Summary
The mechanism of tissue plasminogen activator (t-PA) release during arm and leg venous
occlusions and DDAVP (1 desamino- 8-D-arginine vasopressin) infusion was studied in
10 healthy males. The following determinations were carried out on venous blood: t-PA
antigen (ELISA), t-PA activity, and t-PA inhibitor (PAI) activity (amidolytic assays).
Before DDAVP, there was a 270% t-PA antigen increase in the arm at the end of occlusion as opposed
to only a 40% increase in the leg. After DDAVP, t-PA antigen at the end of arm and leg occlusion reached an equal level which was
significantly higher than in the arm before DDAVP. The study produced no evidence
of PAI release during venous occlusion of a limb. It is concluded that DDAVP is able
to elicit t-PA release from arm as well as from leg vessels. The poor fibrinolytic
response of leg vessels to venous occlusion is not due to a high PAT release or t-PA
stores depletion in leg vessels, but rather to low basal t-PA release in leg vessels.
Keywords
Tissue plasminogen activator - Venous occlusion - DDAVP - Mechanism of release