핵분열생성물중의 하나인 방사성스트론튬은 임신한 쥐에서 태반을 빠르게 통과하여 태아를 오염시킨다. 독성이 적은 천연착화제로서 마우스체내의 방사성스트론들(Sr-85)의 제거에 효과적인 것으로 알려진 카이토산을 이용하여 Sr-85의 태반오염억제에 관한 연구를 하였다. 실험군은 일반식이를 공급한 대조군과 임신 17일째에 수용성카이토산을 피하(1% 카이토산), 구강(10% 카이토산), 복강(0.3% 카이토산)으로 주사한 카이토산군으로 분류하였다. 피하주사군은 Sr-85 오염후 카이토산을 주사한 군이며 복강과 구강주사군은 Sr-85 오염전 15일간 카이토산을 공급한 군이었다. 출산과 동시에 어린마우스의 전신을 측정한 결과 출생후 7일째에 대조군이 $2.8{pm}0.3%$의 전신축적율을 나타낸 반면 피하, 구강, 복강 주사군은 각각 $1.2{pm}0.1%,;1.4{pm}0.1%,;1.6{pm}0.2%$로 나타났다. 결과적으로 임신한 마우스에서 수용성카이토산은 방사성스트론튬의 태반오염을 유의하게 억제하는 것으로 사료된다.
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.
