抗阻、耐力运动对大鼠骨骼肌Perilipin、HSL基因表达及血清FFA含量的影响

目的 研究长期不同强度运动对大鼠胫骨前肌HSL、Perilipin基因表达及血清FFA含量的影响.方法 46只雄性SD大鼠,适应练习时淘汰6只.将40只大鼠随即分为安静对照组(C组)、中等耐力运动组(M组)、大强度运动组(N组)、抗阻训练组(R组).10周训练结束后采用生化方法测定各组大鼠血清FFA含量,RT- PCR法测定ATGL、HSL基因表达.结果 与C组相比,运动各组血清中FFA含量增加(P＜ 0.05,P＜ 0.01);R组、N组HSL基因表达上调(P＜0.05),其中R组基因表达量最多;R组、N组Perilipin基因表达下调(P＜0.05),其中以R组基因表达最少.结论 抗阻、耐力训练均可以导致骨骼肌HSL基因表达上调,Perilipin基因表达下调,血清FFA含量增加.抗阻、大强度耐力训练显著提高HSL基因表达水平,降低Perilipin基因表达水平,提示Perilipin基因表达的下调似乎可以促进HSL基因表达上调,提高骨骼肌脂肪水解能力.     

乙苯染毒对大鼠肺的氧化应激损伤及病理的影响

目的 观察亚慢性吸人乙苯染毒对大鼠肺组织氧化应激损伤和组织病理结构、细胞超微结构的影响.方法 将40只健康3周龄SPF级SD雄性大鼠随机分为4组,分别为对照组(新鲜空气)和低(433.5 mg/m3)、中(4335 mg/m3)和高(6500 mg/m3)剂量乙苯染毒组,每组10只.每天染毒6h,每周5d,连续染毒13周.检测肺组织中还原型谷胱甘肽(GSH)、谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活力和丙二醛(MDA)含量并进行超微结构和病理学观察.结果 乙苯染毒大鼠肺组织出现肺泡壁毛细血管充血,肺泡间纤维组织增生、增厚等病理变化,超微结构的变化主要表现为肺组织大部分血管内皮细胞肿胀,胞质厚度增加.与对照组相比,各染毒组大鼠肺组织MDA含量均明显升高,差异有统计学意义(P＜0.05).中剂量组和高剂量组大鼠肺组织GSH和GSH-Px含量均明显低于对照组和低剂量组,差异有统计学意义(P＜0.05).与对照组相比,各剂量组大鼠肺组织SOD和CAT活力呈先升高后降低趋势;与低剂量组比较,中剂量组和高剂量组大鼠肺组织SOD活力和CAT含量均明显降低,差异有统计学意义(P均＜0.05).结论 亚慢性吸入乙苯染毒可诱导大鼠肺组织氧化应激损伤及组织病理结构、组织细胞超微结构的改变.     

高强度离心运动后热休克蛋白70在骨骼肌细胞中的表达及其特征分析

[目的]探讨经高强度离心运动后热休克蛋白70(HSP70)在骨骼肌细胞中的的表达以及特征性分析。[方法]采用2～6个月的SD大鼠56只,电动炮台,间歇性离心运动训练方案,随机分为对照组、离心训练4周组、离心训练8周组,每组8只,后将对照组及训练8周的大鼠进行高强度的离心运动;取大鼠的脾细胞、外周淋巴细胞,采用蛋白免疫印迹分析HSP70含量变化,采用免疫组织化学法分析骨架蛋白Desmin的变化。[结果]8周间歇性离心训练后HSP70含量显著增加,训练SD大鼠在进行高强度离心运动时,具有适应性,骨架蛋白Desmin丢失量降低,CK显著降低,表明增加的HSP70对骨架蛋白具有保护作用;对照组及离心训练4周组大鼠在高强度离心后表现出显著的应激反应,骨架蛋白Desmin显著缺失,HSP70显著增加。[结论]热休克蛋白70(HSP70)在高强度离心运动后在骨骼肌中蛋白表达有持续性和延迟性,在引起的骨架蛋白损伤中可能起到补充保护的作用机制。     

复合营养素对寒冷暴露大鼠骨骼肌功能的保护作用

目的观察复合营养素对寒冷暴露大鼠骨骼肌功能的保护作用。方法雄性SD大鼠32只,按体重随机平均分为饮用水灌胃室温对照组(n=8)、复合营养素灌胃室温对照组(n=8)、饮用水灌胃寒冷暴露组(n=8)和复合营养素灌胃寒冷暴露组(n=8)。灌胃3周后进行急性寒冷暴露,暴露温度-15℃,时间6h。观察每组大鼠骨骼肌细胞ATP含量变化及细胞超微结构的改变。结果①寒冷暴露使大鼠骨骼肌细胞ATP含量下降(1.353±0.873μmol/L),明显低于室温对照组(6.594±0.421μmol/L)(P0.01),电镜结果显示:细胞线粒体肿胀、易位,肌浆网肿胀,Z线紊乱。②复合营养素可以明显增加寒冷暴露大鼠骨骼肌细胞ATP含量(5.887±0.385μmol/L),与室温对照组(6.594±0.421μmol/L)相比差异无统计学意义(P0.05),电镜结果显示:骨骼肌细胞超微结构正常,线粒体形态完整、排列整齐。结论复合营养素对寒冷暴露大鼠骨骼肌功能有很好的保护作用。     

限制性通血防治骨骼肌缺血-再灌注损伤的实验研究

[目的]通过实验,研究限制性通血防治骨骼肌缺血-再灌注损伤. [方法]将18只成年大耳白兔随机分为3组,分别为正常对照组(对照组),限制通血时间组(实验组1)和限制血流量组(实验组2).使骨骼肌在经历了5 h的急性缺血后,进行限制性通血处理. [结果]血浆中CPK,LDH,GOT的含量明显降低,电镜的检查结果与其一致. [结论]实验证明,通过限制再通血流的流量或时间,能明显的减轻骨骼肌缺血-再灌注损伤程度.     

三乙醇胺染毒对大鼠机体危害的研究

[目的]实验观察三乙醇胺染毒大鼠血清脂质过氧化代谢产物(MDA)含量,超氧化歧化酶(SOD)和全血谷胱甘肽氧化酶(GSH-PX)的活性及组织病理学改变。[方法]32只大鼠分别经染毒不同剂量的三乙醇胺(250、500、750mg/kg),每周1次,7周后断头取血检测酶学指标,同时进行大体剖检和组织病理学检查。[结果]染毒大鼠血清MDA含量明显增高,SOD和全血GSH-PX活性明显降低,与对照组比较差异均有统计学意义(P＜0.01);500mg/kg、750mg/kg染毒组脏器系数增大,肝、脾、肾器官有不同程度的病理学改变。[结论]接触一定量的三乙醇胺可增强染毒大鼠脂质过氧化水平,对染毒大鼠肝、脾、肾脏组织有损伤作用。     

噪声对大鼠空间学习记忆及海马神经元形态学的影响

[目的]拟观察噪声对大鼠学习记忆及海马神经元的影响,探讨噪声对大鼠学习记忆的影响机制。[方法]将32只Wistar大鼠,随机分为噪声组和对照组,噪声组在80dB(A)噪声下持续暴露1个月,用Morris水迷宫测试大鼠的空间学习记忆能力。HE染色和透射电镜观察大鼠海马神经元形态和超微结构。[结果]Morris水迷宫定航实验中,噪声组大鼠寻找平台的平均逃避潜伏期均较对照组明显延长(P﹤0.05);空间搜索实验中噪声组大鼠第一次寻找原平台的潜伏期、穿越原平台的次数、时间百分比以及距离百分比,均较对照组明显降低(P﹤0.01)。HE染色光镜下观察发现噪声组大鼠海马组织无明显异常,透射电镜下观察发现噪声组大鼠海马神经元超微结构也未见明显异常。[结论]噪声暴露对大鼠海马神经元无器质性损害。噪声暴露下大鼠学习记忆能力的损害可能只与海马神经元功能改变有关。     

贫铀长期植入对大鼠生殖系统损伤效应的研究

[目的]研究贫铀植入后大鼠体内性激素含量及睾丸超微结构的改变.[方法]初成年大鼠20只,右后肢手术植入贫铀片(0.2±0.02)g,采用放射免疫分析法植测大鼠体内促卵泡生成素、促黄体生成素和睾酮水平,并分别在植入贫铀后3、6、12、18个月进行大鼠睾丸的病理组织学及超微结构观察.[结果]性激素水平测定发现睾酮、促黄体生成素、促卵泡生成素含量在贫铀接触后第3个月均有不同程度的增高.贫铀对睾丸的影响病理组织学观察主要为间质细胞增生,后期出现曲细精管的萎缩.[结论]低剂量贫铀植入对大鼠睾丸具有损伤效应,并可引发生殖系统的功能紊乱.     

高原低氧对大鼠血清中低氧诱导因子-1α含量和血浆中活性氧含量及肝细胞超微结构的影响

目的 探讨高原低氧对大鼠血清中低氧诱导因子-1α(HIF-1α)含量和血浆中活性氧(ROS)含量及肝细胞超微结构的影响.方法 将50只健康成年SPF级雄性SD大鼠随机分为对照组(海拔2262 km)和高原组(海拔4300km),每组25只.喂养30 d后,测定血清HIF-1α和血浆ROS水平,观察肝细胞超微结构.结果 与对照组比较,高原组大鼠血清中HIF-1α含量明显增高,血浆中ROS含量明显降低,差异均有统计学意义(P＜0.01);肝细胞线粒体肿胀,粗面内质网扩张,部分轻度脱粒现象.结论 高原低氧环境可能通过调节ROS、HIF-1α水平保护细胞,促进低氧适应.     

亚急性冷暴露对大鼠锌铜代谢及SOD活性和MDA含量的影响

目的探讨亚急性冷暴露对机体微量元素代谢的影响.方法雄性SD大鼠48只,置于1±1℃自动控温冷库内,进行1周和2周冷暴露.观察不同时间冷暴露对大鼠体内锌(Zn)、铜(Cu)、血清丙二醛(MDA)含量及超氧化物岐化酶(SOD)活性影响.结果冷暴露后大鼠肝及骨骼肌Zn显著升高(P＜0.01),血清SOD活性降低显著(P＜0.01),而骨骼肌SOD明显升高(P＜0.05).冷暴露2周后MDA明显升高(P＜0.05),骨骼肌Cu明显下降(P＜0.05).结论亚急性冷暴露可使大鼠体内Zn、Cu代谢及SOD活性发生变化,其机理有待探讨.     

支链氨基酸提高大鼠游泳耐力作用探讨

目的 :　探讨支链氨基酸 (BCAA)对提高大鼠运动耐力的作用。方法 :　取雄性Wistar大鼠 2 1只 ,随机分为三组 :正常组、游泳对照组及游泳补充 5% BCAA饲料组。两个游泳组每天游泳训练 1 h,1 0 d后 ,游泳 6h,观察游泳大鼠的存活率 ,测定血乳酸和尿素氮水平 ,血清和骨骼肌乳酸脱氢酶 (LDH)活力 ,线粒体脂质过氧化物 (LPO)水平和线粒体膜的粘度系数。另取昆明种小鼠 ,随机分为三组 ,用实验一相同的饲料喂养 ,两周后 ,于每只小鼠尾静脉注射 15N-甘氨酸 (15N-Gly) 1 .0 mg,注射后 和 组立即游泳 ,分别于注射后的 1、2、3及 4h,测定各组骨骼肌蛋白质中15N-甘氨酸 (15N- Gly)的丰度。结果 :　BCAA可明显提高大鼠游泳存活率 ,抑制游泳运动后大鼠的血乳酸浓度、LDH活力、骨骼肌 LPO的升高幅度 ,抑制骨骼肌 LDH活力和膜流动性下降的趋势。并且 BCAA还可增加 15N- Gly在骨骼肌蛋白质中的滞留时间。结论 :　BCAA可改善运动后骨骼肌线粒体功能 ,改善运动性疲劳 ,提高大鼠的运动耐力     

Dietary soya protein intake and exercise training have an additive effect on skeletal muscle fatty acid oxidation enzyme activities and mRNA levels in rats

Exercise training and regular physical activity increase oxidation of fat. Enhanced oxidation of fat is important for preventing lifestyle diseases such as hypertension and obesity. The aim of the present study in rats was to determine whether intake of dietary soya protein and exercise training have an additive effect on the activity and mRNA expression of enzymes involved in skeletal muscle fatty acid oxidation. Male Sprague-Dawley rats (n 32) were assigned randomly into four groups (eight rats per group) and then divided further into sedentary or exercise-trained groups fed either casein or soya protein diets. Rats in the exercise groups were trained for 2 weeks by swimming for 120 min/d, 6 d/week. Exercise training decreased hepatic triacylglycerol levels and retroperitoneal adipose tissue weight and increased skeletal muscle carnitine palmitoyltransferase 1 (CPT1) activity and mRNA expression of CPT1, beta-hydroxyacyl-CoA dehydrogenase (HAD), acyl-CoA oxidase, PPARgamma coactivator 1alpha (PGC1alpha) and PPARalpha. Soya protein significantly decreased hepatic triacylglycerol levels and epididymal adipose tissue weight and increased skeletal muscle CPT1 activity and CPT1, HAD, acyl-CoA oxidase, medium-chain acyl-CoA dehydrogenase, PGC1alpha and PPARalpha mRNA levels. Furthermore, skeletal muscle HAD activity was the highest in exercise-trained rats fed soya protein. We conclude that exercise training and soya protein intake have an important additive role on induction of PPAR pathways, leading to increased activity and mRNA expression of enzymes involved in fatty acid oxidation in skeletal muscle and reduced accumulation of body fat.     

三种食物多酚对化学诱导DM大鼠糖脂代谢的影响

目的探讨膳食多酚[绿原酸、表没食子儿茶素没食子酸酯(EGCG)、槲皮素]对链脲佐菌素(STZ)诱导的糖尿病大鼠血糖、血脂、肝脏中葡萄糖-6-磷酸酶(G-6-pase)和骨胳肌组织中葡萄糖转运体4(GLUT4)表达的影响。方法单次腹腔注射链脲佐菌素(STZ,35 mg/kg)结合高脂饮食建立糖尿病大鼠模型,将成模大鼠分成5组[糖尿病模型组(DM)、糖尿病模型+二甲双胍组(S)、糖尿病模型+绿原酸组(CA)、糖尿病模型+EGCG组(E)、糖尿病模型+槲皮素组(Q)],另设正常对照组(NC),分别灌喂二甲双胍、绿原酸、EGCG和槲皮素4w后,测定其糖耐量、空腹胰岛素、甘油三酯、胆固醇、G-6-pase和GLUT4 mRNA的表达。结果绿原酸、EGCG、槲皮素均表现出改善STZ诱导的糖尿病大鼠血糖、甘油三酯(TG)和胆固醇(TC)的含量,并能改善糖尿病模型大鼠的胰岛素敏感性,抑制肝脏G-6-pase mRNA的表达,且提高了骨胳肌GLUT4 mRNA的表达,其中以绿原酸效果最佳。仅仅其糖耐量改善弱于槲皮素作用,但均弱于阳性对照组二甲双胍的作用。结论绿原酸、EGCG、槲皮素均能有效改善STZ诱导的SD糖尿病大鼠的糖代射、脂代射、胰岛素敏感生及肝脏G-6-pase mRNA和骨胳肌GLUT4 mRNA的表达,绿原酸的效果最佳。[营养学报,2012,34(6):572-575,581]     

苯并[a]芘对大鼠学习记忆能力及氨基酸类神经递质的影响

[目的]探讨苯并[a]芘(B[a]P)对大鼠学习记忆能力的影响及机制。[方法]40只Wistar大鼠随机分为5组:空白对照组、溶剂对照组和3个染毒组(分别为6.25、2.5和1mg/kg体重),连续腹腔染毒B[a]P13周(90d)。染毒结束后用Morris水迷宫测定大鼠的空间学习记忆能力,用免疫组化法观察其大脑皮层、海马内γ-氨基丁酸(GABA)及谷氨酸(Glu)阳性神经元表达。[结果]在Morris水迷宫试验中,高、中剂量组寻找平台的潜伏期较对照组延长(P﹤0.05),末次跨平台次数和在目标区域游泳时间所占比例较对照组明显减少(P﹤0.05),各暴露组Glu、GABA阳性平均光密度与对照组比较差异有统计学意义(P﹤0.05)。[结论]苯并[a]芘可能通过影响大鼠海马和大脑皮质Glu和GABA含量,使大鼠学习记忆能力降低。     

Dietary whey protein downregulates fatty acid synthesis in the liver, but upregulates it in skeletal muscle of exercise-trained rats

OBJECTIVE: This study compared the effects of casein and whey protein as the source of dietary protein on the activity of lipogenic enzymes and mRNA levels in the liver and skeletal muscle of exercise-trained rats. METHODS: Twenty-eight male Sprague-Dawley rats were randomly assigned to one of four groups (n = 7/group). Rats were assigned to sedentary or exercise-trained groups and were fed the casein or whey protein diet. Rats in the exercise groups were trained for 2 wk using a swimming exercise for 120 min/d and 6 d/wk. RESULTS: A significant decrease in the activity of the hepatic lipogenic enzymes, glucose-6-phosphate dehydrogenase, malic enzyme, adenosine triphosphate citrate lyase, acetyl-coenzyme A carboxylase, and fatty acid synthase (FASN) was observed in rats fed whey protein compared with animals fed casein. Compared with the casein diet, the whey protein diet also lowered mRNA expression of these enzymes, except for FASN. In contrast to the findings in liver, whey protein, as compared with casein, increased skeletal muscle FASN activity and mRNA. Further, exercise training resulted in increased skeletal muscle glucose-6-phosphate dehydrogenase and FASN activity and adenosine triphosphate citrate lyase, acetyl-coenzyme A carboxylase-1, and FASN mRNA expression. CONCLUSIONS: Exercise training or whey protein may play an important role in suppressing hepatic fatty acid synthesis, thereby decreasing accumulation of body fat and stimulating the skeletal muscle to increase energy substrate as fat during prolonged exercise.     

Dietary whey protein increases liver and skeletal muscle glycogen levels in exercise-trained rats

We investigated the effect of different types of dietary protein on glycogen content in liver and skeletal muscle of exercise-trained rats. Twenty-four male Sprague-Dawley rats (approximately 100 g; n 6 per group) were divided into sedentary or exercise-trained groups with each group being fed either casein or whey protein as the source of dietary protein. Rats in the exercised groups were trained during 2 weeks using swimming exercise for 120 min/d, 6 d/week. Exercise training resulted in an increase in the skeletal muscle glycogen content. Furthermore, the whey protein group significantly increased the skeletal muscle glycogen content compared with the casein group. The increase in glycogen content in liver was significantly greater in rats fed the whey protein diet compared with those fed the casein diet. We also found that the whey protein diet increased the activity of liver glucokinase, whereas it decreased the activities of 6-phosphofructokinase and pyruvate kinase compared with the casein diet. However, hepatic total glycogen synthase activity and mRNA expression were similar with the two diets. In the skeletal muscle, whey protein decreased only 6-phosphofructokinase activity compared with casein. Total glycogen synthase activity in the skeletal muscle in the whey protein group was significantly higher than that in the casein group. The present study is the first to demonstrate that a diet based on whey protein may increase glycogen content in liver and skeletal muscle of exercise-trained rats. We also observed that whey protein regulated glycogen metabolism in these two tissues by different mechanisms.     

左旋精氨酸对冷暴露大鼠骨骼组织氧化应激酶系的影响

目的研究补充左旋精氨酸(L-Arg)对冷暴露大鼠骨骼肌组织氧化应激酶系的影响,了解一氧化氮(NO)对冷暴露大鼠骨骼肌氧化应激酶系的调节作用。方法将88只大鼠分为3组:①对照组(8只);②冷暴露组(40只);③L-Arg+冷暴露组(40只)。冷暴露组和L-Arg+冷暴露组又分别分成5个小组,每组8只:分别于冷暴露1、3、7、14、21 d处死,对照级饲养7d处死。对照组于室温下饲养,冷暴露组和L-Arg+冷暴露组于(0±4)℃饲养1、3、7、14、21 d,L-Arg+冷暴露组大鼠每天给予L-Arg水溶液2 ml灌胃,相当于50 mg/kg的剂量。在冷暴露后各时间点取大鼠小腿骨骼肌组织检测丙二醛(MDA)含量和抗氧化酶活力:铜锌超氧化物歧化酶(CuZnSOD)、锰超氧化物歧化酶(MnSOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)。结果冷暴露组在冷暴露1～14 d时,大鼠骨骼肌组织中MDA含量明显高于对照组(P0.05,P0.01);在冷暴露21 d时恢复正常。L-Arg+冷暴露组在冷暴露1～7 d时明显高于对照组(P0.01),在冷暴露1～3 d时明显高于冷暴露组(P0.05,P0.01),在冷暴露14d时恢复对照水平。CuZnSOD、MnSOD、CAT、GSH-Px的活力在冷暴露组从冷暴露第3天开始明显升高(P0.05),除CuZnSOD活力在冷暴露14～21 d时恢复正常外,其他抗氧化酶活力在整个冷暴露期间均明显高于对照组(P0.05,P0.01)。而L-Arg+冷暴露组CuZnSOD、MnSOD、CAT、GSH-Px的活力在冷暴露1～21 d时均明显高于对照组和冷暴露组(P0.05,P0.01)。结论补充L-Arg能明显提高冷暴露过程中大鼠骨骼肌抗氧化防护能力,同时提示,NO对冷暴露大鼠骨骼肌氧化应激酶系有一定调节作用。     

表没食子儿茶素没食子酸酯对束缚应激大鼠行为学表现的影响

目的观察绿茶多酚(GTPs)单体成分表没食子儿茶素没食子酸酯(EGCG)对束缚应激大鼠行为学表现的影响。方法 40只健康雄性Wistar大鼠随机分为4组:正常对照(CT)组、束缚应激(ST)组、GTPs干预应激(GST)组和EGCG干预应激(EST)组。以束缚制动的方法建立应激动物模型,GTPs和EGCG以灌胃方式给予,实验周期30d。通过旷场实验及避暗实验检测大鼠的认知行为和学习记忆能力;分别以放免法、双抗夹心ELISA法检测血浆中皮质醇和神经递质含量。结果与CT组相比,ST组在旷场中的潜伏期延长,穿格数明显减少;GST组和EST组与ST组相比有显著性差别。避暗实验显示,与CT组相比,ST组潜伏期显著降低,电击次数出现明显增加,而GST组与EST组潜伏期比ST组显著增长,电击次数显著降低。此外,ST组血浆皮质醇水平明显增加,多巴胺和5-羟色胺水平降低;而GST组与EST组与ST组相比,皮质醇水平降低,多巴胺及5-羟色胺含量升高;EST组比GST组总的行为表现稍好。而且动物的行为表现与血浆皮质醇和神经递质含量之间存在相关关系。结论束缚应激引起动物行为学表现异常,应激激素分泌增加。而适量补充EGCG可改善应激大鼠的行为学表现,提高应激机体的自主活动和探究行为以及学习记忆能力。[营养学报,2013,35(2):167-171]     

Analysis of cellular responses to free radicals: focus on exercise and skeletal muscle

Muscular exercise results in an increased production of radicals and other forms of reactive oxygen species (ROS). Recent evidence suggests that radicals and other ROS are an underlying aetiology in exercise-induced disturbances in muscle redox status. These exercise-induced redox disturbances in skeletal muscle are postulated to contribute to both muscle fatigue and/or exercise-induced muscle injury. To defend against ROS, muscle cells contain complex cellular defence mechanisms to reduce the risk of oxidative injury. Two major classes (enzymic and non-enzymic) of endogenous protective mechanisms work together to reduce the harmful effects of oxidants in the cell. Primary antioxidant enzymes include superoxide dismutase (EC 1.15.1.1; SOD), GSH peroxidase (EC 1.11.1.9; GPX), and catalase (EC 1.11.1.6); these enzymes are responsible for removing superoxide radicals, H2O2 and organic hydroperoxides, and H2O2 respectively. Important non-enzymic antioxidants include vitamins E and C, beta-carotene, GSH and ubiquinones. Vitamin E, beta-carotene and ubiquinone are located in lipid regions of the cell, whereas GSH and vitamin C are in aqueous compartments of the cell. Regular endurance training promotes an increase in both total SOD and GPX activity in actively-recruited skeletal muscles. High-intensity exercise training has been shown to be generally superior to low-intensity exercise in the upregulation of muscle SOD and GPX activities. Also, training-induced upregulation of antioxidant enzymes is limited to highly-oxidative skeletal muscles. The effects of endurance training on non-enzymic antioxidants remain a relatively uninvestigated area.