Objective To establish a HPLC method for the determination of octopamine in fish sauce.Methods A phenomenes luna C18 column was used.The mobile phase was 0.02?g?mL-1 citric acid-0.02?g?mL-1 sodium dihydrogen phosphate(7∶3,v/v) and detection wavelength was 274 nm.Results The linear range of octopamine was 104.0%,RSD=1.53%.The detection limit was 5.7ng?mL-1.Conclusion This method is simple,rapid and reliable.It could be used for the determination of octopamine and its related substances in fish sauce.The content of octopamine in Engraulis japonicus sauce is 1055?g?mL-1.

Objective To establish a technical process for the separation of octopamine.MethodsTaking the absorptive capacity and elution efficiency of octopamine as indexes,the absorption characteristics and elution parameters of separation with macroporous resin were investigated.Results The static adsorption capacity of H103 type macroporous resin was 2.925mg g-1.The static elution ratio was 98.04%.Conclusion H103 type macroporous resin is effective to separate the octopamine and improve the flavour of fish sauce.

Objective To determine the content of octopamine,a kind of ?3-adrenergic receptor agonists in edible part of various fresh water and seawater aquatic products,and provide data for exploitation and utilization of octopamine in aquatic products.Methods After homogenate and ultrasound treatment,edible parts of fish,shellfish and cephalopodium were centrifugalized,then octopamine content in supernatant liquid was detected with HPLC.Results In eight kinds of fresh water fish,the octopamine contents of dorsal meat were generally higher than abdominal meat,which were in the range of 30~130?g?g-1 and roughly similar to seawater fish and freshwater shellfish.The octopamine contents in seawater shellfish were particularly high,almost dozens even thousands times of those in fish and freshwater shellfish.Cephalopodium also had a high content of octopamine while it was not detected in ocean algae.Conclusion Seawater mollusks are the most affluent resource of octopamine in aquatic products and ideal food of weight-watchers and diabetics.

In the present study, we examined the regulation of the expression and function of AB CA1 by modified LDL (ox-LDL) in vitro. After incubation with apoA-Ⅰ for 24 h, RAW264.7 cells effluxed 37.65 % cholesterol loaded by acetyl LDL (ac-LDL), and 9.78 % cholesterol in ox-LDL group. The level of ABCA1 Mrna increased about three times either when cells were incubated with 100 μg/Ml ac-LDL or with 100μg/Ml ox-LDL. However, the level of ABCA1 protein rose by 1.57 times in ac-LDL group and 1.26 times in ox-LDL group. These results demonstrated that ox-LDL had different effect on the expression and function of ABCA1, ox-LDL might decrease the cholesterol efflux mediated by ABCA1 through other unknown mechanisms.

Summary: To explore the functions of very low density lipoprotein receptor (VLDL-R) subtype II in lipoprotein metabolism and foam cells formation, the recombinant plasmid with the two subtypes cDNA was constructed respectively, the ldl-A7 cell lines were transfected and two cell lines expressing VLDL-R were obtained: one stably expressing the VLDLR with the O-linked sugar region (type I VLDLR) and the other without the O-linked sugar region (type II VLDLR). In the study on binding of VLDLR to their nuclein labeled natural ligands (VLDL and β-VLDL), it was found that surface binding of 125I-VLDL or 125I-β-VLDL of ldl-A7 cells transfected with type I VLDLR recombinant (ldl-A7-VRI) was more higher than that of ldl-A7 cells transfected with type II VLDLR recombinant (ldl-A7-VRII). After being incubated with VLDL for different time, the contents of triglyceride and total cholesterol in cells were mensurated, and the formation of foam cells and accumulation of lipid in cells was observed by oil-red O staining. The results showed that the contents of triglyceride and total cholesterol in ldl-A7-VR I were much higher than those in ldl-A7-VR II, and ldl-A7-VR I could transform into foam cells notably. It was suggested that type I VLDLR binds with relative higher affinity to VLDL and β-VLDL, and internalizes much more lipoprotein into cells. As a result, we can conclude that type I VLDLR plays a more important role in lipoprotein metabolism and foam cells formation than type II VLDLR.

The role of very low density lipoprotein receptor (LVLDR) in the process of foam cell formation was investigated. After the primary cultured mouse peritoneal macrophages were incubated with VLDL, beta-VLDL or low density lipoprotein (LDL), respectively for 24 h and 48 h, foam cells formation was identified by oil red O staining and cellular contents of triglyceride (TG) and total cholesterol (TC) were determined. The mRNA levels of LDLR, LDLR related protein (ILRP) and VLDLR were detected by semi-quantitative RT-PCR. The results demonstrated that VLDL, beta-VLDL and LDL could increase the contents of TG and TC in macrophages. Cells treated with VLDL or beta-VLDL showed markedly increased expression of VLDLR and decreased expression of LDLR, whereas LRP was up-regulated slightly. For identifying the effect of VLDL receptor on cellular lipid accumulation, ldl-A7-VR cells, which expresses VLDLR and trace amount of LRP without functional LDLR, was used to incubate with lipoproteins for further examination. The results elucidated that the uptake of triglyceride-rich lipoprotein mediated by VLDLR plays an important role in accumulation of lipid and the formation of foam cells.
Animals ; Arteriosclerosis ; metabolism ; pathology ; Cells, Cultured ; Cholesterol, LDL ; metabolism ; pharmacology ; Female ; Foam Cells ; cytology ; metabolism ; Lipoproteins, VLDL ; pharmacology ; Macrophages, Peritoneal ; cytology ; metabolism ; Mice ; Receptors, LDL ; metabolism ; Triglycerides ; metabolism

Very low density lipoprotein receptor (VLDLR) is thought to participate in the patho-genesis of atherosclerosis induced by VLDL and β-VLDL. The present study was undertaken to elu-cidate the effects of VLDL and β-VLDL on VLDLR expression and its signaling pathway. RAW264.7 cells were incubated with VLDL and β-VLDL. The expression of VLDLR mRNA was detected by RT-PCR. The transcriptional activity of VLDLR gene was detected in recombinant plasmid pGL4.2VR-luciferase transfected RAW264.7. Western blot assay was used to detect the changes of phosphorylated ERK1/2 protein. Inhibitors or activators were used to observe the signal pathway in-volving VLDLR expression regulation. The results showed that VLDL and β-VLDL stimulated ERKI/2 activity in a PKC-dependent manner. VLDL or β-VLDL-induced VLDLR expression on macrophages was extremely abolished by inhibitors ERKI/2 or PKC. Our findings revealed that VLDL or β-VLDL-induced VLDLR expression via PKC/ERK cascades and the effect was linked to the transcriptional activation of VLDLR gene promoter.