Production of nitric oxide in anaphylaxis in rabbits

To verify production of nitric oxide (NO) in anaphylaxis, we measured NO in peripheral tissue in anaphylactic rabbits using an NO-sensitive electrode. Rabbits were sensitized to horse serum, which was later administered over 10 s into the systemic circulation to induce anaphylaxis. Blood pressure (BP), central venous pressure (CVP), heart rate, and NO were recorded continuously for 80 min after antigen challenge. The NO-sensitive electrode was placed between the superficial abdominal fascia and the rectus abdominis fascia. The NO concentration increased to 3000-4800 pA (about 3-4.8 microM NO) within 4 min after initiation of anaphylaxis, at which time BP was decreased and CVP increased; however, NO production was continuously observed 30-60 min after antigen challenge, during which time changes in BP and CVP were not correlated with changes in NO concentration. In conclusion, NO production can be detected using an NO-selective electrode in anaphylactic rabbits.