Evidence for modulation of pericryptal sheath myofibroblasts in rat descending colon by Transforming Growth Factor β and Angiotensin II.Reportar como inadecuado




Evidence for modulation of pericryptal sheath myofibroblasts in rat descending colon by Transforming Growth Factor β and Angiotensin II. - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

BMC Gastroenterology

, 2:4

First Online: 12 February 2002Received: 19 November 2001Accepted: 12 February 2002

Abstract

BackgroundAbsorption of water and Na in descending colonic crypts is dependent on the barrier function of the surrounding myofibroblastic pericryptal sheath. Here the effects of high and low Na diets and exposure to whole body ionising radiation on the growth and activation of the descending colonic pericryptal myofibroblasts are evaluated. In addition the effect of a post-irradiation treatment with the angiotensin converting enzyme inhibitor Captopril was investigated.

MethodsThe levels of Angiotensin II type 1 receptor AT1, ACE, collagen type IV, transforming growth factor-β type 1 receptor TGF-βR1, OB cadherin and α-smooth muscle actin in both descending colon and caecum were evaluated, using immunocytochemistry and confocal microscopy, in rats fed on high and low Na diets LS. These parameters were also determined during 3 months post-irradiation with 8Gy from a Co source in the presence and absence of the angiotensin converting enzyme inhibitor, Captopril.

ResultsIncreases in AT1 receptor 135.6% ± 18.3, P < 0.001; ACE 70.1% ± 13.1, P < 0.001; collagen type IV 49.6% ± 15.3, P < 0.001; TGF-β1 receptors 291.0% ± 26.5, P < 0.001; OB-cadherin 26.3% ± 13.8, P < 0.05 and α-smooth muscle actin 82.5% ± 12.4, P < 0.001 were observed in the pericryptal myofibroblasts of the descending colon after LS diet. There are also increases in AT1 receptor and TGF-β1 receptor, smooth muscle actin and collagen type IV after irradiation. Captopril reduced all these effects of irradiation on the pericryptal sheath and also decreased the amount of collagen and smooth muscle actin in control rats P < 0.001.

ConclusionsThese results demonstrate an activation of descending colonic myofibroblasts to trophic stimuli, or irradiation, which can be attenuated by Captopril, indicative of local trophic control by angiotensin II and TGF-β release.

AbbreviationsAT1Angiotensin II type 1 receptor

ACEAngiotensin converting enzyme

TGF-βR1Transforming growth factor β type I receptor

Electronic supplementary materialThe online version of this article doi:10.1186-1471-230X-2-4 contains supplementary material, which is available to authorized users.

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Autor: Jay R Thiagarajah - Nina M Griffiths - Kevin C Pedley - Richard J Naftalin

Fuente: https://link.springer.com/







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