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Pituitary 2009Hormone secretion by somatotropinomas, corticotropinomas and prolactinomas exhibits increased pulse frequency, basal and pulsatile secretion, accompanied by greater...
Hormone secretion by somatotropinomas, corticotropinomas and prolactinomas exhibits increased pulse frequency, basal and pulsatile secretion, accompanied by greater disorderliness. Increased concentrations of growth hormone (GH) or prolactin (PRL) are observed in about 30% of thyrotropinomas leading to acromegaly or disturbed sexual functions beyond thyrotropin (TSH)-induced hyperthyroidism. Regulation of non-TSH pituitary hormones in this context is not well understood. We there therefore evaluated TSH, GH and PRL secretion in 6 patients with up-to-date analytical and mathematical tools by 24-h blood sampling at 10-min intervals in a clinical research laboratory. The profiles were analyzed with a new deconvolution method, approximate entropy, cross-approximate entropy, cross-correlation and cosinor regression. TSH burst frequency and basal and pulsatile secretion were increased in patients compared with controls. TSH secretion patterns in patients were more irregular, but the diurnal rhythm was preserved at a higher mean with a 2.5 h phase delay. Although only one patient had clinical acromegaly, GH secretion and IGF-I levels were increased in two other patients and all three had a significant cross-correlation between the GH and TSH. PRL secretion was increased in one patient, but all patients had a significant cross-correlation with TSH and showed decreased PRL regularity. Cross-ApEn synchrony between TSH and GH did not differ between patients and controls, but TSH and PRL synchrony was reduced in patients. We conclude that TSH secretion by thyrotropinomas shares many characteristics of other pituitary hormone-secreting adenomas. In addition, abnormalities in GH and PRL secretion exist ranging from decreased (joint) regularity to overt hypersecretion, although not always clinically obvious, suggesting tumoral transformation of thyrotrope lineage cells.
Topics: Adenoma; Adult; Aged; Female; Fluoroimmunoassay; Growth Hormone; Humans; Insulin-Like Growth Factor I; Male; Middle Aged; Pituitary Hormones; Pituitary Neoplasms; Prolactin; Radioimmunoassay; Thyrotropin
PubMed: 19051037
DOI: 10.1007/s11102-008-0159-6 -
European Journal of Endocrinology Sep 1999
Review
Topics: Adolescent; Adult; Animals; Child; DNA-Binding Proteins; Disease Models, Animal; Dwarfism; Human Growth Hormone; Humans; Infant; Male; Mice; Pituitary Hormones; Point Mutation; Prolactin; Thyrotropin; Transcription Factor Pit-1; Transcription Factors
PubMed: 10474115
DOI: 10.1530/eje.0.1410211 -
Reviews in Endocrine & Metabolic... Jan 2000T3 suppression of TSH subunit gene transcription is an important step in maintaining thyroid hormone homeostasis, and recent investigations have increased our... (Review)
Review
T3 suppression of TSH subunit gene transcription is an important step in maintaining thyroid hormone homeostasis, and recent investigations have increased our understanding of this process. Thyrotrope-specific proteins play a critical role in TSH subunit gene expression, and influence T3-mediated regulatory mechanisms. The structure and placement of the TSH gene TREs define suppressive regulation by T3, and this process is favored by the TR isoforms expressed in the pituitary. Elimination of TR beta function compromises the pituitary response to T3. TR beta 2, the isoform specifically expressed in pituitary and neural tissue, contains a transferable domain that both increases T3-independent gene transcription and enhances T3-suppressed transcription. The functional interaction of TR beta 2 with other regulatory proteins is distinct from that of other TR isoforms, and likely plays a critical role in pituitary physiology and in pituitary resistance to thyroid hormone. The development of novel thyrotrope cell lines will allow investigators to define new proteins and molecular mechanisms that distinguish negative from positive T3 transcriptional regulation.
Topics: Animals; Gene Expression; Humans; Pituitary Gland; Pituitary Hormones; Protein Isoforms; Receptors, Thyroid Hormone; Response Elements; Thyrotropin; Triiodothyronine
PubMed: 11704990
DOI: 10.1023/a:1010008318961 -
Clinical Endocrinology Aug 2005The past 12 years have witnessed an explosion in our understanding of the development of the anterior pituitary gland, and of mechanisms that underlie the diagnosis of... (Review)
Review
The past 12 years have witnessed an explosion in our understanding of the development of the anterior pituitary gland, and of mechanisms that underlie the diagnosis of growth hormone deficiency (GHD) and combined pituitary hormone deficiency (CPHD). The anterior pituitary is the end-product of a carefully orchestrated pattern of expression of signalling molecules and transcription factors that leads to the development of this complex organ secreting six hormones from five different cell types. Naturally occurring and transgenic murine models have demonstrated a role for many of these molecules in the aetiology of GHD/CPHD. These include the transcription factors HESX1, PROP1, POU1F1, LHX3, LHX4, GLI2 and SOX3. Depending upon the expression patterns of these molecules, the phenotype may consist of isolated hypopituitarism, or more complex disorders such as septo-optic dysplasia (SOD) and holoprosencephaly. The phenotype and the mode of inheritance can be highly variable. Novel mutations within the GH-1 and GHRHR genes have also shed light on the phenotype and pathogenesis of isolated GHD (IGHD). To date, genetic mutations have been identified in a modest proportion of patients with IGHD/CPHD and associated syndromes such as SOD. It is, however, clear that many genes remain to be identified, and characterization of these will further elucidate the pathogenesis of these complex conditions.
Topics: DNA-Binding Proteins; Genes; Genetic Linkage; Genotype; Homeodomain Proteins; Human Growth Hormone; Humans; Hypopituitarism; LIM-Homeodomain Proteins; Mutation; Pituitary Gland; Pituitary Hormones; Transcription Factor Pit-1; Transcription Factors
PubMed: 16060904
DOI: 10.1111/j.1365-2265.2005.02289.x -
Annales D'endocrinologie Apr 2012Congenital hypopituitarism is a rare disease, usually induced by mutations of genes coding for transcription factors involved in pituitary development. PROP1 mutations... (Review)
Review
Congenital hypopituitarism is a rare disease, usually induced by mutations of genes coding for transcription factors involved in pituitary development. PROP1 mutations represent the first cause of identified congenital hypopituitarism. Current techniques only identify 10-20% of congenital hypopituitarism etiologies, suggesting that new techniques are needed to improve this ratio. This should lead to a better management and follow-up of patients presenting with combined pituitary hormone deficiencies.
Topics: Genes; Genetic Predisposition to Disease; Humans; Hypopituitarism; Mutation; Pituitary Hormones
PubMed: 22521856
DOI: 10.1016/j.ando.2012.03.025 -
Journal of Pediatric Endocrinology &... Jul 2001The overview in this paper focuses on ways of achieving optimal auxological results in puberty, principally in idiopathic and congenital multiple pituitary hormone... (Review)
Review
The overview in this paper focuses on ways of achieving optimal auxological results in puberty, principally in idiopathic and congenital multiple pituitary hormone deficiency (MPHD), suggested by the co-authors. We agreed that diagnosing gonadotrophin insufficiency/deficiency is difficult in young children and should be repeated in late prepuberty, but a firm diagnosis of MPHD helps avoid endocrine re-testing at the end of growth. The hypothalamic-pituitary axis must be reassessed periodically in evolving endocrinopathies, though current practice varies widely. Optimum age to induce puberty is 11-12 years in girls and 13-14 boys, and sex steroids are the preferred agents. Short-course testosterone to increase micropenis size is advantageous, but inducing early testicular maturation is not known to improve later fertility. There is also little evidence for increasing the dose of GH during puberty, though therapy should continue to final height, and possibly until peak bone mass is achieved. Delaying puberty is an option in septo-optic dysplasia, and minimising the dose of hydrocortisone is crucial in treating ACTH/cortisol insufficiency. Many unresolved questions remain in this difficult area.
Topics: Adolescent; Child; Female; Growth Disorders; Growth Hormone; Humans; Male; Pituitary Hormones; Puberty
PubMed: 11529397
DOI: 10.1515/jpem-2001-s214 -
Orvosi Hetilap Feb 2018Developmental disorders affecting the hypothalamic-pituitary system can result in pituitary hormone deficiency showing a diverse clinical presentation. A significant... (Review)
Review
Developmental disorders affecting the hypothalamic-pituitary system can result in pituitary hormone deficiency showing a diverse clinical presentation. A significant majority of these disorders are closely linked to defects in transcription factor genes which play a major role in pituitary development. Those affecting the early phase of organogenesis typically lead to complex conditions affecting the pituitary as well as structures in the central nervous system. Transcription factors involved in the late phase can result in combined but rarely isolated pituitary hormone deficiency without extra-pituitary manifestation. Identifying the defects in these pituitary transcription factor genes may provide a useful tool in predicting disease progression as well as screening family members. Several pituitary transcription factors can be detected in the adult gland as well which is strongly emphasized in the World Health Organization's most recent guideline for pituitary tumor classification. Our review summarizes the current essential knowledge relevant for clinical endocrinologists. Orv Hetil. 2018; 159(7): 278-284.
Topics: DNA Mutational Analysis; Humans; Hypopituitarism; Hypothalamo-Hypophyseal System; Pituitary Gland; Pituitary Hormones
PubMed: 29429351
DOI: 10.1556/650.2018.31029 -
Archives of Physiology and Biochemistry Apr 2002Cells displaying combined expression of different pituitary hormone genes (further referred to as 'multi-hormone mRNA cells') were identified in normal rat and mouse... (Review)
Review
Cells displaying combined expression of different pituitary hormone genes (further referred to as 'multi-hormone mRNA cells') were identified in normal rat and mouse pituitary by single cell RT-PCR. These cells do not seem to produce or store all the respective hormones the mRNAs encode for. The cells are already developed at day 16 of embryonic life (E16) in the mouse. Different peptides, such as gamma3-melanocyte-stimulating hormone (gamma3-MSH) and gonadotropin-releasing hormone (GnRH), affect different subsets of these cells. In culture, estrogen and GnRH increase the number of 'multi-hormone mRNA cells' that contain prolactin (PRL) mRNA or mRNA of the alpha-subunit of the glycoprotein hormones (alpha-GSU) but not the number of 'multi-hormone mRNA cells' not containing PRL or alpha-GSU mRNA. 'Multi-hormone mRNA cells' may function as 'reserve cells' in which a particular hormone mRNA may be translated under a particular physiological condition demanding a rapid increase of that hormone.
Topics: Animals; Gene Expression; Mice; Pituitary Gland; Pituitary Hormones; RNA, Messenger; Rats; Reverse Transcriptase Polymerase Chain Reaction
PubMed: 11935395
DOI: 10.1076/apab.110.1.12.904 -
Endocrinology Apr 1995
Topics: Animals; Male; Pituitary Hormones, Anterior; Rats
PubMed: 7895643
DOI: 10.1210/endo.136.4.7895643 -
Endocrinology and Metabolism (Seoul,... Oct 2022Over the past years, pituitary hormones and their receptors have been shown to have non-traditional actions that allow them to bypass the hypothalamus-pituitary-effector...
Over the past years, pituitary hormones and their receptors have been shown to have non-traditional actions that allow them to bypass the hypothalamus-pituitary-effector glands axis. Bone cells-osteoblasts and osteoclasts-express receptors for growth hormone, follicle stimulating hormone (FSH), thyroid stimulating hormone (TSH), adrenocorticotrophic hormone (ACTH), prolactin, oxytocin, and vasopressin. Independent skeletal actions of pituitary hormones on bone have been studied using genetically modified mice with haploinsufficiency and by activating or inactivating the receptors pharmacologically, without altering systemic effector hormone levels. On another front, the discovery of a TSH variant (TSH-βv) in immune cells in the bone marrow and skeletal action of FSHβ through tumor necrosis factor α provides new insights underscoring the integrated physiology of bone-immune-endocrine axis. Here we discuss the interaction of each pituitary hormone with bone and the potential it holds in understanding bone physiology and as a therapeutic target.
Topics: Mice; Animals; Pituitary Hormones; Thyrotropin; Follicle Stimulating Hormone; Prolactin; Adrenocorticotropic Hormone
PubMed: 36168775
DOI: 10.3803/EnM.2022.1573