Increased clearance of indoxyl sulphate in renal failure rats with the addition of water-soluble poly-ß-cyclodextrin to the dialysate.

AIM: Indoxyl sulphate (IS), a protein-bound uremic toxin that dramatically increases in the sera of patients with end-stage renal disease (ESRD), is poorly removed by conventional haemodialysis (HD). The purpose of this study was to explore whether the addition of water-soluble sorbent poly-ß-cyclodextrins (PCDs) to dialysate can increase the clearance of IS in uremic rats in vivo. METHODS: Male SD rats (450-550 g, n = 18) with nephrectomy plus IS injection (10-mg/kg) were randomly divided into three groups: 1. The HD group (n = 6): conventional HD for 4 h; 2. the 2% PCD group: 2% PCD added to the dialysate, HD for 4 h; and 3. the 4% PCD group: 4% PCD added to the dialysate, HD for 4 h. The serum IS levels in model rats were similar to those of ESRD patients. A stable and safe rat HD treatment mode was established by adjusting the vascular access, blood flow rate, dialysate flow rate, dialysis pipe, dialysate configuration, temperature, treatment environment, and other aspects. RESULTS: Our study found that adding 2% PCD to dialysate significantly improved the clearance of IS approximately twofold compared with conventional HD. Further increasing the PCD concentration to 4% did not increase IS clearance. CONCLUSION: Therefore, our study showed that adding water-soluble sorbent PCDs to dialysate significantly improved the clearance of IS in uremic rats in vivo.

Population genetic structure in six sympatric and widespread aquatic plants inhabiting diverse lake environments in China.

Many aquatic plant species are distributed over large areas and diverse environments with populations interconnected by abiotic and biotic mediators. Here, we examined differences and similarities in the population genetic structure of six sympatric and widespread aquatic plant species. We sampled the aquatic species from six Chinese lakes found on plateaus, plains, and different river systems and analyzed them using inter-simple sequence repeat (ISSR) markers. Samples originating from each lake tended to cluster together. Of the six species, only Nymphoides peltata and Myriophyllum spicatum could be divided into plateau and plain groups, once Taihu Lake individuals were excluded. Genetic similarities between populations connected by the Yangtze River were not consistently higher than unconnected populations. Populations from Taihu Lake and/or Weishanhu Lake were distant from other lake populations for all species except Potamogeton lucens. The Taihu and Weishanhu populations clustered for Ceratophyllum demersum and Typha latifolia. Hydrophilous C. demersum had the lowest gene flow (Nm = 0.913), whereas the entomophilous Hydrocharis dubia (Nm = 2.084) and N. peltata (Nm = 2.204) had the highest gene flow. The genetic relationships among distant populations of aquatic plants reflect the comprehensive effects of environmental selection pressure and biotic and abiotic connectivity. Differences in environmental factors between plateau and plain lakes and long distance hydrochory have limited importance on aquatic plant genetic structures. Among multiple evolutionary forces, gene flow mediated by birds may play the most important role in the formation of genetic patterns in the six species examined. For example, the close genetic relationship between Taihu Lake and Weishanhu Lake populations, each in different river systems and with different climates, may be related to the migration routes of birds. Differences in gene flow among the six aquatic plants may be attributable to different bird-transport and the fruit traits of each species.