Blood flow measurements in rabbit sinus mucosa. A comparison between fluorescein flowmetry and blood flow measurements with microspheres and Rb86Cl.

The blood flow of the sinus mucosa was studied in 14 rabbits of the New Zealand White strain. The blood flow was determined by fluorescein flowmetry and the values were compared with those obtained from the same sinus mucosa with use of Sn113 radioactively labelled microspheres and with Rb86Cl. One sinus cavity in each animal received nose drops prior to the blood flow measurement. The blood flow index in the sinus mucosa was 0.039 +/- 0.019 density units Xs-1 and was significantly reduced to 0.016 +/- 0.011 density units Xs-1 by administration of nose drops. Blood flow in the sinus mucosa was 1.0 +/- 0.53 ml X min-1 X g-1 as measured with microspheres and 0.52 +/- 0.12 ml X min-1 X g-1 with the Rb86Cl method. Following administration of nose drops the values were reduced to 0.29 +/- 0.13 and 0.22 +/- 0.07 ml X min-1 X g-1 respectively. There was a significant difference in blood flow obtained with the Rb86Cl and microsphere methods in the sinus mucosa without decongestion. This might be explained by possible shunting of blood in the mucosa due to hyperaemia caused by the surgical trauma to the sinus.