Recent studies of the cellular uptake of long chain free fatty acids.

Over the last 12 years, we and others have demonstrated that fatty acid uptake is not simply a passive, diffusive process, but an interesting, facilitated mechanism the regulation of which has specific implications for disease. This work also tells another tale. Our earliest experiments were called "squirt studies" by our technician because they involved "squirting" a bolus of labelled metabolite intravenously into one limb of the subject and drawing blood samples from another. These studies were conducted in patients, and later in intact animals. From these we moved progressively to investigations in isolated perfused organs, isolated cells, and sub-cellular organelles and membrane vesicles; to the chemistry of membrane proteins, and most recently, to studies combining recombinant DNA technology with cellular biologic studies of controlled differentiation in tissue culture (Figure 5). The work has been not only a continuing process of scientific investigation but, for the investigators, an on-going process of self-education.