[Myocardial Slit2/Robo4 expression and impact of exogenous Slit2 on proliferation and migration of cardiac microvascular endothelial cells].

OBJECTIVE: To detect expression of Slit2 and Robo4 in mouse ventricular muscle blood vessel and explore the impact of exogenous Slit2 on proliferation and migrate of mouse cardiac microvascular endothelial cells. METHODS: Slit2 and Robo4 expression in mouse ventricular muscle blood vessel was detected by immunohistochemistry. Slit2 and Robo4 expression in cardiac microvascular endothelial cells isolated from mouse ventricular muscle were detected by euzymelinked immunosorbent assay and immunofluorescence, respectively. The effects of various concentrations exogenous Slit2 on proliferation of mouse cardiac microvascular endothelial cells was examined by CCK-8 cell proliferation kit. Transwell chamber was used to detect migration of mouse cardiac microvascular endothelial cells treated with 800 µl M199 culture medium containing 20%FBS (negative control), 10 ng/ml VEGF(positive control), 100 ng/ml Slit2(Slit2) and 100 ng/ml Slit2+10 ng/ml VEGF (Slit2+VEGF) and incubated for 18 h at 37 °C and 5%CO(2). RESULTS: Both Slit2 and Robo4 protein expressions were detected in ventricular muscle blood vessel. Slit2 protein expression was detected in mouse microvascular endothelial cells. Protein and mRNA Robo4 expressions were also evidenced in mouse microvascular endothelial cells. Proliferation of mouse cardiac microvascular endothelial cells was not affected by exogenous Slit2. Migration of mouse cardiac microvascular endothelial cells was not affected by exogenous Slit2 (22.1 ± 2.8 vs. 23.2 ± 3.8 in negative control, P > 0.05) and significantly enhanced by VEGF (65.3 ± 3.8, P < 0.05 vs. Slip2 and negative control), this effect could be blocked by cotreatment with Slip2 (29.2 ± 3.4 in Slip2+VEGF, P < 0.05 vs. VEGF) CONCLUSION: Slit2 and Robo4 are expressed in mouse ventricular muscle blood vessels and cardiac microvascular endothelial cells. Exogenous Slit2 has no impact on the proliferation of mouse cardiac microvascular endothelial cells but could inhibit VEGF-induced mouse cardiac microvascular endothelial cell migration.

Effect of different oxytetracycline addition methods on its degradation behavior in soil.

The degradation behavior of veterinary antibiotics in soil is commonly studied using the following methods of adding antibiotics to the soil: (i) adding manure collected from animals fed with a diet containing antibiotics, (ii) adding antibiotic-free animal manure spiked with antibiotics and (iii) directly adding antibiotics. No research simultaneously comparing different antibiotic addition methods was found. Oxytetracycline (OTC) was used as a model antibiotic to compare the effect of the three commonly used antibiotic addition methods on OTC degradation behavior in soil. The three treatment methods have similar trends, though OTC degradation half-lives show the following significant differences (P<0.05): manure from swine fed OTC (treatment A)