Multichannel analysis of intracellular control and intercellular transfer of molecules.

The metabolic regulation and exchanges within intracellular organelles or a cell cluster are studied by multichannel microfluorometry and microinjection of metabolites or tracers. The determination of structure-function relationships relies on the retrieval of cells after microfluorometry, for subsequent morphological evaluation. Rate constants of coenzyme reduction-reoxidation were deduced from a mathematical model of NAD(P) in equilibrium with NAD(P)H transients due to microinjection of metabolites into cultured cells belonging to a variety of normal or malignant lines. Nuclear and cytoplasmic sites operate synchronously or not, depending upon metabolic demand or pathological alterations. Intercellular transit times are determined for tracers and metabolites. Within cell clusters 'communicating territories' are described, which can show metabolically a multicellular integrated state. Microfluorometry in conjunction with ultrastructural and other studies can be used to develop a cybernetic model of the living cell, also yielding dynamic models of cooperative and regulatory interactions between different kinds of specialised cells within a cell cluster.