Gastric mucosal injury and repair: effect of aging

• Majumdar, A. P. N. ^[1] ; Fligiel, S. E. G. ^[1] ; Jaszewski, R. ^[1]
  1. [1] Wayne State University

     Wayne State University

     City of Detroit, Estados Unidos

     
• Localización: Histology and histopathology: cellular and molecular biology, ISSN-e 1699-5848, ISSN 0213-3911, Vol. 12, Nº. 2, 1997, págs. 491-501
• Idioma: inglés
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• Resumen

  • Although the gastric mucosa of healthy adu lt a nima ls possesses the inhe re nt capacity to promptl y repa ir (ofte n within 24 h) after a mino r to moderate injury, agi ng appears to diminish its reparative capacity.

    At least two different repair mechanisms are thought to participate in full repair of the damaged gastric mucosa:

    the initial rapid process of mucosal restitution begins by migration of viable epithelial cells from gastric pits and glands; the subsequent slowe r process is replacement of lost cells by ce ll division. Intrace llul a r eve nts that regul ate these processes are poorl y understood, nor do we know how they may be affected by aging. However, evidence is accumul ating which suggests that a number of gastro int esti na l hormones/grow th factors, most notabl y EGF and TGF-a may playa critical rol e in regul ati ng gastri c mucosal reparative processes. Since EGF and TGF-a exe rt the ir ph ysio logical actions by activating the intrinsic tyrosine kinase (Tyr-k) activity of their common receptor, the EGF-R, studi es have been performed to assess th e ro le of EG F-R Ty r-k in regul ating mucosal reparative processes during aging.

    Rece nt data s uggest th a t the age -re la ted dec lin e in mucosal repair after acute injury could in part be due to dec rease d ac tivation of EGF-R Tyr-k. In ad dition , polyamines and prostaglandins are also thought to be inv o lved in gastric mucosa l repara ti ve processes.

    A ltho ug h the involveme nt of po lyamin es in gastri c mucosal reparative processes during aging has not yet been studi ed, decreased mucosal prostaglandin levels in the aged are tho ught to be a causative factor for the increased susceptibility of the mucosa to injury. These and other relevant matters are discussed in the current revIew.