אינסולין

האם אינסולין משפיע על צמיחת השיער? שמעתי כי אנשים רבים שתזונתם עשירה בסוכרים ופחמימות סובלים משיער מיותר

אתה מפזר חצי שאלה בכל פורום. אם היית אומר מה מטריד אותך ונותן פרטים מלאים של שאלתך היית מקבל תשובה ענינית. זה החומר המתיחס לחלק ההורמונים והכי קרוב לגורמים הקרובים לאינסולין. It was recently discovered that basic fibroblast growth factor (bFGF) and platelet-derived growth factor (PDGF) potentiate the growth of dermal papilla cells. It is proposed that these proteins increase the synthesis of stromelysin (an enzyme, matrix metalloproteinase) which acts on the papilla cells and accelerates their growth. Another cytokine, transforming growth factor beta (TGF- ), inhibits mitogen - induced dermal papilla cell proliferation.[8] On the other hand, dermal papilla cells produce numerous cytokines which influence proliferation of hair matrix cells. Some of them are stimulators, and some inhibitors. Interleukin 1- (IL-1 ) inhibits growth of hair and follicle, but only after 2-4 days of latency.[9] The increase of IL-1 concentration in extracellular fluid during inflammation could be one of the reasons for alopecia following certain infectious diseases. Apart from IL-1alpha, both fibroblast growth factor (FGF) and epidermal growth factor (EGF) inhibit growth of the hair and hair follicle. Fibroblast growth factor type 5 (FGF5) is an especially potent inhibitor.[10] Receptors for these ligands were found by immunohistochemical methods on papilla cells, matrix cells and stem sells in the bulge region of the hair follicle.[11,12] Another cytokine produced by cells of the dermal papilla, keratinocyte growth factor (KGF), induces extensive hair growth in murine models of alopecia. Receptors for KGF were found on keratinocytes in the basal epidermis and throughout developing hair follicles of rat embryos and neonates.[13] Insulin-like growth factor I (IGF-I) accelerates, in a concentration-dependent manner, growth of hair and hair follicles.[14] The actions of IGF-I are modulated by proteins produced in dermal papilla cells which bind IGF (insulin-like growth factor-binding proteins: IGFBPs); the exact mechanism of modulation has not yet been resolved.[15] However, it has been shown that IGFBP-3 (which is the most abundant IGFBP type in dermal papilla cells) forms a complex with free IGF-I to reduce the concentration of IGF-I available for stimulation of hair elongation and maintenance of the anagen phase.[16] Retinoids and glucocorticoids stimulate production of IGFBP-3 in dermal papilla cells. Insulin itself has the same effect as IGF-I; it has been observed that body hair in patients with hyperinsulinism has a male distribution pattern.[17,18] On the other hand, growth hormone (somatotropin) has no direct influence on follicle and hair growth.[14] References 9 Harmon CS, Nevins TD. IL-1 alpha inhibits human hair follicle growth and hair fiber production in whole organ cultures. Lymphokine Cytokine Res 1993; 12: 197-203. 10. Herbert JM, Rosenquis T, Gotz J et al. FGF 5 as a regulator of the hair growth cycle: evidence from targeted and spontaneous mutations. Cell 1994; 78: 1017-25. 11. Du Cros DL. Fibroblast growth factor and epidermal growth factor in hair development. J Invest Dermatol 1993; 101(1 Suppl): 106S-113S. 12. Akiyama M, Smith LT, Holbrook KA. Growth factor and growth factor receptor localization in the hair follicle bulge and associated tissue in human fetus. J Invest Dermatol 1996; 106: 391-6. 13. Danilenko DM, Ring BD, Yanagihara D, et al. Keratinocyte growth factor is an important endogenous mediator of hair follicle growth, development, and differentiation. Normalization of the nu/nu follicular differentiation defect and amelioration od chemotherapy-induced alopecia. Am J Pathol 1995; 147: 145-54. 14. Philpott MP, Sanders DA, Kealey T. Effects of insulin and insulin-like growth factors on cultured human hair follicles: IGF-I at physiologic. J Invest Dermatol 1994; 102: 857-61. 15. Batch JA, Mercuri FA, Werther GA. Identification and localization of insulin-like growth factor-binding protein (IGFBP) messenger RNAs in human hair follicle dermal papilla. J Invest Dermatol 1996; 106: 471-5. 16. Hembree JR, Harmon CS, Nevins TD, et al. Regulation of human dermal papilla cell production of insulin-like growth factor binding protein-3 by retinoic acid, glucocorticoids, and insulin-like growth factor-1. J Cell Physiol 1996; 167: 556-61. 17. Fossati P, Fontaine P. Endocrine and metabolic consequences of massive obesity. Rev Prat 1993; 43: 1935-9. 18. Hrnciar J, Hrnciarova M, Jakubikova K, et al. Insulin resistance and arterial hypertension. Hyperinsulinism as a basic etiopathogenic factor in essential arterial hypertension and associated phenomena. Vnitr Lek 1992; 38: 868-78. 19. Paus R, Heinzelmann T, Schultz KD, et al. Hair growth induction by substance P. Lab Invest 1994; 71: 134-40. 20. Holick MF, Ray S, Chen TC, et al. A parathyroid hormone antagonist stimulates epidermal proliferation and hair growth in mice. Proc Natl Acad Sci USA 1994; 91: 8014-6. 21. Harmon CS, Nevins TD. Biphasic effect of 1,25-dihydroxyvitamin D3 on human hair follicle growth and hair fiber production in whole-organ cultures. J Invest Dermatol 1994; 103: 318-22. 22. Randall VA, Thorton MJ, Hamada K, Messenger AG. Androgen action in cultured dermal papilla cells from human hair follicles. Skin Pharmacol 1994; 7: 20-6. 23. Sawaya ME. Purification of androgen receptors in human sebocytes and hair. J Invest Dermatol 1992; 98(6 Suppl):925-965. 24. Chondrhry R, Hodgins MB, Van-der Kwast TH, et al. Localisation of androgen receptors in human skin by immunohistochemistry: implications for the hormonal regulation of hair growth, sebaceous glands and sweat glands. J Endocrinol 1992; 133: 467-75. 25. Randall VA, Thornton MJ, Messenger AG, et al. Hormones and hair growth: variations in androgen receptor content of dermal papilla cells cultured from human and red deer (Cervus elaphus) hair follicles. J Invest Dermatol 1993; 101(1 Suppl): 1145-1205. 26. Randall VA, Thornton MJ, Messenger AG. Cultured dermal papilla cells from androgen-dependent human hair follicles (e. g. beard) contain more androgen receptors than those from non-bolding areas of scalp. J Endocrinol 1992; 133: 141-7. 27. Randall VA, Thornton MJ, Hamada K, et al. Mechanism of androgen action in cultured dermal papilla cells derived from human hair follicles with varying responses to androgens in vivo. J Invest Dermatol 1992; 98(6 Suppl): 86S-91S. 28. Itami S, Kurata S, Sonoda T, et al. Interaction between dermal papilla cells and follicular epithelial cells in vitro: effect of androgen. Br J Dermatol 1995; 132: 527-32. 29. Yong CY, Murtha PE, Andrews PE, et al. Antagonism of androgen action in prostate tumor cells by retinoic acid. Prostate 1994; 25: 39-45. 30. Allgood VE, Cidlowski JA. Vitamin B6 modulates transcriptional activation by multiple members of the steroid hormone receptor superfamily. J Biol Chem 1992; 267: 3819-24. 31. Dedhar S, Rennie PS, Shago M. et al. Inhibition of nuclear hormone receptor activity by calreticulin. Nature 1994; 367: 480-3. 32. Randall VA. Role of 5 alpha-reductase in health and disease. Bailliers Clin Endocrinol Metab 1994; 8: 405-31. 33. Verchoore M. Hyperandrogenie et folicule pilo-sebace. Rev Prat 1994; 43: 2363-9. 34. Horton R. Dihydrotestosterone is a peripheral paracrine hormone. J Androl 1992; 13: 23-7. 35. Toscano V, Balducci R, Bianchi P. et al. Two different pathogenetic mechanisms may play a role in acne and in hirsutism . Clin Endocrinol Oxf 1993; 39: 551-6. 36. Carmina E, Janni A, Lobo RA. Physiological estrogen replacement may enhance the effectiveness of the gonadotropin-releasing hormone agonist in the treatment of hirsutism. J Clin Endocrinol Metab 1994; 78: 126-30. 37 Fruzzeti F, de Lorenzo D, Parrini D, et al. Effects of finasteride, a 5 alpha-reductase inhibitor, on circulating androgens and gonadotropin secretion in hirsute women. J Clin Endocrinol Metab 1994; 79: 831-5. 38 Mellin TN, Busch RD, Rasmusson GH. Azasteroids as inhibitors of testosterone 5 alpha-reductase in mammalian skin. J Steroid Biochem Mol Biol 1993; 44: 121-31.