头孢克洛在健康人体内的药物动力学研究

采用ＨＰＬＣ测定健康志愿者血浆中头孢克洛的浓度。方法简便快速，结果准确。平均回收率为１０２．１８±４．０１％，日间及日内ＲＳＤ均小于６％。血药浓度－时间曲线符合一室模型。     

豨莶脂溶性成分的研究

从豨莶(Siegesbeckia orientalis L.)的地上部分,分离出八个化合物,其中I和I根据理化性质和光谱数据确定其结构为ent-17-acetoxy-18-isobutyryloxy-16(α)-kauran-19-oicacid(I)和ent-17-ethoxy-16(α)-kauran-19-oicacid(II),均为新化合物,分别被命为豨莶酯酸(siegesesteric acid,I)和豨莶醚酸(siegesetheric acid,I)。其余化合物分别鉴定为腺梗豨莶萜醇酸(ent-16β,17-dihydroxy-kauran-19-oicacid,II),奇任醇(kirenol,IV,β-谷甾醇葡萄糖甙(β-sitosterolglucoside,V),二十一醇(heneicosanol,VI),花生酸甲酯(methyl arachidate,VII)和β-谷甾醇(β-sitosterol,VII)。除奇任醇和β-谷甾醇外,均为首次从该植物中分得。     

L-arginine reverses the antinatriuretic effect of cyclosporin in renal transplant patients

BACKGROUND: Cyclosporin has been shown to facilitate renal vasoconstriction and to have an antinatriuretic effect. The existence of an interference of cyclosporin with the vasodilating properties of endothelium mediated by nitric oxide production could mediate these effects. On the other hand, the infusion of the nitric oxide precursor L-arginine has been shown to induce renal vasodilatation and to facilitate natriuresis in normal volunteers. We have investigated the renal effects of the administration of an infusion of L-arginine in renal transplant patients chronically treated with cyclosporin. To facilitate the analysis of the data the effects of the administration of a similar dose of cyclosporin on renal function during the infusion of a vehicle were also investigated during the administration of a vehicle of L-arginine. DESIGN: Ten male renal transplant patients, chronically treated with cyclosporin and with a stable renal function were studied during 2 consecutive days after the administration of the usual morning dose of cyclosporin. The first day they received an intravenous infusion of vehicle and the second the infusion of graded doses of L-arginine (50, 100, 150 mg/kg/h) during 3 consecutive h. RESULTS: The first day, after cyclosporin administration a significant fall (P < 0.01) was observed in natriuresis and kaliuresis in the absence of changes in renal plasma flow and glomerular filtration rate. After the administration of L-arginine significant (P < 0.01) increases of renal plasma flow, glomerular filtration rate, and natriuresis were seen. The increase in blood levels of cyclosporin after its administration did not differ between days 1 and 2. CONCLUSION: These results indicate that L-arginine facilitates renal vasodilatation and natriuresis in renal transplant patients. Furthermore, the observed increase in sodium excretion could indicate that L-arginine counteracts the antinatriuretic effect of cyclosporin.