Pharmacokinetics of cytotoxin 14 from Naja naja atra venom

The pharmacokinetics of cytotoxin 14 (CT 14) from Naja naja atra venom was studied with biotin-avidin enzyme-linked immunosorbent assay. The plasma concentration-time curve of CT 14 after bolus i.v. 0.2 mg.kg-1 into rabbits was found to fit a two-compartment open model. T1/2 alpha was 5.8 +/- 0.6 min and T1/2 beta was 3.5 +/- 0.2 h. A rapid absorption was seen after im injection (0.5 mg.kg-1) to rabbits. The peak level was 260 +/- 90 ng.ml-1 and Tpeak was 13.6 +/- 2.4 min. The absolute bioavailability was 34 +/- 9%. It was shown that CT 14 was absorbed by gut. The peak level was 75 +/- 15 ng.ml-1 after a gastric gavage of 50 mg.kg-1 to rats.