IGF-1

インスリン様成長因子-I

WordNet

1. the 9th letter of the Roman alphabet (同)i

PrepTutorEJDIC

1. 『私は』私が
2. iodineの化学記号

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/01/19 18:11:47」(JST)

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Insulin-like growth factor 1 (somatomedin C)
PDB rendering based on 1bqt.
Available structures PDB Ortholog search: PDBe, RCSB List of PDB id codes 1B9G, 1BQT, 1GF1, 1GZR, 1GZY, 1GZZ, 1H02, 1H59, 1IMX, 1PMX, 1TGR, 1WQJ, 2DSP, 2DSQ, 2DSR, 2GF1, 3GF1, 3LRI
Identifiers
Symbols	IGF1 ; IGF-I; IGF1A; IGFI
External IDs	OMIM: 147440 MGI: 96432 HomoloGene: 515 GeneCards: IGF1 Gene
Gene ontology Molecular function • insulin receptor binding • insulin-like growth factor receptor binding • integrin binding • hormone activity • protein binding • growth factor activity Cellular component • extracellular region • extracellular space • plasma membrane • insulin-like growth factor binding protein complex • platelet alpha granule lumen Biological process • skeletal system development • cell activation • blood vessel remodeling • platelet degranulation • DNA replication • cellular component movement • signal transduction • Ras protein signal transduction • muscle organ development • blood coagulation • positive regulation of cell proliferation • negative regulation of cell proliferation • glycolate metabolic process • glial cell differentiation • positive regulation of cardiac muscle hypertrophy • positive regulation of phosphatidylinositol 3-kinase signaling • skeletal muscle satellite cell maintenance involved in skeletal muscle regeneration • muscle hypertrophy • myotube cell development • positive regulation of smooth muscle cell migration • positive regulation of cerebellar granule cell precursor proliferation • water homeostasis • proteoglycan biosynthetic process • platelet activation • mammary gland development • exocrine pancreas development • regulation of establishment or maintenance of cell polarity • positive regulation of protein import into nucleus, translocation • negative regulation of smooth muscle cell apoptotic process • multicellular organism growth • bone mineralization involved in bone maturation • regulation of multicellular organism growth • positive regulation of activated T cell proliferation • positive regulation of tyrosine phosphorylation of Stat5 protein • positive regulation of DNA binding • positive regulation of MAPK cascade • positive regulation of insulin-like growth factor receptor signaling pathway • cellular protein metabolic process • myoblast differentiation • positive regulation of osteoblast differentiation • positive regulation of glycogen biosynthetic process • positive regulation of DNA replication • positive regulation of glycolytic process • positive regulation of mitosis • positive regulation of transcription, DNA-templated • positive regulation of transcription from RNA polymerase II promoter • positive regulation of glucose import • positive regulation of Ras protein signal transduction • insulin-like growth factor receptor signaling pathway • phosphatidylinositol-mediated signaling • positive regulation of fibroblast proliferation • lung alveolus development • positive regulation of smooth muscle cell proliferation • branching morphogenesis of an epithelial tube • inner ear development • chondroitin sulfate proteoglycan biosynthetic process • positive regulation of epithelial cell proliferation • positive regulation of peptidyl-tyrosine phosphorylation • myoblast proliferation • positive regulation of protein kinase B signaling • lung vasculature development • lung lobe morphogenesis • Type I pneumocyte differentiation • Type II pneumocyte differentiation • prostate epithelial cord arborization involved in prostate glandular acinus morphogenesis • prostate gland growth • prostate gland stromal morphogenesis • negative regulation of androgen receptor signaling pathway • negative regulation of ERK1 and ERK2 cascade • positive regulation of calcineurin-NFAT signaling cascade • negative regulation of release of cytochrome c from mitochondria • extrinsic apoptotic signaling pathway in absence of ligand • positive regulation of myoblast proliferation • negative regulation of extrinsic apoptotic signaling pathway Sources: Amigo / QuickGO
RNA expression pattern
More reference expression data
Orthologs
Species	Human	Mouse
Entrez	3479	16000
Ensembl	ENSG00000017427	ENSMUSG00000020053
UniProt	P05019	P05017
RefSeq (mRNA)	NM_000618	NM_001111274
RefSeq (protein)	NP_000609	NP_001104744
Location (UCSC)	Chr 12: 102.79 – 102.87 Mb	Chr 10: 87.86 – 87.94 Mb
PubMed search	[1]	[2]

Insulin-like growth factor 1 (IGF-1), also called somatomedin C, is a protein that in humans is encoded by the IGF1 gene. IGF-1 has also been referred to as a "sulfation factor" and its effects were termed "nonsuppressible insulin-like activity" (NSILA) in the 1970s.

IGF-1 is a hormone similar in molecular structure to insulin. It plays an important role in childhood growth and continues to have anabolic effects in adults. A synthetic analog of IGF-1, mecasermin, is used for the treatment of growth failure.

IGF-1 consists of 70 amino acids in a single chain with three intramolecular disulfide bridges. IGF-1 has a molecular weight of 7,649 daltons.

Synthesis and circulation

IGF-1 is produced primarily by the liver as an endocrine hormone as well as in target tissues in a paracrine/autocrine fashion. Production is stimulated by growth hormone (GH) and can be retarded by undernutrition, growth hormone insensitivity, lack of growth hormone receptors, or failures of the downstream signalling pathway post GH receptor including SHP2 and STAT5B. Approximately 98% of IGF-1 is always bound to one of 6 binding proteins (IGF-BP). IGFBP-3, the most abundant protein, accounts for 80% of all IGF binding. IGF-1 binds to IGFBP-3 in a 1:1 molar ratio.

IGF-1 is produced throughout life. The highest rates of IGF-1 production occur during the pubertal growth spurt. The lowest levels occur in infancy and old age.

3-d model of IGF-1

Protein intake increases IGF-1 levels in humans, independent of total calorie consumption. Factors that are known to cause variation in the levels of growth hormone (GH) and IGF-1 in the circulation include: genetic make-up, the time of day, age, sex, exercise status, stress levels, nutrition level and body mass index (BMI), disease state, race, estrogen status and xenobiotic intake.

Fasting, including intermittent fasting, can reduce IGF-1 levels rapidly and dramatically.

Mechanism of action

Its primary action is mediated by binding to its specific receptor, the insulin-like growth factor 1 receptor (IGF1R), which is present on many cell types in many tissues. Binding to the IGF1R, a receptor tyrosine kinase, initiates intracellular signaling; IGF-1 is one of the most potent natural activators of the AKT signaling pathway, a stimulator of cell growth and proliferation, and a potent inhibitor of programmed cell death . IGF-1 binds to at least two cell surface receptors: the IGF-1 receptor (IGF1R), and the insulin receptor. The IGF-1 receptor seems to be the "physiologic" receptor - it binds IGF-1 at significantly higher affinity than the IGF-1 that is bound to the insulin receptor. Like the insulin receptor, the IGF-1 receptor is a receptor tyrosine kinase - meaning it signals by causing the addition of a phosphate molecule on particular tyrosines. IGF-1 activates the insulin receptor at approximately 0.1 times the potency of insulin. Part of this signaling may be via IGF1R/Insulin Receptor heterodimers (the reason for the confusion is that binding studies show that IGF1 binds the insulin receptor 100-fold less well than insulin, yet that does not correlate with the actual potency of IGF1 in vivo at inducing phosphorylation of the insulin receptor, and hypoglycemia).

IGF-1 is a primary mediator of the effects of growth hormone (GH). Growth hormone is made in the anterior pituitary gland, is released into the blood stream, and then stimulates the liver to produce IGF-1. IGF-1 then stimulates systemic body growth, and has growth-promoting effects on almost every cell in the body, especially skeletal muscle, cartilage, bone, liver, kidney, nerves, skin, hematopoietic cell, and lungs. In addition to the insulin-like effects, IGF-1 can also regulate cell growth and development, especially in nerve cells, as well as cellular DNA synthesis.

Insulin-like growth factor 1 receptor (IGF-1R) and other tyrosine kinase growth factor receptors signal through multiple pathways. A key pathway is regulated by phosphatidylinositol-3 kinase (PI3K) and its downstream partner, the mammalian target of rapamycin (mTOR). Rapamycins complex with FKBPP12 to inhibit the mTORC1 complex. mTORC2 remains unaffected and responds by upregulating Akt, driving signals through the inhibited mTORC1. Phosphorylation of eukaryotic initiation factor 4e (eif-4E) [4EBP] by mTOR inhibits the capacity of 4EBP to inhibit eif-4E and slow metabolism.

Insulin-like growth factor 1 has been shown to bind and interact with all the IGF-1 binding proteins (IGFBPs), of which there are seven: IGFBP1, IGFBP2, IGFBP3, IGFBP4, IGFBP5, IGFBP6, and IGFBP7. Some IGFBPs are inhibitory. For example, both IGFBP-2 and IGFBP-5 bind IGF-1 at a higher affinity than it binds its receptor. Therefore, increases in serum levels of these two IGFBPs result in a decrease in IGF-1 activity.

Related growth factors

IGF-1 is closely related to a second protein called "IGF-2". IGF-2 also binds the IGF-1 receptor. However, IGF-2 alone binds a receptor called the "IGF-2 receptor" (also called the mannose-6 phosphate receptor). The insulin-like growth factor-II receptor (IGF2R) lacks signal transduction capacity, and its main role is to act as a sink for IGF-2 and make less IGF-2 available for binding with IGF-1R. As the name "insulin-like growth factor 1" implies, IGF-1 is structurally related to insulin, and is even capable of binding the insulin receptor, albeit at lower affinity than insulin.

A splice variant of IGF-1 sharing an identical mature region, but with a different E domain is known as mechano-growth factor (MGF).

Clinical significance

Dwarfism

Rare diseases characterized by inability to make or respond to IGF-1 produce a distinctive type of growth failure. One such disorder, termed Laron dwarfism does not respond at all to growth hormone treatment due to a lack of GH receptors. The FDA has grouped these diseases into a disorder called severe primary IGF deficiency. Patients with severe primary IGFD typically present with normal to high GH levels, height below -3 standard deviations (SD), and IGF-1 levels below -3SD. Severe primary IGFD includes patients with mutations in the GH receptor, post-receptor mutations or IGF mutations, as previously described. As a result, these patients cannot be expected to respond to GH treatment.

People with Laron syndrome have strikingly low rates of cancer and diabetes.

Diagnostic test

IGF-1 levels can be measured in the blood in 10-1000 ng/ml amounts. As levels do not fluctuate greatly throughout the day for an individual person, IGF-1 is used by physicians as a screening test for growth hormone deficiency and excess in acromegaly and gigantism.

Interpretation of IGF-1 levels is complicated by the wide normal ranges, and marked variations by age, sex, and pubertal stage. Clinically significant conditions and changes may be masked by the wide normal ranges. Sequential management over time is often useful for the management of several types of pituitary disease, undernutrition, and growth problems.

As a therapeutic agent

Patients with severe primary insulin-like growth factor-1 deficiency (IGFD) may be treated with either IGF-1 alone or in combination with IGFBP-3. Mecasermin (brand name Increlex) is a synthetic analog of IGF-1 which is approved for the treatment of growth failure. IGF-1 has been manufactured recombinantly on a large scale using both yeast and E. coli.

Research

Contribution to aging

It is now widely accepted that signaling through the insulin/IGF-1-like receptor pathway is a significant contributor to the biological aging process in many organisms. This avenue of research first achieved prominence with the work of Cynthia Kenyon, who showed that mutations in the daf-2 gene double the lifespan of the roundworm, C. elegans. Daf-2 encodes the worm's unified insulin/IGF-1-like receptor. Despite the impact of IGF1-like on C. elegans longevity, direct application to mammalian aging is not as clear as mammals do not form dauer-like developmental stages.

Insulin/IGF-1-like signaling is conserved from worms to humans. In vitro experiments show that mutations that reduce insulin/IGF-1 signaling have been shown, in laboratory conditions, to decelerate the degenerative aging process and extend lifespan in a wide range of organisms, including Drosophila melanogaster, mice,. Reduced IGF-1 signaling is also thought to contribute to the "anti-aging" effects of Calorie restriction.

Neuropathy

Therapeutic administration with neurotrophic proteins (IGF I) is associated with potential reversal of degeneration of spinal cord motor neuron axons in certain peripheral neuropathies.

Cancer

The IGF signaling pathway has a pathogenic role in cancer. Studies have shown that decreased levels of IGF lead to decreased growth of existing cancer cells. People with Laron syndrome have also recently been shown to be of much less risk to develop cancer. Dietary interventions and modifications such as vegan diets shown to down regulate IGF-1 activity, has been associated with lower risk of cancer.

Stroke

IGF-1 has also been shown to be effective in animal models of stroke when combined with erythropoietin. Both behavioural and cellular improvements were found.

Clinical trials

Recombinant protein

Several companies have evaluated IGF-1 in clinical trials for a variety of indications, including type 1 diabetes, type 2 diabetes, amyotrophic lateral sclerosis (ALS aka "Lou Gehrig's Disease"), severe burn injury and myotonic muscular dystrophy (MMD). Results of clinical trials evaluating the efficacy of IGF-1 in type 1 diabetes and type 2 diabetes showed great promise in reducing hemoglobin A1C levels, as well as daily insulin consumption. However, the sponsor, Genentech, discontinued the program due to an exacerbation of diabetic retinopathy in patients coupled with a shift in corporate focus towards oncology. Cephalon and Chiron conducted two pivotal clinical studies of IGF-1 for ALS, and although one study demonstrated efficacy, the second was equivocal, and the product has never been approved by the FDA.

Small molecules that upregulate IGF-1

In a clinical trial of an investigational compound ibutamoren, which raises IGF-1 in patients, did not result in an improvement in patients' Alzheimer's symptoms. Another clinical demonstrated that Cephalon's IGF-1 does not slow the progression of weakness in ALS patients, but other studies shown strong beneficial effects of IGF-I replacement therapy in ALS patients, and therefore IGF-I may have the potential to be an effective and safe medicine against ALS, however other studies had conflicting results.

Society and culture

Insmed was found to infringe on patents licensed by Tercica, which then sought to get a U.S. district court judge to ban sales of Iplex. To settle patent infringement charges and resolve all litigation between the two companies, in March 2007 Insmed agreed to withdraw Iplex from the U.S. market, leaving Tercica's Increlex as the sole version of IGF-1 available in the United States.

Numerous sources have claimed that Deer Antler Spray, purportedly extracted from cervid sources, contains IGF-1. Credence to this claim comes from the fact that deer's antlers grow extremely rapidly and that the associated cellular factors can similarly aid in skeletal healing in humans. IGF-1 is currently banned by various sporting bodies. However, sprays and pills claiming to be 'deer antler velvet extracts' are freely available on the market. As IGF-1 is a protein, it cannot be absorbed orally since it is rapidly broken down in the gastrointestinal tract. In September, 2013, the headquarters of SWATS, an infamous distributor of deer antler spray and other controversial products, was raided and ordered to shut down by Alabama's attorney general citing "numerous serious and willful violations of Alabama’s deceptive trade practices act".

Anthony Bosch, of the Biogenesis clinic in Miami, Florida, alleged to have supplied and injected New York Yankee Alex Rodriguez with Insulin-like growth factor 1, along with several other performance enhancing drugs.

References

Further reading

• Butler AA, Yakar S, LeRoith D (2002). "Insulin-like growth factor-I: compartmentalization within the somatotropic axis?". News Physiol. Sci. 17: 82–5. PMID 11909998. 
• Maccario M, Tassone F, Grottoli S, Rossetto R, Gauna C, Ghigo E (2002). "Neuroendocrine and metabolic determinants of the adaptation of GH/IGF-I axis to obesity". Ann. Endocrinol. (Paris) 63 (2 Pt 1): 140–4. PMID 11994678. 
• Camacho-Hübner C, Woods KA, Clark AJ, Savage MO (2003). "Insulin-like growth factor (IGF)-I gene deletion". Reviews in endocrine & metabolic disorders 3 (4): 357–61. doi:10.1023/A:1020957809082. PMID 12424437. 
• Dantzer B, Swanson EM (2012). "Mediation of vertebrate life histories via insulin-like growth factor-1". Biological Reviews 87 (2): 414–429. doi:10.1111/j.1469-185X.2011.00204.x. PMID 21981025. 
• Trojan LA, Kopinski P, Wei MX, Ly A, Glogowska A, Czarny J et al. (2004). "IGF-I: from diagnostic to triple-helix gene therapy of solid tumors". Acta Biochim. Pol. 49 (4): 979–90. PMID 12545204. 
• Winn N, Paul A, Musaró A, Rosenthal N (2003). "Insulin-like growth factor isoforms in skeletal muscle aging, regeneration, and disease". Cold Spring Harb. Symp. Quant. Biol. 67: 507–18. doi:10.1101/sqb.2002.67.507. PMID 12858577. 
• Delafontaine P, Song YH, Li Y (2005). "Expression, regulation, and function of IGF-1, IGF-1R, and IGF-1 binding proteins in blood vessels". Arterioscler. Thromb. Vasc. Biol. 24 (3): 435–44. doi:10.1161/01.ATV.0000105902.89459.09. PMID 14604834. 
• Trejo JL, Carro E, Garcia-Galloway E, Torres-Aleman I (2004). "Role of insulin-like growth factor I signaling in neurodegenerative diseases". J. Mol. Med. 82 (3): 156–62. doi:10.1007/s00109-003-0499-7. PMID 14647921. 
• Rabinovsky ED (2004). "The multifunctional role of IGF-1 in peripheral nerve regeneration". Neurol. Res. 26 (2): 204–10. doi:10.1179/016164104225013851. PMID 15072640. 
• Rincon M, Muzumdar R, Atzmon G, Barzilai N (2005). "The paradox of the insulin/IGF-1 signaling pathway in longevity". Mech. Ageing Dev. 125 (6): 397–403. doi:10.1016/j.mad.2004.03.006. PMID 15272501. 
• Conti E, Carrozza C, Capoluongo E, Volpe M, Crea F, Zuppi C et al. (2005). "Insulin-like growth factor-1 as a vascular protective factor". Circulation 110 (15): 2260–5. doi:10.1161/01.CIR.0000144309.87183.FB. PMID 15477425. 
• Wood AW, Duan C, Bern HA (2005). "Insulin-like growth factor signaling in fish". Int. Rev. Cytol. International Review of Cytology 243: 215–85. doi:10.1016/S0074-7696(05)43004-1. ISBN 9780123646477. PMID 15797461. 
• Sandhu MS (2005). "Insulin-like growth factor-I and risk of type 2 diabetes and coronary heart disease: molecular epidemiology". Endocrine development. Endocrine Development 9: 44–54. doi:10.1159/000085755. ISBN 3-8055-7926-8. PMID 15879687. 
• Ye P, D'Ercole AJ (2006). "Insulin-like growth factor actions during development of neural stem cells and progenitors in the central nervous system". J. Neurosci. Res. 83 (1): 1–6. doi:10.1002/jnr.20688. PMID 16294334. 
• Gómez JM (2006). "The role of insulin-like growth factor I components in the regulation of vitamin D". Current pharmaceutical biotechnology 7 (2): 125–32. doi:10.2174/138920106776597621. PMID 16724947. 
• Federico G, Street ME, Maghnie M, Caruso-Nicoletti M, Loche S, Bertelloni S et al. (2006). "Assessment of serum IGF-I concentrations in the diagnosis of isolated childhood-onset GH deficiency: a proposal of the Italian Society for Pediatric Endocrinology and Diabetes (SIEDP/ISPED)". J. Endocrinol. Invest. 29 (8): 732–7. doi:10.1007/bf03344184. PMID 17033263. 
• Zakula Z, Koricanac G, Putnikovic B, Markovic L, Isenovic ER (2007). "Regulation of the inducible nitric oxide synthase and sodium pump in type 1 diabetes". Med. Hypotheses 69 (2): 302–6. doi:10.1016/j.mehy.2006.11.045. PMID 17289286. 
• Trojan J, Cloix JF, Ardourel MY, Chatel M, Anthony DD (2007). "Insulin-like growth factor type I biology and targeting in malignant gliomas". Neuroscience 145 (3): 795–811. doi:10.1016/j.neuroscience.2007.01.021. PMID 17320297. 
• Venkatasubramanian G, Chittiprol S, Neelakantachar N, Naveen MN, Thirthall J, Gangadhar BN et al. (October 2007). "Insulin and insulin-like growth factor-1 abnormalities in antipsychotic-naive schizophrenia". Am J Psychiatry 164 (10): 1557–60. doi:10.1176/appi.ajp.2007.07020233. PMID 17898347. 

External links

• Insulin-Like Growth Factor I at the US National Library of Medicine Medical Subject Headings (MeSH)
• IGF-1 at Lab Tests Online
• IGF-1 recombinant GFP labeled at Protean Ltd.

UpToDate Contents

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• 1. インスリン様成長因子 Iの生理学 physiology of insulin like growth factor i
• 2. 小児における成長ホルモン欠乏症の診断 diagnosis of growth hormone deficiency in children
• 3. 先端巨大症の診断 diagnosis of acromegaly
• 4. 成人における成長ホルモン欠乏症 growth hormone deficiency in adults
• 5. 小児における成長ホルモン欠乏症の治療 treatment of growth hormone deficiency in children

English Journal

• Increased micro-RNA 29b in the aged brain correlates with the reduction of insulin-like growth factor-1 and fractalkine ligand.

• Fenn AM, Smith KM, Lovett-Racke AE, Guerau-de-Arellano M, Whitacre CC, Godbout JP.SourceDepartment of Neuroscience, The Ohio State University, Columbus, OH, USA.
• Neurobiology of aging.Neurobiol Aging.2013 Dec;34(12):2748-58. doi: 10.1016/j.neurobiolaging.2013.06.007. Epub 2013 Jul 21.
• Microglia develop an inflammatory phenotype during normal aging. The mechanism by which this occurs is not well understood, but might be related to impairments in several key immunoregulatory systems. Here we show that micro-RNA (miR)-29a and miR-29b, 2 immunoregulatory micro-RNAs, were increased in
• PMID 23880139

• Estrogen and insulin-like growth factor 1 synergistically promote the development of lung adenocarcinoma in mice.

• Tang H, Liao Y, Xu L, Zhang C, Liu Z, Deng Y, Jiang Z, Fu S, Chen Z, Zhou S.SourceDepartment of Thoracic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China; Department of Thoracic Surgery, The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China.
• International journal of cancer. Journal international du cancer.Int J Cancer.2013 Nov 15;133(10):2473-82. doi: 10.1002/ijc.28262. Epub 2013 Jun 12.
• Estrogen receptor (ER) and insulin-like growth factor-1 receptor (IGF-1R) signaling are implicated in lung cancer progression. Based on their previous findings, the authors sought to investigate whether estrogen and IGF-1 act synergistically to promote lung adenocarcinoma (LADE) development in mice.
• PMID 23649836

• Extra-adrenal glucocorticoid synthesis: Immune regulation and aspects on local organ homeostasis.

• Talabér G, Jondal M, Okret S.SourceDepartment of Biosciences and Nutrition, Karolinska Institutet, Novum, SE-141 83 Huddinge, Sweden.
• Molecular and cellular endocrinology.Mol Cell Endocrinol.2013 Nov 5;380(1-2):89-98. doi: 10.1016/j.mce.2013.05.007. Epub 2013 May 21.
• Systemic glucocorticoids (GCs) mainly originate from de novo synthesis in the adrenal cortex under the control of the hypothalamus-pituitary-adrenal (HPA)-axis. However, research during the last 1-2 decades has revealed that additional organs express the necessary enzymes and have the capacity for d
• PMID 23707789

Japanese Journal

• 子宮内発育不全の分子遺伝的解析による早期診断とその意義 (ミニ特集 知っておきたい新生児疾患の早期診断)

• 緒方 勤
• 小児科臨床 66(2), 215-225, 2013-02
• NAID 40019546978

• 全国農業共済協会長賞 日齢体重が異なる黒毛和種子牛の血中アミノ酸濃度とアミノ酸製剤給与効果 (平成23年度家畜診療等技術全国研究集会・入賞論文)

• 芝野 健一,宇？ 敬与,宮本 孝明 [他]
• 家畜診療 = Journal of livestock medicine 59(11), 685-696, 2012-11
• NAID 40019480394

Related Links

• IGF-1： - 海外サプリメント通販【サプリンクス】公式通販サイト

海外サプリメント通販サプリンクス【公式サイト】IGF-1ページ。サプリンクスではIGF-1配合商品をはじめ高品質で低価格なサプリメントや日本で入手困難な最新のサプリメント&コスメをロサンゼルスより直送しています。

• IGF-1が不足するとどうなるのか？

IGF-1が不足していると体にどのような影響を引き起こしてしまうのでしょうか？また増やすことでどのようなことが起きるのかについてなどを解説してみました！

Related Pictures

---

★リンクテーブル★

国試過去問	「114A042」
リンク元	「低血糖」「インスリン様成長因子-I」
拡張検索	「IGF-1受容体」「IGF-1レセプター」「IGF-1 receptor」
関連記事	「I」「IGF」

「114A042」

　　[★]

• 34歳の男性。頭痛、顔つきの変化および手足の容積増大を主訴に来院した。2年前から家人に顔貌の変化を指摘されている。1年前から頭痛を自覚するようになった。身長 182cm、体重 98kg。脈拍 80/分、整。血圧 156/90mmHg。顔面は眉弓部の膨隆、鼻と口唇の肥大、巨舌を認める。胸部と腹部とに異常は認めない。内分泌検査所見：GH 8.5ng/mL(男性の基準 2.5以下)、IGF-1 780ng/mL(34歳男性の基準 102～283)、ACTH 35pg/mL(基準 7.2～63.3)、プロラクチン 62.0ng/mL(基準 3.6～12.8)、コルチゾール 14μg/dL(基準 6.24～18.0)。頭部単純エックス線写真(別冊No. 15)を別に示す。
• この患者でみられないのはどれか。

• a　心肥大
• b　耐糖能異常
• c　低リン血症
• d　睡眠時無呼吸
• e　手根管症候群

[正答]

C

※国試ナビ4※　［114A041］←［国試_114］→［114A043］

「低血糖」

　　[★]

英

hypoglycemia

同

低血糖症、低血糖発作 hypoglycemic episode、血糖減少症

関

ウィップルの3主徴、低血糖

[show details]

低血糖症 : 約 385,000 件
低血糖発作 : 約 67,300 件

定義

• 血糖値：

• (成人の場合)50mg/dl以下 (IMD)　　←　文献によっては60mg/dl以下とも
• (新生児・乳児) → 新生児低血糖症

PALS

• 早期産・満期産の新生児：　＜45mg/dl
• 乳児・小児・青少年　　：　＜60mg/dl

症状

• 交感神経症状：発汗、振戦、動悸、不安感
• 中枢神経症状：判断力低下、眠気、意識障害、痙攣、昏睡

新生児・乳児の低血糖

新生児低血糖症 (SPE.127,210)

低血糖を引きおこす病態

DMR.295

• 1. 各種ホルモン分泌不全

• 下垂体機能不全
• 成長ホルモン単独欠損症
• ACTH単独欠損症
• 副腎不全

• 2. 敗血症
• 3. 腎不全
• 4．肝不全
• 5．うっ血性心不全
• 6．乳酸アシドーシス
• 7．飢餓状態，神経性食思不振症
• 8．ショック
• 9．非β細胞腫瘍(IGF-1 or IGF-2産生腫瘍)
• 10．褐色細胞腫の切除後

低血糖の鑑別方法

(書きかけ)

• 1. 空腹時低血糖　：インスリノーマ、インスリン自己免疫症候群、糖原病、肝細胞癌、間葉系腫瘍
• 2. 食後低血糖　　：発症初期の糖尿病
• 3. 誘発性低血糖　：医原性、アルコール

「インスリン様成長因子-I」

　　[★]

英

insulin-like growth factor I insuline-like growth factor-I IGF-I IGF-1

同

インスリン様増殖因子I、インスリン様成長因子I。ソマトメジンC somatomedin C, ソマトメジン somatomedin

性状

• ペプチド

産生組織

• 肝臓を始めとする多くの臓器

標的組織

• 血行性にホルモンとして、自己分泌的、傍分泌的に作用。

作用

• IGF-IはGH依存性に種々の組織で合成、分泌され、主にオートクリン作用によって組織の増殖を促進する。

分泌の調整

• 分泌促進：成長ホルモン、インスリン
• 分泌抑制：絶食(GH↑だが)、エストロゲン、コルチゾール

「IGF-1受容体」

　　[★]

英

IGF-1 receptor、IGF type 1 receptor

関

IGF-1レセプター、IGF-Iレセプター、IGF受容体1型、インスリン様増殖因子I受容体

「IGF-1レセプター」

　　[★]

英

IGF-1 receptor、IGF type 1 receptor

関

IGF-1受容体、IGF-Iレセプター、IGF受容体1型、インスリン様増殖因子I受容体

「IGF-1 receptor」

　　[★]

• IGF-1受容体、IGF-1レセプター

関

IGF type 1 receptor、IGF-I receptor、insulin-like growth factor I receptor

「I」

　　[★]

• イソロイシン isoleucine
• イノシン inosine
• 阻害剤 inhibitor
• iodine
• ヨード iodide
• I因子 factor I

　 　 　

「IGF」

　　[★]

• インスリン様増殖因子 インスリン様成長因子 insulin-like growth factor