[Effects of x-ray irradiation on circadian rhythm of the level of microsomal hemoproteins in the rat liver].

The influence of X-irradiation of 12 Gy on the state of biorhythms of microsomal hemoproteins P-450 and b5 of the liver in male rats was studied. The content of these cytochromes was measured at 4, 10, 12, 15 and 21 hours in the course of the first and second days after X-irradiation and also on the fourth day (day of mass death of the irradiated rats). It has been found that disturbance of diurnal rhythms of these cytochromes begins already with third hour after X-irradiation and revealed in expressed depression of their acrophase. The diurnal rhythm of level of cytochrome P-450 is smoothed and takes the character of slowing down process, biorhythm of cytochrome b5 not being traced.