Initial stages of endogenous DNA degradation in rat liver nuclei isolated and incubated in the presence of Mg 2+ or polyamines

Abstract

1. 1. This paper compares electrophoretic patterns of initial endogenous DNA degradation products, extracted from rat liver nuclei isolated and incubated in the presence of 5 mM of MgCl 2 or polyamines—0.15 mM of spermine and 0.5 mM of spermidine—for selected periods of time at 37° C. 2. 2. It was found that polyamines significantly slowed down the rate of DNA degradation in rat liver nuclei and did not essentially affect the pattern of supranucleosomal step of DNA breakdown. 3. 3. The differential stability of DNA in magnesium and polyamine nuclei were better expressed in the course of long-term incubation of nuclei at 4°C.