Poly ADP-ribosylation was studied, which is a post translational modification of chromatin protein catalysed by the enzyme poly ADPR polymerase using NAD+ as the substrate. Poly ADP-ribosylation has been shown to be involved in several aspects of chromatin function and structure.
The enzyme activity was increased in liver and testis and was decreased in diencephalon and brain cortex. No altered enzyme activity was found in kidney and spleen.
The results of the NAD+ level estimation was diametrically opposed to the enzyme activity: A drop of NAD+ levels was found in liver and testis whereas cortex and diencephalon showed an increase. The determination of protein by SDS-PAGE showed no changes at all to the controls.