bluuebunny/crossref_metadata_2025 huggingface dataset:
Perinatal ontogeny of porcine growth hormone receptor gene expression is modulated by thyroid status
Authors: Duchamp C , Burton KA , Herpin P , Dauncey MJ
Published: December 2008

Duchamp C, Burton KA, Herpin P, Dauncey MJ, Perinatal ontogeny of porcine growth hormone receptor gene expression is modulated by thyroid status. Eur J Endocrinol 1996;134:524–31

The ontogeny of growth hormone receptors (GHR) represents a critical stage in growth and metabolism. We have investigated the perinatal ontogeny of hepatic and skeletal muscle GHR gene expression in piglets, and its modulation by GH and thyroid hormones. Test piglets were rendered hypothyroid in late gestation by feeding the sow a high-glucosinolate rapeseed meal. Plasma and tissue samples were obtained from test and control piglets at various ages between 80 days of fetal life (80F) and 2 days postnatally. Plasma hormone levels were determined by radioimmunoassay and GHR mRNA by RNase protection assays. In controls, plasma thyroxine (T4) and 3,5,3′-triiodothyronine (T3) levels increased between 80F and birth and the early postnatal period was characterized by a marked surge in plasma T3. Test piglets were hypothyroid at 110F with total T4, total T3 and free T3 levels being reduced by 28, 53 and 33% respectively. By contrast, the postnatal increase in T3 was more marked in test than in control animals. Plasma GH levels decreased over the perinatal period and there was no effect of treatment. Hepatic GHR mRNA was at the lower limit of detection at 80F but by 11 OF was expressed in both groups of animals. However, fetal hypothyroidism at 11 OF resulted in a marked 70% decrease in hepatic GHR mRNA (p < 0.01). The higher postnatal rise in T3 in test piglets was accompanied by a recovery of hepatic GHR mRNA levels. By contrast with liver, skeletal muscle (longissimus dorsi) expressed high levels of GHR mRNA at 80F and hypothyroidism induced a 68% increase in GHR mRNA (p < 0.001). The present results suggest that thyroid hormones may modulate the perinatal ontogeny of GHR gene expression, in addition to other hormonal factors, and that this modulation is tissue-specific.

MJ Dauncey, Department of Cellular Physiology, The Babraham Institute, Cambridge CB2 4AT, UK
True insulin and intact proinsulin levels in acromegalic patients
Authors: Tavares Edelweiss F , Dalbosco Ivaldir S , Abucham Julio , Russo Ewaldo MK
Published: December 2008

Tavares EF, Dalbosco IS, Abucham J, Russo EMK. True insulin and intact proinsulin levels in acromegalic patients. Eur J Endocrinol 1996;134:549–53. ISSN 0804–4643

To determine whether proinsulin (PI) contributes significantly to the immunoreactive insulin (IRI) concentrations in acromegalics, we measure PI, "true insulin" and IRI in a group of acromegalics compared with a control group. Serum PI was determined by the immunofluroimetric assay (IFMA). Insulin was also determined by an IFMA that measures true insulin and by a radioimmunoassay (RIA). We performed an oral glucose tolerance test (OGTT) in a total group of 46 subjects: 10 controls with normal OGTT and body mass index <25 kg/m2 (control group I), 10 controls with normal OGTT and body mass index > 25 kg/m2 (control group II), 15 patients with active acromegaly and normal OGTT and 11 patients with active acromegaly and IGT. Plasma glucose, serum GH, insulin and proinsulin were measured in all OGTT samples. Basal levels of insulin-like growth factor I (IGF-I) were measured in acromegalics. Mean body mass index in acromegalics with normal and impaired glucose tolerance were significantly higher compared with control group I and similar when compared with control group II. Proinsulin increased during OGTT in acromegalics with impaired glucose tolerance compared to control group I, and only fasting proinsulin compared to control group II. In normal OGTT acromegalics, only fasting proinsulin was increased. The RIA insulin during OGTT was significantly higher for both acromegalic groups compared to control group I and only at fasting when compared with control group II. This difference was not evident when insulin was measured by IFMA. These results suggest that in acromegalics, hyperinsulinism measured by RIA was at least in part due to hyperproinsulinism.

Ewaldo MK Russo, PO Box 20266, CEP 04034-970, Sáo Paulo, SP, Brazil
Octreotide treatment increases exercise capacity in patients with acromegaly
Authors: Padayatty Sebastian J , Perrins Edward J , Belchetz Paul E
Published: December 2008

Padayatty SJ, Perrins EJ, Belchetz PE. Octreotide treatment increases exercise capacity in patients with acromegaly. Eur J Endocrinol 1996:134:554–9. ISSN 0804–4643

This prospective study was conducted to determine the effect of Octreotide treatment on cardiovascular function in patients with active acromegaly. Ten acromegalic patients who failed to suppress growth hormone (GH) to < 5 mU/l during a 2 h oral glucose tolerance test were treated with 100 μg of Octreotide subcutaneously three times daily for 2 months, followed by 200 μg three times daily if the mean GH level was > 5 mU/l, for a total of 1 year. All patients had GH and insulin-like growth factor I (IGF-I) estimation, ejection fraction determined by Echocardiogram and multigated image acquisition scan, electrocardiogram (ECG), exercise ECG, 24-h ECG and chest x-ray. At 6 and 12 months, both GH and IGF-I were reduced but ECG, heart size and ejection fraction were unchanged. The patients improved symptomatically and had significant reduction in resting heart rate and increase in weight. Exercise time (mean±sd) increased from 637 ± 137s at baseline to 787 ± 101s at 1 year (p < 0.01) and work done increased from 9 ± 3.3 to 11.9 ± 2.7 metabolic equivalents (p< 0.001). We conclude that the decrease in GH and IGF-I following Octreotide treatment of acromegaly is accompanied by decreased heart rate and increased exercise capacity despite an unchanged ejection fraction.

Sebastian J Padayatty, Division of Endocrinology, Baylor College of Medicine, One Baylor Plaza, Room 537E, Houston TX 77030, USA
Autoimmune hypothyroidism and hyperthyroidism in patients with Turner's syndrome
Authors: Chiovato Luca , Larizza Daniela , Bendinelli Giovanna , Tonacchera Massimo , Marinò Michele , Mammoli Claudia , Lorini Renata , Severi Francesca , Pinchera Aldo
Published: December 2008

Chiovato L, Larizza D, Bendinelli G, Tonacchera M, Marinò M, Mammoli C, Lorini R, Severi F, Pinchera A. Autoimmune hypothyroidism and hyperthyroidism in patients with Turner's syndrome. Eur J Endocrinol 1996;134:568–75. ISSN 0804–4643

A high prevalence of autoimmune thyroid disease (AITD) has been described in Turner's syndrome (TS) but the extent of this association is controversial for the prevalence of thyroid autoantibody and the clinical impact of thyroid dysfunction. In this study we searched for thyroid disease and thyroid autoantibodies in patients with TS. Seventy-five unselected TS patients (age range 3–30 years) were studied. Sera were tested for thyroid hormones, thyrotropin (TSH), thyroglobulin (TG-ab) and thyroperoxidase (TPO-ab) antibodies. The TSH-receptor antibodies with thyroid-stimulating (TS-ab) or TSH-blocking activity (TSHB-ab) were measured in the IgG fraction using a bioassay. Ten out of 75 (13.3%) TS patients had AITD: eight had autoimmune thyroiditis (AT) (six with subclinical and two with overt hypothyroidism and one with euthyroidism) and one had Graves' disease. The prevalence of AITD increased significantly (p < 0.05) from the first (15%) to the third (30%) decade of life. The prevalence of TPO-ab and/or TG-ab (20%) was higher (p < 0.05) in TS than in age-matched female controls and increased from the first (15%) to the third (30%) decade of life. Clinical AITD was diagnosed in 46% of TS patients with TPO-ab and/or TG-ab. Thyroid-stimulating antibody was detected in the hyperthyroid patient, and TSHB-ab was found in one of eight patients with hypothyroid AT. It was concluded that: TS patients are at higher than average risk of developing AITD not only in adolescence and adult age but also in childhood; hypothyroidism, mainly subclinical, is the most frequent thyroid dysfunction; elevated TPO-ab and/or TG-ab alone do not imply thyroid dysfunction; TS-ab or TSHB-ab are always associated with thyroid dysfunction although most cases of autoimmune hypothyroidism are not due to the latter antibody.

Luca Chiovato, Istituto di Endocrinologia, Università di Pisa, Viale del Tirreno, 64, 56018 Tirrenia, Pisa, Italy
Evidence for a role for insulin-like growth factor binding proteins in glucocorticoid inhibition of normal human osteoblast-like cell proliferation
Authors: Chevalley Thierry , Strong Donna D , Mohan Subburaman , Baylink David J , Linkhart Thomas A
Published: December 2008

Chevalley T, Strong DD, Mohan S, Baylink DJ, Linkhart TA. Evidence for a role for insulin-like growth factor binding proteins in glucocorticoid inhibition of normal human osteoblast-like cell proliferation. Eur J Endocrinol 1996;134:591–601. ISSN 0804–4643

Glucocorticoids (GCs) inhibit bone formation in vivo and inhibit osteoblast proliferation and collagen synthesis in vitro. These effects may be mediated by alterations in the insulin-like growth factor (IGF) system. In the present study of normal human osteoblast-like (HOB) cells, we tested the hypothesis that dexamethasone (Dex) inhibits IGF anabolic activity in bone by altering expression of IGF binding proteins (IGFBPs), particularly by decreasing expression of IGFBP-5 and IGFBP-3 (which enhance IGF activity) and increasing expression of IGFBP-4 (which inhibits IGF actions). Dexamethasone treatment caused a dose-dependent inhibition of HOB cell proliferation (69 ± 4% of control at 10−8 mol/l Dex) in seven separate experiments. Dexamethasone decreased IGFBP-5 mRNA levels to 20–30% of control (10−8 and 10−7 mol/l for 24 h). In six of six HOB preparations, 10−8 mol/l Dex decreased IGFBP-5 mRNA levels (35 ± 7% of control) and this effect was time dependent. Dexamethasone also decreased IGFBP-3 mRNA levels (74 ± 9% of control in three HOB preparations). Dexamethasone decreased secretion of 29–31-kD IGFBP-5 and 38–42-kD IGFBP-3 proteins, determined by Western ligand blot and IGFBP-5 immunoblot, and induced a dose-dependent decrease in IGFBP-3 and IGFBP-5 secretion determined by specific radioimmunoassays. The effects of Dex on IGFBP-4 mRNA and on secretion of 25-kD IGFBP-4 levels were inconsistent between different cell preparations. Results suggest that GC inhibition of IGFBP-5 and IGFBP-3 production could decrease IGF activities and contribute to GC inhibition of bone formation.

Thomas A. Linkhart, Mineral Metabolism (151), Pettis VA Hospital, 11201 Benton Street, Loma Linda, CA 92357, USA
Stressful life events in the pathogenesis of Graves' disease
Authors: Radosavljević Vladan R , Janković Slavenka M , Marinković Jelena M
Published: December 2008

Radosavljević VR, Janković SM, Marinković JM. Stressful life events in the pathogenesis of Graves' disease. Eur J Endocrinol 1996;134:699–701. ISSN 0804–4643

A case-control study was conducted in order to assess possible relationships between life events and Graves' disease. The study included 100 newly diagnosed patients with Graves' disease and 100 controls matched with respect to sex, age (±2 years) and type of residence (rural, urban). Paykel's Interview for Recent Life Events (a semistructured research interview covering 61 life events) was administered to each subject. In comparison with controls, the patients claimed to have had significantly more life events in the 12 months preceding the diagnosis (p = 0.0001). The following eight life events were significantly more prevalent among patients than controls: change in time spent on work (much overtime work, second job, much less work than usual) (McNemar = 12.04; RR= 7.00;95%CI= 2.35–20.80;p= 0.0001), unemployment for at least 1 month (McNemar = 4.00; RR = 8.00; 95%CI = 1.04–61.39; p = 0.039), arguments with one's superior at work or a coworker (McNemar = 4.50; RR = 3.50; 95%CI = 1.10–11.08; p = 0.031), change in the work conditions (new company division, new chief, large reorganization) (McNemar = 4.26; RR = 4.00; 95%CI = 1.07–14.92; p = 0.035), increased arguments with spouse (McNemar = 6.75; RR = 11.00; 95%CI = 1.82–66.44; p = 0.006), increased arguments with fiancé/fiancée or a steady date (McNemar = 4.00; RR = 8.00; 95%CI = 1.04–61.39; p = 0.039), hospitalization of a family member for serious illness (McNemar = 3.76; RR = 3.25; 95%CI = 1.01–10.68; p = 0.049) and moderate financial difficulties (McNemar = 8.50; RR = 3.25; 95%CI = 1.47–7.16; p = 0.003). Our findings indicate that life events may be a risk factor for Graves' disease.

Slavenka Janković, Institute of Epidemiology, Višegradska 26, PO Box 456, 11000 Belgrade, Yugoslavia
Bone mass, bone turnover and body composition in former hypothyroid patients receiving replacement therapy
Authors: Langdahl Bente L , Loft Anne Gitte R , Eriksen Erik F , Mosekilde Leif , Charles Peder
Published: December 2008

Langdahl BL, Loft AGR, Eriksen EF, Mosekilde L, Charles P. Bone mass, bone turnover and body composition in former hypothyroid patients receiving replacement therapy. Eur J Endocrinol 1996;134:702–9. ISSN 0804–4643

The aim of the present cross-sectional study was to disclose whether long-term thyroxine replacement therapy (TRT) in primary hypothyroidism causes osteopenia. We compared 36 adult biochemically and clinically euthyroid patients who had received TRT for more than 5 years (mean 13 years) for primary hypothyroidism with 80 sex- and age-matched normal controls. Height, body weight and lean body mass were similar, but the patients had 21% higher fat body mass (p < 0.01) than their controls. Furthermore, compared to controls the patients had 29% higher serum thyroxine (T4) and 31% higher serum free T4 index (FT4I) levels (p < 0.001), whereas serum triiodothyronine (T3) and FT3I levels were both reduced by 7% (p < 0.05). In the patients, serum TSH was reduced significantly (p < 0.001). No significant differences were observed between patients and normals in regional or total bone mineral content or bone mineral density levels, apart from 20% higher lumbar bone mineral content among the premenopausal patients (p < 0.05). Surprisingly, the mean serum calcium level was slightly elevated (2.38 ± 0.08 vs 2.33 ± 0.07 nmol/l, p < 0.001), serum phosphate decreased (1.13 ± 0.19 vs 1.23 ± 0.16 mmol/l, p < 0.01) and 24-h renal calcium excretion was reduced by 19% (p < 0.05). No changes were observed in serum magnesium, intact parathyroid hormone or calcitriol. The biochemical markers of bone resorption (serum carboxyterminal telopeptide of type I collagen, renal excretion of hydroxyproline, pyridinoline and deoxypyridinoline) and formation (serum levels of carboxyterminal propeptide of type I procollagen, osteocalcin and total and bone alkaline phosphatase) were similar in the two groups. We conclude that long-term thyroxine replacement therapy in primary hypothyroidism does not exert a negative effect on bone mass or alter bone turnover.

Bente L Langdahl, University Department of Endocrinology and Metabolism, Aarhus Amtssygehus, Tage Hansensgade 2, DK-8000, Aarhus C, Denmark
Thermal regulatory dysfunction of growth hormone in classical heat stroke?
Authors: Alzeer Abdulaziz , Arifi Abdullah Al , El-Hazmi Mohsen , Warsy Arjumand S , Nylen Eric S
Published: December 2008

Alzeer A, Al Arifi A, El-Hazmi M, Warsy AS, Nylen ES. Thermal regulatory dysfunction of growth hormone in classical heat stroke? Eur J Endocrinol 1996;134:727–30. ISSN 0804–4643

Growth hormone (GH) secretion associated with classical (non-exertional) heat stroke (HS) was evaluated in 26 HS victims and 10 control (non heat-exhausted) subjects during the annual Hajj in Makkah, Saudi Arabia. On admission to the HS treatment unit, the GH level was 1.54 ± 0.14 ng/ml (approximately 3.5-fold higher in the HS victims compared to controls; p = 0.005). The GH levels subsequently declined by 78% by 24 h. The categorized GH response was significantly associated with survival for those subjects with a GH level of < 5.53 ng/ml by 6 h (chi-squared test; p = 0.06). In those patients who died (N = 6), there was a continued increase in GH levels from the time of admission, which peaked at 6 h. In those patients who survived, the GH levels peaked at the time of admission and declined rapidly thereafter. There was a direct correlation of age and GH level upon admission (p = 0.02), as well as to peak GH (p = 0.041). However, there was no relationship of GH level to either body core temperature or the cooling time. In summary, HS induced significant GH secretion. The degree of GH response was not related to the body core temperature and was more pronounced in older individuals and in those that died. Although patients with GH deficiency and HS are characterized by anhidrosis/hypohidrosis, there does not appear to be dysfunction of GH response to heat stress-associated HS. In contrast, a vigorous GH response at 6 h suggested a worse outcome.

ES Nylen, Rm GE 246, VAMC, 50 Irving St, NW Washington, DC 20422, USA
Metabolic and clinical events preceding diabetes mellitus onset in cystic fibrosis
Authors: Cucinotta Domenico , Arrigo Teresa , De Luca Filippo , Di Benedetto Antonino , Lombardo Fortunato , Scoglio Riccardo , Sferlazzas Concetta , Magazzú Giuseppe
Published: December 2008

Cucinotta D, Arrigo T, De Luca F, Di Benedetto A, Lombardo F, Scoglio R, Sferlazzas C, Magazzú G. Metabolic and clinical events preceding diabetes mellitus onset in cystic fibrosis. Eur J Endocrinol 1996;134:731–6. ISSN 0804–4643

Serial assessments of glucose tolerance, of glucose and insulin areas during an oral glucose tolerance test (OGTT) and of clinical parameters as well were evaluated retrospectively in seven diabetic cystic fibrosis patients (study group) during the 4–6.3 years that preceded diabetes mellitus diagnosis. The same metabolic and clinical parameters were also evaluated in seven age-matched patients who did not develop diabetes during a similar observation period (control group). In the study group, glucose tolerance was impaired in all patients but one since the first OGTT and glucose areas progressively increased over time, whereas in the control group glucose tolerance remained stable during the whole observation period. A significant and progressive blunting of insulin secretion occurred over time in both groups. Insulin secretion, however, was reduced but not exhausted at diabetes diagnosis. Neither modification of glycosylated haemoglobin levels over time nor serum islet cell antibodies at diabetes onset were observed in the study group. The overall clinical course of the disease was not different in either group and remained stable during the observation period. These results indicate that in cystic fibrosis diabetes mellitus onset is preceded by a long-standing deterioration of glucose tolerance, whilst insulin secretion progressively declines over time, irrespectively of glucose tolerance status. The prediabetic worsening of glucose tolerance is not necessarily linked to a worsening of overall clinical status.

Filippo De Luca, Istituto di Clinica Pediatrica, Policlinico Universitario, 98100 Messina, Italy
Role of protein kinase C in the regulation of ATP-triggered intracellular Ca2+ oscillations in chicken granulosa cells
Authors: Morley Paul , Chakravarthy Balu R , Mealing Geoffrey AR , Tsang Benjamin K , Whitfield James F
Published: December 2008

Morley P. Chakravarthy BR, Mealing GAR, Tsang BK, Whitfield JF. Role of protein kinase C in the regulation of ATP-triggered intracellular Ca2+ oscillations in chicken granulosa cells. Eur J Endocrinol 1996;134:743–50. ISSN 0804–4643

These studies were designed to investigate the role of protein kinase C (PKC) in the regulation of ATP-triggered intracellular Ca2+ ([Ca2+]i) oscillations in chicken granulosa cells. Granulosa cells were obtained from the two largest preovulatory follicles (F1 and F2) of hens and [Ca2+]i was measured in cells loaded with the Ca2+-responsive fluorescent dye fura-2. Adenosine triphosphate (100 μmol/l) triggered an immediate, large [Ca2+]i spike that was followed by oscillations that returned to the resting level between spikes. The ATP (100 μmol/l) also stimulated a 1.70 ± 0.1-fold increase in membrane-associated PKC activity over control levels. The frequency of the ATP-triggered [Ca2+]i oscillations was reduced in a concentration-dependent (1–10 nmol/l) manner by treating the cells for 2 min with a PKC activator, 12-O-tetradecanoyl phorbol-13-acetate (TPA). A higher TPA concentration (100 nmol/l) completely prevented ATP from triggering the initial [Ca2+]i spike and oscillations. Adding TPA during the ATP-triggered [Ca2+]i oscillations immediately stopped the oscillatory activity. Interestingly, PKC inhibitors failed to amplify the ATP-triggered [Ca2+]i oscillations. Instead, adding the PKC inhibitors staurosporine (20 nmol/l), calphostin C (200 nmol/l) or 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H7; 100 μmol/l), either before or during the ATP (100μmol/l)-triggered [Ca2+]i response, also completely blocked the [Ca2+]i oscillations. Therefore, ATP-triggered [Ca2+]i oscillations in chicken granulosa cells appear to be regulated by a negative feedback loop requiring PKC, because the [Ca2+]i oscillations were prevented by either full activation or inhibition of PKC activity.

Paul Morley, Institute for Biological Sciences, National Research Council of Canada, Building M54, Montreal Road, Ottawa, Ontario, K1A OR6, Canada
Developmental aspects of prolactin receptor gene expression in fetal and neonatal mice
Authors: Brown-Borg Holly M , Zhang Fu-Ping , Huhtaniemi Ilpo , Bartke Andrzej
Published: December 2008

Brown-Borg HM, Zhang F-P, Huhtaniemi I, Bartke A. Developmental aspects of prolactin receptor gene expression in fetal and neonatal mice. Eur J Endocrinol 1996;134:751–7. ISSN 0804–4643

The prolactin receptor (PRL-R), a member of the hematopoietin cytokine receptor superfamily, is widely distributed among mammalian tissues. To understand better the potential sites of action and onset of potential PRL responsiveness, the developmental distribution pattern of PRL-R mRNA expression in fetal and neonatal mice was examined. Fetal mouse tissues were collected at distinct stages from timed pregnancies. Following extraction of total RNA, onset of gene expression was evaluated via reverse transcription-polymerase chain reaction (RT-PCR) and Southern hybridization was employed for verification. Expression of PRL-R mRNA was first observed on day 14 in the liver and cranium and on day 15 in the kidney, lung and thymus gland. Pituitary and adrenal glands were positive for PRL-R at day 18 of gestation through to day 1 of postnatal life. Neither whole fetuses prior to day 14 (days 10–13) of gestation nor skin and bladder tissues from 2-day-old mice generated detectable RT-PCR signals for PRL-R. The presence of PRL-R mRNA in fetal thymus and spleen tissues suggests a possible role for PRL in the development of the immune system. Prolactin may act directly on the pituitary to influence its own secretion and/or that of other pituitary-derived factors, as evidenced by the presence of PRL-R mRNA in the pituitary glands of fetal and 1-day-old mice. These data are the first to show the presence of PRL-R gene expression in various organ systems in fetal mice and suggest that PRL is among several factors necessary to coordinate developmental activities.

Holly M Brown-Borg, Department of Physiology, University of North Dakota School of Medicine, Grand Forks, ND 58202-9037, USA
c-myc Expression is associated with increased proliferation activity in thyroid follicular cells of Graves' disease as stimulated by autoantibodies
Authors: Kashima Kenji , Yokoyama Shigeo , Daa Tsutomu , Takahashi Kenji , Nakayama Iwao , Noguchi Shiro
Published: December 2008

Kashima K, Yokoyama S, Daa T, Takahashi K, Nakayama I, Noguchi S. c-myc Expression is associated with increased proliferation activity in thyroid follicular cells of Graves' disease as stimulated by autoantibodies. Eur J Endocrinol 1996:135:69–76. ISSN 0804–4643

Expression on thyroid follicular cells of HLA-DR, c-myc protein and proliferating cell nuclear antigen (PCNA) was examined immunohistochemically in 28 cases of Graves' disease (GD) and in 29 cases of Hashimoto's thyroiditis (HT). Immunoreactivity for PCNA in GD was seen not only in follicular cells adjacent to a lymphocytic infiltration, where the follicular cells were positive for HLA-DR, but also in hyperplastic follicular cells without the infiltration. The distribution of expressed c-myc protein was similar to that of PCNA in GD but not in HT. Semiquantitatively graded degrees of lymphocytic infiltration and expression of HLA-DR, c-myc and PCNA in GD showed a high correlation with one another. However, the degrees of c-myc expression in HT showed no significant correlation with any other degrees. Intraperitoneal injection of bovine TSH or of immunoglobulins derived from a patient with GD in rabbits induced hyperplastic change of thyroid follicular cells, as reflected in PCNA and c-myc immunoreactivity, as well as strong peroxidase and acid phosphatase activity. Immunization with synthesized peptide of thyrotropin receptor also exhibited the same results in the rabbit thyroids. Our results indicate that c-myc expression on follicular cells of GD may reflect a stimulation by autoantibodies mediated through the thyrotropin receptor.

Kenji Kashima, Department of Pathology, Oita Medical University, 1-1 Oita-gun, Oita 879-55, Japan
Correlation of pinopod development on uterine luminal epithelial surface with hormonal events and endometrial sensitivity in rat
Authors: Singh MM , Chauhan SC , Trivedi RN , Maitra SC , Kamboj VP
Published: December 2008

Singh MM, Chauhan SC, Trivedi RN, Maitra SC, Kamboj VP. Correlation of pinopod development on uterine luminal epithelial surface with hormonal events and endometrial sensitivity in rat. Eur J Endocrinol 1996;135:107–17. ISSN 0804–4643

Intrinsic role of preovulatory and nidatory estrogen and progesterone and presence of viable blastocysts in utero in pinopod development on the uterine luminal epithelial surface and correlation between time of their development and onset of endometrial sensitivity were investigated. In adult rats, pinopods were observed on the entire epithelium even before secretion of nidatory estrogen, i.e. at 14.00 h on day 4 post-coitum (p.c.). Apparently, their number increased, more so on the antimesometrial than the mesometrial side, at 10.00 h on day 5, but were fewer and mostly collapsed at 10.00 h on day 6. Pinopods on day 4 were located within epithelial depressions and foldings, but protruded from the surface on days 5 and 6. Normal pinopods were also present on day 8 p.c. in rats under delayed implantation, but an implantation-inducing dose of estradiol-17β administered about 18 h earlier caused their collapse like that on day 6 in intact rats. Development and appearance of pinopods in intact or delayed rats was unaffected when native preimplantation embryos were prevented from entering the uterus. Normal pinopods were seen in immature rats receiving progesterone for at least 3 days or cyproterone acetate for 4 days, but not after estradiol alone. In animals receiving progesterone or priming/sensitizing estradiol in addition to progesterone, the decidual response was suboptimal, irrespective of the presence of pinopods on the day of stimulation. In animals in which a condition mimicking preimplantation had been produced by suitable hormone supplementation, optimal endometrial sensitivity and decidual response were elicited, even though most pinopods appeared collapsed, resembling those on day 6 in intact rats and about 18 h after estradiol in implantation-delayed rats. Findings confirm that pinopod development on uterine luminal epithelium was dependent on progesterone alone and demonstrate that: (i) preovulatory (priming) or nidatory (endometrial sensitizing) estrogen or viable blastocysts in utero have no role in their development. Nidatory estrogen, instead, appears to limit pinopod development by causing their collapse; (ii) pinopod development/presence on the endometrial surface might indicate the uterus coming into a period of sensitivity rather than actually being in it and might thus serve as a useful marker of "transfer window" rather than "implantation window"; (iii) in the rat, pinopod development might serve as an alternate assay for evaluation of progestational activity of newer test agents.

MM Singh, Division of Endocrinology, Central Drug Research Institute, Lucknow 226 001, India
Three-step immunoscintigraphy with anti-chromogranin A monoclonal antibody in tumours of the pituitary region
Authors: Colombo Paolo , Siccardi Antonio G , Paganelli Giovanni , Magnani Patrizia , Songini Cristina , Buffa Roberto , Faglia Giovanni , Fazio Ferruccio
Published: December 2008

Colombo P, Siccardi AG, Paganelli G, Magnani P, Songini C, Buffa R, Faglia G, Fazio F. Three-step immunoscintigraphy with anti-chromogranin A monoclonal antibody in tumours of the pituitary region. Eur J Endocrinol 1996;135:216–21. ISSN 0804–4643

In the present paper we evaluated the ability of pretargeted immunoscintigraphy (ISG) with antichromogranin A (CgA) monoclonal antibody (Mc-ab A11) in visualizing pituitary masses. The results obtained in 23 patients are described along with those of [111In]pentetreotide scintigraphy (Octreoscan®) in 18 cases. Positive ISG was obtained in 9/11 (82%) non-functioning, 1/4 growth hormone-, 1/2 prolactin-, 1/2 thyrotropin-, 1/1 follicle-stimulating hormone-, 0/1 adrenocorticotrophin-secreting pituitary adenomas. In one patient with a positive ISG scan of a non-functioning pituitary adenoma, an associated neurinoma of the acoustic nerve was not imaged. The same occurred in one patient with a pituitary deposit from a mammary carcinoma and in another one with a cyst of the Rathke's pouch. Chromogranin A immunohistochemistry, carried out in 10 tumours, was positive in eight pituitary adenomas and negative in two non-adenomatous lesions. A concordant ISG occurred in all cases except for two pituitary adenomas: one cystic and necrotized and one post-operative remnant very small in size. In 18 patients with pituitary adenoma both ISG and Octreoscan® were positive in 61% of cases but with a different distribution among tumours. At variance with ISG, Octreoscan® visualized only 5/10 (50%) non-functioning pituitary adenomas and all (4/4) somatotropinomas. In conclusion, ISG is able to image pituitary tumours and particularly non-functioning pituitary adenomas. In this respect, it may be helpful in discriminating non-neuroendocrine masses of the pituitary region from non-functioning pituitary adenomas.

G Faglia, Institute of Endocrine Sciences, University of Milan, Ospedale Maggiore IRCCS, via F. Sforza 35, 1-20122 Milan, Italy
Immunoglobulins from Graves' disease patients stimulate phospholipase A2 and C systems in FRTL-5 and human thyroid cells
Authors: Atwa Mohamed A , Smallridge Robert C , Burch Henry B , Gist Irene D , Lu Rui , Abo-Hashem Ekbal M , El-Kannishy Mohamed H , Burman Kenneth D
Published: December 2008

Atwa MA, Smallridge RC, Burch HB, Gist ID, Lu R, Abo-Hashem EM, El-Kannishy MH, Burman KD. Immunoglobulins from Graves' disease patients stimulate phospholipase A2 and C systems in FRTL-5 and human thyroid cells. Eur J Endocrinol 1996;135:322–7. ISSN 0804–4643

We have studied the effects of immunoglobulin G from Graves' disease patients on phospholipase A2 (PLA2) and C (PLC) systems in FRTL-5 and human thyroid cells. Immunoglobulin G (IgG) from Graves' disease patients stimulated arachidonic acid (AA) release in a time- and dose-dependent manner. In FRTL-5 thyroid cells, removal of external calcium had no significant effect on the IgG (20 μg/ml)-induced AA release in FRTL-5 thyroid cells. U-73122 (3 μmol/l), a PLC inhibitor, and quinacrine (100 μmol/l) but not U-26384 (5 μmol/l), PLA2 inhibitors, blocked the IgG-induced (20 μg/ml) AA release in FRTL-5 thyroid cells. Immunoglobulin G (100 μg/ml) also stimulated accumulation of inositol-1,4,5-triphosphate (IP3) in a time- and dose-dependent (20–300 μg/ml) manner in FRTL-5 cells. Immunoglobulin G from Graves' disease patients induced a significant increase of IP3 production (p = 0.01) compared to IgG from normal subjects. Removal of external calcium had no significant effect on the IgG-induced IP3 production. The PLC inhibitor U-73122 completely blocked IgG-induced IP3 production from FRTL-5 thyroid cells. Also, in human thyroid cells, IgG from Graves' disease patients induced a significant increase of AA release (p = 0.001) and IP3 production (p = 0.004) compared to the IgG from normal subjects. These data indicate that IgG from Graves' disease patients induced PLA2 activity that was PLC dependent, a pattern referred to as sequential activation. Our studies suggest that IgG from Graves' disease patients activates PLA2 and PLC systems in FRTL-5 and human thyroid cells. These signal transduction pathways could be involved in the pathogenesis of Graves' disease and future studies are warranted to investigate this area.

Kenneth D Burman, Endocrine Section, Washington Hospital Center, 110 Irving St. NW, Washington, DC 20010, USA
Episodic secretion of activin A in pregnant women
Authors: Gallinelli A , Gallo R , Genazzani AD , Matteo ML , Caruso A , Woodruff TK , Petraglia F
Published: December 2008

Gallinelli A, Gallo R, Genazzani AD, Matteo ML. Caruso A, Woodruff TK. Petraglia F. Episodic secretion of activin A in pregnant women. Eur J Endocrinol 1996,135:340–4. ISSN 0804–4643

The aim of the present study was to determine the characteristics of activin A secretion in women with normal and abnormal pregnancy. With this purpose, a prospective study was done to evaluate the putative pulsatile pattern of serum activin A in serial specimens of blood collected during a certain amount of time (every 15 min for 3 h). A group of pregnant women (N = 24) participated in a crosssectional study. They were subdivided into three groups: healthy pregnant women (N = 8), patients with preterm labor (N = 8) and patients with gestational diabetes (N = 8) before and after insulin therapy. Secretory pulses of serum activin A were determined in all patients with a specific frequency and amplitude by using two different computerized analyses, i.e. DETECT and CLUSTER. Mean ± sem values of serum activin A were significantly higher in patients with preterm labor and gestational diabetes than in controls (p < 0.01), showing a significant decrease following insulin therapy in diabetic patients (p < 0.01). Specific pulses of serum activin A levels were observed in all women. The mean pulse frequency did not change significantly between healthy controls and the different pathological groups. Patients with gestational diabetes after insulin therapy showed a pulse frequency that was significantly higher than in controls (p < 0.05). When the mean peak amplitude of activin A pulses was evaluated, patients with preterm labor or gestational diabetes showed values that were significantly higher than in healthy pregnant women (p < 0.01). A significant, inverse correlation between pulse frequency and amplitude was found both in healthy pregnant women (p < 0.05) and in patients with gestational diabetes (p < 0.001). The present study showed that circulating activin A levels in pregnant women change in a pulsatile pattern whose pulse amplitude is modified in the presence of gestational diseases, such as preterm labor or gestational diabetes.

Felice Petraglia, Department of Obstetrics and Gynecology, University of Pisa, via Roma 67, 56100 Pisa, Italy
Short-term administration of intranasal or oral Hexarelin, a synthetic hexapeptide, does not desensitize the growth hormone responsiveness in human aging
Authors: Ghigo E , Arvat E , Gianotti L , Grottoli S , Rizzi G , Ceda GP , Boghen MF , Deghenghi R , Camanni F
Published: December 2008

Ghigo E, Arvat E, Gianotti L, Grottoli S. Rizzi G, Ceda GP, Boghen MF, Deghenghi R, Camanni F. Shortterm administration of intranasal or oral Hexarelin, a synthetic hexapeptide. does not desensitize the growth hormone responsiveness in human aging. Eur J Endocrinol 1996;135:417–12. ISSN 0804–4643

The function of the growth hormone–insulin-like growth factor I (GH–IGF-I) axis is reduced in aging, although the secretory capacity of somatotrope cells is preserved. Previous studies have suggested that continuous administration of GH-releasing peptides (GHRPs) results in homologous desensitization to the GH-releasing effect of the peptides. In the present study we have studied whether healthy elderly subjects would remain responsive to short-term, intermittent treatment with Hexarelin (HEX), a GHRP, and whether this treatment would result in an increase in serum IGF-I. In study I, the effect of an 8-day treatment with intranasal administration of 1.25 mg (about 18 μg/kg) t.i.d. HEX on the acute GH response to the hexapeptide and on serum IGF-I, IGF binding protein 3 (IGFBP-3), prolactin and cortisol levels was studied in seven elderly subjects (four males and three females, aged 67–80 years). In study II, the same parameters were studied before and after a 15-day treatment with oral administration of 20 mg (about 300 μg/kg) t.i.d. HEX in seven elderly women (aged 63–80 years). The GH response to the intranasal HEX administration was not significantly higher than that induced by 1 μg/kg iv GHRH (229.4± 35.9 vs 145.8 ± 26.9 μg·1−1·h−1) and was maintained with a trend towards increase after an 8-day treatment with the peptide (342.5 ± 199.3 μg·1−1·h−1). On the other hand, HEX treatment did not significantly modify IGF-I (138.7 ± 11.1 vs 122.4 ± 14.1 μg/l) but increased IGFBP-3 levels (2.4 ± 0.2 vs 1.6 ± 0.2 mg/l, p < 0.02). The GH response to the oral HEX administration was also not significantly higher than that to iv GHRH (257.6 ± 72.0 vs 179.0 ±42.8 μg·1−1·h−1) and did not change after a 15-day treatment with the peptide (237.8±42.8 μg·1−1·h−1). Both IGF-I and IGFBP-3 levels were slightly but significantly increased by oral HEX treatment (156.0 ± 10.7 vs 141.6 ± 13.6 μg/l. p< 0.03, 3.4 ±0.2 vs 3.1 ± 0.2 mg/l, p < 0.03, respectively). Neither intranasal nor oral HEX treatment modified PRL or cortisol levels and did not induce any side effect. In conclusion, these results indicate that chronic but intermittent treatment with HEX, administered either by intranasal or oral route, does not desensitize the GH response to the peptide. Moreover, after HEX treatment a trend towards increase was shown for IGF-I and IGFBP-3 levels. Thus, our findings strengthen the hypothesis that prolonged treatment with HEX may restore the reduced GH release in aging.

F Camanni, Divisione di Endocrinologia. Ospedale Molinette. C. so Dogliotti 14, 10126 Torino. Italy
Acute administration of recombinant human growth hormone inhibits the somatotrope responsiveness to growth hormone-releasing hormone in childhood
Authors: Bellone J , Aimaretti G , Valetto MR , Bellone S , Baffoni C , Arvat E , Seminara S , Camanni F , Ghigo E
Published: December 2008

Bellone J. Aimaretti G, Valetto MR, Bellone S, Baffoni C, Arvat E, Seminara S, Camanni F, Ghigo E, Acute administration of recombinant human growth hormone inhibits the somatotrope responsiveness to growth hormone-releasing hormone in childhood. Eur J Endocrinol 1996:135: 421–4. ISSN 0804–4643

In adulthood the growth hormone (GH) response to growth hormone-releasing hormone (GHRH) is inhibited by previous acute administration of either GH or GHRH and it is restored by substances that inhibit hypothalamic somatostatin release. Because in children the GH response to GHRH is not affected by previous neurohormone administration, it has been suggested that in childhood a GH increase is not able to trigger the somatostatin-mediated negative GH autofeedback mechanism. To verify this hypothesis, in 25 children (8 girls and 17 boys; 15 prepubertal and 10 in pubertal stages II–IV) with familial short stature (normal height velocity and insulin-like growth factor I levels) we studied the effect of acute iv administration of different recombinant human GH doses (group 1, N = 5, 0.06U/kg; group 2, N = 6, 0.01 U/kg; group 3, N = 7, 0.005 U/kg at −150 min or saline on the GH response to GHRH (1 μg/kg iv at 0 min). In another group (N = 7), we studied the effect of 0.005 U/kg iv recombinant human GH or saline on the GH response to GHRH combined with arginine (0.5 g/kg iv over 30 min), which likely inhibits hypothalamic somatostatin release. Serum GH increases after recombinant human GH were dose-dependent (GH peak, mean±sem, 171.7 ± 24.4, 33.3 ± 3.9 and 21.8 ± 5.1 μg/l, respectively). The administration of recombinant human GH strongly inhibited the GHRH-induced GH rise in all groups (group 1, 7.1 ± 1.7 vs 23.1 ± 7.6 μg/l, p < 0.05; group 2, 9.5 ±2.8 vs 26.9±8.5 μg/l, p < 0.05; group 3, 9.1 ±2.7 vs 34.8 ± 7.2 μg/l, p< 0.02). The GH response to arginine + GHRH (56.9 ± 13.3 μg/l) was higher than that to GHRH alone recorded in group 1 (p < 0.005), group 2 (p < 0.01) and group 3 (p < 0.01), while exogenous recombinant human GH failed to inhibit it (45.0 ± 9.4 μg/l). Our results demonstrate that in childhood, as well as in adulthood, recombinant human GH administration inhibits the somatotrope responsiveness to GHRH. This inhibitory effect is likely to be mediated by hypothalamic somatostatin release.

Ezio Ghigo, Divisione di Endocrinologia, Ospedale Molinette, C.so Dogliotti 14, 10126 Torino, Italy
Altered parathyroid hormone-related protein secretion and mRNA expression in squamous carcinoma cells in vitro
Authors: Gröne Andrea , Weckmann Michelle T , Steinmeyer Carole L , Capen Charles C , Rosol Thomas J
Published: December 2008

Gröne A, Weckmann MT, Steinmeyer CL, Capen CC, Rosol TJ. Altered parathyroid hormone-related protein secretion and mRNA expression in squamous carcinoma cells in vitro. Eur J Endocrinol 1996;135:498–505. ISSN 0804–4643

Parathyroid hormone-related protein (PTHrP), a major factor in the pathogenesis of humoral hypercalcemia of malignancy, is produced by many squamous carcinoma cells (SCCs). Two SCC lines were grown in multilayered culture systems and compared to cells grown as monolayers to evaluate the effects of cell proliferation, confluence and differentiation on PTHrP secretion and mRNA expression. Well-differentiated (SCC 2/88) and poorly differentiated (SCC-A253) SCCs were grown as monolayer and three-dimensional cultures on collagen-coated membranes to compare the regulation of PTHrP expression and secretion by the cell lines in vitro. Parathyroid hormone-related protein secretion was evaluated by radioimmunoassay and immunohistochemistry. Messenger RNA expression was analyzed by RNase protection assay and in situ hybridization. Secretion of PTHrP was greatest in preconfluent SCC 2/88 cells in monolayer culture and decreased after confluence, which was the result of decreased PTHrP mRNA expression. In contrast, PTHrP secretion in cultures of SCC-A2 5 3 cells reached maximal levels after confluence. In multilayered cultures, total PTHrP secretion and mRNA expression remained high in both SCC 2/88 and SCC-A253 cells, and secretion by the multi-layered cultures was principally in the basal direction. Parathyroid hormone-related protein was present in all cell layers in three-dimensional cultures as determined by immunohistochemistry. These results indicated that multilayered cultures of SCCs produced PTHrP continuously, whereas decreased proliferation in monolayer cultures was associated with decreased PTHrP production. Multilayered cultures represent a better system to investigate PTHrP secretion and mRNA expression in vitro and PTHrP secretion by SCCs in vivo may be greatest by proliferating cells.

Thomas J Rosol, 1925 Coffey Road, Columbus, OH 43210, USA
Effects of methimazole in the early and established phases of NG-nitro-l-arginine methyl ester hypertension
Authors: Vargas Félix , Fernandez-Rivas Antonio , Osuna Antonio
Published: December 2008

Vargas F, Fernandez-Rivas A, Osuna A. Effects of methimazole in the early and established phases of NG-nitro 4643 c-nitro-l-arginine methyl ester hypertension. Eur J Endocrinol 1996;135:506–13. ISSN 0804–

In the present study we evaluated the effects of methimazole, an antithyroid drug, on blood pressure and other variables in the early and established phases of hypertension induced by the inhibition of nitric oxide synthesis with the oral administration of NG-nitro-l-arginine methyl ester (l-NAME), 75 mg/100 ml in the drinking water. Moreover, we also evaluated the acute pressor effect of l-NAME on systemic blood pressure in control and rats treated chronically with methimazole, administered via drinking water (30 mg/100 ml). Oral administration of methimazole maintained the blood pressure of l-NAME-treated rats at normal levels 25 days after induction of hypertension. However, after 25 days of methimazole treatment in rats made hypertensive with l-NAME (for 25 days), high blood pressure was similar in methimazole-treated and non-treated l-NAME rats, despite the fact that a hypothyroid state had been achieved in the methimazole-treated rats. Acute intravenous injection of l-NAME caused a similar increase in mean arterial pressure in control and methimazole-treated rats at the lowest dose; however, smaller pressor responses were observed with increasing doses in hypothyroid rats. These results clearly demonstrate that hypothyroidism induced by methimazole prevents, but does not reverse, l-NAME hypertension and reduces the acute pressor responsiveness to l-NAME administration.

F Vargas, Departamento de Fisiología, Facultad de Medicina, E-18012, Granada, Spain
Modulatory actions of progesterone on gonadotropin-releasing hormone-induced arachidonic acid liberation from perifused rat pituitary cells
Authors: Ortmann Olaf , Ansari-Pirsarai Bijan , Bloh Peter , Schulz Klaus-Dieter , Emons Günter
Published: December 2008

Ortmann O, Ansari-Pirsarai B, Bloh P, Schulz K-D, Emons G. Modulatory actions of progesterone on gonadotropin-releasing hormone-induced arachidonic acid liberation from perifused rat pituitary cells. Eur J Endocrinol 1996;135:626–30. ISSN 0804–4643

The stimulatory action of gonadotropin-releasing hormone (GnRH) on gonadotropin secretion from cultured rat pituitary cells is modulated by estradiol and progesterone. Recent studies provided evidence that both steroids exert effects on different pathways of GnRH signal transduction, which might be responsible for their actions on luteinizing hormone (LH) release. Here we investigated whether the steroids are able to modulate GnRH-induced liberation of arachidonic acid, which is thought to be involved in GnRH signal transduction. Pituitary cells obtained from female rats were treated for 48 h with vehicle, 1 nmol/l estradiol or 1 nmol/l estradiol +100 nmol/l progesterone, 48 h with 1 nmol/l estradiol and 2 h with 100 nmol/l progesterone. In addition, these cells were prelabeled with [3H]arachidonic acid. Then the cells were transferred to a perifusion system and challenged with a 6-min pulse of 100 nmol/l GnRH. Estradiol treatment enhanced the LH secretory response while GnRH-induced [3H]arachidonic acid liberation remained unaffected. However, progesterone modulated both LH secretion and [3H]arachidonic acid release in response to the GnRH stimulus. The shortterm progesterone treatment paradigm enhanced the LH and arachidonic acid responses by up to 160 ±13 and 204 ±18%, respectively, while long-term treatment was inhibitory (59 ± 9 and 63 ± 4% vs control). Because arachidonic acid has been shown to be involved in GnRH signal transduction, it seems reasonable to speculate that the actions of progesterone described in the present study are related to its modulatory effect on GnRH-induced LH secretion.

O Ortmann, Department of Obstetrics and Gynecology, Medical University of Lübeck, Ratzeburger Allee 160, D-23538 Lübeck, Germany