New approaches to the study of the cellular biology of the cardiovascular system

Recent findings suggest that the local renin-angiotensin systems, locally generated catecholamines, and possibly other locally generated peptides interact in a complex fashion to regulate the cellular biology of the myocardium, the vascular wall, and other tissues. New evidence indicates that the components of the renin-angiotensin system are synthesized in cardiovascular tissues, that the synthesis of these components can be modulated by pharmacologic agents, and that angiotensin II, the effector protein of the renin system, appears to be capable of producing hypertrophy or hyperplasia in specific tissues. In addition, recent studies suggest the participation of enhanced proto-oncogene transcriptional activity in the development of hyperplasia and hypertrophy in cardiovascular tissue. Taken together, these data raise the possibility that angiotensin and perhaps other components of the renin system can be viewed as locally active growth factors capable of acting in a fashion similar to that associated with cytokines in other systems.