[Evaluation of biological sequelae for cattle in the zone of the Chernobyl accident].

The influence of Chernobyl NPP outburst on cattle from farms in Russia and Belorussia was examined since 1988 to 1996. Changes in the level of thyroid hormones and imbalance in cAMP/cGMP ratio with increased cAMP concentration in blood were found. The content of cAMP and E, F2a prostaglandins was varied because of the disturbances in the rate of their metabolism. Two critical periods of pregnancy in cows were revealed. In the first half of pregnancy (the 4th-5th month) disorders in thyroid prevailed. In the second half (7th-9th month) changes in testosterone, progesterone, estradiol and estriol concentration were the most actual.