Trehalose solution protects mesothelium and reduces bowel adhesions.

BACKGROUND: Preventing interbowel adhesions still remains a challenge. Peritoneal mesothelial damage can induce postoperative adhesions. Our study evaluated the effects of 3% trehalose solution on mesothelial protection and adhesion prevention. Also, we compared this novel solution with Seprafilm regarding efficacy. METHODS: Mesothelial damage was induced on the cultured human mesothelial cell (Met-5A) and rabbit cecum-serosal surface by air-drying for 60 min, and trehalose solution was applied. Cell integrity was tested by measuring lactate dehydrogenase, and serosal-morphologic changes were analyzed using scanning electron microscopy. Intra-abdominal adhesions were induced in rabbits by the combination of abrasion and air-drying procedures. Animals were divided into four groups: control, 3% trehalose solution, Seprafilm, and 3% trehalose solution with Seprafilm. Adhesions were evaluated blindly 7 d later. RESULTS: Lactate dehydrogenase release from the Met-5A cells was reduced dose-dependently by trehalose (P < 0.05). Morphologic studies clearly showed that mesothelial cells on the serosal surface were kept intact by 3% trehalose solution. In a rabbit adhesion model, 3% trehalose solution reduced adhesions between bowel and bowel or bowel and surrounding structures (P < 0.01 versus control and Seprafilm). Seprafilm reduced adhesions between abdominal wall and underlying viscera (P < 0.01 versus control and 3% trehalose solution). Three-percent trehalose solution with Seprafilm showed additive effects of adhesion prevention, reducing adhesion formation at the previously mentioned sites. CONCLUSIONS: Three-percent trehalose solution protects mesothelial cells and leads to reduced adhesions between bowel and bowel or bowel and surrounding structures. This effect seems to be resulted from the characteristics of the solution covering most areas that potentially develop adhesions.

[Studies of the Various Chronic Kidney Failure Rat Models and Hemodialysis Mini-pig Model for the Evaluation of Anti-hyperphosphatemia Drugs].

Animal models of chronic kidney failure (CKF) have been developed for the pharmacodynamic evaluation of various phosphate binders that are used clinically to treat hyperphosphatemia in patients with chronic kidney disease. However, these models represent different disease states and severities, depending on the experimental conditions and are not clearly defined for pharmacological evaluation. In addition, experimental models have not yet been established for artificial dialysis. The purpose of this study was to confirm the utility of the various rat models of CKF and the mini-pig model of hemodialysis as models of hyperphosphatemia for pharmacodynamic evaluation. Various rat models of pre-dialysis CKF (oral adenine dosing, 5/6 resection, and ligation nephrectomy model) were evaluated through determinations of serum and urinary parameters (osmolality, creatinine, and phosphorus), pathological observations of kidney, and the phosphorus-absorbing properties of lanthanum carbonate (La) formulations. The rat and mini-pig models were compared based on each evaluation index. In the oral adenine dosing model, serum phosphorus increased markedly and the area under the serum phosphorus concentration-time curve (phosphorus AUC) decreased in a dose-dependent manner with the administration of La formulations. In contrast, a significant decrease in serum phosphorus AUC, a prolongation of the dialysis interval, and an improvement in dialysis efficiency were observed after administration of La formulations to the mini-pig hemodialysis model. Furthermore, the results of bioequivalence studies between two La formulations (Fosrenol and SW670, a generic formulation) suggested that the rat and mini-pig models are useful and precise as pre-dialysis and dialysis models, respectively.