Tibetan Medicine "zuota" Absorption Kinetics

Tibet drug "ZUO TA",also named "ZUO TAI",is one of the raw material of many valuable Tibet drugs,such as "seventy sapidities of margarita pill".Frequently,this drug also serves as a precious ingredient of other common drugs to raise their therapeutic effect." ZUO TA",with mercuric compound as its main material,is produced with special processing technology.To discuss its safe mechanism of clinic application,we have built a HPLC method of the content of mercury in "zuo ta". With this method,we have determine the absorption of mercury of "zuo ta" in the small intestinal and its accumulation in rats' liver,kidney and blood after long-term administration.With these absorption kinesics data,our study indicates:A high performance liquid chromatographic method was established for the determination of Hg in "ZUO TA" using diethyldithiocarbamate(DEDTC) chelate. A Diamonsil^TM C₁₈(250×4.6mm,5μm) column was used with a mixture of methanolwater (containing 22umol/L DEDTC)(90:10,V/V) as the mobile phase,with the speed at 1.0 ml/min,the temperature in 30℃and a detector set at 272nm.The calibration curve was linear(r=0.9997) in the range of 21.0ug/ml～210.0ug/m of Hg²⁺. The recoveries were 102.59%,with RSD of 1.66%.Comparing with the ICP-MS, the HPLC method is proved to be precise,reproducibility and reliable.It is suitable for determination of Hg,and has a great value in the further research about "ZUO TA".To study the Hg absorption rate at different segment of rats and to determine if specific absorption site existed,everted gut sac was used to compare the absorption of Hg in "ZUO TA" and mercury chloride in jejunum,ileum,duodenum and colon. The concentration of H in the intestinal medium was determined by HPLC method. The highest absorption extent of Hg in mercury chloride was observed in jejunum, ileum,duodenum and colon.While,no significant absorption of Hg in "ZUO TA" was observed in each segment of the rats' intestine,except determining a very low concentration of Hg after 120 min. Using the HPLC method,there in no Hg chromatography peak of the portal vein samples collecting from the manhood rat after administrating "ZUO TA" at high dose over 90s of man at several times.Using the HPLC method,there in no Hg chromatography peak of the portal vein samples collecting from the manhood rat after administrating "ZUO TA" at high dose over 90s of man at several times.When the old rat was administrated high dose of "ZUO TA" over 90s of man with 14days,The HPLC determine result show that the Hg in "ZUO TA" was distributed in the liver,kidney and blood,and curmulated in high level in these tissues, especially in kidney 10 over the normal rats.The study shows:the Hg in "ZUO TA" will not dectected in the intestines absorption at a once administration of "ZUO TA",while it can be cumulated in the old rat's tissues at long term and doubling dosage.