Deleterious effects of calcium deprivation on freshly isolated hepatocytes

Biochemical and morphological properties of rat hepatic parenchymal cells isolated without calcium were compared to cells isolated by adding calcium to the isolation medium at the time of addition of collagenase. Calcium contents of the two cell preparations were 4.5 +/- 0.3 and 10.5 +/- 0.5 nmol/mg dry wt, respectively (P les than 0.001). Magnesium content of both preparations was 37 nmol/mg dry wt. Potassium contents were 92 and 154 meq/l, respectively (P less than 0.001). Potassium content of calcium-deficient cells increased to 161 meq/l following incubation for 30 min in a medium containing 1.6 mM ionized calcium. When incubated in a medium containing a subphysiologic concentration of ionized calcium, calcium-deficient cells rapidly lost the ability to exclude trypan blue and to retain lactate dehydrogenase activity. As contrasted to calcium-sufficient hepatocytes, calcium-deficient cells failed to accumulate alpha-aminoisobutyric acid by active transport and lacked microvilli and nuclear contents. This study supports simultaneous addition of calcium and collagenase to the isolation medium as a means for preserving physical, functional, and morphological integrity of isolated hepatic parenchymal cells.