Objective: To study on the intestinal absorption characteristics of Eucommiae Cortex extract in normal rats and spontaneously hypertensive rats. Method: Everted intestinal sac model was utilized.Intestinal sac fluid samples at different time after administration of 10.0 g · L-1 of Eucommiae Cortex extract were collected and the contents of geniposidic acid

protocatechuic acid

neochlorogenic acid

chlorogenic acid

cryptochlorogenic acid

pinoresinol diglucoside and (+)-piresil-4-O-β-D-glucopyraside in intestine samples were determined by UPLC-MS/MS.Accumulative absorption (Q) and absorption rate constants (Ka) of these seven compenents were calculated

while absorbance of indicator components in intestinal absorbent liquid between normal rats and spontaneously hypertensive rats (SHR) was compared. Result: The intestinal absorption of 7 components in Eucommiae Cortex extract was linear absorption with R2 >0.99

the main absorption area was in the small intestine

and the absorption of duodenum was the best under normal conditions.Protocatechuic acid and pinoresinol diglucoside had better absorption in the jejunum under hypertensive conditions

which suggested that pathological conditions may alter the specific site of drug absorption.Compared with normal rats

the intestinal absorption of the 7 index components in spontaneously hypertensive rats model showed different degrees of difference.The absorption of geniposidic acid in the intestinal segments of spontaneously hypertensive rats model was weaker than that of normal rats

but the other components represented by pinoresinol diglucoside showed no a consistent absorption trend. Conclusion: Spontaneous hypertension can affect the intestinal absorption of Eucommiae Cortex extract

these differences can not be fully explained from the perspective of intestinal mucosal permeability reduction and back shift of absorption site

which may be related to the presence of intestinal enzymes and transporters

and the specific mechanism needs further study.