OBJECTIVETo study the relationship between tissue quantitative distribution and pharmacokinetics of 3H-achyranthes bidentata ecdysterone and the channel-tropism of herbal drugs in mice.

METHOD3H-achyranthes bidentata ecdysterone was used as a tracer agent and injected into mice by the caudal vein. In 36 hours, the contents of the tracer agent of samples involving 9 different tracing phases and organ or tissue were determined in order to observe the dynamic quantitative distribution and excretion and pharmacokinetics of 3H-achyranthes bidentata ecdysterone and to understand the channel-tropism of herbal drugs achyranthes bidentata.

RESULT3H-achyranthes bidentata ecdysterone of same organs in different tracing phases and the contents of 3H-achyranthes bidentata ecdysterone in same tracing phases of different organs were significantly different (P<0.01). 3H-achyranthes bidentata ecdysterone was mainly distributed, in the liver, kidney, adrenal gland, small intestine and lung. The concentration-time profiles of achyranthes bidentata ecdysterone in rats injected into mice by the caudal vein were shown to fit a two-compartment open model with half-lives of (778.65 +/- 12.36) min, the elimination of achyranthes bidentata ecdysterone from plasma was found to be in accord with linear kinetics.

CONCLUSIONThe above mentioned selective distribution of 3H-achyranthes bidentata ecdysterone basically coincides with the meridian affinity and zang fu selection of the traditional Chinese medicine drug Achyranthes bidentata. This study will provide a scientific basis for the channel-tropism of A. bidentata.