ADMINISTRATION OF A NITRIC-OXIDE DONOR DOES NOT AFFECT HYPOTENSION INDUCED BY 35-GHZ MICROWAVE-HEATING

Sustained whole body exposure to 35-GHz radiofrequency radiation produ ces localized hyperthermia and hypotension, leading to circulatory fai lure and death. We previously demonstrated that pressor responses to n itric oxide (NO) synthesis inhibition are reduced following 35-GHz mic rowave (MMW) heating, implying that NO levels might also be reduced. T his study therefore sought to determine whether administration of S-ni troso-N-acetylpenicillamine (SNAP), a NO donor, influences MMW-induced hypotension in ketamine-anesthetized rats. First, rats were exposed t o MMW until mean arterial pressure (MAP) fell to 75 mmHg. MMW exposure was then discontinued and either SNAP (300 mu g/kg/h) or saline was i nfused. SNAP infusion affected neither the hypotension nor the surviva l time following MMW exposure. In a second protocol, SNAP (300 mu g/kg /h) or saline was infused prior to and throughout MMW exposure, which was continued until death. SNAP infusion did not alter either the onse t or the magnitude of terminal hypotension. Therefore, we conclude tha t exogenous NO does not affect cardiovascular responses to 35-GHz MMW heating.