Mastocyto

Mastocyto (MC) es un typo de leukocyto presente in connective texitos. Se caracterisa per le presentia in su cytoplasma de multe granulas continente chimic mediarores como serotonina, histamina, tryptase o heparina.

Iste cellulas contribue al defensa contra infectiose agentes e al cicatrisation, ma son alsi associate al allergia et al phenomeno de anaphylaxia..

Description
Mastocytos serea de origine embryonari, con progenitores proveniente del sacco vitellin e de cellulas staminal hematopoietic (CSH)R.Gentek, C.Ghigo, G.Hoeffel, M.J.Bulle, R.Msallam, G.Gautier,P.Launay, J.Chen, F.Ginhoux & M.Bajénoff. 2018. "Hemogenic endothelial fate mapping reveals dual developmental origin of mast cells". Immunity. 48:1160–1171.e5. Z.Li, S.Liu, J.Xu, X.Zhang, D.Han, J.Liu, M.Xia, L.Yi, Q.Shen, S.Xu , 2018. "Adult connective tissue-resident mast cells originate from late erythro-myeloid progenitors". Immunity. 49:640–653.e5. Nilsson, G. & J.S.Dahlin. 2019. "New insights into the origin of mast cells". Allergy. 74:844–845.  Postea, embryonari mastocytos serea reimplaciate progressivemente per progenitores exite del medulla ossee.

Mastocytos son morphologicamente proxime del basophile granulocytos, ma mastocytos resida in texitos, quando un basophile es un cellula sanguinee circulante. Lor differentiation es assurate per cytokinas: le stamcellula factor pro mastocytos e interleukina-3 pro basophiles. Ambes son implicate in allergia ligate al immunoglobulina E e in immunitate innate, ma mediatores liberate son differente.M. Arock, "Similitudes et différences entre les mastocytes et le polynucléaire basophile", Revue française d’allergologie et d'immunologie clinique 44 (2004) 23–36

Subtypos
Se distingue septe typos de mastocyto appellate de CM-1 ad CM-7. CM1 se trova in vesica, CM-4, CM-6 e CM-7 in pelle, CM-2 in vias respiratori inferior, lymphatic gangliones, vasos sanguinee e vesica, CM-5 in musculos, pulmones e vesica. CM3 es distribuite in differente organos cuje le pancreas.https://presse.inserm.fr/premiere-cartographie-digitale-des-cellules-immunitaires-responsables-des-allergies/67370/

Allergia
Quando in contacto con un allergene, un mastocyto con specific IgE a su superficie libera rapidemente (mecanismo de exocytose) granulas caracteristic ric in histamina e heparina, e differente hormonal mediatores e chimiokinas. Histamina induce vasodilatation, causante assi differente signos caracteristic del inflammation, e recruta neutrophilos e macrophagos.

Le mesme activation induce de maniera plus retardate (alcun horas) le synthese de numerose cytokinas (commo TNF-alpha) e chimiokinas (chimiotactismo) como interleukinas e leukotrienes. Assi, allergic reactiones son activate, aliquando sever como un choc anaphylactic qui genera un hypotension.

Sodium cromoglycato (cromoglicic acido) bloca mastocyto degranulation, fixante se sur lor membrana plasmic. 

Categoria:Biologia cellular
Categoria:Granulocyto