Vasopeptidase inhibition: a new direction in cardiovascular treatment

The first preclinical pharmacotoxicological safety assessment of CGS 35601, a triple vasopeptidase inhibitor, in chronically instrumented, conscious, and unrestrained spontaneously hypertensive rats

CGS 35601 is a triple vasopeptidase inhibitor (VPI) of angiotensin-converting enzyme, neutral endopeptidase, and endothelin-converting enzyme-1 with respective IC50 values of 22, 2, and 55 nM. We characterized the safety profile and toxicity of escalating doses of CGS 35601 over a 20-day period in chronically instrumented, unrestrained, conscious, male, spontaneously hypertensive rats (SHR). Once instrumented with an arterial catheter, the SHR were placed in metabolic cages allowing daily assessment of hemodynamics and blood sampling for biochemical and hematological measurements. After a 7-day stabilization period, the SHR were divided into 2 groups: Gr. 1, (n = 13 to 18) receiving CGS 35601 at 0.01, 0.1, 1 and 5 mg kg(-1) day(-1) (continuous i.a. infusion) for 5 consecutive days/dose, followed by a 5-day washout; and Gr. 2, (n = 10) receiving vehicle (saline). The highest dose of CGS 35601 dose-dependently reduced MABP from 156 +/- 4 up to 94 +/- 5 mm Hg, whereas heart rate, metabolic, electrolytic, and hematological profiles, growth, diuresis, and renal activity were unaffected, and no hepatic or liver toxicities were observed. These results suggest that this novel triple VPI presents no safety concerns at this stage and may become of interest for the treatment of hypertension and other cardiovascular disorders. Long-term chronic experiments are needed to assess possible angioedema and increases in vascular permeability.

Transmembrane proteases in cell growth and invasion: new contributors to angiogenesis?

Transmembrane proteases (TPs) are proteins anchored in the plasma membrane with their catalytic site exposed to the external surface of the membrane. TPs are widely expressed, and their dysregulated expression is associated with cancer, infection, inflammation, autoimmune and cardiovascular diseases, all diseases where angiogenesis is part of the pathology. TPs participate in extracellular proteolysis (degradation of extracellular matrix components, regulation of chemokine activity, release of membrane-anchored cytokines, cytokine receptors and adhesion molecules) and influence cell functions (growth, secretion of angiogenic molecules, motility). Recent attention has been focused on the ADAM-17 (a disintegrin and metalloprotease)/TACE/CD156q, the MT1-MMP (membrane-type-1 matrix metallo proteinase)/MMP-14, and the ectopeptidases aminopeptidase N (APN/CD13), dipeptidyl peptidase IV (DPPIV/CD26) and angiotensin-converting enzyme (ACE/CD143), that appear to have a critical role in angiogenesis. This article summarizes current knowledge on these TPs, and reviews recent investigations that document their participation during angiogenic-related events. Through their multiple roles, TPs may thereby provide critical links in angiogenesis.

Effects of omapatrilat on pharmacodynamic biomarkers of neutral endopeptidase and Angiotensin-converting enzyme activity in humans

Vasopeptidase inhibition is a new concept in blood pressure management. A single molecule simultaneously inhibits two enzymes that regulate cardiovascular function: neutral endopeptidase (NEP) and angiotensin-converting enzyme (ACE)[1]. Development of vasopeptidase inhibitors stemmed from the need for new and more efficacious antihypertensive agents that not only reduce blood pressure but also treat hypertension as part of a larger syndrome involving endothelial dysfunction [2]. By inhibiting NEP and ACE, vasopeptidase inhibitors enhance the natriuretic peptide and kallikrein-kinin systems and inhibit the renin-angiotensin-aldosterone system. This article outlines the pharmacodynamic effects of the vasopeptidase inhibitor omapatrilat on biomarkers of NEP and ACE activity in humans.

The human genome project: a historical perspective

Efforts in genomics over the last decade have created a stream of opportunities for drug discovery. High-throughput DNA sequencing has forced a re-definition of the paradigm for identification and validation of targets for drug development. One purpose of this review is to delineate the different approaches to sequence data generation and to establish their various uses for the definition of gene function. There still remain crucial dilemmas for the pharmaceutical industry. The multitude of potential targets can each absorb enormous validation costs and the vast majority are likely to prove academically interesting but useless for drug development. An additional dimension arises from the importance of sequence variation between different individuals. These differences can determine response to therapy and must inform both the drug development process and healthcare delivery. This presents great challenges and opportunities for drug companies, their customers and society as a whole. I will review the technological aspects in some detail and give my view of the legal and social aspects. The field of bioinformatics is at the core of functional and pharmacogenomics and advances will depend on the continuing evolution of tools to interpret data. For the most part this evolution is reviewed in the context of specific application areas rather than as a discrete field, in recognition of its all-pervasive effects.