缺锌对生长期大鼠骨形态计量学参数的影响

目的　研究缺锌对生长期大鼠股骨远端骨干骨形态计量学参数的影响 ,阐明锌与骨骼发育的关系 ,为生长发育期儿童合理补充锌提供科学依据。方法　 3 0只 Wistar大鼠 ,雌雄各半 ,体重 (1 0 0± 2 0 ) g,按体重随机分为三组 ,每组 1 0只 ,缺锌组和对照组饲料锌含量分别为 3 .9和2 4 .7mg/kg,对喂组喂对照组饲料 ,饲料摄入量与缺锌组相同。动物喂养 8w后处死 ,用骨形态计量学方法研究缺锌对大鼠骨组织形态学和动态学参数的影响。结果　与对照组和对喂组相比 ,缺锌组骨小梁体积显著减少、骨小梁板密度降低而间隙明显增大、骨小梁个数减少、骨形成速度降低、类骨质表面积显著减少、骨基质成熟时间明显延长、矿化沉积速率降低、矿化延迟时间增加 ,且均有显著性差异 (P<0 .0 5 )。结论　缺锌可明显降低骨形成 ,延迟骨矿化 ,破坏骨的空间结构 ,并使骨小梁连接性减弱 ,离散程度增加。     

大鼠的实验性铁与锌营养缺乏

目的观察铁锌同时缺乏和单独缺乏对大鼠铁锌营养状况的影响。方法按照2×2析因设计,将4w龄雄性wistar大鼠随机分为4组:缺铁缺锌组(F0Z0):喂以低铁低锌饲料(铁7.10mg/kg,锌5.14mg/kg),自由进食;单纯缺铁组(F0Z1):喂以低铁饲料(铁7.10mg/kg,锌40mg/kg);单纯缺锌组(F1Z0):喂以低锌饲料(锌5.14mg/kg,铁40mg/kg);铁锌正常组(F1Z1):喂以铁锌正常饲料(铁40mg/kg,锌40mg/kg);后3组均与F0Z0组对喂。喂养42d后,处死大鼠,分别测定Hb、Hct、血清铁、血清锌、肝脏铁、肝脏锌、胫骨锌等指标。结果实验结束时F0Z0组大鼠的Hb平均水平降至82.36g/L,血清锌0.78μg/ml,成功建立缺铁缺锌大鼠模型。4组大鼠的各项指标水平大多以F0Z0组最低,F0Z1组或F1Z0组次之,F1Z1组最高;铁缺乏可导致大鼠血清铁、肝脏铁含量明显下降,也可降低肝脏锌水平;锌缺乏能显著降低机体肝脏锌、胫骨锌水平;在体重、Hb、Hct、血清锌这四项指标上存在铁锌交互作用。结论大鼠铁锌同时缺乏时铁锌营养状况最差,缺锌可能会增加对铁的吸收利用,缺铁会减少体内锌储存量。     

不同剂量锌缺乏对小鼠及其胚胎发育的影响

目的 :　用昆明种雌性小鼠建立成不同程度缺锌动物模型 ,研究不同程度锌缺乏和孕早期补锌对小鼠及其胚胎发育的影响 ,并探求其发育毒性作用的阈剂量。方法 :　实验分两阶段进行。实验一用 36只初断乳 1 4～ 1 8g小鼠 ,分为低锌 (ZD)、中锌 (ZM)、常锌 (ZN)三组 ,喂饲含锌分别为 3.0± 0 .5、1 5、30 mg/kg的饲料 ,经 50 d喂养平均体重达 30 g后交配。实验二选用 80只 ,2 5～ 30 g成熟小鼠 ,随机分为低锌组 [ZD,饲料含锌 (3.0± 0 .5) mg/kg];低锌补锌组 (ZS,于孕第 7d将低锌饲料换为含锌 30 mg/kg的常锌饲料 ) ;边缘缺锌组 (MD,饲料含锌 9mg/kg) ;常锌组(ZN,饲料含锌 30 mg/kg)。 2 5d锌耗竭性喂养后交配。所有孕鼠于妊第 1 8d活杀。结果 :　实验一 :低锌组小鼠锌水平显著低于常锌组 (P<0 .0 5) ,有典型缺锌症状 ,几乎全部出现生长抑制 ,58.33%的小鼠衰竭死亡 ,存活小鼠亦不能正常交配妊娠。 1 5mg/kg剂量组小鼠则生长发育良好 ,各项指标与常锌组间无异 (P>0 .0 5)。实验二 :ZD组小鼠血清碱性磷酸酶 (AKP)活性 ,股骨锌含量显著低于 ZN组 (P<0 .0 1 ) ;该组小鼠胚胎有明显发育不良 ,畸胎及死胎出现率显著高于 ZN组 (P<0 .0 1 )。ZS组小鼠在孕第 7d补锌后活胎仔大小已趋正常 (P>0 .0 5) ,畸胎出现率与 ZD?     

缺锌及补锌对大鼠甲状腺激素的影响

目的了解锌缺乏及补锌对大鼠甲状腺激素的影响。方法将出生后断乳1周的SD大鼠随机分为缺锌组、配喂组、对照组、补锌组和高锌组,缺锌组、对照组、高锌组分别用缺锌饲料(Zn含量<1mg/kg),常锌饲料(Zn含量为50mg/kg)和高锌饲料(Zn含量为150mg/kg)喂养8周,补锌组用缺锌饲料喂养3周后改用高锌饲料喂养5周,配喂组用常锌饲料喂养,给料量按缺锌组前一天实际进食量添加。8周后处死,用极谱法测定血清中锌的含量,用放射免疫法测定血清中FT3、FT4的含量。结果缺锌使大鼠血清中锌含量显著降低,血清中FT3含量下降,补锌后恢复正常,缺锌对FT4无影响。结论缺锌引起甲状腺激素FT3下降,而FT4不受影响。     

牛磺酸对大鼠染铅所致贫血的疗效

[目的 ]探讨牛磺酸 (Tau)对大鼠染铅所致贫血的治疗作用。 [方法 ] 40只Wistar大鼠随机均分为 5组 :①空白对照组 ;②染铅组 :醋酸铅 40mg/(kg·d)连续灌胃 4周 ;③Tau治疗 1、2、3组 :与染铅组相同处理 4周后分别以 10 0、40 0、80 0mg/(kg·d)Tau灌胃 4周。实验第 8周末测定各组大鼠血红蛋白 (Hb)含量及红细胞 (RBC)数 ,并处死动物 ,颈动脉取血 ,测定血铅和血清丙二醛 (MDA)含量、超氧化物歧化酶 (SOD)水平。 [结果 ]①Tau 10 0mg/kg组和Tau 40 0mg/kg组大鼠Hb分别为 ( 13 1.98± 6.83 )g/L和 ( 13 6.2 5± 5 .97)g/L ,与染铅组大鼠Hb( 118.74± 5 .3 5 )g/L相比明显升高 ,差异有显著性(P <0 .0 1)。②Tau 10 0mg/kg、Tau 40 0mg/kg组大鼠RBC分别为 ( 4 .71± 0 .40 )× 10 12 /L和 ( 4 .89± 0 .44 )× 10 12 /L ,与染铅组大鼠RBC( 3 .5 3± 0 .19)× 10 12 /L相比明显升高 ,差异有显著性 (P <0 .0 1)。③Tau 10 0mg/kg、Tau 40 0mg/kg组大鼠血铅水平分别为 ( 2 .47± 0 .2 8) μmol/L、( 2 .3 4± 0 .48) μmol/L ,与染铅组大鼠血铅 ( 3 .5 4± 0 .75 ) μmol/L相比明显降低 ,差异有显著性 (P <0 .0 5 )。④Tau 10 0mg/kg和 40 0mg/kg组大鼠血清MDA含量分别为 ( 4 .96± 0 .5 5 )nmol/ml和 ( 4 .45     

缺锌并补锌对大鼠睾丸及血清睾酮的影响

目的　为了解锌缺乏及补锌对大鼠睾丸的重量及血清睾酮的影响。　方法　将出生后断乳一周的SD大鼠随机分为缺锌组、配喂组、对照组、补锌组和高锌组五组 ,缺锌组、对照组和高锌组分别用缺锌饲料 (锌含量 <1mg/kg)、常锌饲料 (锌含量为 5 0mg/kg)和高锌饲料 (锌含量为 15 0mg/kg)喂养 8周 ,补锌组用缺锌饲料喂养三周后改用高锌饲料喂养五周 ,配喂组用常锌饲料喂养 ,给料量按缺锌组前一天实际进食量添加。 8周后处死 ,用极谱法测定血清中锌含量 ,用原子吸收分光光度法测定睾丸中锌含量 ,采用双抗体放射免疫分析法测定血清中睾酮的含量。　结果　缺锌组大鼠睾丸及血清中锌含量降低 ,睾丸重量减轻。血清中睾酮含量下降 ,缺锌大鼠补锌后可恢复正常。　结论　说明锌缺乏直接影响睾丸及血清中锌的水平 ,从而影响大鼠睾丸的发育及睾酮的分泌与合成。     

松花粉对缺锌幼鼠营养作用的实验研究

目的　观察松花粉对缺锌幼鼠的营养作用。方法　选用雄性 SD大鼠 70只 ,体重( 4 2± 4) g,随机分为 7组。 1组为对照组 ,饲料含锌 32 .2 mg/kg;2组为锌严重缺乏组、饲料含锌 3.4mg/kg均自由进食。 3组饲料含锌 84.9mg/kg;4与 6组饲料中分别添加 2 %与 5%的松花粉 ,5组和 7组是 4组与 6组的对照组 ,采用与松花粉能量和蛋白质含量相同的交换饲料配制 ;5组饲料含锌与 4组相等 ( 4 .4mg/kg)、7组与 6组相等 ( 5.5mg/kg)。3～ 7组均同 2组对喂。结果　摄入基础饲料组和含等量锌的松花粉的饲料组间生长情况和生化、血液学指标均未见差异 ,其营养作用是等同的 ,松花粉添加组大鼠体重增加量均稍低于其对照组。在饲料能量、锌和蛋白质含量及其它营养素都一致的情况下 ,尽管松花粉添加量已达饲料的 2 %与 5% ,但对幼鼠仍未显示刺激生长作用。结论　松花粉具有较好的安全性 ,可用于儿童作补锌食物     

生长期缺锌对大鼠血清元素的影响

目的:研究膳食锌缺乏对生长期大鼠血清各种元素的影响。方法:刚断奶的SD大鼠,按体重相近配伍,随机分为3组,每组8只:缺锌组(ZD),配饲组(PF),对照组(ZA)。缺锌饲料、正常饲料含锌量分别为0.4mg/kg3、0 mg/kg,实验期15 d。用等离子电感耦合质谱仪(ICP—MS)测定大鼠血清元素锌、铁、铜、硒、锰、钴、铬、钙、镁、镉的含量。结果:缺锌组大鼠:血清铁(573.86±201.71μg/L)明显低于配饲组(1372.37±118.69μg/L)和正常组(1463.55±331.66μg/L)(P<0.05);血清锰(12.28±5.33μg/L)明显高于配饲组(4.24±0.73μg/L)和正常组(3.10±1.10μg/L)(P<0.05);血清铜(534.71±113.77μg/L)、硒(262.55±38.57μg/L)、镁(25.26±9.29μg/dl)低于正常组(铜725.91±158.27μg/L,硒465.90±132.18μg/L,镁39.84±14.10μg/dl)(P<0.05),与配饲组无明显差异(铜566.86±134.96μg/L,硒336.71±112.30μg/L,镁29.59±6.99μg/dl)(P>0.05);相比于配饲组与正常组,血清钙有下降趋势,但差异无显著性(P>0.05),血清钴、铬、镉有升高趋势,但差异无显著性(P>0.05)。结论:膳食锌缺乏影响生长期大鼠体内的微量元素水平。     

营养

042 70 5　大鼠缺锌时股骨骺生长板的病理形态学改变/张月红…∥卫生研究 2 0 0 3 ,3 2 (1 ) 1 6～ 1 9为观察大鼠缺锌时股骨骺生长板的病理形态学改变 ,将 3 0只Wistar大鼠按体重随机分为 3组 :缺锌组 ,对照组和对喂组 ,每组动物 1 0只。缺锌组和对照组饲料锌含量分别为 3 9和 2 4 7mg/kg ,对喂组饲对照组饲料 ,饲料摄入量与缺锌组相同。动物喂养 8周后处死 ,在普通光学显微镜下观察大鼠股骨组织病理变化并运用形态计量学方法定量描述 ,测定血清骨钙素和生长激素含量。结果发现缺锌组大鼠股骨骺生长板软骨细胞畸形、数量减少 ,骺端骨…     

铅对大鼠脑组织神经生长因子表达的影响及甲状腺激素的调节作用

目的　研究醋酸铅对大鼠脑组织神经生长因子 (NGF)表达的影响及甲状腺激素的调节作用。方法　对SD大鼠用 2 5、5 0、10 0mg/kg体重的醋酸铅腹腔注射 ;用丙基硫氧嘧啶 (PTU)制作甲状腺机能减退大鼠模型 ,再给予 5 0mg/kg体重的醋酸铅 ,分别以免疫组化测定脑组织中NGF蛋白的表达。以放射免疫方法测定血清中三碘甲状腺原氨酸 (T3 )、甲状腺素 (T4)、促甲状腺激素 (TSH)的含量及脑组织中T3 、T4的含量。结果　中、高剂量组皮层组织NGF平均灰度 (180 .4 9± 10 .33、16 9.72±19 .75 )与对照组 (2 0 0 .75± 3.2 7)相比 ,差异有显著性 (P <0 .0 1) ;各剂量组海马组织NGF面密度 (0 .0 8± 0 .14、0 .12± 0 .0 2、0 .13± 0 .0 4 )与对照组 (0 .0 2 5± 0 .0 15 )相比 ,差异有显著性 (P <0 .0 5 )。甲状腺机能减退后再用醋酸铅处理 ,皮层、海马组织NGF面密度和平均灰度未见明显改变。各剂量染铅组大鼠血清中T3 [(0 .6 8± 0 .0 2 )、(0 .5 7± 0 .0 4 )、(0 .5 4± 0 .0 2 ) μg/L]和T4[(2 8.30± 1.83)、(2 7.35± 2 .5 5 )、(2 4 .0 0± 3.0 1) μg/L]含量明显下降 ,而TSH[(6 .34± 1.13)、(7.74± 0 .79)、(9.16± 0 .77)IU]增高 ,与对照组T3 [(0 .97± 0 .14 ) μg/L]、T4[(5 4 .5 0± 3.70 ) μg/L]和TSH     

Reduced growth and skeletal changes in zinc-deficient growing rats are due to impaired growth plate activity and inanition

We investigated the effects of dietary zinc deficiency on skeletal metabolism in an animal model. Thirty 21-d-old male Sprague-Dawley rats were fed for 28 d either a zinc-deficient (ZD) diet (1 mg zinc/kg) or a normal diet ad libitum (AL, 50 mg zinc/kg) or in the same quantity as the ZD (pair-fed, PF). Only in the ZD group were general physical signs of zinc deficiency observed. Compared with the AL and PF rats, ZD rats showed significantly lower mean values in ponderal growth rate, femur weight and length, circulating levels of insulin-like growth factor-I, bone mechanical properties and concentration of zinc and, on histomorphometry, a decrease in the thicknesses of the overall growth plate and hypertrophic cartilage. In contrast, although bone volume was significantly lower in the ZD and PF rats than in the AL rats, no difference was observed between the ZD and PF rats. Osteoclast surface/bone surface and osteoclast number/bone surface ratios were significantly greater in PF rats than in the other two groups and not different in ZD and AL rats. Collectively, these data indicate that zinc deficiency has profound effects on the skeletal system of growing rats. In particular, the effects of zinc deficiency on bone growth and mass are the result of the reduced activity of the growth plate, likely mediated by impairment in the insulin-like growth factor-I system. We did not demonstrate an effect on bone mass via increased bone resorption.     

生长期大鼠缺锌时股骨病理形态学的改变

目的　通过建立生长期缺锌大鼠模型以阐明锌缺乏对生长期儿童骨骼发育的影响 ,为儿童生长发育迟缓的防治提供理论依据。方法　刚断奶的雄性大鼠随机分为对照组 (ZA)、缺锌组 (ZD)、配饲组 (PF) 3组 ,每组 10只。喂养 15天后处死 ,取股骨称量重量及测量长度、直径 ,并做病理组织切片 ,观察股骨病理改变。结果　ZD组股骨长度 [(2 4 . 80± 0 . 4 2 )mm]明显低于PF组 [(2 6 . 70± 0 . 4 8)mm]及ZA组 [(2 7. 90± 0 . 32 )mm](P <0 . 0 1) ;ZD组股骨直径 [(2 . 0 9± 0 .0 9)mm]明显低于PF组 [(2 . 70± 0 . 0 8)mm]及ZA组 [(2 . 80± 0 . 0 8)mm](P <0 . 0 1) ;ZD组股骨重量 [(0 .5 1± 0 . 0 5 )g]明显低于PF组 [(0 . 6 5± 0 . 0 8) ]及ZA组 [(0 . 76± 0 . 10 )g](P<0 . 0 1)。缺锌组大鼠股骨骺生长板软骨细胞畸形、数量减少 ,骺端骨小梁纤细、疏松、排列紊乱、髓腔相对扩大 ,骨小梁体积显著减少 ,骨小梁板密度降低 ,骨小梁间隙增大。结论　生长期动物缺锌可导致骨骼的形态及病理发生改变而影响骨骼的生长发育。     

修饰蓖麻毒素减轻其对小鼠肝毒性的研究

目的　探讨化学修饰后的蓖麻毒素 (RT)对小鼠肝脏毒性及其抗癌作用的变化。方法　测定RT及其修饰物N [3 (2 吡啶二硫基 )丙酰基 ]蓖麻毒素 (RT PDP)染毒小鼠血清谷胱甘肽转硫酶 (GST)活力、肝组织谷胱甘肽 (GSH)含量 ,电镜下观察染毒小鼠肝脏的病理改变。结果　随着RT及RT PDP染毒剂量的增加 ,小鼠血清GST活力随之增加 ,且RT组小鼠血清GST活力高于RT PDP组。当染毒剂量均为 12 .5、15 .0 μg/kg时 ,RT组小鼠血清GST活力 [(93.6 5± 12 .30 )、(15 3.71±2 6 .6 4 )IU/L]明显高于RT PDP组 [(6 2 .97± 11.2 2 )、(78.2 0± 15 .71)IU/L],差异有显著性 (P <0 .0 5 ) ;RT和RT PDP各剂量染毒组小鼠肝组织GSH含量均随染毒剂量增加而下降 ,当染毒剂量为 2 .5、5 .0、7.5、10 .0、15 .0 μg/kg时 ,RT组小鼠肝组织匀浆中GSH含量分别为 (3.5 3± 0 .95 )、(2 .12± 0 .5 4 )、(1.82±0 .71)、(1.5 2± 0 .34)、(0 .81± 0 .36 ) μmol/L ,RT PDP组小鼠肝组织匀浆中GSH含量分别为 (6 .34±1.4 3)、(4.14± 1.82 )、(3.5 4± 0 .6 4 )、(2 .73± 1.82 )、(1.82± 0 .6 2 ) μmol/L ,RT PDP组仍明显高于RT组 ,差异均有显著性 (P <0 .0 1) ;电镜观察显示 ,RT对小鼠肝细胞的损伤大于RT PDP。结论　化学修饰蓖麻毒素可     

锌缺乏对生长期雄性大鼠海马泛素C末端水解酶L1表达的影响

[目的]观察缺锌对生长期大鼠海马泛素C末端水解酶L1(UCH-L1)表达的影响。[方法]将SD大鼠随机分为正常组、缺锌配喂组和缺锌组,正常组喂饲常锌饲料(32.5mg/kg),缺锌配喂组喂饲高锌饲料(73.5mg/kg),缺锌组喂饲缺锌饲料(1.2mg/kg)。饲养4周后处死动物,取海马组织,RT-PCR法检测UCH-L1mRNA的表达水平,Westernblot法检测UCH-L1蛋白的表达水平。[结果]与正常组和缺锌配喂组比较,缺锌大鼠海马中UCH-L1mRNA和蛋白的表达水平均显著下调。[结论]缺锌大鼠海马UCH-L1的表达异常,可能是缺锌导致认知损伤的重要机制之一。     

Effect of protein intake on bone mineralization during weight loss: a 6-month trial

OBJECTIVE: The long-term effect of dietary protein on bone mineralization is not well understood. RESEARCH METHODS AND PROCEDURES: Sixty-five overweight (body mass index, 25 to 29.9 kg/m(2)) or obese (> or =30 kg/m(2)) subjects were enrolled in a randomized, placebo-controlled, 6-month dietary-intervention study comparing two controlled ad libitum diets with matched fat contents: high protein (HP) or low protein (LP). Body composition was assessed by DXA. RESULTS: In the HP group, dietary-protein intake increased from 91.4 g/d to a 6-month intervention mean of 107.8 g/d (p < 0.05) and decreased in the LP group from 91.1 g/d to 70.4 g/d (p < 0.05). Total weight loss after 6 months was 8.9 kg in the HP group, 5.1 kg in the LP group, and none in the control group. After 6 months, bone mineral content (BMC) had declined by 111 +/- 13 g (4%) in the HP group and by 85 +/- 13 g (3%) in the LP group (not significant). Loss of BMC was more positively correlated with loss of body fat mass (r = 0.83; p < 0.0001) than with loss of body weight. Six-month BMC loss, adjusted for differences in fat loss, was greater in the LP group than in the HP group [difference in LP vs. HP, 44.8 g (95% confidence interval, 16 to 73.8 g); p < 0.05]. Independent of change in body weight and composition during the intervention, highprotein intake was associated with a diminished loss of BMC (p < 0.01). DISCUSSION: Body-fat loss was the major determinant of loss of BMC, and we found no adverse effects of 6 months of high-protein intake on BMC.     

锌缺乏对孕鼠发育及体内促生长有关激素水平的影响

目的　探讨锌缺乏对妊娠大鼠发育及体内促生长有关激素含量的影响。方法　将Wistar妊娠大鼠随机分为缺锌组 (ZD)、对喂组 (PF)、补锌组 (ZS)及正常对照组 (Cont) ,分别给予缺锌 (0 .7mg/ kg)和正常锌 (1 0 0 mg/ kg)饲料喂养 ,观察孕鼠及胎鼠发育情况 ,并采用放射免疫法检测血清中甲状腺素 (T3 、T4 )、促甲状腺素 (TSH)和生长激素 (GH)含量。结果　缺锌组孕鼠在妊娠期间体重没有增加 ;胎鼠出生体重显著低于其他三组 ;血清中激素含量显著低于补锌组和正常对照组。结论　锌缺乏可降低孕鼠血液中促生长有关激素含量 ,导致孕鼠及胎儿生长发育迟缓。     

锌对D-半乳糖诱导的衰老小鼠学习和记忆行为的影响

目的: 研究缺锌和补锌对衰老小鼠的学习和记忆能力的影响及其机制。方法: 取雄性小鼠70只,随机分组,按剂量100 mg/kg bw给予D-半乳糖注射液,颈背部皮下注射,青龄对照组给予等剂量的生理盐水,连续30 d。衰老缺锌组和补锌组开始均给予缺锌饲料(含锌1.61 mg/kg),其他组给予正常饲料(含锌50 mg/kg)。补锌组在实验最后2w给予补锌饲料(100 mg/kg)。在实验的最后1 w进行有关行为学试验,期满后断颈处死小鼠后取样检测。结果: 与衰老模型组相比,衰老缺锌组血清锌水平下降,老年小鼠自主活动度降低,学习和记忆能力下降。彗星试验显示缺锌使得老龄小鼠脑细胞DNA损伤程度加重,彗星细胞尾长/总长比值显著增加。补锌后上述指标均有显著改善。结论: 缺锌可以降低DNA的损伤修复功能,进而影响小鼠的学习和记忆能力。而补锌则有助于改善这一现象。     

Nitric oxide synthase inhibitor attenuates intestinal damage induced by zinc deficiency in rats

A nitric oxide synthase (NOS) inhibitor, NG-nitro-L -arginine methyl ester (L-NAME), was given to zinc-deficient (ZD) rats to determine whether it prevents the intestinal damage usually observed under these conditions. Weanling male rats were given free access to a ZD diet (2 mg zinc/kg), whereas control rats including pair-fed (PF) and ad libitum consumption (AL) groups were given a zinc-supplemented (50.8 mg zinc/kg) diet for 4 wk. Half of the ZD rats received L-NAME (0.3 g/L in drinking water) for 3 wk starting at the wk 2 of the deficient period. Plasma zinc concentration in ZD rats was significantly lower (P < 0.05) than that of AL and PF rats. Administration of L-NAME did not alter this concentration. Intestinal zinc concentration did not differ among groups. However, metallothionein-1 (MT-1) mRNA level was significantly lower in the intestine of ZD rats than in AL or PF rats. Treatment of ZD rats with L-NAME did not affect this level. Intestinal microvascular permeability evaluated by Evans blue showed significantly higher extravasation in ZD rats than in AL rats, whereas L-NAME administration inhibited the extravasation. Expression of inducible NOS mRNA was observed in intestine of ZD but not of AL or PF rats, and there was no significant difference between ZD rats, regardless of L-NAME treatment. The activity ratio of inducible NOS to total NOS in ZD rats not receiving L-NAME was significantly higher than that in AL rats or ZD rats treated with L-NAME (P < 0.05). The number of apoptotic-positive and goblet cells in intestinal villi was significantly higher in ZD rats compared with AL or PF rats. L-NAME administration in ZD rats reversed this effect. These results indicate that inhibition of NOS ameliorates zinc deficiency-induced intestinal damage in rats.     

Studies of marginal zinc deprivation in rhesus monkeys. III. Effects on vitamin A metabolism

The relationship between dietary zinc, vitamin A, and retinol-binding protein (RBP) was studied in pregnant rhesus monkeys. Beginning on day 0 of gestation, monkeys were divided into three groups; 1) eight ad libitum-fed controls (AL) fed a diet containing 100 micrograms/g zinc, 2) 15 zinc-deprived (ZD) fed a diet containing 4 micrograms/g zinc, 3) 11 pair-fed controls (PF) fed the 100 micrograms/g control diet in amounts equal to those consumed by ZD animals. ZD monkeys had lower plasma zinc levels than did the AL and PF groups at day 135 of gestation, and at 1 and 3 months gestation. A positive correlation between plasma vitamin A and plasma zinc was observed (r = 0.5150, p less than 0.05) and between RBP and zinc (r = 0.883, p less than 0.001) in the ZD group at day 135 of pregnancy. By 3 months postpartum, plasma zinc levels increased in all groups; a positive correlation between zinc and vitamin A was observed in the ZD group (r = 0.5162, p less than 0.05) and in the PF group (r = 0.6353, p less than 0.05); however, no correlation between zinc and RBP was observed. In ZD monkeys, the ratio of RBP to vitamin A was higher (p less than 0.05) than in controls at day 135 of pregnancy. Polynomial regression of the interaction between plasma vitamin A and zinc, and the RBP/vitamin A and zinc, indicated a curvilinear relationship between plasma zinc and these two parameters.(ABSTRACT TRUNCATED AT 250 WORDS)