INFLUENCE OF SONOGRAPHIC CONTRAST-MEDIA ON MICROCIRCULATION IN RATS

In an open placebo-controlled study the influence of the injection of different sonographic contrast media on the microcirculation was prove d The study was performed in 7 Sprague-Dawley rats. In order to examin e this query two different sonographic contrast media in comparison to agitated electrolyte solution (as the placebo) were injected into the abdominal aorta of 7 anaesthetized rats as a 2 ml/kg bolus at 10-min intervals Examined were a newly developed agitated ultrasound solution (AK I: an aequeous solution of a vegetable phospholipid) and a radiog raphic contrast agent (AK II 741 mg Ioversol or 350 mg iodine, respect ively, per ml) which is used in an agitated form as ultrasound contras t agent, too 1 min before and until 2 min after each injection the cap illary perfusion of the same vessel area in the major omentum was meas ured (video-recording by use of intravital microscopy). The erythrocyt e velocity was determined off-line by an image analysing system. Where as the agitated X-ray contrast medium AK II decreases the mean capilla ry perfusion (temporary flow stagnation in single capillaries), AK I a s well as agitated electrolyte solution did not influence the capillar y erythrocyte velocity in the major omentum The gaps which appeared im mediately after the injection of AK I seem to have been brought about by spherosomes of AK I. Still the spherosomes are so small that they c an pass through rite capillaries, or if they are larger which cannot b e determined using in vivo microscopy the flow force necessary for the deformation of the bubbles is so small that the capillary perfusion i s not influenced The injection of agitated AK I does not lead to signi ficant changes of the microcirculation.