THE IMPORTANCE OF THE THERAPY TIME POINT FOR THE EFFECT OF SYSTEMIC AND LOCAL THERAPY WITH THE ACE-INHIBITOR CAPTOPRIL ON INTESTINAL MICROCIRCULATION IN NONOCCLUSIVE MESENTERIC ISCHEMIA - A PORCINE EXPERIMENTAL ANIMAL MODE

We present the results of a study based on an animal model concurring whether captopril can improve microcirculation in the small intestine in nonocclusive mesenteric ischemia dependent on when therapy is begun . Cardiogenic shock was produced by pericardial tamponade with starch solution. The flow in the carotid artery could be reduced to 43% of th e preshock value. In four therapy groups and a control group the intes tinal microcirculation was examined by laser Doppler flowmetry in the serosa and mucosa. The measurements were taken at regular intervals du ring the 4 h of the experiments. Captopril was either given systemical ly or locoregionally through the up per mesenteric artery. Therapy was given at the beginning of the shock or 1 h after induction of shock a t a dosage of 0.25 mg/kg body weight as a bolus and continuous applica tion of 10 mu g/kg body wt. Concerning the hemodynamic changes during shock the group receiving captopril systemically at the beginning of s hock showed a significant (P=0.05) improvement in microcirculation com pared to the controls and other therapy groups. Flow reduction was see n in the controls (156-32 relative flow units=RFU) in group Ia(systemi c therapy 1 h after shock), as well as the controls (129 to 12 RFU) an d, in group Ib (systemic therapy beginning with shock) a flow rise cou ld be seen (307 to 481 RFU). In group IIa (local therapy Ih after shoc k) (a steady flow was seen (168-170 RFU) and in group IIb (local thera py beginning with shock) and group Ib an increase in flow was also mea sured (226-303 RFU). This positive effect of captopril on the intestin al perfusion was observed when applied 1 h after the induction of shoc k.