Accumulative effect of DDAVP and heparin in increasing plasma factor VIII levels.

DDAVP (l-desaminocysteine-(8-D-arginine)-vasopressin) produces a marked increase in plasma factor VIII procoagulant (F VIII:C) levels. Previously, we have reported that blood collected into heparin rather than into CPD anticoagulant results in higher starting levels of plasma F VIII:C activity. We therefore wished to determine whether the effects of these two agents were accumulative and whether they would result in any difference in the relative molecular distribution of F VIII:C. Blood was collected into CPD or heparin immediately before and 15 min after an intravenous dose of 0.2 micrograms/kg body weight of DDAVP. Pre-stimulation factor VIII levels were approximately 36% higher in heparinized plasma than in CPD plasma. Following DDAVP stimulation, the final factor VIII activity was increased 3.9-fold when either of the anticoagulants was used, with the heparin sample maintaining a 37% increase over the CPD sample. Column chromatography on Sepharose CL-6B of pre- and post-DDAVP plasma samples collected into either heparin or CPD indicated that there was no change in the relative distribution of the high and low molecular weight forms of F VIII:C. The heparinized sample showed the typical distribution of approximately 60% F VIII:C at void volume (Vo) and 40% at 2.3 Vo, suggesting that DDAVP-stimulated increases of plasma F VIII:C are equally distributed between the carrier and non-carrier associated F VIII:C activities.