[A comparative study on the absorption kinetics parameters of rhubarb free anthraquinones between normal dogs and dogs with severe acute pancreatitis].

Objective: To study the effects of severe acute pancreatitis (SAP) on absorption kinetic parameters of rhubarb free anthraquinones.

Methods: Eleven healthy Beagle dogs were randomly divided into the normal group (n = 6) and the SAP group (n = 5). The SAP animal model was prepared by surgery through portal vein blood channel building to collect blood from normal dogs and dogs with SAP. The free anthraquinones (20 mg/kg) was given by gastrogavage. The concentrations of five anthraquinones (aloe emodin, rhein, emodin, chrysophanol, and physcion) in the blood plasma of the portal vein and the femoral artery were determined using high performance liquid chromatography (HPLC). The kinetic parameters were calculated using MATLAB2007B Software. The half life (t(1/2Ka)), the absorption peak time (Tmax), the peak concentration (Cmax), the area under the curve [AUC(0-infinity)], and the mean residence time (MRT) were calculated using the statistical moment method. The transport velocity of corresponding medicines from the gastrointestinal tract to the blood (ka) was calculated.

Results: There was no difference in the chemical composition absorption type of the portal vein and the femoral artery between the two groups. Aloe emodin could be detected in the portal vein of each animal at each time point, and they were in the quantitative range. Rhein could be detected in the portal vein of each animal at each time point, and they were lower than the quantitative limit at few time points. Emodin and chrysophanol could be detected in the portal vein of partial animals at each time point, and most of them were higher than the quantitative limit. Physcion could be detected only in the portal vein of less animals at few time points. Rhein could be detected in the femoral artery at most time points, but the rhein plasma concentration at most time points were lower than the quantitative limit. Lower concentration of aloe emodin, emodin, and chrysophanol could be detected in the femoral artery at only few time points. Physcion was not detected in the femoral artery. The rhein plasma concentration of the femoral artery and the chrysophanol Cmax of the portal vein at 45 min were higher in the SAP group than in the normal group with statistical difference (P<0.05). There was no statistical difference in the rest indices. The AUC of rhein in the two groups were 59.32% and 66.07% of the total free anthraquinones respectively.

Conclusions: SAP could not obviously affect the absorption kinetics parameters of rhubarb free anthraquinones. The intestinal tract and the liver might possibly play important roles in metabolizing or transforming rhubarb free anthraquinones.