Founded in 1959 by its current Editor, the series has moved from its initial focus on medicinal chemistry to a much wider scope. Today it encompasses all fields concerned with the development of new therapeutic drugs and the elucidation of their mechanisms of action, reflecting the increasingly complex nature of modern drug research. Invited authors present their biological, chemical, biochemical, physiological, immunological, pharmaceutical, toxicological, pharmacological and clinical expertise in carefully written reviews and provide the newcomer and the specialist alike with an up-to-date comprehensive list of prime references. Each volume of Progress in Drug Research contains fully cross-referencing indices which link the books together, forming a virtually encyclopaedic work. The series thus serves as an important, time-saving source of information for researchers concerned with drug research and all those who need to keep abreast of the many recent developments in the quest for new and better medicines.

Founded in 1959 by its current Editor, the series has moved from its initial focus on medicinal chemistry to a much wider scope. Today it encompasses all fields concerned with the development of new therapeutic drugs and the elucidation of their mechanisms of action, reflecting the increasingly complex nature of modern drug research. Invited authors present their biological, chemical, biochemical, physiological, immunological, pharmaceutical, toxicological, pharmacological and clinical expertise in carefully written reviews and provide the newcomer and the specialist alike with an up-to-date comprehensive list of prime references. Each volume of Progress in Drug Research contains fully cross-referencing indices which link the books together, forming a virtually encyclopaedic work. The series thus serves as an important, time-saving source of information for researchers concerned with drug research and all those who need to keep abreast of the many recent developments in the quest for new and better medicines.

Hypertension is one of the cardiovascular diseases which is most common throughout the world. It is generally defined as an elevation of systolic and/or diastolic arterial blood pressure, which is 120/80 mm Hg in normal situation. A value of 140/90 mm is generally accepted as the upper limit of normotension. Hypertension with certain risk factors such as hypercholes terolemia, diabetes, smoking and a family history of vascular disease pre disposes to arteriosclerosis and consequent cardiovascular morbidity and mortality. The treatment of hypertension leads to reduced risk of hyperten sive renal failure, haemorrhagic stroke, myocardial infarction and cardiac failure. In most cases, the cause of the hypertension can not be clearly defined. Such hypertension is termed as essential hypertension. In a few cases (5- 15%), the hypertension is secondary to definable causes, such as renal artery stenosis, a pheochromocytoma, or an endocrine disorder. This type of hyper tension is known as secondary hypertenSion. Although the exact etiology of essential hypertension is still not well known, the following factors are sup posed to play causative roles."

Volume 45 of "Progress in Drug Research" contains eight reviews and the various indexes which facilitate its use and establish the connection with the previous volumes. The articles in this volume deal with neuro peptides as native immune modulators, with Calmodulin and with effects of cell stimuli and drugs on cellular activation, with recent advances in benzodiazepine receptor binding studies, with the medicinal chemistry and therapeutic potentials of ligands of the histamine H3 receptor, with Serotonin uptake inhibitors, with computer-aided drug design, with natri uretic hormones and with the recent developments in the chemotherapy of osteoporosis. In the 36 years that PDR has existed, the Editor has enjoyed the valu able help and advice of many colleagues. Readers, the authors of the reviews and, last but not least, the reviewers have all contributed greatly to the success of this series. Although the comments received so far have generally been favorable, it is nevertheless necessary to analyze and to reassess the current position and the future direction of such a series of monographs. So far, it has been the Editor's intention to help disseminate information on the vast domain of drug research, and to provide the reader with a tool with which to keep abreast of the latest developments and trends. The reviews in PDR are useful to the nonspecialist, who can obtain an overview of a particular field of drug research in a relatively short time."