实验性脾虚证大鼠肝脏和肌肉组织中糖原变化的组织学观察

将45只大白鼠随机分成对照组、脾虚模型组及治疗组,每组15只。以利血平(1mg/kg·d)复制大白鼠脾虚证模型,四君子汤辅助治疗,在实验进行至第7天和第14天分别捕杀各组大白鼠,取肝脏、肌肉组织,用组织化学方法测定在不同组间和不同实验阶段其中糖原的变化。结果,在第7天时,脾虚组和治疗组糖原含量明显低于正常对照组,第14天时,与正常对照组相比较,脾虚组和治疗组糖原含量显著升高,且脾虚组糖原含量较其它两组高,提示肝脏和肌肉组织中糖原的变化可能是脾虚证发生发展的重要指标。     

日本血吸虫GSK3蛋白编码cDNA的克隆、表达及其重组蛋白的免疫保护研究

本研究利用生物信息学分析了日本血吸虫(Schistosoma japonicum,sj)Glycogen synthase kinase 3(GSK3)蛋白,并对其中一个GSK3蛋白的编码cDNA进行了克隆和原核表达,制备了特异性的多克隆抗体.同时,还初步评估了重组蛋白的免疫保护效果.生物信息学分析表明在日本血吸虫数据库存在两种GSK3蛋白,且其中一个SjGSK3在日本血吸虫不同发育时期均有转录.Western blot结果表明本研究制备的抗体能特异性识别日本血吸虫SjGSK3重组蛋白,表明该重组蛋白具有良好的免疫原性.动物实验表明免疫SjGSK3重组蛋白的动物与佐剂对照组比较分别获得了平均10.6％减虫率和40.5％肝脏减卵率.     

Metabolic function of hepatic hexokinase in perch, Perca fluviatilis

Feeding previously fasted perch with a carbohydrate‐rich pelleted diet resulted in a rapid transient insulin response followed by a transient increase in the activity of the hepatic low‐affinity hexokinase (glucokinase, GK). The activity of the high‐affinity hexokinase (hexokinase, HK) increased more slowly and steadily to about seven times the fasting value on the 10th day after start of feeding, in parallel with an increase in the hepatic glycogen content. An insulin response was also observed when fasted perch were fed a diet consisting of boiled fillet of cod (a high‐protein, very low‐fat and practically carbohydrate‐free diet). In this case no GK activity was observed, whereas the glycogen content increased steadily from the start of feeding to about the same level as when fish were given the carbohydrate‐rich diet. There was a delayed increase in the activity of HK, starting on about the sixth day (after the glycogen stores were filled), concomitant with increased activities of lipogenic enzymes (glucose‐6‐phosphate dehydrogenase, ATP citrate lyase and malic enzyme). The results are in line with the hypothesis that the mitochondria‐bound hepatic HK has a particular anabolic function in glycogen and fat synthesis.     

Blood chemistry and organ nutrient composition in Atlantic salmon, Salmo salar L., fed graded amounts of wheat starch

After feeding Atlantic salmon, Salmo salar L., five graded amounts of wheat starch from 0 to 310 g kg^?1, low but increased levels of glycogen in kidney, heart and gills were determined. No variations were found in proximate or glycogen compositions of muscle, whereas the liver composition reflected the diet composition. Whole-body homogenates varied in dry matter and lipid levels; the variation was according to g lipid eaten per fish. Plasma glucose levels ranged above average levels only when the starch level in the feed was higher than 220 g kg^?1. Although feed intake and thereby lipid intake increased as dietary carbohydrate increased in the present experiment, no differences in plasma concentrations of cholesterol and only small changes in triglycerides were determined. The increase in dietary carbohydrate was balanced with protein, and total plasma protein concentrations followed the decrease in feed protein content. Haematocrit, haemoglobin, mean cell volume and mean cell haemoglobin all showed significantly reduced levels as dietary starch increased, indicating a fibre effect from ‘left-over’ starch in the intestine followed by reduced absorption of divalent ions, such as iron.     

The changes in proximate compositions and glycogen contents in the dorsal ordinary muscles of the full-cycle cultured Pacific bluefin tuna Thunnus orientalis occurring with growth

ABSTRACT:   Using full-cycle cultured (FC) Pacific bluefin tuna (body length [BL], 42.6–66.4 cm; body weight [BW], 1.66–7.40 kg, n  = 15), the changes in chemical compositions and histological structure of the cephalal parts of the dorsal ordinary muscles (DOM) occurring with growth were investigated. A positive correlation ( r  = 0.9644, P  < 0.05) was observed between BL and BW with growth. The protein, lipid and ash contents of DOM and condition factor did not change with growth. However, the glycogen content of DOM increased ( P  < 0.05) from approximately 55 cm (BL) in this study. Using optical microscopic photographs, the various shapes of muscle fibers were observed and it was noted that the muscle fiber diameter increased ( P  < 0.05) with growth. Using transmission electron microscopic observation, many glycogen granules were observed in muscle fibers (especially, side of connective tissue) of DOM throughout the growth stage in this study. These results indicate that the glycogen content of DOM of FC Pacific bluefin tuna increases before the lipid with growth.     

Feed deprivation of channel catfish, Ictalurus punctatus (Rafinesque), influences organosomatic indices, chemical composition and susceptibility to Flavobacterium columnare

Withholding feed has been suggested as a strategy to manage infectious disease of channel catfish, Ictalurus punctatus (Rafinesque). In a previous study, we demonstrated that deprivation of feed for as little as 7 days reduced innate resistance of catfish to Flavobacterium columnare. This study was conducted to evaluate the effect of feeding regimens [no feeding (NF), fed once every other day to satiation (FEOD) and fed once daily to satiation (FD)] on organosomatic indices, physiological changes and susceptibility of channel catfish to F. columnare. Fish that were not fed for 2 and 4 weeks had a significant increase (P < 0.05) in gutted weight:-wet weight ratio and decrease in other organosomatic indices [gut index (GI), mesenteric fat index (MFI) and hepatosomatic index (HSI)]. Haematology was not effected by feeding regimen except at week 4, when a significantly higher haemoglobin level was observed in the NF fish. Serum protein did not differ at week 2, but the level at week 4 of the NF fish (35.91 mg mL(-1)) was significantly lower than that of the FD fish (41.77 mg mL(-1)). Significantly lower (P < 0.05) blood glucose (39.5 and 40.3 mg dL(-1)) and liver glycogen (1.7 and 1.8 mg g(-1)) were seen in the NF fish at weeks 2 and 4, respectively, as compared with blood glucose and liver glycogen levels of FD fish (67.5 and 92.8 mg dL(-1) and 46.5 and 52.6 mg g(-1) at weeks 2 and 4, respectively) and FEOD (82.8 and 85.5 mg dL(-1) and 45.1 and 51.4 mg g(-1) at weeks 2 and 4, respectively). Mortality in the NF fish caused by F. columnare (78%) was significantly higher (P < 0.05) than mortality in the FD and FEOD treatments (0.0 and 1.7%, respectively). Blood glucose and liver glycogen showed the same trend of low values for NF fish following challenge (week 6). Blood glucose, liver glycogen, GI and HSI are sensitive indicators for channel catfish deprived of feed (NF) for 4 weeks. Blood glucose and liver glycogen levels around 40 mg dL(-1) and 2 mg g(-1), respectively, are indicative of starvation in juvenile channel catfish. Moreover, NF fish were susceptible to F. columnare infection. Thus, it is suggested that in the absence of natural food, juvenile channel catfish should be fed at least once every other day to apparent satiation to maintain normal physiological function and improve resistance to F. columnare.     

Utilization of dietary starch and glucose tolerance in juvenile chinook salmon (Oncorhynchus tshawytscha) of different strains in seawater

Juvenile chinook salmon of three strains responded to inclusion of 28.7% of gelatinized starch in the diet with different degrees of reduction in growth rate and feed efficiency relative to control fish of the respective strains fed a low-starch, high-lipid diet of similar protein (46%) and estimated metabolizable energy content (16 mJ/kg). The productive protein value of the diet was not reduced to the same extent by the high intake of starch. Carcasses of fish fed the high-starch diet contained higher concentrations of protein and lower concentrations of lipid than control fish. The accumulation of liver glycogen in response to the high-starch diet differed among strains. Glucose tolerance curves also varied among strains but were poorly correlated with plasma concentrations of insulin. Tolerance to glucose loading was improved in fish previously fed the high-starch diet.     

谷氨酰胺的抗疲劳生化机制研究

用两批各 48只小鼠分 4组 (n =12 )每天分别灌喂生理盐水和 3 4mmol·kg-1的谷氨酰胺、谷氨酸和天冬酰胺 ,连续 10d。结果显示 ,三者都可提高小鼠血清、肝和骨骼肌中的肌酸磷酸激酶活性 ,降低乳酸脱氢酶活性 ,并显著增加肝、骨骼肌糖原积累。其中有相同碳架结构的谷氨酰胺、谷氨酸能极显著提高小鼠的游泳耐力 ,但与谷氨酰胺有相等酰胺氮的天冬酰胺作用不强。结果提示 ,谷氨酰胺提高机体抗疲劳作用与其碳架结构有关     

猪RN基因的研究

RN基因是影响猪肉质性状的一个主效基因,已被定位在猪的15号染色体上(15q25),包含显性的不利等位基因(RN)为影响猪肉的工艺产量和隐性正常的等位基因(rn)。最近发现的与肌肉过量糖原含量相关的PRKAG3基因的非保守替换(R200Q),被认为是引起酸肉的主要原因。     

Hypophosphatemia Induced by Dietary Aluminium Hydroxide Supplementation in Growing Pigs: Effects on Erythrocytes,Myocardium, Skeletal Muscle and Liver

Håglin, L., B. Essén-Gustavsson and A. Lindholm: Hypophosphatemia induced by dietary aluminium hydroxide supplementation in growing pigs: Effects on erythrocytes, myocardium, skeletal muscle and liver. Acta vet. scand. 1994, 35, 263-271.– Three groups of pigs were studied during and after 10 weeks of treatment with either Al(OH)₃ (Al[OH]₃-group, n=8) to induce hypophosphatemia, A1P0₄ (AlP0₄-group, n=8, aluminium control without hypophosphatemia) or no addition to the feed (control group, n=8). Blood samples were taken at the start of the experiment and after 3, 6 and 10 weeks and were analyzed for phosphate, calcium and 2,3-diphosphoglycerate (2,3-DPG). Samples from myocardium, skeletal muscle and liver were obtained in connection with exsanguination and analyzed for glycogen, adenosine-tri-phosphate (ATP), creatine phosphate (CP), glucose-6-phosphate (G-6-P) and lactate. The Al(OH)₃-group became hypophosphatemic and hypercalcémie with low levels of 2,3-DPG in erythrocytes within 3 weeks and showed a retarded growth rate. After 10 weeks the Al(OH)₃-group had low levels of ATP in myocardium as compared with the control-group and low levels of G-6-P as compared with the AlP0₄-group. No disturbances on electro-cardiograms registered at rest could be documented. G-6-P concentration was low in the biceps muscle in the Al(OH)₃-group as compared with the AlP0₄-group and in the liver low G-6-P concentration was seen in addition to high lactate concentration. The fibre type composition in M. Longissimus did not differ between groups, but the Al(OH)₃-group had, due to retardation in growth, smaller mean fibre-areas than pigs in the AlP0₄-group. Hypophosphatemia gave rise to high serum calcium levels, low concentration of 2,3-DPG in erythrocytes and influenced G-6-P concentration in skeletal muscle, G-6-P and ATP in myocardium, G-6-P and lactate in liver. Retarded growth was one serious consequence of hypophosphatemia and the disturbed energy metabolism.