Abstract:
:Effects of primary hypothyroidism (HYPO) on the male gonadal axis are controversial, with only scanty data on the gonadotroph cell response and no information on GnRH tuberoinfundibular neurons, even in animal models. HYPO has been reported to variably induce hypogonadotropic hypogonadism, a hypergonadotropic state, or to have no effects on basal levels of pituitary gonadotropins, both in adult male rats and humans. Similarly, the exogenous administration of GnRH to HYPO rats and humans may increase or decrease gonadotropin secretion. Since inhibitory effects of HYPO on the GnRH-gonadotropin axis are reversed by replacement with L-T4, it has been suggested that thyroid hormone (TH) may regulate tuberoinfundibular GnRH and pituitary gonadotropin biosynthesis and/or secretion. To shed light on this hypothesis, we conducted immunocytochemical studies on the distribution and immunostaining characteristics of hypophysiotropic GnRH neurons, LH, PRL and vasoactive intestinal polypeptide (VIP) immunoreactive (IR) cells in the pituitary of adult, male rats. We show that HYPO reduces IR-GnRH in a restricted population of tuberoinfundibular perikarya and their proximal axons compared to euthyroid controls, but increases IR-VIP both in pituitary cells in direct association with LH-gonadotrophs and within IR-LH cells, itself. We propose that VIP may serve as a juxtacrine/paracrine/autocrine regulator of LH secretion and that, when GnRH biosynthesis is reduced by HYPO, gonadotropin secretion may be rescued by local activating effects of VIP. Polychlorinated biphenyls (PCB), industry toxicants found in food and water, also have inhibitory effects on the gonadal axis, decreasing fertility and suppressing basal and GnRHinduced LH release in male rats. Since PCB may also exert endocrine disruptor-dependent (EDD) effects on the thyroid axis producing a non-thyroidal illness syndrome (NTIS) (coined EDD-NTIS), we developed a rat model of EDD-NTIS to determine whether central hypothyroidism may contribute to the pathophysiology of PCB-induced hypogonadism. On the basis of preliminary animal data, we speculate that one of the mechanisms for Partial Androgen Deficiency of the Aging Male may involve central hypothyroidism and EDD-NTIS, resulting in inhibition of the GnRH-gonadotroph axis.
journal_name
J Endocrinol Investjournal_title
Journal of endocrinological investigationauthors
Toni R,Della Casa C,Castorina S,Cocchi D,Celotti Fsubject
Has Abstractpub_date
2005-01-01 00:00:00pages
20-7issue
11 Suppl Proceedingseissn
0391-4097issn
1720-8386journal_volume
28pub_type
杂志文章,评审abstract::The TSH responses to the catecholamine depleting agent monoiodotyrosine (1 g po) and the dopamine receptor blocking drug metoclopramide (10 mg po) have been compared in euthyroid and hypothyroid subjects. Both drugs lead to a prompt and significant rise in TSH levels (peak values at 60-75 min) which is very much great...
journal_title:Journal of endocrinological investigation
pub_type: 杂志文章
doi:10.1007/BF03348238
更新日期:1980-04-01 00:00:00
abstract::Thyroid diseases may lead to endothelial dysfunction; however, the mechanism underlying the endothelial dysfunction in thyroid disease is not clear yet. Asymmetric dimethylarginine (ADMA), a novel inhibitor of endothelial nitric oxide synthase (eNOS), blocks nitric oxide (NO) synthesis from L-arginine. Symmetric dimet...
journal_title:Journal of endocrinological investigation
pub_type: 杂志文章
doi:10.1007/BF03347423
更新日期:2007-03-01 00:00:00
abstract:BACKGROUND:Thyroid gland is highly dependent on dietary intake of iodine for normal function, so it is particularly subjected to "endocrine disruptor" action. The human sodium/iodide symporter (hNIS) is an integral plasma membrane glycoprotein mediating the active transport of iodide into thyroid follicular cells, a cr...
journal_title:Journal of endocrinological investigation
pub_type: 杂志文章
doi:10.1007/BF03347061
更新日期:2011-03-01 00:00:00
abstract:PURPOSE:To report the long-term effectiveness and safety of the recombinant human growth hormone Omnitrope®, a somatropin biosimilar to Genotropin®, in Italian patients with growth hormone deficiency (GHD) enrolled in the PATRO Adults study. METHODS:The PATRO Adults study is an ongoing observational, longitudinal, non...
journal_title:Journal of endocrinological investigation
pub_type: 杂志文章,多中心研究
doi:10.1007/s40618-016-0604-8
更新日期:2017-06-01 00:00:00
abstract:BACKGROUND:Type 1 diabetes (T1DM) is an autoimmune disease in which both genetic and environmental factors play a role in the etiology. AIM:The aim of this study was to analyze the incidence of T1DM. METHODS:A retrospective technique was used to register all newly diagnosed cases of T1DM in Belgrade (Serbia) children...
journal_title:Journal of endocrinological investigation
pub_type: 杂志文章,多中心研究
doi:10.3275/8619
更新日期:2013-05-01 00:00:00
abstract::The intravenous injection of calcium gluconate (0.11 mM/kg body weight) into conscious thyroidectomized pigs elicits a 30% rise in both ionized and total calcium concentrations of plasma, which return to basal levels within 180 min. The administration of calcitonin (2.5-10 MRC U/kg body weight) reduces this time to 30...
journal_title:Journal of endocrinological investigation
pub_type: 杂志文章
doi:10.1007/BF03350579
更新日期:1983-04-01 00:00:00
abstract::D-aspartic acid (D-Asp), aromatase enzyme activity and the putative D-Asp involvement on aromatase induction have been studied in the testis of mature boars. The peroxidase-antiperoxidase and the indirect immunofluorescence methods, applied to cryostat and paraffin sections, were used to evaluate D-Asp and aromatase d...
journal_title:Journal of endocrinological investigation
pub_type: 杂志文章
doi:10.1007/BF03344087
更新日期:2006-02-01 00:00:00
abstract:BACKGROUND:The coexistence of insulin and ACTH hypersecretion in the same patient is extremely rare. A diabetic patient with a pancreatic endocrine tumor (PET) co-secreting insulin and ACTH is even rarer and has never been described. The combination of these two endocrine syndromes results in a peculiar clinical pictur...
journal_title:Journal of endocrinological investigation
pub_type: 杂志文章
doi:10.1007/BF03347062
更新日期:2011-03-01 00:00:00
abstract::Human gonadotropins are widely used for induction of ovulation in the treatment of anovulatory infertility and for induction of multiple follicular development (MFD) in in vitro fertilization (IVF), gamete intrafallopian transfer (GIFT), and artificial insemination with husband's semen (AIH) programs. Reported is a pa...
journal_title:Journal of endocrinological investigation
pub_type: 杂志文章
doi:10.1007/BF03349615
更新日期:1990-10-01 00:00:00
abstract::Abnormalities of the gene encoding the sequence-specific DNA-binding protein, nuclear phosphorprotein p53, are among the most common genetic alterations observed in human cancers. A mutation of this tumor suppressor gene has been reported with a low prevalence in differentiated thyroid carcinomas, while the prevalence...
journal_title:Journal of endocrinological investigation
pub_type: 杂志文章
doi:10.1007/BF03347774
更新日期:1994-11-01 00:00:00
abstract::Ghrelin is a 28-amino-acid hormone produced mainly by the stomach which strongly promotes food intake. It is the only known peripheral orexigenic hormone that induces the release of GH. Ghrelin has been proposed as a link between the enteric system and central regulation of energy balance and growth. Although it has r...
journal_title:Journal of endocrinological investigation
pub_type: 杂志文章
doi:10.1007/BF03350806
更新日期:2007-10-01 00:00:00
abstract:OBJECTIVE:Elimination of thyroid antigens by total thyroid ablation (TTA), namely, thyroidectomy followed by radioiodine, may be beneficial for Graves' Orbitopathy (GO). TTA is usually performed with a 131I dose of 30 mCi. In Italy, this dose must be followed by a 24-h protected hospitalization, with increase in the wa...
journal_title:Journal of endocrinological investigation
pub_type: 杂志文章
doi:10.1007/s40618-017-0754-3
更新日期:2018-03-01 00:00:00
abstract:PURPOSE:We recently demonstrated a protective effect of the farnesoid X receptor agonist obeticholic acid (OCA) in rat models of bleomycin-induced pulmonary fibrosis (PF). Aim of the present study was to investigate whether the positive effects of OCA treatment are apparent also on ongoing bleomycin-induced PF, i.e., a...
journal_title:Journal of endocrinological investigation
pub_type: 杂志文章
doi:10.1007/s40618-018-0913-1
更新日期:2019-03-01 00:00:00
abstract:CONTEXT:The antiproliferative mechanism of mycophenolate acid (MPA) suggests a beneficial effect in patients with Graves' orbitopathy (GO). OBJECTIVE:To systematically analyze for the first time adverse events (AEs) during MPA treatment in GO. DESIGN:Prospective longitudinal study. SETTING:Academic tertiary referral...
journal_title:Journal of endocrinological investigation
pub_type: 杂志文章
doi:10.1007/s40618-016-0441-9
更新日期:2016-06-01 00:00:00
abstract:PURPOSE:Nonalcoholic fatty liver disease (NAFLD) is associated with various metabolic abnormalities that can increase the risk of an osteoporotic fracture. Across the few previous studies of the association between NAFLD and bone mineral density (BMD), the association was not consistent. We examined the association bet...
journal_title:Journal of endocrinological investigation
pub_type: 杂志文章
doi:10.1007/s40618-016-0528-3
更新日期:2016-11-01 00:00:00
abstract::Isolated hypothyroxinemia (IH) is defined as a thyroxine level in the lower 5th (severe IH) or 10th percentile (mild IH) of the pregnancy-related reference range and a normal TSH. The etiology of IH remains unknown. This review aims to evaluate the biochemical criteria used to define IH in different published studies ...
journal_title:Journal of endocrinological investigation
pub_type: 杂志文章,评审
doi:10.1007/s40618-014-0203-5
更新日期:2015-02-01 00:00:00
abstract::Homocysteine (HCY) is a sulfur-containing amino acid involved in two metabolic pathways, catalized by cystathionine-B-synthase and methionine synthase, depending on vitamin (vit) B6, B12, and folate levels and enzymatic activity of methylenetetrahydrofolate. High HCY levels (HHCY) are associated with cardiovascular (C...
journal_title:Journal of endocrinological investigation
pub_type: 杂志文章,评审
doi:
更新日期:2009-01-01 00:00:00
abstract::To determine the role of endogenous opioid peptides in regulating pulsatile luteinizing hormone (LH) release in the early follicular phase of the menstrual cycle of eumenorrheic women, we evaluated serum LH concentrations in blood collected every 10 min for 12 h in 27 women each studied during two menstrual cycles: (1...
journal_title:Journal of endocrinological investigation
pub_type: 杂志文章
doi:10.1007/BF03348799
更新日期:1992-07-01 00:00:00
abstract:OBJECTIVE:Thyroid hormone resistance (RTH β) is a rare genetic disorder characterized by an altered response of target tissue to the action of thyroid hormone. Few studies on RTH β have been carried out in southern European populations. We aimed to describe the clinical and genetic characteristics at the time of diagno...
journal_title:Journal of endocrinological investigation
pub_type: 杂志文章
doi:10.1007/s40618-019-1007-4
更新日期:2019-08-01 00:00:00
abstract:PURPOSE:Achieving biochemical control (normalization of insulin-like growth factor-1 [IGF-1] and growth hormone [GH]) is a key goal in acromegaly management. However, IGF-1 and GH fluctuate over time. The true potential impact of time-varying biochemical control status on comorbidities is unclear and relies on multiple...
journal_title:Journal of endocrinological investigation
pub_type: 杂志文章
doi:10.1007/s40618-019-01138-y
更新日期:2020-04-01 00:00:00
abstract:BACKGROUND:In contrast with maximal voluntary resistance exercise, which is allegedly considered a potent GH stimulus in young subjects, evaluation of GH response to whole-body vibrations (WBV) has yielded conflicting results. METHODS:The acute effects of WBV alone (test A), maximal voluntary isometric contractions (M...
journal_title:Journal of endocrinological investigation
pub_type: 杂志文章
doi:10.1007/BF03347069
更新日期:2011-03-01 00:00:00
abstract::To verify if the entity of the peak GH responses to the GHRH+arginine (ARG) test is able to show different degree forms of GH deficiency (GHD), we linked these responses with the number of other anterior pituitary deficits. These anterior pituitary deficits were also related with IGF-I levels. To this purpose, we stud...
journal_title:Journal of endocrinological investigation
pub_type: 杂志文章
doi:10.1007/BF03345381
更新日期:2005-03-01 00:00:00
abstract::In acromegaly, clinical features are of the utmost importance, and biochemical confirmation is rarely difficult. However, some clinically manifest acromegalics have subtle abnormalities in GH secretion resulting in post-glucose GH nadir in the designated "normal" range with high IGF-I levels. Clinical decision may be ...
journal_title:Journal of endocrinological investigation
pub_type: 杂志文章,评审
doi:
更新日期:2005-01-01 00:00:00
abstract::It has recently been suggested that the classical routine of glucocorticoid administration before and after transsphenoidal surgery (TSS) in Cushing's disease (CD) patients may not be necessary, since it is likely that peritumoral normal corticotrophs are not completely suppressed during this period. We compared the d...
journal_title:Journal of endocrinological investigation
pub_type: 杂志文章
doi:10.1007/BF03347237
更新日期:2005-06-01 00:00:00
abstract::Up to now, the diagnosis of silent corticotroph cell pituitary adenomas has been made only on histopathological basis. In this paper we describe 6 women affected with pituitary adenomas, without evident clinical features of hypercortisolism, in whom retrospective data suggested the possibility of clinically diagnosing...
journal_title:Journal of endocrinological investigation
pub_type: 杂志文章
doi:10.1007/BF03348769
更新日期:1992-06-01 00:00:00
abstract:BACKGROUND:We previously identified a four-generation family with medullary thyroid cancer (MTC) and a germline p.Y791F RET mutation whose cancer lacked a strong genotype-phenotype correlation. The entire gene coding region of the RET gene should be sequenced when genotype-phenotype discrepancies are observed in patien...
journal_title:Journal of endocrinological investigation
pub_type: 杂志文章
doi:10.3275/8997
更新日期:2013-12-01 00:00:00
abstract:BACKGROUND:The adiponectin gene has been identified as a susceptibility locus for metabolic syndrome, diabetes and cardiovascular disease. AIM:To examine the influence of two single nucleotide polymorphisms (SNPs) of this gene (+276G>T and +45T>G) on circulating adiponectin concentrations, and to evaluate their relati...
journal_title:Journal of endocrinological investigation
pub_type: 杂志文章,随机对照试验
doi:10.3275/8972
更新日期:2013-11-01 00:00:00
abstract::In order to precise the relationships between TSH, FT3, and FT4 nycthemeral variations and the relationships between thyroid hormone variations and sleep, 8 healthy young males were studied twice, once during a 24-h experiment with normal nocturnal sleep, and once during a night of sleep deprivation. The subjects rece...
journal_title:Journal of endocrinological investigation
pub_type: 杂志文章
doi:10.1007/BF03347712
更新日期:1994-03-01 00:00:00
abstract:UNLABELLED:Hypercalcemia occurring in patients with advanced breast cancer (BC) is generally due to osteolytic metastases or to the activity of circulating tumor-derived products. In these conditions, the production of endogenous PTH is reduced. The frequency of hypercalcemia due to primary hyperparathyroidism in breas...
journal_title:Journal of endocrinological investigation
pub_type: 杂志文章
doi:10.1007/BF03343867
更新日期:2001-05-01 00:00:00
abstract::Multiple endocrine neoplasia type 1 (MEN1) is characterized by parathyroid, enteropancreatic endocrine and pituitary adenomas as well as germline mutation of the MEN1 gene. We describe 2 families with MEN1 with novel mutations in the MEN1 gene. One family was of Turkish origin, and the index patient had primary hyperp...
journal_title:Journal of endocrinological investigation
pub_type: 杂志文章
doi:10.1007/BF03344142
更新日期:2006-06-01 00:00:00