Evaluation and Investigation of Pituitary Disease
R James A England, Eamon Shamil, Rajeev Mathew, Manohar Bance, Pavol Surda, Jemy Jose, Omar Hilmi, Adam J Donne in Scott-Brown's Essential Otorhinolaryngology, 2022
The pituitary gland sits within the sella turcica of the sphenoid bone, inferior to the hypothalamus and optic chiasm. It is surgically accessible transnasally via the sphenoid sinus. The gland is composed of two lobes. The anterior pituitary (adenohypophysis) secretes luteinising hormone (LH), follicle-stimulating hormone (FSH), growth hormone (GH), adrenocorticotropic hormone (ACTH), thyroid-stimulating hormone (TSH), and prolactin. The posterior pituitary (neurohypophysis) is not a gland in itself, but a projection of the hypothalamus, and it releases antidiuretic hormone (ADH) and oxytocin. It is connected to the hypothalamus above by the pituitary stalk (infundibulum), which passes through the diaphragm that forms the roof of the sella. The function of the anterior pituitary is controlled chiefly by hypothalamic hormonal control; the hypothalamic-pituitary-peripheral axis is regulated by multiple feedback loops.
The endocrine system
Laurie K. McCorry, Martin M. Zdanowicz, Cynthia Y. Gonnella in Essentials of Human Physiology and Pathophysiology for Pharmacy and Allied Health, 2019
The release of GH from the adenohypophysis is regulated by two hypothalamic hormones, growth hormone-releasing hormone (GHRH) and growth hormone-inhibiting hormone (GHIH, somatostatin). Any factor or condition that enhances the secretion of GH could do so by stimulating GHRH release or by inhibiting GHIH release. The secretion of GH follows a diurnal rhythm with GH levels low and constant throughout the day and with a marked burst of GH secretion approximately 1 hour following the onset of sleep (deep or stages III and IV sleep). Other factors that stimulate GH secretion include exercise, stress, trauma, hypoglycemia and starvation, especially with severe protein deficiency. Factors that inhibit GH secretion include hyperglycemia and aging. In most individuals, the production of GH decreases after 30 years of age and falls to about 25% of the adolescent level in very old age. This decrease in GH production is likely a critical factor in the loss of lean muscle mass at a rate of 5% per decade and the gain of body fat at the same rate after 40 years of age.
The Pituitary Gland Eva Nagy
Istvan Berczi in Pituitary Function and Immunity, 2019
The pituitary gland is located in the base of the skull in the sella turcica, a cavity within the sphenoid bone, and is attached to the hypothalamus with a stalk. The pituitary is a small organ; it weighs about 0.5 g in man and it may approach 1 g in weight during pregnancy. We distinguish the anterior lobe of pituitary that is also called adenohypophysis, and the posterior lobe, or neurohypophysis, and an intermediate portion or pars intermedia. The anterior lobe amounts to approximately 75% of the total weight of the gland. The pars intermedia is missing or is present in traces (2%) in man. The pituitary gland is embryologically derived from cells of both stomodeal ectoderm (Rathke’s pouch) and neural ectoderm of the floor of the forebrain.5 By the 12th week of intrauterine life, the pituitary is identifiable macroscopically, secretory granules appear in the cytoplasm of adenohypophyseal cells, and pituitary hormones can be detected by radioimmunoassay.
Growth hormone improved oxidative stress in follicle fluid by influencing Nrf2/Keap1 expression in women of advanced age undergoing IVF
Published in Gynecological Endocrinology, 2022
Zhaoyan Nie, Na Zhang, Lina Guo, Cuiting Lv, Yi Zhang, Congmin Wang, Haifeng Wu
Growth Hormone (GH), secreted by adenohypophysis cells, has attracted significant attention due to the possibility that GH might enhance fertility. GH binds to the GH receptor (GHR), which augments the effects of gonadotropin (Gn) on GCs and thecal cells and improves follicle development [5]. For this reason, GH has been widely applied to treat pathologies associated with OS. GH exerted beneficial effects by enhancing antioxidant defenses and reducing oxidative stress in myocardial cells in rats [6]. GH acts as an antioxidant that contributes to ovarian health [7]. GH showed a radioprotective effect and rescued the ovarian reserve by counteracting oxidative stress-mediated apoptosis [8]. GH protects against GC apoptosis by alleviating oxidative stress and enhancing mitochondrial function [9]. In poor ovarian responders, GH alleviates OS and improves the IVF outcome [10]. Studies have shown that GH administration improves oocyte quality and IVF outcome in older women and/or patients with poor ovarian response [11]. GH supplementation may improve the pregnancy rate and endometrial receptivity in women aged more than 40 years undergoing IVF-ET [12]. However, the mechanisms by which GH improves IVF outcomes in advanced age have not yet been clarified.
Prevalence and risk factors of hyperprolactinemia among patients with various psychiatric diagnoses and medications
Published in International Journal of Psychiatry in Clinical Practice, 2018
Fahad D. Alosaimi, Ebtihaj O. Fallata, Mohammed Abalhassan, Abdulhadi Alhabbad, Nasser Alzain, Bandar Alhaddad, Mohammed Z. Alassiry
Prolactin is a polypeptide hormone secreted by the anterior pituitary gland to induce lactation and other reproductive functions (Halbreich, Kinon, Gilmore, & Kahn, 2003). Several endogenous substances have been found to affect the prolactin level, with dopamine inhibiting and serotonin stimulating its release (Voicu, Medvedovici, Ranetti, & Rădulescu, 2013). Additionally, physiological conditions (such as pregnancy, lactation and sleep), neurological diseases, hormonal disorders, systemic diseases and medications have been associated with elevated prolactin levels (Holt, 2008; Peuskens, Pani, Detraux, & De Hert, 2014). Hyperprolactinemia is defined as elevated prolactin levels above gender-specific normal levels, which have been variably defined in previous studies (Halbreich et al., 2003; Peuskens et al., 2014). Hyperprolactinemia can affect sexual and reproductive functions in both genders, and the clinical presentation generally depends on the magnitude of prolactin elevation (Serri, Chik, Ur, & Ezzat, 2003). Additionally, chronic hyperprolactinemia has been linked to an increased risk of osteoporosis and probably breast cancer (Kohen & Wildgust, 2008; Misra, Papakostas, & Klibanski, 2004).
Association between dopamine transporter gene (DAT1/SLC6A3) variants and infertility in the Turkish females
Published in Gynecological Endocrinology, 2022
Orcun Avsar, Nesibe Derinoz, Filiz Yilmaz, Musa Yilmaz, Umit Gorkem
Prolactin (PRL) which is primarily produced and secreted by the anterior pituitary gland is a peptide hormone and modulates various biological processes such as lactogenesis, immune response, reproductive behavior, angiogenesis, and osmoregulation [7]. Hyperprolactinemia (high amount of circulating PRL) impairs ovulation and may be one of the causes of infertility in females and males. The females with higher amount of prolactin during menstrual cycle have worse chance to conceive [8]. Tuberoinfundibular dopaminergic pathway regulates prolactin secretion negatively [9]. In this regard, disturbances in dopamine neurotransmission can lead to abnormal prolactin gene expression and secretion. Dopamine transporter (DAT) that is one of the key players of dopamine neurotransmission reuptakes dopamine from synaptic cleft into presynaptic dopaminergic neuron and terminates neurotransmission. Mutations in SLC6A3 gene that encodes dopamine transporter protein may be associated with various diseases [10].
Related Knowledge Centers
- Lactation
- Physiology
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- Endocrine System
- Posterior Pituitary
- Pituitary Gland
- Gland
- Development of The Human Body
- Reproduction
- Blood Test