These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Regulation of the myocardial endothelin system by angiotensin-II and losartan.
    Author: McEwan PE, Sherry L, Kenyon CJ, Webb DJ, Gray GA.
    Journal: J Cardiovasc Pharmacol; 2000 Nov; 36(5 Suppl 1):S144-7. PubMed ID: 11078361.
    Abstract:
    Evidence for interactions between the endothelin (ET) and renin-angiotensin systems is plentiful in vitro, but few studies have investigated these interactions in vivo. In the study reported here, we have investigated the influence of chronic angiotensin-II (A-II) infusion in vivo on expression of preproendothelin-1 (PPET-1) and endothelin-A- (ET(A)) and endothelin-B- (ET(B)) receptor mRNA in the heart. The role of the angiotensin type 1 (AT1)-receptor in mediating the actions of A-II was studied using losartan, the selective AT1-receptor antagonist. Male rats received an infusion of A-II (200 ng/kg/min) or vehicle for 14 days via mini-osmotic pumps; losartan (10 mg/kg/day) was administered in the drinking water. PPET-1 and ET(A)- and ET(B)-receptor mRNA were detected in heart sections using nonradioactive antisense in situ hybridization. Independent treatments with either A-II or losartan had no significant effect on PPET-1, ET(A)- or ET(B)-receptor expression. Combined treatment resulted in an increase in PPET-1 mRNA (p < 0.001) and ET(B)-receptor mRNA expression (p < 0.01), while ET(A)-receptor mRNA expression was decreased (p < 0.001). These results suggest that selective AT1-receptor blockade, in the presence of an elevated plasma A-II concentration, causes upregulation of ET-1 synthesis in the myocardium as well as modification of ET receptor expression. These effects may be mediated via angiotensin type 2 (AT2)-receptors.
    [Abstract] [Full Text] [Related] [New Search]