Salutary properties of YC-1 in the cardiovascular and hematological systems.

The soluble guanylate cyclase (sGC)/cyclic guanosine monophosphate (cGMP) second messenger system provides a complex and highly regulated mechanism for signal transduction events and ensuing functional responses through a cascade of serine/threonine protein kinase-dependent pathways. Nitric oxide (NO) and carbon monoxide (CO), two unique diatomic gases endogenously produced by the respective enzymes nitric oxide synthase (NOS) and heme oxygenase (HO), stimulate cellular sGC and synthesize cGMP within the vasculature. Emerging evidence suggests that the independent NOS and HO systems provide reciprocal and complimentary approaches that act to regulate cardiovascular and hematological homeostasis as well as provide protection to the vasculature in response to inimical stimuli or following the onset of vasoproliferative disease. Recent results from our laboratory and others suggest that the newly identified, chemically synthesized benzyl indazole derivative YC-1 is capable of exerting multifunctional and broad-ranging effects in the cardiovascular and hematological systems. YC-1 has been demonstrated to possess redundant biochemical mechanisms that confer significant stimulation upon NO- and CO-regulated, cyclase-dependent events. Ultimately, these acute molecular processes eventuate in YC-1-dependent modulation of platelet and vascular smooth muscle cell (SMC) and endothelial cell (EC) function under both eutrophic and deleterious conditions. Based on accumulating evidence, YC-1 has been suggested to serve as a potential therapeutic adjuvant to be used in interventional medicine, and these results may indicate the existence of an endogenous " YC-1-like" compound that would be the focus of much anticipated investigation. The purpose of this review, therefore, is to provide update information on the mechanisms and physiologic and pathophysiologic roles of the pivotal new multifunctional agent YC-1 in the cardiovascular and hematological systems, and to provide evidence for its potential use as a clinically relevant salutary agent.