Pharmacokinetics of habutobin in rabbits

Following the administration of habutobin, the fibrinogen level in the circulating blood of the rabbits decreased. These results showed that the activity of habutobin was retained in vivo. The plasma level of habutobin was determined by a ELISA-double sandwich method. The pharmacokinetics of habutobin from Trimeresurus flavoviridis venom was studied in rabbits following i.v. administration of 50 micrograms kg-1 of habutobin. The time course of the plasma concentration of habutobin fitted a two-compartment open model. The half-life of the distribution phase was 4.43 +/- 1.28 min and that of the elimination phase was 50.42 +/- 7.89 min. The area under the plasma concentration-time curve (AUC) was 38.69 +/- 6.68 micrograms min ml-1. The total body clearance was 3.82 +/- 1.08 ml min-1. When the steady state was reached, the concentration ratio of habutobin in the tissue (Ct) to that in the plasma (Cc), Ct:Cc was 0.47:1. These findings suggest that relatively little habutobin tended to remain in the tissue.