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Query: UMLS:C0004135 (ATM)
 13,001 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The renin-angiotensin system (RAS) contributes to fibrogenesis in a variety of organs. We recently showed that a lack of angiotensin (Ang) II type 1 (AT1) receptor activity reduces liver fibrosis. In this study, we investigated whether the Ang II type 2 (AT2) receptor is implicated in the development of liver fibrosis. A comparison was made between AT2-receptor knockout (AT2KO) and wild type (WT) mice after 4 weeks of treatment with carbon tetrachloride (CCl4). Fibrosis was assessed by Azan-Mallory staining and hepatic hydroxyproline (HP) content. The expression of fibrogenic mRNA was measured by real-time quantitative reverse-transcription polymerase chain reaction (PCR). Liver fibrosis evaluated by regular histological analyses and immunohistochemical alpha-SMA staining was observed in both groups of mice. The extent of fibrosis was greatest in the AT2KO mice. Fibrosis was associated with increases in hepatic HP content and mRNA expression for TGF-beta1 and alpha-SMA, as well as an increase in hepatic TBARS. These findings suggest that CCl4 induces oxidative stress which leads to activation of hepatic stellate cells (HSCs). These changes were considerably more pronounced in the AT2KO mice than the WT mice. Taken together, we conclude that AT2 signal has anti-fibrogenic and/or cytoprotective effects on oxidative stress-induced liver fibrosis. We therefore suggest that RAS-associated liver fibrogenesis may be determined by the balance between AT1 and AT2 signals.
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PMID:Anti-fibrogenic function of angiotensin II type 2 receptor in CCl4-induced liver fibrosis. 1677 39

To investigate the effects of beta-elemene on the ANG II-AT1 receptor pathway in rats with liver fibrosis, a model of hepatic fibrosis was induced by hypodermical injection of carbon tetrachloride (CCl4) into Wistar male rats. beta-elemene was intraperitonealy administered into the rats for 8 weeks (0.1 mL/100 g body weight per day). Masson staining was used to observe the liver fibrosis of rats and liver functions were measured by enzymatic kinetic analysis. The content of hydroxyproline in liver tissues was detected by specimen alkaline hydrolysis. The level of plasma ANG in blood II plasma was detected by radioimmunoassay. The expression of AT1R in rat liver were measured using reverse transcriptional-polymerase chain reaction and immunohistochemistry respectively. The results showed that beta-elemene could reduce the collagen disposition in liver and inhibit the progression of liver fibrosis. In addition, the levels of plasma ANG II and the expression of hepatic AT1R in rats with liver fibrosis were also suppressed by beta-elemene. It is concluded that the ANG II-AT1 receptor pathway plays an important role in the development of hepatic fibrosis and beta-elemene could down-regulate the levels of plasma ANG II and the expression of hepatic AT1R in rats with liver fibrosis.
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PMID:ANG II-AT1 receptor pathway is involved in the anti-fibrotic effect of beta-elemene. 1939