Inhibition of Radiostrontium Contamination to Fetus by Water Soluble Chitosan in Pregnant Mice
Kim, Kwang-Yoon;Bom, Hee-Seoung;Yang, Kwang-Hee;Choi, Keun-Hee;Chae, Ki-Moon;Kim, Ji-Yeul;
ABSTRACT
Radiostrontium passes the placental barrier in pregnant rodents very well. Chitosan, a natural nontoxic chelator, was reported to reduce whole body retention of radiostrontium in mice. The aim of the present study was to evaluate water soluble chitosan as a blocking agent of transplacental transfer of radiostrontium in pregnant mice. Twenty pregnant mice were divided into four groups: control and three groups of chitosan treatment (groups 1 to 3). Sr-85(15KBq in 0.2ml saline) was subcutaneously injected into pregnant mice at the 17th day of pregnancy. In control mice, 0.2ml saline was given 5 hours after the injection of Sr-85. In group 1, 1% water soluble chitosan was given subcutanously for two days, twice daily after the injection of Sr-85. In group 2, 10% water soluble chitosan was given orally for 15 days before conception. In group 3, 0.3% water soluble chitosan was injected intravenously for 15 days, once daily before conception. Gamma counting of newborns were done at days 0, 2 and 7 after their births. Whole body retention of Sr-85 in newborns of control mice at days 0, 2, 7 were $3.1{pm}0.3%,;2.9{pm}0.3%,;2.8{pm}0.3%$ respectively. In experimental groups, whole body retention of Sr-85 was significantly lower than that of control (p<0.01) and no statistical difference was noted between them. In group 1, the values were $2.1{pm}0.3%,;1.4{pm}0.1%,;1.4{pm}0.1%$, respectively. In group 3, they were $2.1{pm}0.2%,;1.7{pm}0.2%,;1.6{pm}0.2%$, respectively. In conclusion, the water soluble chitosan reduced transplacental contamination of radiostrontium in pregnant mice.