data are presented indicating that both exogenous catecholamines ( i.e. , isoproterenol ) and endogenous catecholamines ( released from tyramine ) are able to bring about a degree of myocardial hypertrophy associated with a significant increase in the ventricular concentrations of hydroxyproline , without affecting hemodynamic parameters ( blood pressures and heart rate ) .
C0022245
isoproterenol
C0007412
catecholamines