Preparation of rat thoracic aortic vascular smooth muscle cells by modified enzyme double digestion / 中国比较医学杂志

Objective This paper reports a modified method for the isolation of rat thoracic aortic vascular smooth muscle cells based on combined enzyme double digestion.Methods An enzyme mixture containing collagenase II, soybean trypsin inhibitor and elastase was prepared and used to remove the aortic tunica intima and tunica adventitia, and then the tunica media was subjected to second digestion using the same enzyme mixture and to isolate vascular smooth muscle cells.Results The isolated VSMCs were cultured in vitro and the growing cells had an elongated spindle-shape, reached confluence within a week, and displaying a typical hill-and-valley pattern.After 1 week, the cells were passaged.Contractile smooth muscle markers(α-SMA, myosin-II and β-tubulin) were highly expressed in the isolated cells.More than 90% of the cells significantly expressed alpha smooth muscle actin and myosin-II.Conclusions Themethod established in this study has advantages of simple and easy to operate, and good reproducibility, with a high activity and purity of the separated cells.It can ensure to obtain a large amount of contraction-type vascular smooth muscle cells within a short time.

Effects of chemical compositions and ensiling on the biogas productivity and degradation rates of agricultural and food processing by-products.

The objective of this study was to investigate the effects of chemical compositions and ensiling on the biogas productivity and degradation rates of agricultural and food processing by-products (AFPBPs) using the biogas potential test. The AFPBPs were classified based on their chemical compositions (i.e., carbohydrate, protein and fat contents). The biogas and methane potentials of AFPBPs were calculated to range from 450 to 777 mL/g volatile solids (VS) and 260-543 mL/g VS, respectively. AFPBPs with high fat and protein contents produced significantly higher amounts of biogas than AFPBPs with high carbohydrate and low fat contents. The degradation rate was faster for AFPBPs with high carbohydrate contents compared to AFPBPs with high protein and fat contents. The lag phase and biogas production duration were lower when using ensiled AFPBPs than when using nonsilage AFPBPs. Among the four different silages tested, two silages significantly improved biogas production compared to the nonsilage AFPBPs.