Turnover of tPA in rabbits: influence of carbohydrate moieties.
The turnover of tissue plasminogen activator (tPA) was studied in rabbits using a double-label technique which allowed the comparison of various tPA derivatives with a standard tPA in individual animals. Purified recombinant tPA (Alteplase) was labelled with 125I and used as a standard for each experiment. Various tPA preparations which lacked specific carbohydrate structures were labelled with 131I (in separate experiments) and injected along with the 125I-tPA standard into rabbits. The clearance of standard tPA was biphasic with an average T 1/2 alpha and T 1/2 beta of 0.85 min and 12 min respectively. Type II tPA which lacks a portion of carbohydrate associated with Type I tPA as well as desialated tPA demonstrated a longer T 1/2 beta than standard tPA.
D000818:Animals; D004591:Electrophoresis, Polyacrylamide Gel; D006031:Glycosylation; D007457:Iodine Radioisotopes; D011817:Rabbits; D012794:Sialic Acids; D010959:Tissue Plasminogen Activator / Q000378:metabolism*
D007457:Iodine Radioisotopes; D012794:Sialic Acids; D010959:Tissue Plasminogen Activator