[Thymidine phosphorylation with the participation of rat thymic and hepatic thymidine kinase in the presence of a factor from Cl. perfringens (welchii)].

Factor CPW, isolated from Cl. perfringens/welchii was shown to activate latent thymidine kinase (factor N) from liver tissue of rats beginning from 42 days age. CPW factor activated 3.5-fold also thymidine kinase from rat strumous gland; the enzyme was observed during involution of the tissue. The data suggest that increase in thymidine kinase activity in proliferating tissues is related to activation of latent enzymes.