipione Costantino , D'Agata Rosario 
Published: December 2008

Abstract. A gonadotrophin-releasing hormone (GnRH) analogue, D-Ser[TBU]LRH-EA10, (GnRH-A), at a dose of 200 μg was given daily for 2 months to 6 women with polycystic ovarian disease (PCO). Prior to therapy the patients presented elevated LH, testosterone (T), oestrone (E1) and dihydrotestosterone (DHT) in the circulation. In response to GnRH-A, these subjects exhibited a marked decrease in circulating T, DHT and androstenedione (A) levels as measured 24 h after GnRH-A injection, by 4 weeks and onwards (P < 0.05). After 2 weeks of daily administration, the serum LH profile, evaluated by sampling at 2, 4. 7 and 24 h after injection of GnRH-A, was not different from baseline, whereas after 4, 6 and 8 weeks the levels were significantly lower (*P < 0.01). The profile of serum T levels was unmodified at the second week, but significantly decreased thereafter (*P <0.01). At the end of treatment, the E1 concentrations, elevated in pre-injection condition, were markedly decreased.
These data demonstrate that in PCO subjects, GnRH-A significantly lowered the elevated levels of androgens commonly found in these patients. The close correlation observed between reduced serum LH and androgen concentrations suggests that pituitary desensitization could be responsible for the reduction in androgen levels, and may be evidence for a gonadotrophin dependence of the elevated concentrations of T in these patients.
Isolation and partial characterization of six somatomedin-like peptides from human plasma Cohn fraction IV
Authors: Blum Werner F. , Ranke Michael B. , Bierich Jürgen R. 
Published: December 2008

Abstract. Six somatomedin-like peptides were purified from human plasma Cohn fraction IV by a six-step procedure which included ethanol precipitation, reversed-phase extraction, gel filtration, chromatofocusing and reversed-phase high pressure liquid chromatography (HPLC). Purification was monitored with a competitive protein binding assay using a crude preparations of somatomedin carrier protein. The peptides isolated were homogeneous by reversed-phase HPLC and sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Their apparent isoelectric points determined by chromatofocusing were 9.2 (Sm I), (Sm II), 8.2 (Sm III), 6.7 (Sm IV), 6.3 (Sm V), and 6.15 (Sm VI). SDS-PAGE under reducing conditions revealed that they are composed of a single peptide chain with apparent molecular weights of 6800 for Sm I, II and IV and 6400 for Sm III, V, and VI. They were equally potent in the porcine costal cartilage in vitro bioassay. The basic peptides (Sm I–III) were significantly more active in radioimmunoassays for somatomedin C (SmC) and insulin-like growth factor I C-peptide (IGF-I (30–41)), while only the slightly acidic peptides were active in a radioimmunoassay for insulin-like growth factor II C-peptide (IGF-II (33–40)). When receptor binding was tested with human placental cell membranes and Sm III as tracer, the basic peptides were significantly more potent than Sm IV–VI. With rat liver cell membranes and Sm V as tracer the slightly acidic peptides were more potent.
These findings suggest 1) that human plasma may contain other somatomedin-like peptides besides the major components IGF-I/SmC and IGF-II, and 2) that the basic peptides are structurally related to IGF-I/SmC and the slightly acidic peptides are related to IGF-II.
Ovarian multifollicularity, high LH and androgen plasma levels, and anovulation are frequent and strongly linked in adolescent irregular cycles
Authors: Venturoli S. , Porcu E. , Fabbri R. , Paradisi R. , Gammi L. , Passarini M. , Orsini L. F. , Flamigni C. 
Published: December 2008

Abstract. Ninety-seven adolescents (0.5–6.0 years in gynaecological age) suffering from various kinds of menstrual irregularities were studied and compared with 20 adults by performing ovarian ultrasonography and plasma hormonal determinations.
High percentages of multifollicularity (57.7%) and enlarged ovaries (46.3%) were found in the entire group of adolescents.
Adolescents with multifollicular ovaries (more than 4 cystic areas) showed higher percentages of luteinizing hormone (LH: 32%), testosterone (T: 34%), and androstenedione (A: 43%) levels exceeding the upper normal adult range than subjects with homogeneous (less than 4 cystic areas) ovaries (LH: 12%, T: 10%, A: 19%, respectively).
Ovulation can further discriminate the adolescents: in fact, adolescents with homogeneous ovaries and ovulatory cycles have a hormonal pattern almost identical to that of adults. On the contrary, subjects with multifollicular ovaries and anovulatory cycles show low values of follicle-stimulating hormone (FSH) and high values of LH, T and A, significantly different from those in ovulatory subjects with homogeneous ovaries (P < 0.005) and from those in adults (P < 0.005).
Cortical bone mineral content in primary hyperparathyroidism. Changes after parathyroidectomy
Authors: Mautalen Carlos , Reyes Harry Romero , Ghiringhelli Gualterio , Fromm Günther 
Published: December 2008

Abstract. The bone mineral content (BMC) of 35 patients with primary hyperparathyroidism (PHPT) was measured at the mid radius (95% cortical bone) by photon absorptiometry of a 241Am source. The majority of the patients had an overt disease of moderate to severe degree. Average serum calcium of the group was 12.3 mg/100 ml (range 10.6 to 18.0 mg/100 ml). The percentage of normality of the BMC was (Av ± 1 sd) 75.1 ± 13.0% for the whole group.
The average increment of BMC in 14 patients 9 to 26 months after parathyroidectomy was 9.9%, with a wide dispersion. However a highly significant negative correlation (r: 0.83; P < 0.01) was found between the initial bone mass and the percentage increment per month after surgery. No further gain was observed 2 years after parathyroidectomy except in one patient with an extremely severe bone loss. In spite of the gain obtained after surgery the bone mass remained markedly diminished in most patients showing that the cortical bone loss caused by PHPT is mainly irreversible.
Counterregulation of insulin-induced hypoglycaemia in primary hypothyroidism
Authors: Clausen Nina , Lins Per-Eric , Adamson Ulf , Hamberger Bertil , Efendić Suad 
Published: December 2008

Abstract. Hypothyroidism has been alleged to modulate insulin action and influence the secretion of growth hormone and catecholamines. We recently investigated the influence of hypothyroidism on glucose counterregulatory capacity and the hormonal responses to insulin-induced hypoglycaemia in 6 patients with primary hypothyroidism (age 32–52 years, TSH-values 66–200 mU/l). Hypoglycaemia was induced in the hypothyroid state and again when the subjects were euthyroid. After an overnight fast a constant rate infusion of insulin (2.4 U/h) was given for 4 h. Glucose was measured every 15 min and insulin, C-peptide, glucagon, epinephrine, norepinephrine, growth hormone and cortisol every 30 min for 5 h.
During insulin infusion somewhat higher concentrations of the hormone were obtained in the hypothyroid state and simultaneously glucose levels were 0.5 mmol/l lower. As expected, basal norepinephrine levels were higher in hypothyroidism. However, no increase in circulating norepinephrine during hypoglycaemia was registered in the two experiments. The responses of counterregulatory hormones showed an enhanced response of cortisol, similar responses of growth hormone and epinephrine while the glucagon response was paradoxically impaired. Our findings suggest that hypothyroidism alters insulin metabolism, and that the glucagon response to hypoglycaemia is impaired in this condition.
Lipids, apolipoproteins and steroids in serum and in fluid from stimulated and non-stimulated human ovarian follicles
Authors: Enk L. , Crona N. , Olsson J.-H. , Hillensjö T. 
Published: December 2008

Abstract. Steroid production depends on the cholesterol (CH) substrate supplied by circulating lipoproteins which are internalised in the cells by receptormediated mechanisms. Low density lipoproteins (LDL) stimulate progesterone production in vitro. However, studies on follicles indicate low levels of LDL in follicular fluid (FF1).
In the present study FF1 was obtained by ultrasoundguided punctures just before ovulation from 17 women participating in an in vitro fertilization programme. Serum was obtained simultaneously. Follicular development was stimulated with hMG-HCG or clomiphenehMG-hCG combinations. In another 8 women FF1 was collected in connection with surgery for sterilization. FF1 levels of CH, triglycerides (TG), phospholipids (PL), apolipoprotein Al and B (apoAl; apoB), oestradiol and progesterone were assayed in both groups as were the corresponding serum levels in the stimulated patient group.
The FF1 levels of apoAl, TG and PL were approximately half of the levels in HDL in normal serum in both groups. However, CH was slightly lower in the stimulated group. ApoB was not detectable in FF1. Oestradiol was similar in both groups while progesterone was much higher in the stimulated than in the non-stimulated cycles. FF1 levels of apoAl correlated positively to CH and PL in both groups and to progesterone in the stimulated follicles, while the correlation was negative in the other group. The absence of apoB and the levels of CH, TG, PL and apoA1 1 indicate that high density lipoprotein (HDL), but not LDL is present in FF1. The supply of CH needed for the increased production of progesterone in the granulosa cells in the late follicular phase has to be explained by mechanisms other than transportation with LDL particles. It is possible that gonadotrophins facilitate the delivery of CH from HDL, which has been shown to penetrate the 'blood-follicle' barrier.
in Comparison between pituitary computed tomographic findings and tests of hypothalamo-pituitary function 72 patients with hyperprolactinaemia
Authors: Ghigo E. , Ciccarelli E. , Bianchi S. D. , Gatti G. , Molinatti G. M. , Massara F. , Müller E. E. , Camanni F. 
Published: December 2008

Abstract. To verify the diagnostic capacity of some dynamic tests of the prolactin (Prl) secretion, the findings obtained by high-resolution computed tomography (CT) were compared with results obtained from tests using nomifensine (NOM) domperidone (DOM) and thyrotrophin-releasing hormone (TRH) in 72 patients with pathological hyperprolactinaemia.
None of the patients with tumours had a positive Prl response to NOM or to DOM administration; however, a positive response to these tests was present in only 24 and 41%, respectively, of the patients with normal CT picture. The results of TRH testing were similar to those obtained with DOM. Different neuroendocrine patterns were disclosed by comparing pituitary Prl and thyrotrophin (TSH) responses to DOM: 1) some subjects had a reduced Prl response together with an exaggerated or normal TSH response to DOM; they comprised patients with tumour, empty sella, and normal CT picture; 2) other patients with normal CT picture had a positive Prl and a normal TSH response to DOM.
These results demonstrate that a negative Fri response to NOM and DOM characterizes all patients with adenoma; however, the tumour-like responses in patients with no visible tumours seem to reduce the diagnostic value of these tests, unless the latter may predate the radiological appearance of an adenoma. On the other hand, a positive Prl and a normal TSH response to DOM exclude the presence of a pituitary tumour. This diagnostic finding is strengthened by the positive response also to NOM. Whatever may be the diagnostic validity of dynamic tests, they provide sound information on the functional state of dopamine neurotransmission.