Early sequence of cardiac adaptations and growth factor formation in pressure- and volume-overload hypertrophy

• Published in: American journal of physiology. Heart and circulatory physiology Vol. 279; no. 3; p. H976
• Main Authors: Modesti, P A, Vanni, S, Bertolozzi, I, Cecioni, I, Polidori, G, Paniccia, R, Bandinelli, B, Perna, A, Liguori, P, Boddi, M, Galanti, G, Serneri, G G
• Format: Journal Article
• Language: English
• Published: United States 01-09-2000
• Subjects: Adaptation, Physiological; Angiotensin II - biosynthesis; Angiotensin II - genetics; Animals; Blood Pressure; Cardiac Volume; Cardiomegaly - diagnostic imaging; Cardiomegaly - pathology; Cardiomegaly - physiopathology; Disease Models, Animal; Echocardiography; Endothelin-1 - biosynthesis; Endothelin-1 - genetics; Female; Hemodynamics; In Situ Hybridization; Insulin-Like Growth Factor I - biosynthesis; Insulin-Like Growth Factor I - genetics; Male; Myocardium - metabolism; Myocardium - pathology; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - metabolism; Swine
• ISSN: 0363-6135
• DOI: 10.1152/ajpheart.2000.279.3.H976

To investigate the time sequence of cardiac growth factor formation, echocardiographic and hemodynamic measurements were performed at scheduled times, and mRNAs for angiotensinogen, prepro-endothelin-1 (ppET-1), and insulin-like growth factor I (IGF-I) were quantified with RT-PCR and localized with in situ hybridization in pigs (fluothane anesthesia) by use of pressure or volume overload (aortic banding and aorta-cava fistula, respectively). Relative peptide formation was also measured by radioimmunoassay. In pressure overload, angiotensinogen and ppET-1 mRNA overexpression on myocytes (13 times vs. sham at 3 h and 112 times at 6 h, respectively) was followed by recovery (12 h) of initially decreased (0.5-6 h) myocardial contractility. In volume overload, contractility was not decreased, the angiotensinogen gene was slightly upregulated at 6 h (6.7 times), and ppET-1 was not overexpressed. IGF-I mRNA was overexpressed on myocytes (at 24 h) in both volume and pressure overload (14 times and 37 times, respectively). In the latter setting, a second ppET-1 overexpression was detectable on myocytes at 7 days. In conclusion, acute cardiac adaptation responses involve different growth factor activation over time in pressure versus volume overload; growth factors initially support myocardial contractility and thereafter induce myocardial hypertrophy.