Objective: To explore tissues distribution characteristics of icariin and its metabolites including icarisid Ⅰ

icarisid Ⅱ and icaritin in the kidney of osteoporosis model rats after intragastric administration of icariin. Method: Kidney tissues were gotten from rats in 40 min

1.5

2.5

4

12

24 h after intragastric administration of icariin with dosage of 118 mg·kg-1.After pretreated biological samples

HPLC was employed to determine contents of icariin and its metabolites with mobile phase of 0.4% aqueous acetic acid(A)-methanol(B) for gradient elution(0-11 min

43%A;12-30 min

37%A;31-46 min

43%A) and detection wavelength at 270 nm. Result: At 40 min after intragastric administration

icariin(0.017 5 mg·L-1)

icarisid Ⅰ(0.014 2 mg·L-1) and icarisid Ⅱ(0.012 7 mg·L-1) could be checked out;these ingredients reached high concentrations at 2.5 h and eliminated basically after 24 h.Icaritin was checked out at 2.5 h and arrived the high concentration at 4 h

but it still exited at 24 h. Conclusion: Icariin distributed fast and coexisted with its metabolites in the kidney of rats

these ingredients had higher concentrations and maintained a certain period of time in the kidney

which pointed their target may be the kidney

it matched the Chinese medicine theory that Epimedii Folium went through the liver and kidney.This established method was accurate and fast

which could provide a reference for in vivo pharmacokinetic research of icariin.