鳕鱼鱼皮水发工艺及机理研究

[目的]为优化鳕鱼皮水发生产工艺,并尝试对水发机理进行一些理论解释。[方法]以鳕鱼皮为试验原料,以水发率和蛋白损失率为指标,考察浸泡时间、NaOH溶液浓度、浸泡温度对鱼皮水发率的影响,通过正交试验对浸泡工艺进行优化,并考察了漂烫和冷激因素对产品爽脆度的影响。[结果]单因素试验结果显示,试验研究范围内,鳕鱼皮的水发率随NaOH溶液浓度的增大、浸泡时间的延长和浸泡温度的升高而先升高后下降。正交试验结果表明,鳕鱼皮在浓度为0.75 g/L的NaOH溶液中,在25℃条件下浸泡2.5 h时,鱼皮的水发率最好。并且通过80℃水浴,然后冰水浸泡3 min后得到的鱼皮具有较好的爽脆度。[结论]该研究为鳕鱼皮的综合利用提供了参考依据。     

Effect of angiotensin Ⅱ on the remodeling of aorta in spontaneously hypertensive rats

AIM: To investigate the effects of a 10-weeks treatment with angiotensin Ⅱ (Ang Ⅱ) subtype I receptor antagonist losartan on vascular remodeling of thoracic aorta in male spontaneously hypertensive rats (SHR). METHODS: SHR were treated from 16 to 26 weeks of age with losartan at 15 mg/kg·d^-1 or 0.75 mg/kg·d^-1. RESULTS: Losartan (15 mg/kg·d^-1) treatment significantly decreased systolic blood pressure compared with the control group, while losartan (0.75 mg/kg·d^-1) had no the effect, losartan(15 mg) prevents the development of aortic hypertrophy by preventing hypertrophy of vascular smooth muscle cells (VSMC). In the losartan 0.75 group, these parameters were not changed. But in the losartan 15 and losartan 0.75 groups, the collagen content of the aortic media decreased significantly. CONCLUSION: It is inferred that the effect of Ang Ⅱ on stimulating VSMC growth of the aorta in SHR is dependent on arterial pressure, while the effect on collagen fibers is through pressure independent mechanism.     

胶原蛋白交联的研究进展及其对肉的纹理和嫩度的影响

胶原蛋白是肌间结缔组织的主要成分 ,它在肌肉中的含量和质量对肌肉纹理性状的影响实际上是取决于胶原蛋白分子间交联的水平、方式和成熟程度。影响胶原蛋白分子间交联的因素很多 ,包括动物的品种、年龄、性别和肌肉的来源以及其它一些与生长有关的环境因素。本文着重对由一系列酶介导的胶原蛋白分子间的共价交联、胶原蛋白在细胞外的被动修饰、胶原蛋白对烤制后肌肉纹理的影响、胶原蛋白分子间交联及其影响因素和调控机制进行综述和探讨     

Dynamic change of the reticulin fibres and collagen fibres in vitro long-term bone marrow culture of acute myeloid leukemia

AIM and METHOD: The relationship between the evolution of the reticulin fibres(RF) or the collagen fibres(CF) and the growing of hematopoietic cells in long-term bone marrow culture (LTBMC) from 15 paticnts with acute myeloid leukemia (AML) and form 6 normal subjects was observed by inverted microscope, Gomoris staining and Massons staining were used. RESULTS: (1)The amount of RF contents of 8 AMLs, with self- maintained(AMLsm) in the 1~8 weeks-old-culture was significant less than that of normal control and 7 AMLs, without self-maintained(AMLnsm) (P＜0.05). On the contrary, the amount of CF coutents of AMLsm in the 1~6 weeks-old-culture was significant more than that of normal and AMLnsm(P＜0.05). (2) There were many hematopoietic cells in the areas of CF, and there were few in the areas of RF. (3)During the whole culture, the most part of confluence of the adherent layer only observed in 3 AMLsm. CONCLUSION: A proper amounts of fibres in the extracellular matrixes of bone marrow is necessary for hematopoiesis, but the change of the proportion of RF contents to CF contents may play an important role in the development of AML and other malignant blood diseases.     

Effect of acarbose on the aortic collagen nonenzymatic glycosylation in diabetic rats

AIM: To observe the effect of α-glucosindase inhibitor, acarbose on the aortic collagen nonenzymatic glycosylation in streptozotocin-induced diabetic rats . METHODS: The treated group (DM+A) was given acarbose (1 mg·kg^-1). The aortic collagen and its AGEs concentration were measured at the scheduled periods (1, 3 and 6 months ). RESULTS: During the observed period , the aortic collagen and its AGEs concentration were higher than that of control group in a time-dependent manner (P＜0.01 ), but decreased in acarbose-treated rats as compared with untreated group (P＜0.01 ). CONCLUTION:Acarbose can prevent the aortic vascular collagen nonenzymatic glycosylation in diabetic rats.     

醇提法制备鹿茸胶原的初步研究

采用醇提法制备鹿茸胶原,BCATM蛋白浓度测定法、RE-HPLC法和SDS-聚丙烯酰胺凝胶电泳法检测其纯度及其分子量范围,酸水解法测定其氨基酸组成。结果表明,鹿茸醇提物中主要含有Ⅰ型胶原,含量约为70%;相对鲜鹿茸,胶原提取率为10.3%。     

Recombinant MIF induces synthesis of collagen type III in lung fibroblasts via Rho-kinase

AIM: To investigate the effects of recombinant macrophage migration inhibitory factor (rMIF) on the synthesis of collagen type III in fibroblasts.METHODS: The MRC-5 fibroblasts were divided into 2 groups.The cells in treatment group were exposed to rMIF at the concentrations of 25-100 μg/L for 48 h. The cells without rMIF treatment served as control group. Half an hour before challenging with rMIF (100 μg/L), Y27632 (a Rho-kinase inhibitor) was added to the cells in both 2 groups. After challenged for 48 h, total RNA and protein in the cells were extracted. The expression of collagen type III at mRNA and protein levels was analyzed by RT-PCR and Western blotting, respectively.RESULTS: Different concentrations of rMIF significantly increased the expression of collagen type III at mRNA and protein levels in a dose-dependent manner as compared with the control cells (r=0.862 and r=0.914; all P<0.01). These increases were abolished by Y27632 pretreatment(P<0.01).CONCLUSION: rMIF increases the synthesis of collagen type III in MRC-5 cells and Rho-kinase regulates the MIF-induced synthesis of collagen, suggesting that MIF may play important roles in the pathogenesis of airway remodeling.     

Suppressive effect of interferon γ on IL-13-induced fibrosis in fibroblasts

AIM：To investigate the suppressive effect of interferon γ (IFN-γ) on fibrosis induced by interleukin 13 (IL-13) in fibroblasts. METHODS：The fibroblasts were divided into IFN-γ (4×105U/L) group, IL-13 (100 μg/L) group, IFN-γ+IL-13 group and blank control group. At 24 h, 48 h and 72 h, the secreted collagen from fibroblasts was measured by hydroxyproline release assay. The mRNA expression of collagen type I α1 (Col1A1) in fibroblasts was examined by RT-PCR. The protein level of collagen type I synthesized in fibroblasts was analyzed by Western blotting. RESULTS：IFN-γ at 4×105U/ L significantly inhibited the proliferation of fibroblasts and down-regulated Col1A1 mRNA and cellular collagen. The mRNA expression of Col1A1 and the protein level of collagen type I in IFN-γ group were lower than those in blank control group at 48 h and 72 h. At 72 h, the mRNA expression of Col1A1 and the protein level of collagen type I in IL-13 group were substantially higher than those in blank control group, those in IFN-γ + IL-13 group were remarkable lower than those in blank control group, and those in IFN-γ group were also lower than those in blank control group. CONCLUSION：IFN-γ inhibits the fibrotic effect of IL-13 in fibroblasts.     

Sedum sarmentosum Bunge extract inhibits epithelial-mesenchymal transition and collagen accumulation in aristolochic acid-treated rat renal tubular epithelial cells

AIM:To investigate the effect of Sedum sarmentosum Bunge (SSB) extract on epithelial-mesenchymal transition (EMT) and collagen accumulation induced by aristolochic acid (AA) in renal tubular epithelial cells. METHODS:Rat renal tubular epithelial NRK-52E cells were randomly divided into 3 groups, including control group (only treated with solvent), AA group (treated with AA at concentrations ranging from 1 to 100 mg/L) and SSB group (treated with AA at a concentration of 10 mg/L plus SSB extract at concentrations ranging from 10 to 2 000 mg/L). After cultured for 24 h, the morphology of the NRK-52E cells was observed under inverted phase-contrast microscope. The level of transforming growth factor β1 (TGF-β1) in the culture supernatant was measured by ELISA. Immunofluorescent analysis was performed to detect the expression of epithelial marker α-smooth muscle actin (α-SMA), mesenchymal marker E-cadherin, and extracellular cell matrix component type III collagen. The mRNA expression of E-cadherin, α-SMA, bone morphogenetic protein 7 (BMP-7) and type I collagen was also quantified by real-time PCR. RESULTS: Fibrosis-like reaction observed under microscope was obviously increased in AA-treated NRK-52E cells, and aggravated as the increase in the concentration of AA. AA at concentrations of 1 and 10 mg/L increased the expression of α-SMA, type I and type III collagens, and decreased the expression of E-cadherin. With SSB extract treatment, fibrosis in NRK-52E cells was alleviated, accompanied with the decreasing expression of α-SMA, type I and type III collagen, and the enhancing expression of E-cadherin and BMP-7.Moreover, SSB extract down-regulated TGF-β1 level in a concentration-dependent manner. CONCLUSION: AA-induced fibrosis-like reaction in renal tubular epithelial cells is reduced by the treatment with SSB extract. The possible mechanism is that SSB extract decreases TGF-β1 level, and inhibits renal EMT and collagen accumulation induced by AA.［KEY WORDS］Sedum sarmentosum Bunge|Aristolochic acid|Transforming growth factor β1|Epithelial-mesenchymal transition|Collagen