Advantages and disadvantages of using human cells for pharmacological and toxicological studies.

1. Marked species differences in the distribution and affinity of drug receptors, and in the patterns of biotransformation and susceptibility to the toxicity of xenobiotics, provide the impetus for using human tissues for pharmacological and toxicological studies. 2. Studies with intact cells facilitate the correlation of xenobiotic metabolism with cellular indices of toxicity, which can provide the mechanistic basis for understanding species differences in toxicity. 3. Human cells in suspension or primary culture reflect the variability in susceptibility to toxicity in a population. 4. The current limitation to these studies is scarcity of human material, the need for improved (cryo)preservation techniques for human hepatocytes/precision-cut slices and difficulties in predicting in vivo exposure-risk relationships from in vitro dose-response relationships.