Number of congenital anomalies of the kidneys reaches 14% of the total number of anomalies that require searching fot new ways for prevention, diagnosis and treatment. The paper studies changes that occur in the kidney of rats of the first two months of postnatal life on the 1st, 3rd, 7th, 11th, 14th, 21th, 30th, 45th and 60th day of life in health and after intra-fetal antigen challenge. Three groups of animals took part in the experiment: 1st — intact rats, 2nd — rats which on the 18th day of intra fetal were introduced human gamma globulin (has no toxic, pyrogenic and aduvate influence); 3rd group — control, animals which on the 18th day of fetal development were administered 0.9% solution of NaCl.
Experiments revealed that intra-fetal administration of antigen leads to a number of changes in the kidney as compared to the intact animals and animals treated with intra-fetal saline. There is lower total area of the medulla substance in antigen-treated rats. The stages of formation and differentiation of the nephron accelerate. The area of connective tissue component in all periods of observation increase.