Frequently attempts to design experiments utilizing the methodology de scribed in articles in trade journals can be frustrating. Description of procedures, because of space constraints, are not always complete. The present volume attempts to bring together in one reference source many of the techniques which are utilized in the study of the kidney. It provides a thorough compendium of research tools, framed by the critical analysis of the theoretical background of renal physiology, biochemistry, and pharmacology discussed in Volume 4A. Some areas previously dealt with are not covered from a methodological point of view since adequate information does exist elsewhere (e.g., methods of whole kidney ATPase isolation). Since drugs acting on the kidney may alter not only functional but anatomical integrity, a chapter on the preparation of tissue for morphological studies has been included. The important developments in analy sis of minute (ultramicro) quantities of tissue and biological fluids, as well as methodological advances in studies of the isolated kidney, are thoroughly covered. It is my hope that investigators, research fellows, and graduate students will benefit from the information contained in this volume and that, together with its companion tome, it will be a ready reference for the renal physiologist, the renal pharmacologist, and the nephrologist. The contributors have provided painstaking descriptions and, when re quired, mathematical analyses of the techniques described herein. I wish to thank all of them for their enthusiasm and the excellence of their contributions."

This book started out as a "Manual. " The idea was to offer straightforward instruction on how to handle patients in whom renal function is altered by intrinsic as well as systemic or extrarenal disease. While we have attempted to provide simple approaches to most conditions, we have gone beyond that and offer here more detailed description of pathophysiology, diagnosis and therapy. Thus, the "Manual" has become a Handbook. In so doing we hope we have widened the audience for which the book may be useful. As it now stands, we envision that students, house staff, nephrology trainees, nephrologists, primary-care physicians, and nurses of specialized units, interested in kidney-related disturbances and in alterations of the composi tion of the extracellular fluid, will benefit from reading the Handbook. While providing a rational background for the treatments outlined, each author has attempted to narrate the reasons why such therapy is utilized. Frequently, the information is provided in tables and figures to which ready reference can be made. The flow-chart approach has also been utilized to illustrate pathophysiological sequence or steps in therapy. In most instances, the discussion of pathophysiology has been limited to what is widely ac cepted rather than treading into anything controversial, unless the nature of the problem or the nature of our knowledge is ambiguous."

In the years since Homer Smith did his pioneering work in renal physiology, interest in the kidney has grown steadily and robustly. That this wondrously designed machine-in addition to its filtering, secreting, and reabsorptive functions-can serve as an important endocrine organ has made it the investiga tive concern of researchers from a variety of disciplines. Not surprisingly in this era of molecular biology, attempts have been made to understand the orderly functions of the kidney in biochemical and molecular terms, and this has led to the steady entry of renal physiologists and pharmacologists into these areas. Because renal physiology is the foundation on which renal pharmacology is based, this volume has been directed toward describing and interpreting the interrelationships of these two disciplines and their relation to the biochemistry and biophysics of the kidney. Accordingly, extensive critical discussions of the current knowledge of mechanisms affected by pharmacological agents, in addition to descriptions of methods, have been included herein. Not acciden tally, stress is placed on the physiological, pharmacological, and biochemical effect of diuretics. In a specific sense the drugs in this group are true "renal drugs." The scope of the material included on diuretics is wide enough that this book should be of value to almost anyone involved in their use, from the clinician to the cell biologist."