IN-VIVO PRODUCTION OF NITRIC-OXIDE IN THE CANINE HEART IN IGE-MEDIATED ANAPHYLAXIS

We investigated the production of nitric oxide (NO) in the canine anap hylactic heart in vivo using an NO-selective electrode. Seven dogs wit h positive sensitivity to Ascaris Suum were studied, Ascaris Suum was administered into the systemic circulation to induce anaphylaxis, and NO, blood pressure, heart rate, end-diastolic left ventricular pressur e, cardiac output, and the maximum rate of rise of left ventricular pr essure were monitored for 60 min. The electrode was placed on the surf ace of the left ventricle adjacent to the interventricular branches of the left coronary artery, NO concentration increased significantly du ring the period from 2 to 3 min, and tended to increase during the per iod from 4 to 15 min after antigen challenge, and almost returned to b aseline after 20 min, In conclusion, increases in NO in the heart are only observed during the early phase of anaphylaxis.