Release of very-high-molecular-weight VWF multimers by DDAVP during rhIL-11 treatment. VWF:Ag multimer gel analysis of a normal dog, X60, treated daily for 7 consecutive days with rhIL-11 (50 μg/kg subcutaneously; white and gray bars). This dog then received combined rhIL-11 and DDAVP treatment (5 μg/kg intravenously) on days 6 and 7 (gray bar). The same daily dose of DDAVP was continued on days 8 through 14 (black bar). The multimer composition of X60 is shown at baseline (BL), prior to treatment on day 6 (Pre), and 30 minutes following administration of treatments on days 1, 5, 6, 7, and 14. Lanes and molecular weights are labeled as in Figure 2. Note the presence of very-high-molecular-weight multimers after treatment with DDAVP on day 6 (30 minutes) and to a lesser extent on days 7 and 14. This DDAVP-induced release of very-high-molecular-weight VWF multimers was confirmed on the 0.65% agarose gel shown in the panel to the right.