[The content of pyridine coenzymes in the liver of the adult and old rats in stress].

The concentration of oxidized and reduced NAD and NADP in the liver was studied in 36 adult (10-12 month old) and old (22-25 month old) male Wistar rats exposed to immobilization stress. It was established that content of piridine coenzymes in rat liver does not change with age. Immobilization stress decreases NADP reduction in adult animals, increases percentage of NADN in the total pool of reduced piridine coenzymes in the liver. In old stressed rats reduction of the NADP pool diminished accompanied by a distinct lowering of concentration of reduced NAD compared to its level in adult animals. It is suggested that shifts in the system of piridine coenzymes in the liver of adult rats support maintenance of effective function of the microsomal oxigenase chain in stress, in old animals promotes stress attenuation.