title: Angiotensin-II down-regulates cardiac natriuretic peptide receptor-A mediated anti-hypertrophic signaling in experimental rat hearts.
abstract: Atrial natriuretic peptide (ANP) exerts anti-hypertrophic effects in the heart via natriuretic peptide receptor-A (NPR-A). However, ANP mediated anti-hypertrophic activity is decreased in the cardiomyopathic conditions. In the present investigation the in vivo effects of angiotensin II (Ang II), a hypertrophic agonist have been studied on the ventricular expression level of NPR-A in Wistar rat hearts. NPR-A expression at the protein and mRNA levels were found to be markedly reduced by 5-fold respectively in Ang II infused rats heart as compared with sham rat hearts. Moreover, cGMP production in response to ANP was reduced by 77% in the isolated cardiac membrane preparation from the Ang II infused rat hearts. Losartan treatment reversed NPR-A expression and responsiveness to ANP. This study suggests that Ang II down regulates cardiac NPR-A activity by suppressing Npr1 gene transcription.
authors: Department of Biochemistry, University of Madras, Guindy Campus, Chennai 600 025, India.
authors: Venkatachalam
authors: V
authors: Gopi
authors: Arumugam
authors: A
authors: Parthasarathy
authors: Subramanian
authors: S
authors: Umadevi
authors: Elangovan
authors: E
authors: Vellaichamy
mesh_terms: D000804:Angiotensin II / Q000378:metabolism*; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000737:chemistry; D015536:Down-Regulation; D005786:Gene Expression Regulation; D006162:Guanylate Cyclase / Q000378:metabolism; D006321:Heart / Q000502:physiology*; D006352:Heart Ventricles / Q000473:pathology; D017379:Hypertrophy, Left Ventricular / Q000473:pathology; D008297:Male; D008954:Models, Biological; D009206:Myocardium / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D017461:Receptors, Atrial Natriuretic Factor / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D000804:Angiotensin II; D009320:Atrial Natriuretic Factor; D006162:Guanylate Cyclase; D017461:Receptors, Atrial Natriuretic Factor; C091715:atrial natriuretic factor receptor A