INTERLEUKIN-2 ENHANCES THE RELEASE OF ENDOTHELIN-1 FROM THE RAT MESENTERIC-ARTERY

We measured the ET-1 concentration in plasma and in the perfusate of the mesenteric arteries of rats treated with a therapeutic dose of IL-2 for 7 days (100000 U/Kg, iv.). The plasma ET-1 concentration in rats given IL-2 was 14.2 +/- 3.2 pg/ml which was significantly greater than that in the controls (2.5 +/- 0.4 pg/ml, P < 0.05). The mesenteric arteries also released a significantly greater amount of ET-1 (29.5 +/- 1.6 pg/h) than that in controls (16.8 +/- 2.3 pg/h, P < 0.01). The arterial blood pressure was significantly lower after IL-2 treatment than the pre-dosing level (P < 0.05). It is concluded that IL-2 induces ET-1 release from the vascular wall, possibly as a result of reversible endothelial dysfunction caused by IL-2.