Monoamine Oxidase and its Inhibition. CIBA Foundation Symposium 39

seems to be no clear evidence that changes in permeability of the lung and airway linings play an additional role although transport studies with substances of varying molecular size (Egan) suggest that pores in the membranes may increase in radius during birth. The fetal lung produces enormous amounts of liquid (250 ml per day) and its ionic composition is unlike that of a plasma ultrafiltrate. There is evidence of active ion transport in the lungs of fetal lambs as early as 87 days of gestation. Olver suggests that potentially all respiratory epithelial cells may be capable of active ion transport. In contrast with the fetal lung liquid, the fluid which accumulates in the lungs in pulmonary edema is rich in proteins and thus there must be some leak in the membranes. This fluid first enters perivascular and peribronchial interstitial spaces, but where it enters the alveoli is not certain. The common assumption is through leakage, enhanced by pressure differentials, through the alveolar epithelium, but Staub discusses why leakage through the epithelium of small airways may also contribute. Most papers contain useful lists of references up to 1975. There is a brief subject index. The reader is reminded that European scientists are switching over to the Systeme Internationale: pressures are given in cm of water and mm Hg as well as in kilopascals. My only gripe with the book is that several papers do not give sufficient detail about methods-one would need to consult the references to get to the bottom of some of the arguments. A bit more concern for the education of interested outsiders would not have been amiss. This is highly recommended reading for anyone interested in the lungs, but it is not an introduction for the novice.