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Corticotrope
Corticotropic cells, (corticotropes or corticotrophs) are basophilic cells in the anterior pituitary that produce pro-opiomelanocortin (POMC) which undergoes cleavage to adrenocorticotropin (ACTH), β-lipotropin (β-LPH), and melanocyte-stimulating hormone (MSH). These cells are stimulated by corticotropin releasing hormone (CRH) and make up 15–20% of the cells in the anterior pituitary. The release of ACTH from the corticotropic cells is controlled by CRH, which is formed in the cell bodies of parvocellular neurosecretory cells within the paraventricular nucleus of the hypothalamus and passes to the corticotropes in the anterior pituitary via the hypophyseal portal system. Adrenocorticotropin hormone stimulates the adrenal cortex to release glucocorticoids and plays an important role in the stress response. Function The primary function of the corticotropic cells is to produce the prohormone POMC in response to the release of CRH from the hypothalamus. POMC is cleaved in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anterior Pituitary
The anterior pituitary (also called the adenohypophysis or pars anterior) is a major Organ (anatomy), organ of the endocrine system. The anterior pituitary is the glandular, Anatomical terms of location#Usage in human anatomy, anterior lobe that together with the posterior pituitary (or neurohypophysis) makes up the pituitary gland (hypophysis) which, in humans, is located at the base of the Human brain, brain, protruding off the bottom of the hypothalamus. The anterior pituitary regulates several physiological processes, including stress (medicine), stress, Human development (biology), growth, reproduction, and lactation. Proper functioning of the anterior pituitary and of the organs it regulates can often be ascertained via blood tests that measure hormone levels. Structure The pituitary gland sits in a protective bony enclosure called the sella turcica (''Turkish chair/saddle''). It is composed of three lobes: the anterior, intermediate, and posterior lobes. In many animals, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corticotropin Releasing Hormone
Corticotropin-releasing hormone (CRH) (also known as corticotropin-releasing factor (CRF) or corticoliberin; corticotropin may also be spelled corticotrophin) is a peptide hormone involved in stress (biology), stress responses. It is a releasing hormone that belongs to corticotropin-releasing factor family. In humans, it is encoded by the ''CRH'' gene. Its main function is the stimulation of the pituitary synthesis of adrenocorticotropic hormone (ACTH), as part of the hypothalamic–pituitary–adrenal axis (HPA axis). Corticotropin-releasing hormone (CRH) is a 41-amino acid peptide derived from a 196-amino acid preprohormone. CRH is secreted by the paraventricular nucleus (PVN) of the hypothalamus in response to stress (biological), stress. Increased CRH production has been observed to be associated with Alzheimer's disease and major depression, and autosomal recessive hypothalamic corticotropin deficiency has multiple and potentially fatal metabolic consequences including hyp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anterior Pituitary
The anterior pituitary (also called the adenohypophysis or pars anterior) is a major Organ (anatomy), organ of the endocrine system. The anterior pituitary is the glandular, Anatomical terms of location#Usage in human anatomy, anterior lobe that together with the posterior pituitary (or neurohypophysis) makes up the pituitary gland (hypophysis) which, in humans, is located at the base of the Human brain, brain, protruding off the bottom of the hypothalamus. The anterior pituitary regulates several physiological processes, including stress (medicine), stress, Human development (biology), growth, reproduction, and lactation. Proper functioning of the anterior pituitary and of the organs it regulates can often be ascertained via blood tests that measure hormone levels. Structure The pituitary gland sits in a protective bony enclosure called the sella turcica (''Turkish chair/saddle''). It is composed of three lobes: the anterior, intermediate, and posterior lobes. In many animals, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pro-opiomelanocortin
Pro-opiomelanocortin (POMC) is a precursor polypeptide with 241 amino acid residues. POMC is Protein biosynthesis, synthesized in Corticotropic cell, corticotrophs of the anterior pituitary from the 267-amino-acid-long Precursor polypeptide, polypeptide precursor pre-pro-opiomelanocortin (pre-POMC), by the removal of a 26-amino-acid-long signal peptide sequence during translation (biology), translation. POMC is part of the central melanocortin system. Function POMC is cut (cleaved) to give rise to multiple peptide hormones. Each of these peptides is packaged in large dense-core vesicle (biology), vesicles that are released from the cells by exocytosis in response to appropriate stimulation: * Melanocyte-stimulating hormone, α-MSH produced by neurons in the ventromedial nucleus has important roles in the regulation of appetite (POMC neuron stimulation results in Hunger (motivational state), satiety.) and Human sexual activity, sexual behavior, while α-MSH secreted from the pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
POMC
Pro-opiomelanocortin (POMC) is a precursor polypeptide with 241 amino acid residues. POMC is synthesized in corticotrophs of the anterior pituitary from the 267-amino-acid-long polypeptide precursor pre-pro-opiomelanocortin (pre-POMC), by the removal of a 26-amino-acid-long signal peptide sequence during translation. POMC is part of the central melanocortin system. Function POMC is cut (cleaved) to give rise to multiple peptide hormones. Each of these peptides is packaged in large dense-core vesicles that are released from the cells by exocytosis in response to appropriate stimulation: * Melanocyte-stimulating hormone, α-MSH produced by neurons in the ventromedial nucleus has important roles in the regulation of appetite (POMC neuron stimulation results in Hunger (motivational state), satiety.) and Human sexual activity, sexual behavior, while α-MSH secreted from the pars intermedia, intermediate lobe of the pituitary regulates the movement of melanin produced from mela ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peptide Hormone
Peptide hormones are hormones composed of peptide molecules. These hormones influence the endocrine system of animals, including humans. Most hormones are classified as either amino-acid-based hormones (amines, peptides, or proteins) or steroid hormones. Amino-acid-based hormones are water-soluble and act on target cells via second messenger systems, whereas steroid hormones, being lipid-soluble, diffuse through plasma membranes to interact directly with intracellular receptors in the cell nucleus. Like all peptides, peptide hormones are synthesized in cell (biology), cells from amino acids based on Messenger RNA, mRNA transcripts, which are derived from DNA templates inside the cell nucleus. The initial precursors, known as preprohormones, undergo processing in the endoplasmic reticulum. This includes the removal of the N-terminal signal peptide and, in some cases, glycosylation, yielding prohormones. These prohormones are then packaged into secretory vesicle (biology), vesicles, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melanotroph
A melanotroph (or melanotrope) is a cell in the pituitary gland that generates melanocyte-stimulating hormone (α‐MSH) from its precursor pro-opiomelanocortin. Chronic stress can induce the secretion of α‐MSH in melanotrophs and lead to their subsequent degeneration. See also * Chromophobe cell * Chromophil :* Acidophil cell :* Basophil cell * Oxyphil cell :* Oxyphil cell (parathyroid) * Pituitary gland * Neuroendocrine cell * List of distinct cell types in the adult human body The list of human cell types provides an enumeration and description of the various specialized cells found within the human body, highlighting their distinct functions, characteristics, and contributions to overall physiological processes. Cell ... References Endocrine system {{Biochemistry-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arcuate Nucleus
The arcuate nucleus of the hypothalamus (ARH), or ARC, is also known as the infundibular nucleus to distinguish it from the arcuate nucleus of the medulla oblongata in the brainstem. The arcuate nucleus is an aggregation of neurons in the mediobasal hypothalamus, adjacent to the third ventricle and the median eminence. The arcuate nucleus includes several important and diverse populations of neurons that help mediate different neuroendocrine and physiological functions, including neuroendocrine neurons, centrally projecting neurons, and astrocytes. The populations of neurons found in the arcuate nucleus are based on the hormones they secrete or interact with and are responsible for hypothalamic function, such as regulating hormones released from the pituitary gland or secreting their own hormones. Neurons in this region are also responsible for integrating information and providing inputs to other nuclei in the hypothalamus or inputs to areas outside this region of the brain. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melanocyte
Melanocytes are melanin-producing neural-crest, neural crest-derived cell (biology), cells located in the bottom layer (the stratum basale) of the skin's epidermis (skin), epidermis, the middle layer of the eye (the uvea), the inner ear, vaginal epithelium, meninges, bones, and heart found in many mammals and birds. Melanin is a dark pigment primarily responsible for skin color. Once synthesized, melanin is contained in special organelles called melanosomes which can be transported to nearby keratinocytes to induce pigmentation. Thus darker skin tones have more melanosomes present than lighter skin tones. Functionally, melanin serves as protection against Ultraviolet, UV radiation. Melanocytes also have a role in the immune system. Function Through a process called melanogenesis, melanocytes produce melanin, which is a pigment found in the human skin, skin, human eye, eyes, hair, nasal cavity, and inner ear. This melanogenesis leads to a long-lasting pigmentation, which i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proprotein Convertase
Proprotein convertases (PPCs) are a family of proteins that activate other proteins. Many proteins are inactive when they are first synthesized, because they contain chains of amino acids that block their activity. Proprotein convertases remove those chains and activate the protein. The prototypical proprotein convertase is furin. Proprotein convertases have medical significance, because they are involved in many important biological processes, such as cholesterol synthesis. Compounds called proprotein convertase inhibitors can block their action, and block the target proteins from becoming active. Many proprotein convertases, especially furin and PACE4, are involved in pathological processes such as viral infection, inflammation, hypercholesterolemia, and cancer, and have been postulated as therapeutic targets for some of these diseases. History The phenomenon of prohormone conversion was discovered by Donald F. Steiner while examining the biosynthesis of insulin in 1967. At ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beta-lipotropin
Lipotropin is the name for two hormones produced by the cleavage of pro-opiomelanocortin (POMC). The anterior pituitary gland produces the pro-hormone POMC, which is then cleaved again to form adrenocorticotropin (ACTH) and β-lipotropin (β-LPH). β-Lipotropin β-Lipotropin is a 90-amino acid polypeptide Peptides are short chains of amino acids linked by peptide bonds. A polypeptide is a longer, continuous, unbranched peptide chain. Polypeptides that have a molecular mass of 10,000 Da or more are called proteins. Chains of fewer than twenty ... that is the C-terminus, carboxy-terminal fragment of POMC. It was initially reported to stimulate melanocytes to produce melanin. It was also reported to perform lipid-mobilizing functions such as lipolysis and steroidogenesis. However, no subsequent studies have been published that support these early findings and no receptor has been identified for β-lipotropin. β-Lipotropin can be cleaved into smaller peptides. In huma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
