Fig. 1.

The mean observed and model predicted concentration versus time profiles for plasma nitrite and nitrate, erythrocyte nitrite, methemoglobin, and iron-nitrosyl hemoglobin in the systemic circulation. Lines represent model-predicted curves and symbols represent actual observations. The nitrate concentration versus time curve during intravenous administration is simulated and included. Predicted profiles for nitrite, methemoglobin, and iron-nitrosyl hemoglobin during intravenous administration are not shown because these curves are similar to those observed during intra-arterial administration. The inset depicts plasma nitrite and nitrate concentrations at the site of administration.