[The functional status of the small intestine in rats in the dynamics of a bone marrow form of acute radiation sickness].

A study was made of 75Se-methionine absorption rate and contraction and choline-reactivity of smooth muscle cells of rat jejunum longitudinal layer. Whole-body X-irradiation with a dose of 5.8 Gy (LD50/30) caused a sharp decrease in the rate of absorption of 75Se-methionine by the blood from the intestine on days 3--4 after irradiation followed by an incomplete recovery of absorption by the 14th day. At the height of acute radiation sickness there was an 8- to 10-fold decrease in the sensitivity of the smooth muscle cell membrane to acetylcholine the contractile capacity being retained. This was perhaps the cause of the intestine motor activity inhibition. It is concluded that rat intestine functions are suppressed considerably with the bone marrow form of acute radiation sickness.