The acute release of tissue-type plasminogen activator (t-PA) was studied in perfused
rat hindlegs. Pretreatment of rats with the protein synthesis inhibitor cycloheximide
(2 mg/kg) at 1, 3 or 5 h prior to perfusion of rat hindlegs did not influence the
amount of t-PA released by platelet-activating factor (20 nM) or bradykinin (1 μM).
The amount of t-PA activity that could be extracted from hindleg skeletal muscle was
not decreased by cycloheximide pretreatment though it was decreased in lung extracts.
The in vivo release of t-PA was not affected by cycloheximide pre treatment. The data
suggest that the acute release of t-PA from vascular endothelial cells does not require
ongoing protein synthesis, but that acutely released t-PA is derived from a stable
endothelial storage pool.
Keywords
Tissue-type plasminogen activator - Release - Rat - Protein synthesis inhibition -
Cycloheximide
