Gluconeogenesis, its regulation in mammalian species

Despite the adoption of the enfant trouuk-gluconeogenesis-by any biochemist currently professing to a study of metabolic regulation, the number of books devoted to the topic is small indeed. Of those that have appeared in recent years most have been the proceedings of symposia, and superficially this book may appear to be another in the same vein, since it is a multi-author collection of articles canvassed by the editors. However, it differs from most symposia volumes by considering the chosen topics in more breadth and depth. Unfortunately, in allowing the contributors ‘to write whatever seemed appropriate’ the dangers of unevenness in presentation, overlap in subject matter and omission of significant aspects are not always avoided. To the editors’ credit, however, they were clearly aware of the problem and have shown considerable conscientiousness in providing a unifying commentary at the beginning of the book in an extended preface. Nevertheless, the omissions remain, and the most regrettable is the absence of a contribution by Henry Lardy, although this is perhaps understandable since the volume is dedicated to this outstanding biochemist, whose impressive achievements are chronicled briefly at the beginning of the book. Thus a detailed account of the regulatory role of substrate cycling i s absent (fortunately Lardy has reviewed this recently elsewhere). Other omissions include the more physiological aspects of the regulation of gluconeogenesis, such as the role of hormonal interrelationships (John Exton was conspicuous by his absence as a contributor) and the control of substrate flux to gluconeogenic tissues. This was compensated for to some extent by the inclusion of admirable reviews of pathophysiological aspects of gluconeogenesis in the human by Ruderman et al. and Owen et al. and of a review of the gluconeogenic function of the kidney by Pogson et al. The other chapters in the book are uniformly of a similar high standard, and range from thought-provoking considerations of metabolite concentrations and their relation to metabolic rates (in papers by Srere and Veech) to studies using isolated hepatocytes to clarify interrelations between gluconeogenesis and ureogenesis (Krebs et al.). A consistent and praiseworthy feature of many chapters is the extensive discussion of mammalian species other than the rat; indeed, in what is arguably one of the ‘highlights’ of the book, Soling & Kleineke exhaustively review the regulation of gluconeogenesis in different animal species. In separate papers all the key enzymes of gluconeogenesis (pyruvate carboxylase, phosphoenolpyruvate carboxykinase, fructose bisphosphatase and glucose 6-phosphatase) are considered and the implications of their intracellular compartmentation are emphasized. Extending this aspect of compartmentalization of metabolism is an excellent discussion of the regulatory role of mitochondria1 anion transport by John Williamson, which embraces the broader aspects of metabolic regulation. Despite all the information on each of the key enzymes it is nonetheless still impossible to pinpoint which holds regulatory supremacy as the rate-limiting step and, in view of the emphasis placed on mitochondria1 translocations in the book, it is perhaps regrettable that a contribution by Haynes on