PLASMA ENDOTHELIN LEVELS DURING ILOPROST INFUSION IN PATIENTS WITH CRITICAL LEG ISCHEMIA

We studied the behaviour of plasma endothelin levels in 7 elderly pati ents with critical limb ischemia, during iloprost infusion with the ai m to clarify both the interaction among various vasoactive endothelial substances and the endothelin importance in atherosclerotic disease d evelopment. Iloprost (diluted with saline solution in a concentration of 200 ng/ml) was administered intravenously, from 30 to 40 ml/h, for six hours/day and for 4 weeks. Plasma endothelin concentration was det ermined on the 4th day of treatment at time intervals of 4, 2, 4, 6 an d 8 hours: i.e. before the beginning of the infusion, then every two h ours till the sixth hour and two hours after the end of iloprost infus ion. The control group was composed by 7 subjects matched for age affe cted by peripheral obliterant arterial disease at the I and II Fontain e stage: only saline solution was administered to them. The mean +/- S D plasma endothelin level of patients in iloprost infusion was 5.40 +/ - 1.23 pg/ml at T0, 4.24 +/- 0.72 pg/ml at the second hour, 4.22 +/- 0 .74 pg/ml at the fourth hour, 4.24 +/- 0.22 pg/ml at the sixth hour an d 4.49 +/- 0.58 pg/ml at eighth hour. The difference between basal end othelin level and that of the second, fourth and sixth hour was statis tically significant (p < 0.05) while that of the eighth hour was not. In the control group the means +/- SD plasma endothelin levels were re spectively 5.23 +/- 0.55 pg/ml, 4.88 +/- 1.39 pg/ml, 5.44 +/- 1.51 pg/ ml, 5.10 +/- 0.86 pg/ml and 5.60 +/- 1.64 pg/ml at the same intervals. The difference between the basal endothelin level and the successive ones was not statistically different. In atherosclerosis the endotheli al contracting factors become more important whereas the formation and /or effects of the relaxing factors are impaired. Iloprost infusion. t herefore, may restore physiological equilibrium among various vasoacti ve substances, so that tissue perfusion is further improved.