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Effect of valsartan on the expression of angiotensin II receptors in the lung of chronic antigen exposure rats.
Chin Med J (Engl). 2008 Nov 20; 121(22):2312-9.CM

Abstract

BACKGROUND

Many studies have suggested that angiotensin II (Ang II) and its receptors may be involved in the development of asthma. However, the expression of angiotensin II receptors (AGTR) is not clear in the lung tissue of chronic asthmatics. This study was designed to determine the relationship between airway remodeling, dysfunction and the expression of AGTRs in a rat model of asthma.

METHODS

Rats were sensitized with ovalbumin (OVA) for 2 weeks. Sixty minutes before an inhalation challenge, the rats were pretreated either with valsartan (15, 30, 50 mg x kg(-1) x d(-1)) or saline intragastrically. Then the rats received an OVA challenge for 30 alternative days. Acetylcholine (Ach)-induced bronchoconstriction was measured after the final antigen challenge. White cell counts in bronchoalveolar lavage fluid (BALF) and morphological changes in the airways were then assessed. The levels of transforming growth factor-beta 1 (TGF-beta(1)) and platelet-derived growth factor (PDGF) in BALF were detected by ELISA. The levels of AGTR1 and AGTR2 mRNA and protein in lung tissues were measured by RT-PCR and Western blotting.

RESULTS

AGTR1 mRNA and protein levels in repeatedly OVA-challenged rats were significantly increased as compared with negative controls. The AGTR1 mRNA expression versus white cell counts of BALF and airway wall thickness (mainly in small airways) in lungs of chronic antigen-exposed rats were positively correlated. Valsartan decreased the level of AGTR1 in repeatedly OVA-challenged rats. However, AGTR2 mRNA and protein levels in the OVA-challenged rats and high-dose valsartan-treated rats (50 mg x kg(-1) x d(-1)) were also increased. Valsartan significantly decreased inflammatory cell accumulation and attenuated Ach-evoked bronchoconstriction in repeatedly antigen-challenged rats. Valsartan also decreased allergen-induced structural changes in rat airway (including total airway wall thickness and smooth muscle area) and the levels of TGF-beta(1) and PDGF in BALF.

CONCLUSIONS

AGTR1 expression is potentially associated with airway remodeling and dysfunction in asthma. Ang II and AGTR1 may participate in airway inflammation and airway remodeling of chronic antigen-exposed rats. Valsartan, a AGTR1 antagonist, could inhibit AGTR1 expression and partially inhibits structural airway changes as well as airway inflammation in chronic OVA-exposed rats.

Authors+Show Affiliations

Department of Respiratory Medicine, First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, China.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

19080339

Citation

Wang, Tong, et al. "Effect of Valsartan On the Expression of Angiotensin II Receptors in the Lung of Chronic Antigen Exposure Rats." Chinese Medical Journal, vol. 121, no. 22, 2008, pp. 2312-9.
Wang T, Yin KS, Liu KY, et al. Effect of valsartan on the expression of angiotensin II receptors in the lung of chronic antigen exposure rats. Chin Med J (Engl). 2008;121(22):2312-9.
Wang, T., Yin, K. S., Liu, K. Y., Lu, G. J., Li, Y. H., & Chen, J. D. (2008). Effect of valsartan on the expression of angiotensin II receptors in the lung of chronic antigen exposure rats. Chinese Medical Journal, 121(22), 2312-9.
Wang T, et al. Effect of Valsartan On the Expression of Angiotensin II Receptors in the Lung of Chronic Antigen Exposure Rats. Chin Med J (Engl). 2008 Nov 20;121(22):2312-9. PubMed PMID: 19080339.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Effect of valsartan on the expression of angiotensin II receptors in the lung of chronic antigen exposure rats. AU - Wang,Tong, AU - Yin,Kai-sheng, AU - Liu,Kou-yin, AU - Lu,Guo-jun, AU - Li,Yu-hua, AU - Chen,Jun-di, PY - 2008/12/17/entrez PY - 2008/12/17/pubmed PY - 2009/3/27/medline SP - 2312 EP - 9 JF - Chinese medical journal JO - Chin Med J (Engl) VL - 121 IS - 22 N2 - BACKGROUND: Many studies have suggested that angiotensin II (Ang II) and its receptors may be involved in the development of asthma. However, the expression of angiotensin II receptors (AGTR) is not clear in the lung tissue of chronic asthmatics. This study was designed to determine the relationship between airway remodeling, dysfunction and the expression of AGTRs in a rat model of asthma. METHODS: Rats were sensitized with ovalbumin (OVA) for 2 weeks. Sixty minutes before an inhalation challenge, the rats were pretreated either with valsartan (15, 30, 50 mg x kg(-1) x d(-1)) or saline intragastrically. Then the rats received an OVA challenge for 30 alternative days. Acetylcholine (Ach)-induced bronchoconstriction was measured after the final antigen challenge. White cell counts in bronchoalveolar lavage fluid (BALF) and morphological changes in the airways were then assessed. The levels of transforming growth factor-beta 1 (TGF-beta(1)) and platelet-derived growth factor (PDGF) in BALF were detected by ELISA. The levels of AGTR1 and AGTR2 mRNA and protein in lung tissues were measured by RT-PCR and Western blotting. RESULTS: AGTR1 mRNA and protein levels in repeatedly OVA-challenged rats were significantly increased as compared with negative controls. The AGTR1 mRNA expression versus white cell counts of BALF and airway wall thickness (mainly in small airways) in lungs of chronic antigen-exposed rats were positively correlated. Valsartan decreased the level of AGTR1 in repeatedly OVA-challenged rats. However, AGTR2 mRNA and protein levels in the OVA-challenged rats and high-dose valsartan-treated rats (50 mg x kg(-1) x d(-1)) were also increased. Valsartan significantly decreased inflammatory cell accumulation and attenuated Ach-evoked bronchoconstriction in repeatedly antigen-challenged rats. Valsartan also decreased allergen-induced structural changes in rat airway (including total airway wall thickness and smooth muscle area) and the levels of TGF-beta(1) and PDGF in BALF. CONCLUSIONS: AGTR1 expression is potentially associated with airway remodeling and dysfunction in asthma. Ang II and AGTR1 may participate in airway inflammation and airway remodeling of chronic antigen-exposed rats. Valsartan, a AGTR1 antagonist, could inhibit AGTR1 expression and partially inhibits structural airway changes as well as airway inflammation in chronic OVA-exposed rats. SN - 2542-5641 UR - https://www.unboundmedicine.com/medline/citation/19080339/Effect_of_valsartan_on_the_expression_of_angiotensin_II_receptors_in_the_lung_of_chronic_antigen_exposure_rats_ L2 - https://Insights.ovid.com/pubmed?pmid=19080339 DB - PRIME DP - Unbound Medicine ER -