[On corticosteroid control of NAD splitting in rat liver].

Hydrocortisone increases the NAD-glycohydrolase activity in the liver of intact rats. Actinomycin D does not influence the stimulating effect of hydrocartisone with respect to the NADase activity of the liver. The degree of activation of NAD enzymic splitting with administration of 200 mg/kg of nicotinamide depends on the initial hormonal background: with hypercorticoidism it is higher and with hypocorticoidism it is lower than the level found in the intact animals which were given the same dose of the vitamin. An inverse correlation between the steroid-dependent shifts of the NADase activity and the content of NAD in the liver may evidence for their interdependence. A conclusion is drawan on the paramount importance of corticosteroid control of the nucleotide splitting in vivo for formation of NAD cellular pool.