[Tissue-specific inhibition of DNA synthesis by contactins, factors that possess tissue-specific adhesive activity]

Highly purified factors extracted from the liver and lungs of adult rats, tissue-specifically increasing the stability of intercellular contacts and of cell plasma membranes to mechanical disruption, were found to decrease, in the same manner, the labeling index (LI) in explants of the embryonic tissue of mice. The comparison of the action of these factors on the LI, and on mechanical properties of the tissue has shown that the latter effect is manifested earlier than the former one.