Frei M R, Ryan K L, Berger R E, Jauchem J R
Department of Biology, Trinity University, San Antonio, Texas 78212, USA.
Shock. 1995 Oct;4(4):289-93. doi: 10.1097/00024382-199510000-00010.
The objective of this study was to determine the thermal distribution and concomitant cardiovascular changes produced by whole-body exposure of ketamine-anesthetized rats to radiofrequency radiation of millimeter wave (MMW) length. Rats (n = 13) were implanted with a flow probe on the superior mesenteric artery and with a catheter in the carotid artery for the measurement of arterial blood pressure. Temperature was measured at five sites: left (Tsl) and right subcutaneous (sides toward and away From the MMW source, respectively), colonic (Tc), tympanic, and tail. The animals were exposed until death to MMW (35 GHz) at a power density that resulted in a whole-body specific absorption rate of 13 W/kg. During irradiation, the Tsl increase was significantly greater than the Tc increase. Heart rate increased throughout irradiation. Mean arterial pressure (MAP) as well maintained until Tsl reached 42 degrees C, at which point MAP declined until death. Mesenteric vascular resistance tended to increase during the early stages of irradiation but began to decrease at Tsl > or = 41 degrees C. The declines in both mesenteric vascular resistance and MAP began at Tc < 37.5 degrees C; death occurred at Tc = 40.3 +/- .3 degrees C and Tsl = 48.0 +/- .4 degrees C. These data indicate that circulatory failure and subsequent death may occur when skin temperature is rapidly elevated, even in the presence of relatively normal Tc.
本研究的目的是确定氯胺酮麻醉的大鼠全身暴露于毫米波（MMW）射频辐射时产生的热分布及伴随的心血管变化。13只大鼠在肠系膜上动脉植入流量探头，在颈动脉插入导管以测量动脉血压。在五个部位测量温度：左侧（Tsl）和右侧皮下（分别朝向和远离MMW源的一侧）、结肠（Tc）、鼓膜和尾部。动物以能产生13W/kg全身比吸收率的功率密度暴露于MMW（35GHz）直至死亡。在照射期间，Tsl的升高显著大于Tc的升高。照射过程中心率增加。平均动脉压（MAP）在Tsl达到42℃之前一直维持稳定，此时MAP下降直至死亡。照射早期肠系膜血管阻力趋于增加，但在Tsl≥41℃时开始下降。肠系膜血管阻力和MAP的下降在Tc<37.5℃时开始；死亡发生在Tc = 40.3±0.3℃和Tsl = 48.0±0.4℃时。这些数据表明，即使Tc相对正常，当皮肤温度迅速升高时也可能发生循环衰竭及随后的死亡。
