Effect of exposure route on measurement of blood pressure by tail cuff in F-344 rats exposed to OTTO Fuel II.

Male Fischer-344 rats demonstrated a dose-response of blood pressure (BP) to increasing doses of propylene glycol dinitrate (PGDN), the major constituent of OTTO Fuel II (OFII) following administration by subcutaneous injection. Dermal application of the same doses to separate groups of rats resulted in variable responses of BP that were unrelated to dose. A nose-only exposure system was developed but no effect on BP was observed in rats exposed to a nearly saturated atmosphere of PGDN (approx. 750 mg/m3 at 25-degrees-C). This study has indicated both the difficulties associated with the use of tail cuff measurement of BP and the need for either a more sensitive or more specific biomarker of effect for exposure to nitrate esters.