The History of the WHHL Rabbit, an Animal Model of Familial Hypercholesterolemia (I) - Contribution to the Elucidation of the Pathophysiology of Human Hypercholesterolemia and Coronary Heart Disease.

Animal models that closely resemble both human disease findings and their onset mechanism have contributed to the advancement of biomedical science. The Watanabe heritable hyperlipidemic (WHHL) rabbit and its advanced strains (the coronary atherosclerosis-prone and the myocardial infarction-prone WHHL rabbits) developed at Kobe University (Kobe, Japan), an animal model of human familial hypercholesterolemia, have greatly contributed to the elucidation of the pathophysiology of human lipoprotein metabolism, hypercholesterolemia, atherosclerosis, and coronary heart disease, as described below. 1) The main part of human lipoprotein metabolism has been elucidated, and the low-density lipoprotein (LDL) receptor pathway hypothesis derived from studies using fibroblasts was proven in vivo. 2) Oxidized LDL accumulates in the arterial wall, monocyte adhesion molecules are expressed on arterial endothelial cells, and monocyte-derived macrophages infiltrate the arterial intima, resulting in the formation and progression of atherosclerosis. 3) Coronary lesions differ from aortic lesions in lesion composition. 4) Factors involved in the development of atherosclerosis differ between the coronary arteries and aorta. 5) The rupture of coronary lesions requires secondary mechanical forces, such as spasm, in addition to vulnerable plaques. 6) Specific lipid molecules in the blood have been identified as markers of the progression of coronary lesions. At the end of the breeding of the WHHL rabbit family at Kobe University, this review summarizes the history of the development of the WHHL rabbit family and their contribution to biomedical science.

The History of the WHHL Rabbit, an Animal Model of Familial Hypercholesterolemia (II) - Contribution to the Development and Validation of the Therapeutics for Hypercholesterolemia and Atherosclerosis.

A number of effective drugs have been developed through animal experiments, contributing to the health of many patients. In particular, the WHHL rabbit family (WHHL rabbits and its advanced strains (coronary atherosclerosis-prone WHHL-CA rabbits and myocardial infarction-prone WHHLMI rabbits) developed at Kobe University (Kobe, Japan) contributed greatly in the development of cholesterol-lowering agents. The WHHL rabbit family is animal models for human familial hypercholesterolemia, coronary atherosclerosis, and coronary heart disease. At the end of breeding of the WHHL rabbit family, this review summarizes the contribution of the WHHL rabbit family to the development of lipid-lowering agents and anti-atherosclerosis agents. Studies using the WHHL rabbit family demonstrated, for the first time in the world, that lowering serum cholesterol levels or preventing LDL oxidation can suppress the progression and destabilization of coronary lesions. In addition, the WHHL rabbit family contributed to the development of various compounds that exhibit lipid-lowering and anti-atherosclerotic effects and has also been used in studies of gene therapeutics. Furthermore, this review also discusses the causes of the increased discrepancy in drug development between the results of animal experiments and clinical studies, which became a problem in recent years, and addresses the importance of the selection of appropriate animal models used in studies in addition to an appropriate study design.

Pleiotropic effects of statins: new therapeutic targets in drug design.

The HMG Co-enzyme inhibitors and new lipid-modifying agents expand their new therapeutic target options in the field of medical profession. Statins have been described as the most effective class of drugs to reduce serum cholesterol levels. Since the discovery of the first statin nearly 30 years ago, these drugs have become the main therapeutic approach to lower cholesterol levels. The present scientific research demonstrates numerous non-lipid modifiable effects of statins termed as pleiotropic effects of statins, which could be beneficial for the treatment of various devastating disorders. The most important positive effects of statins are anti-inflammatory, anti-proliferative, antioxidant, immunomodulatory, neuroprotective, anti-diabetes, and antithrombotic, improving endothelial dysfunction and attenuating vascular remodeling besides many others which are discussed under the scope of this review. In particular, inhibition of Rho and its downstream target, Rho-associated coiled-coil-containing protein kinase (ROCK), and their agonistic action on peroxisome proliferator-activated receptors (PPARs) can be viewed as the principle mechanisms underlying the pleiotropic effects of statins. With gradually increasing knowledge of new therapeutic targets of statins, their use has also been advocated in chronic inflammatory disorders for example rheumatoid arthritis (RA) and in systemic lupus erythematosus (SLE). In the scope of review, we highlight statins and their pleiotropic effects with reference to their harmful and beneficial effects as a novel approach for their use in the treatment of devastating disorders. Graphical abstract Pleiotropic effect of statins.

Disease-mongering through clinical trials.

Our goal in this paper is to articulate a precise concept of at least a certain kind of disease-mongering, showing how pharmaceutical marketing can commercially exploit certain diseases when their best definition is given through the success of a treatment in a clinical trial. We distinguish two types of disease-mongering according to the way they exploit the definition of the trial population for marketing purposes. We argue that behind these two forms of disease-mongering there are two well-known problems in the statistical methodology of clinical trials (the reference class problem and the distinction between statistical and clinical significance). Overcoming them is far from simple.

Stents and statins: history, clinical outcomes and mechanisms.

The 1980s witnessed the inception of both stents and 3-hydroxy-3-methyl-glutaryl-CoA reductase inhibitors (statins). While they evolved separately, it was soon realized that they each offered a unique and powerful mechanism for targeting the major offender in cardiovascular disease, namely atherosclerosis. Coincidentally, the first statin was approved by the US FDA in 1987, the same year that the coronary stent was conceived. Since that time, stents and statins have revolutionized the field of cardiovascular medicine and their paths have been intertwined. Several pivotal randomized clinical trials have established statins as an effective therapy for improving clinical outcomes after percutaneous coronary intervention (PCI) among patients presenting with stable coronary artery disease and acute coronary syndromes. In addition, chronic statin therapy and acute loading of statins prior to PCI has consistently been shown to limit periprocedural myocardial necrosis. The mechanism for improved clinical outcomes with statins has clearly been associated with statin-induced reductions in LDL. In addition, statins may also exert 'pleiotropic' effects, independent of LDL lowering, that might counteract the inflammatory and prothrombotic mileu created with PCI. This article provides a brief historical perspective of the evolution of the use of statins and stents in patients with coronary artery disease, an evaluation of the available clinical data supporting the use of statins in patients undergoing PCI across a wide spectrum of clinical scenarios, and a discussion of the potential mechanisms of the benefit of statins in these patients.

A historical perspective on the discovery of statins.

Cholesterol is essential for the functioning of all human organs, but it is nevertheless the cause of coronary heart disease. Over the course of nearly a century of investigation, scientists have developed several lines of evidence that establish the causal connection between blood cholesterol, atherosclerosis, and coronary heart disease. Building on that knowledge, scientists and the pharmaceutical industry have successfully developed a remarkably effective class of drugs--the statins--that lower cholesterol levels in blood and reduce the frequency of heart attacks.

The Watanabe heritable hyperlipidemic (WHHL) rabbit, its characteristics and history of development: a tribute to the late Dr. Yoshio Watanabe.

Professor Yoshio Watanabe, who developed the WHHL rabbit, died on December 13, 2008. He had contributed to studies of lipoprotein metabolism and atherosclerosis, and to the development of hypolipidemic and/or anti-atherosclerotic compounds. WHHL rabbits show hypercholesterolemia due to deficiency of LDL receptors, and very similar lipoprotein metabolism to humans. The incidences of coronary atherosclerosis and myocardial infarction in the original WHHL rabbits were very low. After three rounds of selective breeding, the coronary plaques changed to fibroatheromas with thin fibrous caps and myocardial infarction developed spontaneously. In studies with WHHL rabbits, plaque-stabilizing effects of statins were proved. In this review, we admire his achievements and describe the history of studies using WHHL rabbits.

Statins: in the beginning.

Since the first human trial of a hydroxymethylglutaryl-coenzyme A (HMG CoA) reductase inhibitor in 1978, the growth in importance of this drug class, both financially and medically, has been staggering. The aim of this paper is to summarise how this drug class was developed, highlighting the role ofAkira Endo.

History of the cholesterol controversy in Britain.

The lipid hypothesis, the concept that cholesterol plays a causal role in atherosclerosis and cardiovascular disease, has been the subject of a controversy which started in the 1950s, peaked in the 1970s and 80s and then subsided in the 1990s. It was finally resolved by the positive outcome of the Scandinavian Simvastatin Survival Study, the first of 14 prevention trials using statins which showed that lowering cholesterol reduced both cardiovascular events and total mortality. This commentary focuses primarily on the events and people involved in the cholesterol controversy in Britain. The foremost critics of the lipid hypothesis are now deceased but unfortunately for many of the patients with hypercholesterolaemia and coronary heart disease it took the best part of 50 years to disprove the sceptics. This brief account relates why it took so long.

The discovery of statins.

This year, the Lasker Foundation confers its Clinical Medical Research Award on Akira Endo for his isolation from fungi of statins, potent inhibitors of cholesterol synthesis in the liver. The introduction of statins to clinical practice has markedly reduced morbidity and mortality from atherosclerotic cardiovascular disease.

Simvastatin: two decades in a circle.

Simvastatin is an agent of the 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor group of drugs. It is administrated orally once a day in doses of 5-80 mg. Although its main action is to reduce total and low-density lipoprotein (LDL) cholesterol, it is able to reduce triglycerides and increase high-density lipoprotein cholesterol levels, though at a lower extent. Beyond this action, studies enrolled with simvastatin have shown beneficial effect on endothelial function, smooth muscle cell function, hemostasis, vascular wall function, LDL oxidation, and inflammation. All these actions mentioned above are known as pleiotropic effects. In this review, we will present all these effects, as well as the beneficial effects on atherogenesis and the reduction in cardiovascular morbidity and mortality related to simvastatin.

Sobre el descubrimiento de los fármacos hipolipemiantes / About the discovery of hypolipidemic drugs

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