Study on preventing systems of fetus for uteroplacental circulatory disturbances and uteroplacental dysfunctions produced by microwaves

本文试图阐明胎儿神经内分泌系统对微波引起的子宫胎盘循环障碍和子宫胎盘功能障碍的预防机制。我们在孕鼠中模拟了特定吸收比（SAR）为0.4 W/kg的微波条件，这是美国工业卫生学家会议（ACGIH）和美国国家研究所（ANSI）推荐的最大允许暴露水平。静脉注射CRH受体拮抗剂α-螺旋CRH（9-41）和环氧合酶抑制剂吲哚美辛可预防微波引起的子宫胎盘循环障碍。虽然微波并没有引起胎儿下丘脑CRH mRNA的变化，波生坦或吲哚美辛的管理微波暴露前做了。这些结果表明，子宫胎盘胎儿对微波的预防系统，其中胎儿下丘脑CRH参与介导子宫胎盘循环在微波0.4 W/kg。相比之下，我们发现，预防系统在2.0 W/kg的微波期间不起作用，随后导致结肠温度显著升高和子宫胎盘血流量减少。这些结果表明，SAR为0.4 W/kg的微波（最大允许暴露水平）在安全水平范围内，不会产生子宫胎盘功能障碍。远高于最大允许水平的微波可能会在怀孕期间显示出一些有害的变化，这些变化与微波产生的结肠温度升高有关。

We tried to clarify preventing mechanisms including neuroendocrine systems of fetus for uteroplacental circulatory disturbances and uteroplacental dysfunctions produced by microwaves. We simulated the microwave condition in pregnant rats for the specific absorption ratio (SAR) of 0.4 W/kg, which is the maximum permissible exposure level recommended by the American Conference of Industrial Hygienists (ACGIH) and the American National Institute (ANSI). The pretreatment of intravenous (iv) administration of CRH receptor antagonist, α-helical CRH (9-41) as well as a cyclooxygenase inhibitor indomethacin prevented the uteroplacental circulatory disturbances during microwaves. Although microwaves did not induce fetal hypothalamic CRH mRNA change, the administration of bosentan or indomethacin before microwave exposure did it These results suggest a preventing system of uteroplacenta-fetus against microwaves in which fetal hypothalarnic CRH is involved in mediating uteroplacental circulation during microwaves at 0.4 W/kg. By contrast, we found that the preventing systems did not work during microwaves at 2.0 W/kg, subsequently resulting a significant increase in colonic temperature and decrease in uteroplacental blood flow. These results suggest microwaves at the SAR of 0.4 W/kg, which is the maximum permissible exposure level, is within safety levels without producing uteroplacental dysfunctions. Microwaves much above the maximum permissible level may show some harmful changes during pregnancy associated with an increase in colonic temperature produced microwaves.