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Minerva Ginecologica Oct 2018This review article centers upon family of gonadotropin hormones which consists of two pituitary hormones - follicle-stimulating hormone (FSH) and luteinizing hormone... (Review)
Review
This review article centers upon family of gonadotropin hormones which consists of two pituitary hormones - follicle-stimulating hormone (FSH) and luteinizing hormone (LH) as well as one non-pituitary hormone - human chorionic gonadotropin (hCG) secreted by placenta, and their receptors. Gonadotropins play an essential role in proper sexual development, puberty, gametogenesis, maintenance of pregnancy and male sexual differentiation during the fetal development. They belong to the family of glycoprotein hormones thus they constitute heterodimeric proteins built of common α subunit and hormone-specific β-subunit. Hitherto, several mutations in genes encoding both gonadotropins and their receptors have been identified in humans. Their occurrence resulted in a number of different phenotypes including delayed puberty, primary amenorrhea, hermaphroditism, infertility and hypogonadism. In order to understand the effects of mutations on the phenotype observed in affected patients, detailed molecular studies are required to map the relationship between the structure and function of gonadotropins and their receptors. Nonetheless, in vitro assays are often insufficient to understand physiology. Therefore, several animal models have been developed to unravel the physiological roles of gonadotropins and their receptors.
Topics: Animals; Chorionic Gonadotropin; Female; Female Urogenital Diseases; Follicle Stimulating Hormone; Humans; Luteinizing Hormone; Male; Male Urogenital Diseases; Models, Animal; Mutation; Phenotype; Pregnancy; Receptors, Gonadotropin
PubMed: 30264954
DOI: 10.23736/S0026-4784.18.04307-1 -
General and Comparative Endocrinology Sep 2015Growth hormone (GH) and prolactin (PRL) are both endocrines that are synthesized and released from the pituitary gland into systemic circulation. Both are therefore... (Review)
Review
Growth hormone (GH) and prolactin (PRL) are both endocrines that are synthesized and released from the pituitary gland into systemic circulation. Both are therefore hormones and both have numerous physiological roles mediated through a myriad of target sites and both have pathophysiological consequences when present in excess or deficiency. GH or PRL gene expression is not, however, confined to the anterior pituitary gland and it occurs widely in many of their central and peripheral sites of action. This may reflect "leaky gene" phenomena and the fact that all cells have the potential to express every gene that is present in their genome. However, the presence of GH or PRL receptors in these extrapituitary sites of GH and PRL production suggests that they are autocrine or paracrine sites of GH and PRL action. These local actions often occur prior to the ontogeny of pituitary somatotrophs and lactotrophs and they may complement or differ from the roles of their pituitary counterparts. Many of these local actions are also of physiological significance, since they are impaired by a blockade of local GH or PRL production or by an antagonism of local GH or PRL action. These local actions may also be of pathophysiological significance, since autocrine or paracrine actions of GH and PRL are thought to be causally involved in a number of disease states, particularly in cancer. Autocrine GH for instance, is thought to be more oncogenic than pituitary GH and selective targeting of the autocrine moiety may provide a therapeutic approach to prevent tumor progression. In summary, GH and PRL are not just endocrine hormones, as they have autocrine and/or paracrine roles in health and disease.
Topics: Autocrine Communication; Gene Expression; Human Growth Hormone; Humans; Paracrine Communication; Pituitary Gland; Prolactin
PubMed: 25448258
DOI: 10.1016/j.ygcen.2014.11.004 -
Endocrine Journal Jun 2022Although coronavirus disease 2019 (COVID-19) mainly involves the lungs, it also affects many systems. The hypothalamic/pituitary axis is vulnerable to hypoxia,...
Although coronavirus disease 2019 (COVID-19) mainly involves the lungs, it also affects many systems. The hypothalamic/pituitary axis is vulnerable to hypoxia, hypercoagulation, endothelial dysfunction and autoimmune changes induced by COVID-19 infection. Given that there is no extensive investigation on this issue, we investigated the pituitary functions three to seven months after acute COVID-19 infection. Forty-three patients after diagnosis of COVID-19 infection and 11 healthy volunteers were included in the study. In addition to the basal pituitary hormone levels, growth hormone (GH) and hypothalamo-pituitary adrenal (HPA) axes were evaluated by glucagon stimulation test (GST) and low-dose adrenocorticotropic hormone (ACTH) stimulation test, respectively. The peak cortisol responses to low-dose ACTH test were insufficient in seven (16.2%) patients. Twenty (46.5%) and four (9.3%) patients had inadequate GH and cortisol responses to GST, respectively. Serum insulin-like growth factor-1 (IGF-1) values were also lower than age and sex-matched references in four (9.3%) patients. The peak GH responses to GST were lower in the patient group when compared to the control group. Other abnormalities were mild thyroid-stimulating hormone elevation in four (9.3%) patients, mild prolactin elevation in two (4.6%) patients and central hypogonadism in four (9.3%) patients. Mean total testosterone values were lower in male patients when compared to male controls; however, the difference was not significant. These findings suggest that COVID-19 infection may affect pituitary functions, particularly the HPA and GH axes. These insufficiencies should be kept in mind in post-COVID follow-up. Long-term data are needed to determine whether these deficiencies are permanent or not.
Topics: Adrenocorticotropic Hormone; COVID-19; Growth Hormone; Human Growth Hormone; Humans; Hydrocortisone; Hypothalamo-Hypophyseal System; Male; Pituitary Diseases; Pituitary Gland; Pituitary-Adrenal System
PubMed: 34987144
DOI: 10.1507/endocrj.EJ21-0531 -
Frontiers in Endocrinology 2023This study employs case data analysis to elucidate alterations in hormone levels pre and post-surgery among patients with pituitary adenoma. Moreover, it investigates...
OBJECTIVE
This study employs case data analysis to elucidate alterations in hormone levels pre and post-surgery among patients with pituitary adenoma. Moreover, it investigates the influence of various associated factors on endocrine function.
METHODS
A retrospective analysis was conducted on clinical data from 428 patients who underwent surgical treatment within a short period at a single center. Statistical methods were employed to examine detailed hormone level fluctuations before and after surgery in patients with pituitary adenoma, along with their interrelations with different factors.
RESULTS
Between January 2016 and October 2022, a total of 428 consecutive patients with pituitary adenoma underwent surgical treatment. Of these, 232 were males and 196 were females, with an average age of 45.91 years (range: 16-84, standard deviation: 12.18). Univariate analysis indicated that females exhibited a higher susceptibility to preoperative endocrine dysfunction (p < 0.05). Conversely, males, patients with larger tumor volumes, and older patients were more prone to preoperative pituitary insufficiency. Postoperatively, the most substantial remission rate occurred in prolactin (77.4%), followed by growth hormone (GH) (71.8%) and cortisol (4/6). The highest recovery rate in functions was observed in growth hormone secretion function (80%), followed by pituitary-adrenal axis hormone secretion function (56.3%) and pituitary-thyroid axis hormone secretion function (47.5%). The most noteworthy incidence of newly developed postoperative endocrine deficiencies was found in the pituitary-adrenal axis (31.8%), while the occurrence rates of deficiencies in other axes were relatively low. The elevated postoperative remission rate of growth hormone correlated with a higher surgical resection rate and lower preoperative growth hormone levels. Additionally, lower preoperative prolactin levels corresponded to a higher remission rate of prolactin postoperatively. Furthermore, the restoration of postoperative thyroid hormone secretion function was associated with higher preoperative free thyroxine levels. Reduced postoperative cortisol secretion function was linked to multiple surgeries and an extended interval between hormone retesting and surgery.
CONCLUSION
Surgical intervention effectively ameliorates endocrine disorders in pituitary adenoma patients, thereby mitigating symptoms and enhancing their quality of life. Preoperative management of growth hormone and prolactin levels facilitates an increased remission rate of these hormones post pituitary adenoma surgery. Patients displaying preoperative thyroid hormone secretion dysfunction should be considered for active supplementation therapy. Whenever feasible, complete tumor resection is recommended. For patients undergoing reoperation or multiple surgeries, vigilant postoperative cortisol monitoring and supplementation should be thoughtfully administered.
Topics: Male; Female; Humans; Middle Aged; Pituitary Neoplasms; Retrospective Studies; Prolactin; Hydrocortisone; Quality of Life; Adenoma; Growth Hormone; Human Growth Hormone; Thyroid Hormones
PubMed: 37964947
DOI: 10.3389/fendo.2023.1286020 -
Molecular and Cellular Endocrinology Mar 2018In anterior pituitary endocrine cells, large (BK), small (SK) and intermediate (IK) conductance calcium activated potassium channels are key determinants in shaping... (Review)
Review
In anterior pituitary endocrine cells, large (BK), small (SK) and intermediate (IK) conductance calcium activated potassium channels are key determinants in shaping cellular excitability in a cell type- and context-specific manner. Indeed, these channels are targeted by multiple signaling pathways that stimulate or inhibit cellular excitability. BK channels can, paradoxically, both promote electrical bursting as well as terminate bursting and spiking dependent upon intrinsic BK channel properties and proximity to voltage gated calcium channels in somatotrophs, lactotrophs and corticotrophs. In contrast, SK channels are predominantly activated by calcium released from intracellular IP3-sensitive calcium stores and mediate membrane hyperpolarization in cells including gonadotrophs and corticotrophs. IK channels are predominantly expressed in corticotrophs where they limit membrane excitability. A major challenge for the future is to determine the cell-type specific molecular composition of calcium-activated potassium channels and how they control anterior pituitary hormone secretion as well as other calcium-dependent processes.
Topics: Animals; Hormones; Humans; Large-Conductance Calcium-Activated Potassium Channels; Models, Biological; Pituitary Hormones, Anterior; Sex Characteristics
PubMed: 28596131
DOI: 10.1016/j.mce.2017.06.003 -
Frontiers of Hormone Research 2016The presence of large numbers and/or the high affinity of dopamine D2 and/or somatostatin receptors on pituitary adenomas may enable their visualization with... (Review)
Review
The presence of large numbers and/or the high affinity of dopamine D2 and/or somatostatin receptors on pituitary adenomas may enable their visualization with radionuclide-coupled receptor agonists or antagonists. However, the role of these imaging modalities in the differential diagnosis of or therapeutic purposes for pituitary lesions is very limited. Only in very specific cases might these molecular imaging techniques become helpful. These include the differential diagnosis of pituitary lesions, ectopic production of pituitary hormones, such as adrenocorticotrophic hormone, growth hormone (GH) or their releasing hormones (corticotropin-releasing hormone and GH-releasing hormone), and the localization of metastases from pituitary carcinomas.
Topics: Humans; Molecular Imaging; Pituitary Diseases; Pituitary Hormones
PubMed: 27002335
DOI: 10.1159/000442329 -
Mayo Clinic Proceedings Oct 2022To perform a population-based study of pituitary adenoma epidemiology, including longitudinal trends in disease incidence, treatment patterns, and outcomes.
OBJECTIVE
To perform a population-based study of pituitary adenoma epidemiology, including longitudinal trends in disease incidence, treatment patterns, and outcomes.
PATIENTS AND METHODS
In this study of incident pituitary adenomas in Olmsted County, Minnesota, from January 1, 1989, through December 31, 2019, we identified 785 patients who underwent primary screening, 435 of whom were confirmed as harboring incident pituitary adenomas and were included. Primary outcomes of interest included demographic characteristics, presenting features, and disease outcomes (tumor control, biochemical control, and complications).
RESULTS
Among our 435 study patients, 438 unique pituitary adenomas were diagnosed at a median patient age of 39 years (interquartile range [IQR], 27 to 58 years). Adenomas were incidentally identified in 164 of the 438 tumors (37%). Common symptomatic presentations included hyperprolactinemia (188 of 438 [43%]) and visual field deficit (47 of 438 [11%]). Laboratory tests confirmed pituitary hormone hypersecretion in 238 of the 435 patients (55%), which was symptomatic in 222. The median tumor diameter was 8 mm (IQR, 5 to 17 mm). Primary management strategies were observation (156 of 438 tumors [36%]), medication (162 of 438 tumors [37%]), and transsphenoidal resection (120 of 438 tumors [27%]). Tumor and biochemical control were achieved in 398 (95%) and 216 (91%) secreting tumors, respectively. New posttreatment pituitary or visual deficits were noted in 43 (11%) and 8 (2%); apoplexy occurred in 28 (6%). Median clinical follow-up was 98 months (IQR, 47 to 189 months). Standardized incidence rates were 3.77 to 16.87 per 100,000 population, demonstrating linear expansion over time (R=0.67). The mean overall standardized incidence rate was 10.1 per 100,000 population; final point prevalence was 175.1 per 100,000 population.
CONCLUSION
Pituitary adenoma is a highly incident disease, with prolactin-secreting and incidental lesions representing the majority of tumors. Incidence rates and asymptomatic detection appear to be increasing over time. Presenting symptoms and treatment pathways are variable; however, most patients achieve favorable outcomes with observation or a single treatment modality.
Topics: Adenoma; Adult; Humans; Incidence; Middle Aged; Pituitary Hormones; Pituitary Neoplasms; Prolactin; Retrospective Studies; Treatment Outcome
PubMed: 35753823
DOI: 10.1016/j.mayocp.2022.03.017 -
Molecular and Cellular Endocrinology Dec 2017As one of the most basal living vertebrates, lampreys represent an excellent model system to study the evolution of thyroid hormone (TH) signaling. The lamprey... (Review)
Review
As one of the most basal living vertebrates, lampreys represent an excellent model system to study the evolution of thyroid hormone (TH) signaling. The lamprey hypothalamic-pituitary-thyroid and reproductive axes overlap functionally. Lampreys have 3 gonadotropin-releasing hormones and a single glycoprotein hormone from the hypothalamus and pituitary, respectively, that regulate both the reproductive and thyroid axes. TH synthesis in larval lampreys takes place in an endostyle that transforms into typical vertebrate thyroid tissue during metamorphosis; both the endostyle and follicular tissue have all the typical TH synthetic components found in other vertebrates. Furthermore, lampreys also have the vertebrate suite of peripheral regulators including TH distributor proteins (THDPs), deiodinases and TH receptors (TRs). Although at the molecular level the components of the lamprey thyroid system are ancestral to other vertebrates, their functions have been largely conserved. TH signaling as it relates to lamprey metamorphosis represents a particularly interesting phenomenon. Unlike other metamorphosing vertebrates, lamprey THs increase throughout the larval period, peak prior to metamorphosis and decline rapidly at the onset of metamorphosis; patterns of deiodinase activity are consistent with these increases and declines. Moreover, goitrogens (which suppress TH levels) initiate precocious metamorphosis, and exogenous TH treatment blocks goitrogen-induced metamorphosis and disrupts natural metamorphosis. Despite this clear physiological difference, TH action via TRs is consistent with higher vertebrates. Based on observations that TRs are upregulated in a tissue-specific fashion during morphogenesis and the finding that lamprey TRs upregulate genes via THs in a fashion similar to higher vertebrates, we propose the following hypothesis for further testing. THs have a dual role in lampreys where high TH levels promote larval feeding and growth and then at the onset of metamorphosis TH levels decrease rapidly; at this time the relatively low TH levels function via TRs in a fashion similar to that of other metamorphosing vertebrates.
Topics: Animals; Feeding Behavior; Gene Expression Regulation, Developmental; Hypothalamus; Iodide Peroxidase; Lampreys; Larva; Metamorphosis, Biological; Neurosecretory Systems; Pituitary Gland; Pituitary Hormones; Receptors, Thyroid Hormone; Reproduction; Signal Transduction; Thyroid Gland; Thyroid Hormones
PubMed: 28630022
DOI: 10.1016/j.mce.2017.06.015 -
Molecular and Cellular Endocrinology Dec 2017This mini review summarizes the current knowledge of the hypothalamic-pituitary-thyroid (HPT) endocrine system in lampreys, jawless vertebrates. Lampreys and hagfish are... (Review)
Review
This mini review summarizes the current knowledge of the hypothalamic-pituitary-thyroid (HPT) endocrine system in lampreys, jawless vertebrates. Lampreys and hagfish are the only two extant members of the class of agnathans, the oldest lineage of vertebrates. The high conservation of the hypothalamic-pituitary-gonadal (HPG) axis in lampreys makes the lamprey model highly appropriate for comparative and evolutionary analyses. However, there are still many unknown questions concerning the hypothalamic-pituitary (HP) axis in its regulation of thyroid activities in lampreys. As an example, the hypothalamic and pituitary hormone(s) that regulate the HPT axis have not been confirmed and/or characterized. Similar to gnathostomes (jawed vertebrates), lampreys produce thyroxine (T4) and triiodothyronine (T3) from thyroid follicles that are suggested to be involved in larval development, metamorphosis, and reproduction. The existing data provide evidence of a primitive, overlapping yet functional HPG and HPT endocrine system in lamprey. We hypothesize that lampreys are in an evolutionary intermediate stage of hypothalamic-pituitary development, leading to the emergence of the highly specialized HPG and HPT endocrine axes in jawed vertebrates. Study of the ancient lineage of jawless vertebrates, the agnathans, is key to understanding the origins of the neuroendocrine system in vertebrates.
Topics: Animals; Biological Evolution; Gene Expression Regulation; Hypothalamus; Lampreys; Metamorphosis, Biological; Neurosecretory Systems; Phylogeny; Pituitary Gland; Pituitary Hormones; Reproduction; Signal Transduction; Thyroid Epithelial Cells; Thyroxine; Triiodothyronine
PubMed: 28412521
DOI: 10.1016/j.mce.2017.04.012 -
Cells Dec 2023Corticotropin-releasing hormone (CRH) is known for its crucial role in the stress response system, which could induce pituitary adrenocorticotropic hormone (ACTH)...
Corticotropin-releasing hormone (CRH) is known for its crucial role in the stress response system, which could induce pituitary adrenocorticotropic hormone (ACTH) secretion to promote glucocorticoid release in the adrenal gland. However, little is known about other pituitary actions of CRH in teleosts. Somatolactin is a fish-specific hormone released from the neurointermediate lobe (NIL) of the posterior pituitary. A previous study has reported that ACTH was also located in the pituitary NIL region. Interestingly, our present study found that CRH could significantly induce two somatolactin isoforms' (SLα and SLβ) secretion and synthesis in primary cultured grass carp pituitary cells. Pharmacological analysis further demonstrated that CRH-induced pituitary somatolactin expression was mediated by the AC/cAMP/PKA, PLC/IP3/PKC, and Ca/CaM/CaMK-II pathways. Finally, transcriptomic analysis showed that both SLα and SLβ should play an important role in the regulation of lipid metabolism in primary cultured hepatocytes. These results indicate that CRH is a novel stimulator of somatolactins in teleost pituitary cells, and somatolactins may participate in the stress response by regulating energy metabolism.
Topics: Animals; Corticotropin-Releasing Hormone; Pituitary Hormones; Signal Transduction; Fish Proteins; Glycoproteins; Adrenocorticotropic Hormone
PubMed: 38132090
DOI: 10.3390/cells12242770