抗囊虫药物对体内成熟期猪囊尾蚴囊壁生化指标的影响

将无猪囊尾蚴感染的仔猪经人工感染猪带绦虫卵后，确认猪囊尾蚴成熟率达到80％以上后，分为三组，除一组不用任何药物作为对照外，其余两组分别采用囊效0号、囊效1号两种药物，通过检测囊尾蚴囊壁的HK、PK、LDH、MDH、G6PDH活性变化及GLc、LAC含量变化，结果表明药物通过抑制猪囊尾蚴虫体的延胡索酸还原酶复合体，使逆向三羧酸循环受阻，引起MDH、HK活性的抑制，进而干扰其他代谢途径，而宿主体内各系统的参与加速了虫体死亡的进程，应用的两种药物中NX1的药效优于NX0。     

菜芜猪脂肪代谢酶活性的发育性变化及其对肌内脂肪沉积的影响

以40-90kg6个体重阶段莱芜猪和新莱芜猪共72头为试验对象，研究了不同组织中脂肪代谢酶活性的发育性变化规律及其与肌内脂肪含量、背膘厚的关系。结果表明：（1）在生长期随着体重的增大，肌肉组织中脂肪合成酶异柠檬酸脱氢酶（ICDH）活性显著高于苹果酸脱氢酶（MDH）活性（P〈0．01）；ICDH活性在60-70kg时达到峰值，而后开始下降，MDH活性规律不明显；脂肪分解酶激素敏感脂酶（HSL）的活性先降后升，70～80kg时活性最高。（2）背膘中合成酶MDH活性显著高于ICDH活性（P〈0．01）；MDH和ICDH活性都是先降后升，但总体升降幅度不大；HSL活性40～50kg基本稳定，而后逐步增强。（3）肝脏组织中合成酶ICDH活性显著高于MDH活性（P〈0．01）；ICDH、MDH活性逐渐升高，至60kg以后其活性趋于稳定，脂肪分解酶HSL活性的发育性变化规律不明显。（4）肌肉组织中的MDH、HSL活性与肌内脂肪含量呈极显著相关（P〈0．01）；肝脏组织中的MDH、ICDH与肌内脂肪含量呈显著正相关，ICDH还与背膘厚呈极显著正相关；背膘组织中的MDH、HSL与背膘厚呈极显著相关（P〈0．01）。研究结果提示：肌内脂肪的沉积与背膘脂肪的沉积既存在一定的内在联系（通过肝脏），又具有一定的独立性，通过选择肌肉组织中脂肪代谢酶活性，在不显著影响皮下脂肪沉积量的前提下可望提高肌内脂肪的沉积量。     

民猪与大白猪背最长肌能量代谢关键酶活性研究

为了揭示肌纤维类型组成对猪骨骼肌能量代谢酶活性的影响，本实验以民猪和大白猪为研究对象，在比较了民猪和大白猪肌纤维类型组成差异的基础上，采用比色法测定民猪和大白猪背最长肌中能量代谢关键酶乳酸脱氢酶（LDH）、琥珀酸脱氢酶（SDH）和苹果酸脱氢酶（MDH）的活性差异。结果表明，民猪氧化型纤维MyHCI型和IIa型含量显著高于大白猪，酵解型纤维MyHCII b型含量显著低于大白猪，民猪有氧代谢酶SDH和MDH活性显著高于大白猪，无氧酵解酶LDH活性显著低于大白猪，这在一定程度上说明民猪与大白猪能量代谢关键酶活性差异的主要因素是骨骼肌纤维类型组成不同。     

不同浓度奶牛脐带间充质干细胞对奶牛乳腺上皮细胞葡萄糖代谢的影响研究

为探究在不同浓度下奶牛脐带间充质干细胞(UC-MSCs)对奶牛乳腺上皮细胞(BMECs)共培养对共培养体系葡萄糖代谢的影响及其作用机制。研究将P3代UC-MSCs与P3代BMECs,按照浓度为1∶1、1∶2、1∶3、1∶4、1∶5、1∶10、1∶50、1∶100、1∶1 000和2∶1等不同比例随机混合培养,同时设立UC-MSCs与BMECs单纯培养组为对照组,并分别于0、24、48、72、96、120和144 h时提取上清液,检测己糖激酶(HK)、乳酸脱氢酶(LDH)和丙酮酸激酶(PK)的活性,及乳酸(LD)的分泌量。发现将UC-MSCs和BMECs按照不同浓度比例混合共培养后,1∶2浓度组HK的活性显著高于BMECs单纯培养组(P0.05),且72 h时活性显著高于0、24、48和144 h(P0.05);LD的分泌量在1∶2浓度组达到最高,显著高于BMECs单纯培养组(P0.05),且72 h与0 h相比差异显著(P0.05);PK活性在1∶2浓度组达到最高,显著高于BMECs单纯培养组(P0.05),且72 h时达到最高,显著高于0、120和144 h(P0.05);1∶2浓度组的LDH活性显著高于BMECs单纯培养组(P0.05),0 h组与其他各组相比均差异显著(P0.05)。通过研究得出以下结论:不同浓度UC-MSCs和BMECs混合共培养能够促进共培养体系的葡萄糖代谢,其中1∶2浓度组葡萄糖代谢最快,葡萄糖代谢速率最快的时间点为72 h时。其作用机制是UC-MSCs和BMECs混合共培养能够增强HK和PK活性,降低LDH活性,提高LD分泌量。     

胍基乙酸对保育猪生长性能、抗氧化能力和糖代谢关键酶的影响

本试验旨在探讨胍基乙酸对保育猪生长性能、抗氧化能力和糖代谢关键酶的影响。选取体重为(19.03±1.30)kg的健康"杜×长×大"三元杂交仔猪64头,随机分为2组,每组4个重复,每个重复8头猪。对照组饲喂基础饲粮,胍基乙酸组饲粮在基础饲粮中添加600 mg/kg胍基乙酸。预试期7 d,正试期14 d。结果表明:1)与对照组相比,胍基乙酸组保育猪的平均日增重显著升高(P0.05),料重比显著降低(P0.05);2组间的末重和平均日采食量无显著差异(P0.05)。2)胍基乙酸组保育猪的血浆超氧化物歧化酶(SOD)抑制率、谷胱甘肽(GSH)含量和总抗氧化能力(T-AOC)显著高于对照组(P0.05),2组间的血浆丙二醛(MDA)含量无显著差异(P0.05)。3)胍基乙酸组保育猪的血浆果糖-6-磷酸激酶(PFK)、丙酮酸激酶(PK)、异柠檬酸脱氢酶(IDH)、苹果酸脱氢酶(MDH)、烟酰胺腺嘌呤二核苷酸-辅酶Q还原酶(NADHCo Q)和肌酸激酶(CK)活性均极显著高于对照组(P0.01),血浆己糖激酶(HK)活性有低于对照组的趋势(0.05≤P0.10),血浆三磷酸腺苷(ATP)合成酶(ATPase)活性有高于对照组的趋势(0.05≤P0.10)。由此可知,饲粮中添加胍基乙酸可改善保育猪的生长性能,提高其抗氧化能力,并可通过提高糖代谢关键酶(PFK、PK、IDH、MDH)及线粒体呼吸链相关酶(NADH-Co Q、ATPase)活性促进体内的分解代谢,提高机体ATP水平,进而可能促进储能组织(肌肉和脂肪)的合成。     

阿苯达唑和奥芬达唑对体外培养猪囊尾蚴能量代谢变化的影响

测定了在阿苯达唑和奥芬达唑作用下体外培养猪囊尾蚴磷酸烯醇式丙酮酸羧激酶（PEPCK）、丙酮酸激酶（PK）、延胡索酸还原酶（FR）、苹果酸酶（ME）活性的变化及葡萄糖（GLC）、乳酸（LAC）含量的变化。结果表明，2种药物作用均可在体外作用条件下显著改变未成熟期及成熟期猪囊尾蚴的能量代谢。提示，苯并咪唑氨基甲酸酯类药物的作用机理可能是通过干扰虫体能量代谢，阻断能量的产生，导致虫体死亡。     

皮质醇对斜带石斑鱼原代培养肝细胞糖代谢的影响

本试验旨在研究皮质醇对斜带石斑鱼原代培养肝细胞糖代谢的影响。分离斜带石斑鱼肝细胞,选取2个孵育时间(24和36 h)和3个皮质醇浓度[0(对照)、100和1 000 nmol/L],测定培养上清液中葡萄糖含量(即肝细胞葡萄糖释放量),肝细胞糖原和丙酮酸含量以及肝细胞糖代谢关键酶[磷酸烯醇丙酮酸羧激酶(PEPCK)、葡萄糖-6-磷酸酶(G6Pase)、糖原合成酶(GSase)、苹果酸脱氢酶(MDH)、异柠檬酸脱氢酶(ICD)和丙酮酸激酶(PK)]的活性。结果表明:在孵育24和36 h时,与对照组相比,100和1 000 nmol/L皮质醇组肝细胞葡萄糖释放量显著提高(P0.05),而肝细胞丙酮酸含量显著降低(P0.05);皮质醇孵育时间对肝细胞葡萄糖释放量、丙酮酸含量均无显著影响(P0.05)。在孵育24 h时,皮质醇浓度对肝细胞糖原含量无显著影响(P0.05),而在孵育36 h时,肝细胞糖原含量则随着皮质醇浓度的升高而显著降低(P0.05);随着皮质醇孵育时间的延长,肝细胞糖原含量显著下降(P0.05)。在孵育24和36 h时,100和1 000 nmol/L皮质醇显著提高了肝细胞PEPCK和G6Pase的活性(P0.05),显著降低了肝细胞MDH和ICD的活性(P0.05),但对肝细胞GSase活性则无显著影响(P0.05);在孵育24 h时,皮质醇浓度对肝细胞PK活性无显著影响(P0.05),但在孵育36 h时,100和1 000 nmol/L皮质醇则显著提高了肝细胞PK活性(P0.05)。随着孵育时间的延长,肝细胞G6Pase活性显著下降(P0.05),PK活性显著升高(P0.05),而MDH和ICD活性均无显著变化(P0.05)。由此可见,皮质醇能够促进斜带石斑鱼原代培养肝细胞糖异生作用,抑制葡萄糖的分解代谢,而对糖原合成无调节作用。     

营养限制与补偿对蒙古育成羯羊肝脏关键酶活性的影响

本试验旨在阐明营养限制与补偿对蒙古育成羯羊肝脏关键酶活性的影响。试验选用40只平均体重为(14.72±1.10)kg的3月龄蒙古育成羯羊,随机分为对照组(CG)和双限组(RG)。试验分营养限制期(60d)和营养补偿期(90d)。限制期2组饲粮对应能氮水平为代谢能(ME):10.88(对照组)和8.62(双限组)MJ/kg;粗蛋白质(CP):15.0%(对照组)和5.7%(双限组)。补偿期各组饲喂同一能氮水平(ME:9.75 MJ/kg;CP:12.0%)的饲粮。在限制期与补偿期末分别测定蒙古育成羯羊肝脏中己糖激酶(HK)、丙酮酸激酶(PK)、乳酸脱氢酶(LDH)、果糖-1,6-二磷酸酶(FBP1)、苹果酸脱氢酶(MDH)、α-磷酸甘油脱氢酶(GAPDH)、丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)和谷氨酸脱氢酶(GLDH)的活性。结果显示:限制期结束时双限组蒙古育成羯羊肝脏中HK、ALT、AST、GLDH活性显著低于对照组(P<0.05),而PK、LDH、FBP1、MDH、GAPDH活性显著高于对照组(P<0.05);经过90d补偿后,双限组蒙古育成羯羊肝脏中HK、PK、MDH、ALT活性显著高于对照组(P<0.05),而LDH、FBP1、GAPDH、AST、GLDH活性与对照组差异不显著(P>0.05)。结果提示,限制期双限组蒙古育成羯羊糖酵解途径关键酶活性降低,糖异生途径关键酶活性升高,脂肪分解途径关键酶活性升高,这与机体在低能氮营养水平时脂肪动员加强有关,蛋白质代谢途径关键酶活性降低则表明限制期蛋白质代谢降低;补偿期双限组蒙古育成羯羊总体糖酵解、糖异生和脂肪分解途径关键酶活性基本恢复到对照组水平,而PK活性显著提高,脂肪合成和蛋白质代谢途径关键酶活性升高可能与此期较高的生长速率相关。     

饲料中糊精水平对乌克兰鳞鲤生长及糖代谢的影响

为了探讨饲料中糊精水平对乌克兰鳞鲤生长和糖代谢的影响,试验配制蛋白质水平为30%,糊精水平分别为15%和25%的2种试验饲料,以平均体重为3.92 g的乌克兰鳞鲤幼鱼为试验对象,将300尾鱼随机分为2组,每组设3个重复,每个重复50尾鱼。饲养8周后,检测乌克兰鳞鲤生长指标、生化指标和糖代谢酶活性;禁食48 h后再投喂,测定投喂后0、3、6、12、24、48 h肝胰脏和肠道葡萄糖激酶(GK)和葡萄-6-磷酸酶(G6 Pase)mRNA的表达量。结果表明:1)25%糊精组的特定生长率显著高于15%糊精组(P0.05)。2)25%糊精组的血清甘油三酯、胆固醇和葡萄糖含量显著高于15%糊精组(P0.05)。3)25%糊精组血清己糖激酶(HK)、GK、丙酮酸激酶(PK)、苹果酸脱氢酶(MDH)活性,肝胰脏HK、GK、G6 Pase活性显著高于15%糊精组(P0.05),而肝胰脏MDH活性则显著低于15%糊精组(P0.05)。4)再投喂24 h后25%糊精组肝胰脏GK mRNA的表达量显著高于15%糊精组(P0.05)。再投喂6 h后,25%糊精组G6Pase mRNA表达量显著高于15%糊精组(P0.05)。综合分析,在本试验条件下,25%的饲料糊精水平对乌克兰鳞鲤生长和糖代谢的促进作用好于15%的饲料糊精水平。     

日循环高温对肉鸡线粒体活性氧产生量、钙泵活性及胸肌品质的影响

通过研究日循环高温对肉鸡线粒体活性氧产生量、钙泵活性的影响，探讨高温影响肉鸡胸肌品质的机制。研究发现，日循环高温显著升高肝脏线粒体H2O2的产生量（P〈0．05），对胸肌线粒体H2O2产生量有提高趋势（P=0．0674），导致肝脏和胸肌脂质过氧化（P〈0．05），并抑制胸肌和肝脏线粒体钙泵活性（P〈0．05），影响肌纤维膜的完整性，使血液中肌酸激酶（CK）和乳酸脱氢酶（LDH）活性升高（P〈0．01，P〈0．05），表明日循环高温影响肌浆钙离子调控功能，导致肌肉中乳酸含量升高（P=0．0703），最终使肉鸡屠宰后胸肌pH1显著降低（P〈0．05），胸肌L^＊、滴水损失和剪切力显著升高（P〈0．01）。配对组与适温组在线粒体H2O2产生量、钙泵活性、脂质过氧化、乳酸含量以及胸肌pH、L^＊、滴水损失等指标上无显著差异（P〉0．05）。结果表明，日循环高温引起肉鸡氧化应激，影响线粒体钙离子转移系统功能，增加胸肌乳酸的积聚，使屠宰后胸肌pH下降速度加快，导致胸肌蛋白质变性，影响胸肌肉色和持水力，日循环高温对肉鸡线粒体功能及肉品质的影响与高温降低肉鸡采食量无关。     

Changes in Activities of Enzymes Related to Energy Metabolism in Peripheral Leukocytes of Fattening Steers

Glucose, triglyceride, cholesterol and immunoreactive insulin (IRI) concentrations, some enzyme activities in plasma, and activities of enzymes related to energy metabolism in peripheral leukocytes were measured in fattening Japanese Black Wagyu x Holstein steers fed on different diets at 8, 12, 16, 20 and 24 months of age. The plasma IRI concentrations at 20 and 24 months of age were significantly higher than those at 8 months of age. Activities of hexokinase (HK), glucose-6-phosphate dehydrogenase (G6PD), aspartate aminotransferase (AST), and malate dehydrogenase (MDH) in cytosolic fractions, and glutamate dehydrogenase (GLDH), MDH and AST in mitochondrial fractions in peripheral leukocytes of steers at 24 months of age were significantly higher than those at 8 months. Increasing plasma insulin concentration was considered to induce acceleration of glucose utilization in leukocytes of fattening steers. The cytosolic ratio of MDH/lactate dehydrogenase (LDH) activity in leukocytes increased significantly in the fattening process and was considered to be a useful indicator for evaluating changes in energy metabolism in steers.     

Changes in activities of enzymes related to energy metabolism in canine lymphoma cells

Alterations in the activities of enzymes related to energy metabolism in canine lymphoma cells were investigated. Cytosolic pyruvate kinase (PK) and mitochondrial malate dehydrogenase (MDH) activities in lymphoma cells were significantly higher than those in lymphocytes obtained from lymph nodes of healthy dogs, whereas cytosolic lactate dehydrogenase (LDH) activity was significantly lower in lymphoma cells. The cytosolic M/L ratio (MDH activity/LDH activity), which is considered to be a good indicator of energy metabolism related to glucose utilization in animal tissues, was significantly higher in lymphoma cells than in the normal lymphocytes.     

Isoenzyme activities of different strains of Cryptosporidium parvum

Different isoenzyme activities have been assayed in three strains of Cryptosporidium parvum, C1 (C. parvum from infected calves, UK), C2 (C. parvum from infected calves, Egypt) and C3 (C. parvum from infected goats, Egypt). The electrophoretic variations of five enzymes; lactate dehydrogenase (LDH), glucose phosphate isomerase (GPI), hexokinase (HK), malate dehydrogenase (MDH) and glutamate dehydrogenase (GLDH) were compared among the three different isolates using native polyacrylamide gel-electrophoresis. LDH showed an identical pattern in the three isolates. GPI showed two different bands in C3 and C1, with both bands present in C2. HK activity showed a weak band in C1 but no reaction was detected with C2 and C3. Malate dehydrogenase (MDH) showed no reaction in C1, but similar bands in C2 and C3. Glutamate dehydrogenase (GLDH) showed two different patterns, C2 and C3 had one pattern and C1 showed additional zones of reaction. Rat liver homogenate was run at the same time as the parasite extracts as a positive control. This investigation suggests that GPI, HK and GLDH could be used to characterise different Cryptosporidium isolates.     

Activities of enzymes in some types of peripheral leucocytes may reflect the differences in nutrient metabolism between dogs and cats

Plasma metabolites and immunoreactive insulin (IRI) concentrations and enzyme activities of some types of peripheral leucocytes were measured to clarify one aspect of the differences in nutrient metabolism between dogs and cats. There were no significant differences in plasma concentrations of glucose, triglyceride, free fatty acids and IRI between dogs and cats. Higher total cholesterol and lower HDL cholesterol concentrations were observed in feline plasma, and H/T ratio (HDL/total cholesterol concentrations) was significantly lower than that in canine plasma. The cytosolic activities of fructokinase (FK), pyruvate kinase (PK), glucose-6-phosphate dehydrogenase (G6PD) and lactate dehydrogenase (LDH) were significantly higher and the activities of cytosolic malate dehydrogenase (MDH) and mitochondrial glutamate dehydrogenase (GLDH) were significantly lower in feline leucocytes than those in canine leucocytes. Higher activities of FK, PK and G6PD, which regulate the rate of biosynthesis of fatty acids, may reflect the different characteristics in nutrient metabolism in feline tissues from canine tissues.     

日粮蛋白质水平对乌金猪脂肪代谢相关酶活性的影响

为研究日粮不同蛋白质水平对乌金猪脂肪代谢相关酶活性的影响。选取体重约15 kg的乌金猪54头,随机分为3组,每组3个重复,每个重复6头,在15~30 kg体重阶段饲喂18%(高蛋白质组)、16%(中蛋白质组)和14%(低蛋白质组)蛋白质水平的日粮,30~60 kg体重阶段饲喂16%(高蛋白质组)、14%(中蛋白质组)和12%(低蛋白质组)蛋白质水平的日粮, 60~100 kg体重阶段饲喂14%(高蛋白质组)、12%(中蛋白质组)和10%(低蛋白质组)蛋白质水平日粮,在体重30、60和100 kg体重时分批屠宰,取肝脏及背部皮下脂肪组织测定脂肪酶(LPS)、葡萄糖-6-磷酸脱氢酶(G-6-PDH)和苹果酸脱氢酶(MDH)活性。结果表明,在30 kg体重时,日粮蛋白质水平对乌金猪肝脏和脂肪组织中脂肪代谢相关酶活性差异不显着(P>0.05),在60和100 kg体重时,高蛋白质日粮组乌金猪肝脏和脂肪组织LPS的活性明显高于低蛋白质日粮组(P<0.05),G-6-PDH和MDH活性则明显低于低蛋白质日粮组(P<0.05)。因此,高蛋白质日粮增加了生长中后期乌金猪的内源性能量释放,可能影响了体脂沉积比例。     

The Activity Ratio of the Cytosolic MDH/LDH and the Isoenzyme Pattern of LDH in the Peripheral Leukocytes of Dogs,Cats and Rabbits

The activities of malate dehydrogenase (MDH) and lactate dehydrogenase (LDH) and the pattern of the isoenzymes of LDH were determined in the peripheral blood leukocytes of dogs, rabbits and cats. Rabbits had significantly higher plasma glucose concentrations than dogs or cats. Feline leukocytes showed higher LDH and lower MDH activities than canine or rabbit leukocytes. The M/L ratio, defined as the MDH activity divided by the LDH activity in cytosolic fractions, was considered to be a good indicator with which to evaluate the metabolic state in animal tissues. The M/L ratio was highest in canine and lowest in feline leukocytes. LDH-2 and LDH-3 isoenzymes were dominant in canine leukocytes. LDH-1 and LDH-2 were dominant in rabbit leukocytes, whereas LDH-5 was dominant in feline leukocytes. It was evident that there were significant differences in energy metabolism between the leukocytes of dogs, rabbits and cats.     

Histochemical demonstration of enzymes in the uropygial gland of the fowl

From the distribution of enzymes, the alveoli of a uropygial gland may be divided into inner and outer zones ; the former being the region near the cavity, and the latter the peripheral region of the gland.

In the inner zone, there appeared strong activities of 17β‐hydroxy‐steroid dehydrogenase (17β‐OH‐SDH), 30α‐OH‐SDH, glucose‐6‐phosphate dehydrogenase (G‐6‐PDH), lactate dehydrogenase (LDH), NAD‐dependent malate dehydrogenase (MDH) and acid phosphatase (Acid Pase) weak activities of succinate dehydrogenase (SuDH), NADP‐dependent MDH, monoamine oxidase (MAO) and non‐specific esterase (Etase), but no activity of β‐hydroxybutyrate dehydrogenase (β‐HbDH).

In the outer zone, there appeared strong activities of LDH and MDH (NAD), moderate activities of 17β‐OH‐SDH, 3α‐OH‐SDH, G‐6‐PDH and β‐HbDH, weak activities of SuDH, MDH (NADP) and MAO, but no activities of Etase and Acid Pase.

The results were negative concerning ?⁵‐3β‐OH‐SDH, glutamate dehydrogenase, a‐glycerophosphate dehydrogenase, phosphorylase and alkaline phosphatase in both zones. From these results, it was concluded that there must be functional differences between the zones, and that only a part of the metabolic pathways of steroids is being performed.     

长白山野猪与杜洛克猪杂交1代猪肌内脂肪代谢酶HSL和MDH活性的发育性变化规律及其对肌内脂肪沉积影响的研究

为了研究长白山野猪与杜洛克猪杂交1代猪肌内脂肪代谢酶激素敏感脂酶（hormone-sensitive lipase,HSL）和苹果酸脱氢酶（malate dehydrogenase,MDH）活性的发育性变化规律及其对肌内脂肪沉积的影响,试验以5个体重组（20、35、50、70和90 kg）的长白山野猪与杜洛克猪的杂交1代猪（简称野杜F1代猪,各40头,公、母各半）为研究对象,研究了肌肉组织中脂肪代谢酶活性的发育性变化规律与肌内脂肪含量和肌肉嫩度的关系。结果表明,在生长期随着体重的增加,肌肉组织中HSL和MDH的活性差异显著（P<0.05）,野杜F1代猪HSL活性均高于莱芜黑猪的活性（90 kg除外）,且在35 kg时,野杜F1代猪和莱芜黑猪差异极显著（P<0.01）;肌肉组织中的MDH活性变化,野杜F1代猪呈先升后降的趋势,活性最高点在70 kg;在90 kg时野杜F1代猪中MDH活性极显著低于莱芜黑猪（P<0.01）。不同体重阶段,肌肉嫩度差异显著（P<0.05）,且随着体重的增加而呈不断升高的趋势。相关分析结果表明,野杜F1代猪90 kg时肌肉组织中MDH活性与肌内脂肪含量呈极显著正相关（r=0.97,P<0.01）,HSL和MDH的活性与肌肉嫩度呈显著正相关（P<0.05）。研究结果提示,肌肉组织中的HSL和MDH对肌内脂肪的沉积量有一定的影响,可以通过控制其活性调节肌内脂肪的含量,且肌内脂肪的沉积量与肌肉嫩度有一定的联系。