Belorussian Engineering Academy


Gomel State Medical Institute









Edited by Professor Yuri.Bandàzhevsky and Professor V.V. Lelevich


Chapter I






The problem of ionizing radiation effect upon the human organism bas been an ambitious task since the Chernobyl disaster. It is a current specific feature that ionizing radiation chronically affects the organisms of humans and animals through its incorporation with food. During recent years the disaster effects already touch greater contingents of people exposed to the ionizing radiation.

These conditions render the population group of pregnant women and infants critical [1,15,17]. Extensive research has been accomplished to get insight into the problem how radioactive exposure affects pregnancy, fetus and newborn development [3-5, 9, 13, 14]. It bas been revealed that the embryo is specifically vulnerable during critical “peri­ods” when this or that systems undergoes differentiation. Chronic exposure is particularly risky affecting various types of embryonic cells damaging a great number of germinal organs during such critical periods of their development, very small doses of ionizing radiation causing the maximum injury. Among other products of nuclear fission released by Chernobyl 137Cs and 90Sr having a long half life period are most detri­mental for the biological chain. Hence small doses of these radionuclides are continuously incorporated by living organisms with food.

So far there is insufficient insight into the effects of small doses of chronic endogenous incorporation of 137Cs and 90Sr upon the processes of prenatal and postnatal development. The objective of the present study is a comprehensive morphofunctional investigation of the features of prena­tal and postnatal development of common white rats when these radionuclides are incorporated with the components of their diet.

The major objectives of the study are the following:

1. To investigate the features of prenatal development of common white rats during endogenous incorporation of radionuclides (137Cs and 90Sr) with food.

2. To reveal the features of postnatal development of common white rats during endogenous incorporation of radionuclides (137Cs and 90Sr) with food.

3. To investigate the pattern of accumulation of 137Cs during its en­dogenous incorporation with grain by the mother and the offspring.

4 To reveal possible metabolic changes in the organism of female white rats in pregnancy during endogenous incorporation of radionu­clides (137Cs and 90Sr) with food.

The study covered 137 pregnant female common white rats, 745 embryos and 344 infant rats. The first day the sperm would be found in vaginal smears was assumed the pregnancy start. The animals were kept in the vivarium. The fetuses were extracted on the 20th day of intrauter­ine development because by this time the orthogenesis and placenta evolution would be completed

In order to investigate the features of prenatal and postnatal devel­opment the animals were kept on a diet providing a daily incorporation of radionuclides (beef and oats). The concentration in the food (meat and grain) for the diet of the control and test animals is shown in Table 1.1.

The daily incorporation of radionuclides by pregnant rats was esti­mated based on the food consumption (Table 1.2).

Therefore, the food radioactivity was primarily rated based on 137Cs.

The test and control animal groups to investigate prenatal and post­natal development were determined based on the qualitative composition of the diet (beef meat or oats) and the concentration of radionuclides (Table 1.3)

The following techniques were applied to achieve the objectives:

1. The method of Wilson modified by A.P. Dyban (A.P. Dyban et al., 1970) to investigate the condition of internal organs of fetuses.

In order to evaluate the condition of internal organs and the brain the embryos fixed in the Buen mixture were placed on a paraffin table and e series of parallel sections were made with a razor.

2. The Dowson method modified by A.P. Dyban 16] to investigate the bony skeleton of rat fetuses. The size of skeletons (the pariet-to-coccygeal size) was measured with compasses. The ossification analogue sire was measured with the help of an ocular micrometric microscope (MPC-10, ocular 8, magnification 2).



3.    A common technique for hemoglobin, erythrocyte, leucocyte count and the leucocytary formula.

4.    Measurement of 137Cs accumulation in the mother and the offspring. The 137Cs concentration in female common white rats during pregnancy and lactation and in the offspring during lactation was checked in vivo based on ³-emission using a gamma-radiometer L - 92.

5.    A “Synchron” analyzer produced by Beckman (USA) served to evaluate biochemical indicators of the blood serum of pregnant rats.

6.    Evaluation of 137Cs and 90Sr concentration in food was performed using spectrometric anti radiochemical technique of the (Gomel Regional Sanitation and Hygiene Center. The variational statistics technique was used for data processing.

The study has revealed that in case female white rats since the 1st day of pregnancy are kept on a diet of meat with the 137Cs concentration 5587 Bq/kg and 90Sr 23.7 Bq/kg there is a valid increase of preimplantation death — 2.27 ± 0.52 (p <0.05). Consumption of grain with 137Cs  concentration 445.7Bq/kg,  90Sr  — 15.5 Bq/kg by pregnant rats would no produce any essential preimplantation death rate compared with the control group. The postimplantation death rate in the two test group corresponded to the control.

The data about higher preimplantation death rate during radioactive exposure correlate with other reported data about the death rate of fetuse during this period [16,18] The analysis of publications indicates that radiation during the preimplantation period induces more frequent mu­tations of two types or mutations of genes and chromosomes. The genetic mutations hill the zygote. non-lethal mutations may be the cause of monsters [12].

The study has revealed that mothers alter dieting during pregnancies on meat and grain with a higher 137Cs and 90Sr concentration in the test group would have an offspring with a valid reduction of the average size of bony skeletons (the panet-to-coccygeal size) compared with the rele­vant control (Table 1.4).

The mothers alter dieting on meat with a higher 137Cs and 90Sr con­centration would have an offspring with the valid absence of the anlages of ossification of metacarpal and metatarsal bancs compared with the control. No significant difference between the test and control offspring if mothers would diet during pregnancy on the grain (Table 1.4).

Investigation of the condition of bony skeletons of the test fetuses after feeding mothers with the meat containing ‘3’Cs bas revealed a valid symmetrical hypoplasia of the anlages of ossification of ail the bancs manifested to different extent, the bilateral absence of anlages of pubic bones, absence of points of ossification of the 2nd and 4th metacarpal bones. 2nd, 3rd and 4th metatarsal bones (Fig. 11).

Similar studies of bony skeletons of test fetuses born by mothers alter dieting with a higher 137Cs and 90Sr concentration in the grain has re­vealed a valid bilateral reduction OF the size of anlages of ossification of all the bones, excepting the 4th metacarpal and 2nd and 3rd metatarsal bancs (the difference with the control group is insignificant). Also a bi-lateral absence of anlages of pubic bones, the 2nd metacarpal, the 4th metatarsal bones (Fig. 1.2) were found.

Evaluation of the results and comparison with the reported data allow to assume that the major causes of misformation of the bony system among white rat fetuses can be n disordered inductive interaction be­tween the somato-pleural mesoderm and the coating endoderm or the death of mesenchymal ceils caused by the incorporated 137Cs. Another possible cause may be the abnormalities occurring during separate stages of the bone tissue morphogenesis [8].

The 45-day old offspring of the mothers after the meat diet with a higher radiation concentration manifested valid reduction of leucocytes 6.27 ± 0.75 x 10 /1 (p < 0.05), lymphocytes 72.38 ± 3.35% (p < 0.02) in the peripheral blood against the increased eosinophil count 2.63 ± 0.65% (p <0.05) compared with the control group.

Daily 137Cs incorporation by female rats since the lst day of preg­nancy and throughout the lactation period with oats containing 445.7 Bq/kg would result in its significant accumulation in the mother’s organ­ism. The offspring would not manifest any pronounced accumulation of 137Cs (Fig. 1.3).

Similar dynamics was manifested by the control group also when oats contained 44.2 Bq/kg of 137Cs, but it was less pronounced. The 137Cs concentration among the test female rats by the end of pregnancy was 132.77 ± 10.77 Bq/kg and the control rats had 9.22 ± 2.90 Bq/kg. The test offspring had the 137Cs concentration 6.47 ± 2.18 Bq/kg, the control group had 1.61 ±0.87 Bq/kg (Fig. 1.4).

Persistent differences in the 137Cs accumulation between the test and control female rats at the end of pregnancy and during lactation can probably be explained by the fact that the 137Cs absorption is stimulated resulting in its growing accumulation in the mother’s organism.


Persistent differences in the accumulation of this radionuclide be­tween the mother and the offspring and its essential absence in the or­ganism of newly born rats is explained by the barrier function of the mother’s organism.

The growing 137Cs accumulation in the test offspring while they grow and develop is assumed to be due to a gradual reduction of lactation and partial transition to independent nutrition

The test animals on the grain diet with a higher 137Cs and 90Sr con­centration manifest the lbumin concentration 13.83 ± 1.01 (p < 0.05) and calcium 1.87 ± 0.16 (p <0.05 on the 20h day of pregnancy. It can possibly be explained by the processes of compensation and adaptation in the pregnant animal’s organism during endogenous incorporation of radionuclides

Summarizing the obtained facts it can be concluded that daily incor­poration of relativety small amounts of radionuclides (137Cs — 16.84 Bq/kg, 90Sr — 36—54 Bq/kg) by test animals in pregnancy can cause noticeable disorders of the offspring prenatal and postnatal development.




1.    Incorporation by of radionuclides (137Cs and 90Sr) with food (meat and grain) affects the offspring prenatal and postnatal development manifested by embryotoxic effects and abnormal bony system develop­ment.

2. When female rats since the lst day of pregnancy consume meat containing 5587 Bq/kg of 137Cs and 23.7 Bq/kg of 90Sr embryotoxic ef­fects are manifested by a higher preimplantation death rate of fetuses.

3. When female white rats since the lst day of pregnancy consume beef meat containing 5587 Bq/kg of 137Cs and 23.7 Bq/kg of 90Sr and oats containing 445.7 Bq/kg of 137Cs and 15.5 Bq/kg of90Sr it results in abnormal formation of the offspring bony system manifested by the re­duced skeleton size of fetuses, various degrees of hypoplasia of anlages of ossification of skeleton bones, absence of points of ossification of metacarpal and metatarsal bones.

4. The postnatal pathology alter incorporation of radionuclides (137Cs (and 90Sr) by female white rats with food (meat) in pregnancy and lactation manifests reduction of leucocytes, lymphocytes and a higher eosinophil count in the peripheral blood when the offspring reaches the 45th day.

5. Endogenous incorporation of 137Cs with food by female common white rats in pregnancy results in its significant accumulation in their organisms and its significantly less accumulation by the offspring.

6. Daily incorporation of radionuclides (137Cs and 90Sr) by pregnant rats with food (meat and grain) does not cause any substantial disorder of metabolic process compared with the control. The increased albumin and calcium concentration in the blood serum after consumption of grain with a higher concentration of radionuclides is assumed to be due to the process of compensation and adaptation induced by the radionuclides in the pregnant animal’s organism.

7. The obtained experimental data can be useful for development of diagnostic actions, prevention and treatment of pathological conditions of the mother and the fetus exposed to radiation.