[Methods of analysis relating to blood flow measurement of the viscera and aorta in sheep].

Two methods of analysis of blood flow data are presented. They are aimed at reducing: 1) the methodological variability associated with splanchnic blood flows measured by dilution (PAH) and 2) the variability of aortic blood flows measured ultrasonically associated with physical activity. Six multicatheterized ewes were used; they were first fed at maintenance and then at half-maintenance. Observed splanchnic blood flows were very variable when PAH was infused in mesenteric vein only (average CV = 17%). Variability was first reduced by a PAH infusion via both a mesenteric and a ruminal vein (CV = 11%), second by rigorous corrections on instantaneous blood flow data (CV = 13.5%), or by a combination of both (CV = 9.5%). Corrections did not modify the conclusions of the analysis of variance concerning the treatment effect, but reduced the residual variance and eliminated the negative hepatic artery blood flow values. At the hindquarters level, corrections allowed us to approach the aortic blood flows of animals in a similar 'quietly standing' state. They decreased the daily variability (from 22 to 8%) and enabled the detection of a treatment effect, which was not shown by observed data.