24月龄生长母水牛绝食代谢的研究

用传统开路式牛用呼吸面具对24月龄母水牛绝食产热(Fasting heat production,FHP)进行研究。结果表明:①24月龄母水牛FHP为306.013kJ/kgW0.75·d;每天排出内源尿氮(EUN)为39.66g;单位代谢体重每天排出EUN为0.48g;蛋白分解产热占总产热量为17.13%;EUN与FHP比值为1.60mg/kJ。②24月龄母水牛维持净能需要:NEm=397.817kJ/W0.75·d。     

亚麻籽油对糖尿病大鼠辅助降血糖功能的研究

[目的]探讨亚麻籽油对糖尿病大鼠空腹血糖及糖耐量的影响。[方法]高脂饲料喂养SD雄性大鼠建立肥胖模型;将肥胖模型大鼠一次性腹腔注射40 mg/kg链脲菌素建立糖尿病模型;将糖尿病模型大鼠随机分为模型对照组以及亚麻籽油低、中、高剂量组,每组8只,连续灌胃30 d后测定模型大鼠空腹血糖和糖耐量。[结果]亚麻籽油高剂量组可以降低糖尿病大鼠的空腹血糖和糖耐量。[结论]亚麻籽油具有辅助降低糖尿病大鼠血糖的功能。     

12月龄生长母水牛绝食代谢的研究

用传统开路式牛用呼吸面具对12月龄母水牛绝食产热(FHP)进行研究。结果表明:①12月龄母水牛FHP为334.03KJ/KgW0.75·d;每天排出内源尿氮(EUN)为31.06g;代谢体重每天排出EUN为0.53g;蛋白分解产热占总产热量为17.99%;EUN与FHP比值为1.60mg/KJ。②12月龄母水牛维持净能需要:NEm=400.84KJ/W0.75d。     

肉用雏鸡在绝食条件下的卵黄囊营养和维持需要

出壳后肉用仔鸡在绝食至１１２，５８，０１６和１３０时龄时，分别测定全屠体（共６４只）和卵黄囊（共６３只）营养素含量。４５克体重时（１２时龄）维持需要量是代谢能１１千卡（共６０只），和蛋氨酸的耗减量，赖氨酸５１毫克，蛋氨酸为１８毫克。但在绝食 １２至５８时，能量，蛋白质，赖氨酸和蛋氨酸的耗减量，完全由卵黄囊承担。并有余量转贮于体组织内。在平均２４小时内，能量转贮２千卡，蛋白质０．３克，赖氨酸７毫克，     

The cholesterol-lowering property of soybeans fed to rats is related to the fasting duration

Numerous factors affect plasma cholesterol and, therefore, representpotential interferences with the specific effects of diet on lipid metabolism.After casein intake, serum cholesterol levels depend on many experimentalconditions in rats, such as the type of casein, the presence or absence ofcholesterol in the diet, the age and strain of rat, the diet composition, thenutritional status. The effect of fasting duration on selected parameters wasstudied in adult male Wistar rats fed a 20% casein and 1% cholesterol-based diet. No changes were observed in total serum, lipoproteins-B andHDL cholesterol and in triglyceride values after an 8 h-fast compared tonon-fasted animals. A significant decrease was induced in total andlipoproteins-B cholesterol with a 12 h-fast. A prolonged fast resulted ina significant decrease in these parameters and in triglycerides and inHDL-cholesterol levels.Fasted animals fed heated soybean meal instead of casein did not display amarked decrease in serum lipids. It appeared that the fasting effect wasmore marked in animals fed casein than in animals fed soybeans. Theseresults showed the importance of experimental conditions such as nutritional status ofanimals when blood samples are taken in studies of the hypocholesterolemiceffect of soy protein compared to casein.     

日粮纤维素和环境温度对实验大白鼠的影响——Ⅲ 实验大白鼠的能量代谢

环境温度和日粮纤维素水平都可影响大白鼠的产热量及产热量占代谢能(HE/MEI)的比例,其在高纤维素日粮组较低纤维素日粮组高,环境温度为16℃和32℃时较24℃时高。环境温度和高纤维日粮还可增加大白鼠的绝食代谢产热量和生长价。维持代谢能(MEm)并不受日根纤维素的影响,但随环境温度的降低而增加。低纤维日粮和适中的环境温度可使沉积能中脂肪的比例增加。     

Effects of fasting on IGF-I,IGF-II,and IGF-binding protein mRNA concentrations in channel catfish (Ictalurus punctatus)

The effects of fasting on insulin-like growth factor (IGF)-I, IGF-II, and IGF-binding protein (IGFBPs) mRNA in channel catfish were examined. Fed control fish (Fed) were compared to fish that had been fasted for 30 d followed by 15 d of additional feeding (Restricted). Sequence alignment and similarity to orthologous proteins in other vertebrates provided structural evidence that the 3 catfish sequences identified in the present research were IGFBP-1, -2, and -3. Prolonged fasting (30 d) reduced body weight approximately 60% (P < 0.001) and decreased IGF-I mRNA in the liver and muscle (P < 0.01). Fifteen days of re-feeding restored concentrations of hepatic and muscle IGF-I mRNA. Liver IGF-II mRNA was not affected by fasting but was increased 2.2-fold after 15 d of re-feeding (P < 0.05). Abundance of muscle IGF-II mRNA was similar between the fed control group and the restricted group throughout the experimental period. Fasting also increased liver IGFBP-1 mRNA (P < 0.05) and decreased IGFBP-3 mRNA (P < 0.01), whereas abundance of IGFBP-2 mRNA was not significantly affected. Interestingly, re-feeding for 15 d did not restore concentrations of IGFBP-1 and IGFBP-3 mRNA relative to fed control concentrations. The IGF results suggest that IGF-I and IGF-II are differently regulated by nutritional status and probably have a differential effect in promoting muscle growth during recovery from fasting. Similar to mammals, IGFBP-1 mRNA in catfish is increased during catabolism, whereas IGFBP-3 mRNA is decreased during inhibited somatic growth. The IGFBP results provide additional evidence of the conserved nature of the IGF-IGFBP-growth axis in catfish.     

Impact of starvation and handling stress on rigor development and quality of Atlantic salmon (Salmon salar L)

Farmed Atlantic salmon (Salmo salar L) were fed to satiation or starved for 35 d, and subjected to acute pre-slaughter stress or careful handling before slaughtering. Rigor development, post-mortem energy metabolism and quality variations were analysed during 72 h cold storage. The body weight averaged 2.9 and 3.5 kg of the fed and starved salmon, respectively. The starved salmon had lower condition factor (0.99 vs. 1.11) and higher slaughter yield (92.6 vs. 87.5%), but the fat content was similar (11.8–12.9%) in the fed and starved salmon. The initial glycogen level was lower in the starved salmon (21 vs. 29 μmol g^− 1), whereas initial ATP levels (6.4–6.6 μmol g^− 1) were not affected by starvation. Pre-slaughter stress accelerated rigor development, stimulated lactate formation through post-mortem glycolysis, and increased the breakdown of ATP and CP. The effect of stress on rigor development was less pronounced in starved salmon, and a significant interaction was observed between nutritional status and stress. Rigor development was closely correlated to ATP breakdown, especially in fillets. Acute stress accelerated flesh softening during ice storage. After 72 h storage, the fillets of the starved salmon exposed to careful slaughter handling had the significantly firmest texture, whereas the most intense fillet colour was observed in the starved/stressed salmon. Liquid leakage from the muscle during cold storage was lower in the starved salmon, but pre-slaughter stress had no significant impact. It is concluded that a starvation period of five weeks can improve the resistant to acute stress prior to slaughtering of Atlantic salmon that in turn hampers rigor development.     

松花苦桑粉对糖尿病小鼠降血糖的作用

[目的]研究松花苦桑粉的降血糖作用,为其作为辅助降血糖的功能食品提供科学依据。[方法]以正常小鼠、四氧嘧啶(ALX)诱导的糖尿病模型小鼠为材料,按体重随机分组,灌胃给药,测定空腹血糖,进行淀粉负荷糖耐量试验(OSTT)。[结果]松花苦桑粉以13.6、6.6、3.3 g/kg 3种剂量灌胃15 d,以13.6 g/kg剂量效果为好,具有统计学意义(P<0.01)。松花苦桑粉以13.6、6.6、3.3 g/kg 3种剂量灌胃35 d,其中13.6 g/kg剂量组ALX性糖尿病小鼠空腹血糖显著降低(P<0.05);高、中和低剂量组均明显降低ALX性糖尿病小鼠血糖水平。[结论]在空腹血糖试验,松花苦桑粉降低正常小鼠空腹血糖试验结果阳性,降低ALX性糖尿病小鼠空腹血糖试验结果阳性。在糖耐量试验,松花苦桑粉对ALX性糖尿病小鼠的糖耐量试验结果阳性。13.6、6.6和3.3 g/kg松花苦桑粉对ALX性糖尿病小鼠的糖耐量试验结果阳性。     

Influence of circulating GH levels on GH-binding capacity measurements in the hepatic membrane of rainbow trout (Oncorhynchus mykiss): importance of normalization of results

In fish, regulation of the growth hormone (GH) receptor has been mainly analyzed by binding studies, with some discrepancies in the results. The present work aims at determining whether circulating GH levels influence the measurement of hepatic GH-binding capacities. To do this, the effectiveness of the dissociation of the GH/GH receptor (GHR) complex by an MgCl₂ treatment was assessed in rainbow trout, and data on GH-binding capacities under various physiological conditions were studied using different means of expression. Our results reveal that MgCl₂ treatment dissociated the liver GH/GHR complex formed under in vitro conditions (85 ± 23 vs. 361 ± 16 fmol/g of liver; p<0.001) but not in vivo, showing such treatment in trout is not applicable. A comparison of fasted (3 weeks) and fed fish revealed that GH-binding capacities, expressed as femtomoles per milligram protein or femtomoles per gram of liver, were similar in both fed and fasted fish. However, when changes in liver and body size were taken into account, the total GH-binding capacities were lower in the fasted fish (0.026 ± 0.006 vs. 0.062 ± 0.009 fmol/cm³ liver; p<0.05). One day after hypophysectomy or GH injection, changes in the plasma GH levels increased or decreased GH-binding capacities, respectively. Five days later, GH-binding capacities increased in GH-injected fish (527 ± 38 vs. 399 ± 38 fmol/g liver; p<0.01). Our interpretation is that acute treatment modified GH-binding capacities through receptor occupancy and that GH stimulated the synthesis of its own receptor. On the other hand, long-term treatment through successive injections of GH lowered the total binding capacities (approx. 40%), which could result from receptor occupancy. We conclude that circulating GH levels strongly influence the measurement of GH-binding capacities in the liver, thereby limiting interpretation of the binding data and preventing accurate conclusions to be drawn on GHR regulation.