The Pituitary Gland: Embryology, Physiology, and Pathophysiology

2000 ◽  
Vol 19 (2) ◽  
pp. 9-17 ◽  
Author(s):  
Angela Dorton
Keyword(s):  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Pituitary Hormones ◽  
Thyroid Stimulating Hormone ◽  
The Body ◽  
Pars Intermedia ◽  
Pituitary Hormone ◽  
Pars Tuberalis ◽  
Pars Distalis ◽  
Stimulating Hormone

The pituitary gland, the “master gland” of the body, is composed of endocrine cells, which secrete hormones essential for homeostasis. The gland consists of the adenohypophysis (anterior pituitary) and the neurohypophysis (posterior pituitary), two unique structures that differ anatomically and functionally.The neurohypophysis is innervated by nerve cells in the hypothalamus and forms the connection between it and the pituitary gland. The hypothalamus stimulates release and inhibition of pituitary hormones. The neurohypophysis secretes oxytocin and antidiuretic hormone.The adenohypophysis is composed of three structures: the pars distalis, the pars intermedia, and the pars tuberalis. The anterior pituitary (pars distalis) is responsible for the release of hormones that include growth hormone, prolactin, thyroid-stimulating hormone, follicle-stimulating hormone, luteinizing hormone, adrenocorticotropic hormone, and melanocyte-stimulating hormone.Disorders of the pituitary are predominately those of insufficient hormone release and may have profound effects on the neonate. The potential causes of and clinical symptomatology that may accompany pituitary hormone insufficiency in the neonatal period are explored.

scholarly journals In situ hybridization analysis of anterior pituitary hormone gene expression during fetal mouse development.

1994 ◽  
Vol 42 (8) ◽  
pp. 1117-1125 ◽  
Author(s):  
M A Japón ◽  
M Rubinstein ◽  
M J Low
Keyword(s):  
Gene Expression ◽  
Anterior Pituitary ◽  
Beta Subunit ◽  
Pars Intermedia ◽  
Pituitary Hormone ◽  
Pars Distalis ◽  
Mouse Development ◽  
Glycoprotein Hormone ◽  
Anterior Pituitary Hormone ◽  
Stimulating Hormone

We used 35S-labeled oligonucleotides and cRNAs (riboprobes) to detect the temporal order and spatial pattern of anterior pituitary hormone gene expression in (B6CBF1 x B6CBF1)F2 fetal mice from embryonic Day 9.5 (E9.5) to postnatal Day 1 (P1). Pro-opiomelanocortin (POMC) mRNA was expressed in the basal diencephalon on Day E10.5, in the ventromedial zone of the pars distalis on Day E12.5, and in the pars intermedia on Day E14.5. The common alpha-glycoprotein subunit (alpha-GSU) mRNA first appeared in the anterior wall of Rathke's pouch on Day E11.5 and extended to the pars tuberalis and ventromedial zone of the pars distalis on Day E12.5. Thyroid-stimulating hormone-beta (TSH beta) subunit mRNA was expressed initially in both the pas tuberalis and ventromedial pars distalis on Day E14.5, with an identical spatial distribution to alpha-GSU at the time. In contrast, luteinizing hormone-beta (LH beta) subunit and follicle-stimulating hormone beta (FSH beta) subunit mRNAs were detected initially only in the ventromedial pars distalis on Days E16.5 and E17.5, respectively, in an identical distribution to each other. POMC-, alpha-GSU-, TSH beta, LH beta-, and FSH beta-positive cells within the pars distalis all increased in number and autoradiographic signal with differing degrees of spatial expansion posteriorly, laterally, and dorsally up to Day P1. POMC expression was typically the most intense and extended circumferentially to include the entire lateral and dorsal surfaces of the pars distalis. The expression of both growth hormone (GH) and prolactin (PRL) started coincidentally on Day E15.5. However PRL cells localized in the ventromedial area similarly to POMC and the glycoprotein hormone subunits, whereas GH cells were found initially in a more lateral and central distribution within the lobes of the pars distalis. Somatotrophs increased dramatically in number and autoradiographic signal, extending throughout the pars distalis except for the most peripheral layer of cells on Day E17.5. Mammotrophs also increased in number but less abundantly than somatotrophs, and PRL expression remained more confined to central-medial and ventrolateral areas of the pars distalis up to Day P1. These data demonstrate distinctive patterns of expression for each of the major anterior pituitary hormone genes during development of the mouse pituitary gland and suggest that different groups of committed cells are the immediate precursors to the terminally differentiated hormone-secreting cell types.

The pituitary and hypopituitarism

2020 ◽  
pp. 83-120
Author(s):  
Gary Butler ◽  
Jeremy Kirk
Keyword(s):  
Anterior Pituitary ◽  
Pituitary Hormones ◽  
Thyroid Stimulating Hormone ◽  
Hormone Deficiency ◽  
Pituitary Hormone ◽  
Sexual Characteristics ◽  
Biochemical Assessment ◽  
Cranial Diabetes Insipidus ◽  
Clinical Problems ◽  
Stimulating Hormone

• The pituitary is formed of two anatomically and embryologically distinct lobes: ◦ anterior pituitary: which secretes growth hormone (GH), gonadotropins (luteinizing hormone (LH) and follicle-stimulating hormone (FSH)), adrenocorticotropic hormone (ACTH), thyroid-stimulating hormone (TSH), and prolactin ◦ posterior pituitary: which secretes vasopressin and oxytocin. • Hypopituitarism is deficiency of one or more pituitary hormones. Some hormones, e.g. GH (LH/FSH), are more likely to present with isolated deficiencies, while others, e.g. TSH, ACTH, are more often found as part of multiple pituitary hormone deficiency (MPHD). • Deficiencies may be congenital (including genetic) or acquired; secondary to tumour, trauma, infiltration, infection, or irradiation. • GH deficiency: ◦ diagnosed using a combination of clinical, radiological, and biochemical assessment (including GH stimulation testing) ◦ treatment is with GH (including if necessary into adulthood). • LH/FSH deficiency: ◦ If acquired, often one of the first anterior pituitary hormones to be lost. ◦ Congenital forms: ■ present with cryptorchidism and/or micropenis in males ■ may occur in isolation, or in association with anosmia (Kallmann and CHARGE syndromes). ◦ Treatment: sex steroid therapy to induce secondary sexual characteristics, and recombinant FSH/LH to induce fertility potential. • ACTH deficiency: ◦ Unlike primary adrenal problems, hyperpigmentation does not occur. ◦ Although mineralocorticoid production is preserved, hyponatraemia may still occur. ◦ Treatment is with hydrocortisone. • TSH deficiency: ◦ TSH may be low, normal, or raised (but inappropriate for free thyroxine level). ◦ Treatment is with thyroxine. • Vasopressin deficiency: ◦ produces cranial diabetes insipidus ◦ treatment is with DDAVP (orally or nasally). • Prolactin and oxytocin deficiency rarely produce clinical problems.

scholarly journals BODY IMMUNOPROPHYLAXIS OF PREGNANT AND NEWLY-CALVED COWS

REPORTS ◽  
2021 ◽  
Vol 335 (1) ◽  
pp. 39-46
Author(s):  
V.G. Semenov ◽  
V.G. Tyurin ◽  
D.A. Baimukanov ◽  
E.P. Simurzina ◽  
S.G. Kondruchina ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Thyroid Stimulating Hormone ◽  
Anterior Pituitary Gland ◽  
The Body ◽  
Macrophage Receptors ◽  
Service Period ◽  
New Generation ◽  
Opening Up ◽  
Stimulating Hormone

The research was performed to identify the most effective bio immunostimulant. We used PS-2 and Prevention-N-E biologicals developed on the basis of the Chuvash State Agrarian University, as well as widely used in veterinary practice - PDE and E-selenium. Injection of PS-2 and Prevention-NE preparations to dry cows at a dose of 10.0 ml three times 45-40, 25-20 and 15-10 days before calving, as well as PDE and E-selenium at a dose of 20.0 and 10.0 ml 20 days before calving, respectively, prevents postpartum diseases. The mechanism of action of the PS-2 and Prevention-N-E drugs developed and tested by us is manifested, first of all, due to the consecutive processes of macrophage activation, as a result of the action of polysaccharide corpuscles and drug components on macrophage receptors. Secondly, information from the receptors of macrophages and chemoreceptors is transmitted along the afferent pathway to the cerebral cortex, then the signals go to the hypothalamus, which leads to liberin secretion by the nuclei of the ashen tuber of the hypothalamus. Liberins, in turn, increase the release of hormones by the anterior pituitary gland - the adenohypophysis. The anterior pituitary gland releases tropic hormones: somatotropic hormone, adrenocorticotropic hormone, thyroid-stimulating hormone, follicle-stimulating hormone, etc. These hormones are involved in metabolic processes in the body. Under the influence of preparations, in cows the time of membranes sweep was reduced, the risk of uterus subinvolution and endometritis decreased. In cows, the timing of the onset of estrus, the insemination rate, and the service period were shortened, and the conception rate increased in one estrus. In such a way, against the background of the use of biologicals with the help of nonspecific adaptive reactions, the body retains the relative constancy of the internal environment necessary for life - homeostasis, and it actively resists the adverse effects of the external environment, increasing its phylactic power. Consequently, new opportunities are opening up for the implementation of the reproductive and productive qualities of cattle due to the body immunoprophylaxis with complex biological products of a new generation.

Posttraumatic Anterior Hypopituitarism—Revisited: The Role of TRH Provocative Release of Prolactin in the Confirmation of Anterior Pituitary Damage

PEDIATRICS ◽  
1977 ◽  
Vol 59 (6) ◽  
pp. 948-950
Author(s):  
David R. Brown ◽  
J. Michael McMillin
Keyword(s):  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Thyroid Stimulating Hormone ◽  
Anterior Pituitary Gland ◽  
Serum Prolactin ◽  
Pituitary Insufficiency ◽  
Closed Head Trauma ◽  
One Year ◽  
Stimulating Hormone

We have previously reported a case of anterior pituitary insufficiency in a 14-year-old girl following closed head trauma.1 Endocrine evaluation one year after her accident revealed hypopituitarism manifested by cachexia, hypothyroidism, hypogonadism, and hypoadrenocorticism. Laboratory studies demonstrated deficiencies of adrenocorticotropic hormone, thyroid-stimulating hormone (TSH), growth hormone, and gonadotropic hormones (follicle-stimulating hormone and luteinizing hormone). We postulated that her hypopituitarism was due to anterior pituitary gland destruction rather than stalk section or hypothalamic damage. We have recently measured her serum prolactin concentrations following provocative stimulation with thyrotropin-releasing hormone (TRH), and these results strengthen the evidence for direct anterior pituitary gland destruction and provide a more complete delineation of her endocrinologic function.

scholarly journals OR16-05 Single-Cell Sequencing Identifies Novel Regulators of Thyrotrope Populations and POU1F1-Independent Thyroid-Stimulating Hormone Expression

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Leonard Cheung ◽  
Alexandre Daly ◽  
Michelle Brinkmeier ◽  
Sally Ann Camper
Keyword(s):  
Transcription Factor ◽  
Single Cell ◽  
Molecular Mechanisms ◽  
Thyroid Stimulating Hormone ◽  
Pars Tuberalis ◽  
Pituitary Cells ◽  
Pars Distalis ◽  
Mouse Development ◽  
Single Cell Sequencing ◽  
Stimulating Hormone

Abstract We implemented single-cell RNA sequencing (scRNAseq) technology as a discovery tool to identify factors enriched in differentiated thyrotropes. Thyroid-stimulating hormone (TSH) is produced in the pars distalis of the anterior pituitary (AP) and primarily acts on the thyroid gland to regulate metabolism through T3/T4. However, TSH is also produced by cells in the pars tuberalis (PT), which is comprised of a thin layer of cells that extends rostrally from the pars distalis along the pituitary stalk to the median eminence in the hypothalamus. TSH produced by PT thyrotropes acts on hypothalamic tanycytes to regulate seasonal reproduction. PT thyrotropes likely descend from rostral tip thyrotropes that arise at e12.5 of mouse development, which transcribe the TSH beta subunit (Tshb) without detectable expression of the transcription factor POU1F1. POU1F1 is required for Tshb transcription in thyrotropes of the adenohypophysis, and it acts synergistically with GATA2 to drive cell fate. The molecular mechanisms driving Tshb expression independently of Pou1f1 in PT thyrotropes are unclear. Thyrotropes are the least abundant endocrine cell-type in the pituitary gland. We used genetic labeling and fluorescence-activated cell sorting (FACS) to enrich for thyrotropes for single-cell sequencing. We performed scRNAseq on 7-day-old GFP-positive pituitary cells from Tshb-Cre; R26-LSL-eYFP and intact whole pituitaries, recovering more than 15,000 cells altogether. We observe two distinct populations of cells expressing Tshb. The larger thyrotrope population has approximately twenty fold higher levels of Tshb and five fold higher Cga transcripts than the smaller population, and they are also distinguished by expression of Pou1f1, TSH-releasing hormone receptor (Trhr), and deiodinase 2 (Dio2), consistent with expectations for AP thyrotropes. The smaller thyrotrope population does not express Pou1f1, but those cells are characterized by expression of TSH receptor (Tshr) and melatonin receptor 1A (Mtnr1a), consistent with expectations for PT thyrotropes. They express mildly increased levels of Eya3 and Six1, although these genes are expressed in other cell-types including AP thyrotropes, stem cells, and gonadotropes. They have two-fold higher levels of Gata2 transcripts and uniquely express the transcription factor Sox14. SOX14 is a SoxB2 family transcription factor that counteracts the transcriptional activity of SoxB1 family members, such as Sox2. In conclusion, our scRNAseq has identified novel markers of PT thyrotropes and unveils novel insights into the similarities and differences in the development and function of pituitary thyrotrope subpopulations.

scholarly journals Machine-Learning Prediction of Postoperative Pituitary Hormonal Outcomes in Nonfunctioning Pituitary Adenomas: A Multicenter Study

2021 ◽  
Vol 12 ◽  
Author(s):  
Yi Fang ◽  
He Wang ◽  
Ming Feng ◽  
Wentai Zhang ◽  
Lei Cao ◽  
...  
Keyword(s):  
Machine Learning ◽  
Anterior Pituitary ◽  
Characteristic Curve ◽  
Pituitary Hormones ◽  
Thyroid Stimulating Hormone ◽  
Subtotal Resection ◽  
Logistic Regression Models ◽  
Anterior Pituitary Hormones ◽  
Prognostic Assessment ◽  
Stimulating Hormone

ObjectiveNo accurate predictive models were identified for hormonal prognosis in non-functioning pituitary adenoma (NFPA). This study aimed to develop machine learning (ML) models to facilitate the prognostic assessment of pituitary hormonal outcomes after surgery.MethodsA total of 215 male patients with NFPA, who underwent surgery in four medical centers from 2015 to 2021, were retrospectively reviewed. The data were pooled after heterogeneity assessment, and they were randomly divided into training and testing sets (172:43). Six ML models and logistic regression models were developed using six anterior pituitary hormones.ResultsOnly thyroid-stimulating hormone (p < 0.001), follicle-stimulating hormone (p < 0.001), and prolactin (PRL; p < 0.001) decreased significantly following surgery, whereas growth hormone (GH) (p < 0.001) increased significantly. The postoperative GH (p = 0.07) levels were slightly higher in patients with gross total resection, but the PRL (p = 0.03) level was significantly lower than that in patients with subtotal resection. The optimal model achieved area-under-the-receiver-operating-characteristic-curve values of 0.82, 0.74, and 0.85 in predicting hormonal hypofunction, new deficiency, and hormonal recovery following surgery, respectively. According to feature importance analyses, the preoperative levels of the same type and other hormones were all important in predicting postoperative individual hormonal hypofunction.ConclusionFluctuation in anterior pituitary hormones varies with increases and decreases because of transsphenoidal surgery. The ML models could accurately predict postoperative pituitary outcomes based on preoperative anterior pituitary hormones in NFPA.

scholarly journals Molecular economy of nature with two thyrotropins from different parts of the pituitary: pars tuberalis thyroid-stimulating hormone and pars distalis thyroid-stimulating hormone

2021 ◽  
Vol 17 (1) ◽  
pp. 189-195
Author(s):  
Sibel Ertek
Keyword(s):  
Pineal Gland ◽  
Light Stimulus ◽  
Peripheral Circulation ◽  
Thyroid Stimulating Hormone ◽  
Breeding Period ◽  
Pars Tuberalis ◽  
Pars Distalis ◽  
Subunit Expression ◽  
The Brain ◽  
Stimulating Hormone

Thyrotropin (TSH) is classically known to be regulated by negative feedback from thyroid hormones and stimulated by thyrotropin-releasing hormone (TRH) from the hypothalamus. At the end of the 1990s, studies showed that thyrotroph cells from the pars tuberalis (PT) did not have TRH receptors and their TSH regulation was independent from TRH stimulation. Instead, PT-thyrotroph cells were shown to have melatonin-1 (MT-1) receptors and melatonin secretion from the pineal gland stimulates TSH- subunit formation in PT. Electron microscopy examinations also revealed some important differences between PT and pars distalis (PD) thyrotrophs. PT-TSH also have low bioactivity in the peripheral circulation. Studies showed that they have different glycosylations and PT-TSH forms macro-TSH complexes in the periphery and has a longer half-life. Photoperiodism affects LH levels in animals via decreased melatonin causing increased TSH- subunit expression and induction of deiodinase-2 (DIO-2) in the brain. Mammals need a light stimulus carried into the suprachiasmatic nucleus (which is a circadian clock) and then transferred to the pineal gland to synthesize melatonin, but birds have deep brain receptors and they are stimulated directly by light stimuli to have increased PT-TSH, without the need for melatonin. Photoperiodic regulations via TSH and DIO 2/3 also have a role in appetite, seasonal immune regulation, food intake and nest-making behaviour in animals. Since humans have no clear seasonal breeding period, such studies as recent ‘’domestication locus’’ studies in poultry are interesting. PT-TSH that works like a neurotransmitter in the brain may become an important target for future studies about humans.

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