The Biochemical Basis of Neuropharmacology

portant in the fetal and neonatal periods, and finally, EP studies in human disease. The monograph tells us that EP is the principle hormone which regulates erythropoiesis. It is a glycoprotein with a molecular weight of 60,000 to 70,000. The kidney produces either the hormone itself or an enzyme activating the plasma substrate. The site of EP production in the kidney is unknown, but the greatest concentration is separated in a "light mitochondrial" fraction. EP acts by causing a committed but undifferentiated cell to differentiate into an erythroblast, and may also have a role in causing maturation of erythroblasts. In bone marrow culture, EP acts sequentially to increase synthesis of RNA, then DNA, and to increase incorporation of iron into red cells and into heme. On a clinical level, anemias due to hemorrhage, hemolysis, and vitamin deficiencies are associated with elevated EP, whereas the anemias of uremia, protein starvation, and chronic inflammation are not. Administration of EP, when it becomes available, should benefit at least the latter conditions. Polycythemias secondary to hypoxia and tumors may be associated with elevated EP levels, whereas primary polycythemias are not. This information and much more has been acquired largely by using bioassay techniques such as injecting plasma or tissue extracts into the polycythemic mouse and measuring iron incorporation into red cells. In vitro methods for EP measurements are available, but it is yet uncertain that what they measure corresponds to erythropoietic potency. Solution of this problem will be an important breakthrough. Although the book is generally well written, its readability is occasionally compromised by the authors' scholarly approach. All sides of every debate are presented. A positive statement quoted from one publication is likely to be qualified by a second and contradicted by a third. Paragraphs are sometimes interrupted by several lines of reference numbers. (The last 100 pages of the volume are devoted to the reference list.) The scholarly fair play and footnoting will assist EP researchers but may prove tedious to those with a lesser commitment to this field. There are no tables or figures, but there is an index which seems excellent.