Transport of Neutral and Dibasic Amino Acids by Human Leukocytes: Absence of Defect in Cystinuria*

The mechanisms by which cells transport and accumulate vital metabolites such as cations, an- ions, sugars, and amino acids have come under careful scrutiny during recent years. Although this subject is of great interest to investigators of human physiology and disease, the lack of suitable and accessible human cell preparations for in vitro study has made progress in this field difficult. During the past decade methods have been de- vised for the isolation of human leukocytes from peripheral blood, and such cells have been used to study a wide range of physiologic and biochemi- cal mechanisms (1). To date, however, leuko- cytes have been used sparingly in studies of ion or nonelectrolyte transport.