Copper-rich nucleoprotein generated by micrococcal nuclease

The nature of intracrine peptide hormone action

Current theory holds that peptide hormone action results from hormone binding to cell-surface receptors, with the generation of intracellular second messengers. However, a growing body of evidence suggests that intracellular peptide hormone, either internalized or synthesized in situ, can exert physiologically relevant effects. These effects are diverse and poorly understood. I propose that such intracrine action can serve to modulate cellular function over time and thereby play a role in biological memory of various sorts, in the maintenance of hormonal responsiveness, and in cellular differentiation.

The application of molecular genetic techniques to the study of hypertensive diseases

The techniques of modern molecular genetics are shedding new light on hypertension and its sequelae. This article discusses techniques which have identified genes associated with hypertension and have pointed the way toward identifying the full cohort of genes operative in all forms of human hypertension. These techniques have expanded understanding of the pathophysiology of hypertension as well as its prevention.

Emerging issues in the cellular biology of the cardiovascular system

Current theory suggests that life began in a prebiologic era, progressed to a ribonucleic-deoxyribonucleic cellular era, and finally entered an era characterized by multicellular organisms. If this progression is correct, it is not surprising that, as medicine studies living organisms with increasing sophistication, factors that are initially discovered to have systemic effects are, in many instances, later determined to have paracrine, autocrine or even intracellular ("intracrine") effects. This schema is potentially of value in analyzing the pathogenesis of cardiovascular disease and, in particular, the development of the sequelae of hypertension. A case is made for the idea that the actions of common peptide and nonpeptide factors at local tissue levels can play an important role in the development of atherosclerosis and left ventricular hypertrophy. In making this case, the potential roles of insulin, angiotensin II and other vasoactive factors are considered. In addition, it is argued that some peptide and nonpeptide factors with cardiovascular impact may operate in the intracellular environment, thus broadening prospects for study and intervention. Finally, genomic alterations either spontaneously occurring or resulting from chronic stimulation or viral infection are considered and their potential role is discussed.

Cellular mechanisms of growth in cardiovascular tissue

Left ventricular hypertrophy is a complex cellular response to a variety of pathologic states. In recent years it has become clear that a variety of hormones are present in the heart and may participate in the genesis of left ventricular hypertrophy. Our group has demonstrated the synthesis of renin by cultured canine arterial smooth muscle cells and has recently demonstrated the presence of renin and angiotensin II in myocardial cell preparations. Angiotensin II concentration was (+/- standard error of the mean) 4.19 +/- 1.52 pg/10(6) cells. Evidence has been developed to suggest that these components of the renin-angiotensin system are modulatable. These data, taken together with studies from our laboratory and others, raise the distinct possibility that components of the renin-angiotensin system together with catecholamines play a role in the genesis of left ventricular hypertrophy. Recent evidence suggests that the myc proto-oncogene is activated in cells undergoing catecholamine-induced hypertrophy and our laboratory has detected activation of the sis proto-oncogene in at least 1 model of left ventricular hypertrophy. These findings raise the possibility that similar pathogenetic cellular mechanisms operate to produce myocardial hypertrophy, vascular hyperplasia and hypertrophy, and some forms of benign neoplasia. The possible significance of these findings and their relation to peptide hormones and growth factors are discussed.