为了提高水产加工废料的高值化利用,为明胶作为止血产品开发的原料提供依据,研究了明胶的分子量与止血活性之间的关系以及明胶的止血机理。本研究在65℃下采用热水法提取鳕鱼皮明胶,通过SDS-PAGE电泳测定明胶的分子量分布情况。使用100 ku和50 ku的超滤膜对明胶进行超滤处理得到高、中、低三个分子量范围的样品。大鼠断尾止血实验、股动脉止血实验和肝创面止血实验结果表明高分子量组(Mr〉100 ku)的出血时间最短,分别为4.54 min、2.30 min和1.91 min。说明提取的鳕鱼皮明胶样品与自然止血组相比具有止血效果,并且随着明胶分子量的上升,出血时间和出血量均下降,且高分子量明胶样品止血效果较好。APTT测定结果表明明胶可以明显缩短APTT时间,主要对内源性凝血途径起作用,并且可以促进血小板的聚集,还可以增加血小板活性因子PF4、P-选择素和TXB2的释放量从而缩短出血时间,起到快速止血的作用。
To improve the utilization of aquatic byproducts and provide a basis for the development of gelatin as a hemostatic product,the relationship of the molecular weight of gelatin to its hemostatic activities and mechanisms was studied.Pollock skin gelatin was extracted using the hot water method at 65 ℃,and its molecular weight distribution was measured by sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE).High,medium,and low molecular weight gelatin samples were obtained though ultrafiltration using 100 ku and 50 ku membranes.Rat tail cutting,femoral artery cutting,and liver cutting experiments showed that high molecular weight gelatin resulted in the shortest bleeding times,which were 4.54 min,2.30 min and 1.91 min,respectively.Pollock gelatin exhibited hemostatic activity as compared to the control group.Bleeding time and the amount of bleeding declined with increasing gelatin molecular weight.Thus,gelatin with a high molecular weight exhibited a relatively good hemostatic effect.An activated partial thromboplastin time(APTT) test indicated that gelatin significantly reduced APTT and affected the endogenous coagulation pathways.It also promoted platelet aggregation and increased the release of platelet active factors platelet factor 4(PF4),P-selectin,and thromboxane B2(TXB2),thereby shortening bleeding time and showing a hemostatic effect.