不同产地四叶参对产后缺乳大鼠的催乳作用研究

目的观察4个不同产地的四叶参对缺乳大鼠模型泌乳量及血清催乳素(PRL)水平的影响,探讨其催乳机制。方法建立溴隐亭诱导的大鼠缺乳模型,检测4个不同产地的四叶参提取物对母鼠泌乳量及缺乳大鼠血清PRL水平的影响。结果与模型组大鼠比较,4个产地四叶参能提高溴隐亭缺乳大鼠泌乳量及血清PRL含量(P0.01)。结论四叶参能提高产后缺乳模型大鼠的血清PRL水平,畅通泌乳通道,增加泌乳量。     

鲟鱼头汤对产后缺乳大鼠泌乳功能的促进作用

目的：研究经蒸煮后高压液化熬制鲟鱼头汤的催乳功效。方法：将Wistar母鼠随机分为空白组（生理盐水）、缺乳模型组（溴隐亭）、阳性对照组（乳清蛋白鲈鱼粉）和实验组（鲟鱼头汤）,每组6只,对哺乳期Wistar母鼠进行连续14 d灌胃,考察其体质量和泌乳量变化。通过苏木精伊红染色、免疫组化分析、酶联免疫吸附测定与实时荧光定量聚合酶链式反应等方法测定母鼠乳腺组织形态、相关激素与蛋白表达水平。结果：实验组母鼠乳腺的腺管与腺泡中可以观察到棕黄色阳性显色蛋白分泌物数量增多,乳腺小叶间脂肪结缔组织数量减少,相较于模型组有明显恢复。与模型组相比,实验组母鼠每小时泌乳量、乳腺相对质量以及仔鼠窝重净增率均显著提高（P<0.05）,母鼠血清与乳腺组织中催乳素（prolactin,PRL）、催乳素受体（prolactin receptor,PRLR）、β-酪蛋白（β-casein,β-CN）、α-乳清蛋白（α-lactalbumin,α-LA）水平及乳糖合成酶（lactose synthase,LS）和脂肪酸合成酶（fatty acid synthase,FAS）活力也显著提升（P<0.05）。乳腺...     

叶生小皮伞不同发酵产物对硝酸甘油诱导偏头痛大鼠的抗炎、镇痛作用

为研究叶生小皮伞(Marasmius epiphyllus)不同发酵产物对偏头痛大鼠的抗炎、镇痛的作用,本研究采用硝酸甘油诱导的大鼠偏头痛模型,观察大鼠行为学变化;采用酶联免疫吸附试验(ELISA)检测脑组织中5-羟色胺(5-hydroxytryptamine,5-HT)、去甲肾上腺素(norepinephrine,NE)和多巴胺(dopamine,DA)及血清中一氧化氮(NO)、白细胞介素-6(interleukin-6,IL-6)和白细胞介素-1β(interleukin-1β,IL-1β)的含量。结果表明,造模后,大鼠双耳发红,搔头次数频繁;与模型组比较,阳性药组和叶生小皮伞发酵物各给药组均可显著(P<0.05)提高脑组织中5-HT、NE和DA水平;除叶生小皮伞固体发酵物水提物WESF低剂量组、菌丝体水提物WEM低剂量组外,叶生小皮伞各给药组大鼠血清中NO水平均显著降低(P<0.05,P<0.001);除叶生小皮伞菌丝体水提物WEM低剂量组、发酵液LFP低剂量组外,叶生小皮伞各给药组大鼠血清中炎症因子IL-6水平显著降低(P<0.05);除发酵液LFP高剂量组外,叶生小皮伞各给药组大鼠血清中炎症因子IL-1β水平显著降低(P<0.05,P<0.001)。因此,叶生小皮伞发酵产物可调节血管收缩及神经递质分泌,对偏头痛大鼠具有良好的抗炎、镇痛作用。     

沉香提取物对PCPA(对氯苯丙氨酸)致失眠大鼠的镇静催眠作用

探究沉香提取物对PCPA(P-chlorophenylalanine,PCPA)致失眠大鼠的镇静催眠作用。选取SD大鼠90只,10只作为空白组,余80只建立失眠大鼠模型,分为模型组、沉香挥发油高剂量组、沉香挥发油低剂量组、沉香醇提物高剂量组、沉香醇提物低剂量组、沉香水提物高剂量组、沉香水提物低剂量组、地西泮组。观察各组下丘脑5羟色胺(5-HT)、多巴胺(DA)、去甲肾上腺素(NE)、γ-氨基丁酸(GABA)、谷氨酸(Glu)含量及GABAAR_(α1)、GABAAR_(γ2)、5-HT_(1A)受体m RNA相对表达量。给药6 d后,挥发油高剂量组、挥发油低剂量组、醇提物高剂量组、醇提物低剂量组下丘脑5-HT含量分别为4.85 ng/m L、4.84 ng/m L、4.81 ng/m L、4.49 ng/m L,GABA含量分别为1.46 ng/m L,1.44 ng/m L,1.41 ng/m L,1.39 ng/m L,高于模型组(p0.05);挥发油高剂量组、挥发油低剂量组、醇提物高剂量组5-HT_(1A)受体m RNA相对表达量为0.81、0.79、0.74,高于模型组(p0.05);GABAAR_(α1 )m RNA相对表达量分别为0.94、0.84、0.85,GABAAR_(γ2) m RNA相对表达量分别为0.74、0.70、0.73,高于模型组(p0.05)。沉香提取物对PCPA致失眠大鼠具有一定镇静催眠作用。     

茶多酚肉碱复方制剂降血脂的实验研究

探讨茶多酚肉碱复方制剂对高脂血症模型大鼠血脂水平的影响。采用高脂饲料喂养SD大鼠建立预防性高脂血症模型,将实验大鼠分成正常对照组、模型对照组、低剂量组、中剂量组和高剂量组。连续灌胃给药45 d,观察茶多酚肉碱复方制剂对高脂血症大鼠血清甘油三酯(TG)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)的影响。结果表明,与正常对照组比较,高脂饲料连续喂养45 d后,模型对照组大鼠血清TG和TC显著升高(P<0.01);与模型对照组比较,给药45 d后,1)低剂量组大鼠血清TG未见显著性降低(P>0.05),中剂量组和高剂量组血清TG极显著地降低(P<0.01);2)低剂量组大鼠血清TC显著降低(P<0.05),中高剂量组大鼠血清TC极显著降低(P<0.01);3)各剂量组大鼠血清HDL-C无显著性差异。茶多酚肉碱复方制剂具有辅助降血脂的作用。     

百合水提物对对氯苯丙氨酸失眠模型大鼠睡眠改善作用研究

目的 研究不同剂量的百合水提取物对对氯苯丙氨酸(PCPA)失眠模型大鼠睡眠作用的影响。方法 大鼠腹腔注射PCPA混悬液制备大鼠失眠模型。将造模成功大鼠随机分为模型对照组、百合水提物组-低、百合水提物组-中、百合水提物组-高,另设空白对照组。百合水提物组-低 (100 mg/kg.d)、百合水提物组-中(200 mg/kg.d)、百合水提物组-高(300 mg/kg.d)大鼠连续 7 d 给予相应浓度药液,模型对照组和空白对照组连续 7 d 给予生理盐水灌胃。给药期间,观察大鼠一般状态;给药结束后,观察大鼠体质量变化、睡眠潜伏期、总睡眠时间,同时评价不同脑组织中五羟色胺、5-羟基吲哚乙酸、多巴胺含量的变化。结果 百合水提物各剂量组的大鼠在给药期间的一般状态均优于模型组,体质量增加情况也与正常对照组无显著差异;百合水提物中、高剂量组的睡眠潜伏期与模型组相比显著缩短(P＜0.05),百合水提物各剂量组的睡眠时间与模型组相比显著延长(P＜0.05);与模型对照组比较,各给药组大鼠不同脑组织中的5-HT含量显著升高(P < 0.05,P < 0.01),百合水提物中、高剂量组大鼠不同脑组织中的5-HIAA 含量显著升高(P < 0.05,P < 0.01),同时上述２个给药组大鼠的下丘脑、中缝核中的DA含量显著降低(P < 0.05),海马中仅百合水提物高剂量组的DA含量与对照组相比显著降低(P < 0.05)。结论 百合水提物具有改善PCPA失眠模型大鼠睡眠情况的作用。     

药用真菌中麦角甾醇对偏头痛大鼠的作用机制

目的:研究真菌中麦角甾醇对硝酸甘油诱导的偏头痛大鼠的抗炎镇痛的作用及机制。方法:麦角甾醇高剂量（30 mg/kg）和低剂量（15 mg/kg）组灌胃给药后,注射硝酸甘油,诱导大鼠偏头痛模型后,观察大鼠行为学变化;采用酶联免疫吸附试验（ELISA）检测血清中一氧化氮（NO）、白细胞介素IL-1β、IL-6及下丘脑组织中 5-羟色胺（5-HT）、多巴胺（DA）和去甲肾上腺素（NE）的含量;蛋白免疫印迹法 (WB) 检测NF-κBp65、JAK2和STAT3蛋白表达含量。结果:硝酸甘油诱导后,大鼠搔头次数频繁;与模型组比较,麦角甾醇不同剂量组可显著降低血清NO水平（P<0.05）、炎症因子IL-1β、IL-6水平（P<0.001;P<0.05）,同时,麦角甾醇各给药组DA和NE水平也显著升高（P<0.05;P<0.001）,麦角甾醇低剂量组可显著提高下丘脑中5-HT水平（P<0.05）。WB结果表明,麦角甾醇各剂量组均可显著降低偏头痛大鼠脑组织中P-NF-κBp65, P-JAK2 和 P-STAT3蛋白的表达。结论:麦角甾醇具有显著的抗炎、镇痛作用,其作用机制可能通过调节NF-κB、JAK/STAT信号通路实现的。     

叶黄素对母鼠乳腺分泌IgA的促进作用

为明确叶黄素对母鼠乳腺分泌IgA能力的影响,本实验对妊娠母鼠添加饲喂叶黄素,检测母鼠血清中IgG、IgA和IgM含量变化,母鼠乳腺组织中IgA mRNA表达量和IgA抗体分泌细胞数量变化,以及仔鼠胃内容物中IgA浓度变化。结果表明：在妊娠21 d和分娩后7 d时,实验组血清中IgG和IgA浓度显著高于正常对照组（P＜0.05）,IgM含量虽有升高,与正常对照组相比,无显著性差异（P＞0.05）;乳腺组织中IgA mRNA表达量无显著变化（P＞0.05）;分娩后14 d IgA抗体分泌细胞数量显著增加（P＜0.05）;仔鼠胃内容物中IgA含量极显著高于对照组（P＜0.01）。说明给妊娠母鼠添加饲喂叶黄素可以增强乳腺分泌IgA的能力。     

金针菇多糖提取物对记忆障碍模型大鼠、小鼠学习记忆能力的影响

目的:研究金针菇多糖(Flammulina velutipes Polysaccharide,FVP)对氢溴酸东莨菪碱诱导的记忆获得障碍模型大鼠和小鼠学习记忆能力的影响。方法:分别以雄性SD大鼠和雄性KM小鼠为试验对象,均随机分为5组,即:正常对照组、模型组、脑复新组、FVP低剂量组和FVP高剂量组,每组10只。脑复新组(Pyritinol Hy-drochloride Tablets,80 mg/kg)、FVP低剂量组[250mg/(kg.d))]和FVP高剂量组[500mg/(kg.d))]试验前连续灌胃给药5 d,正常对照组及模型对照组分别给予等量的生理盐水。除正常对照组外,其它各试验组于第6日开始利用氢溴酸东莨菪碱(2 mg/kg)造模并做小鼠明暗箱和大鼠Morris水迷宫测试。结果:采用FVP高剂量治疗,可延长记忆障碍模型小鼠明箱停留时间,减少小鼠避暗错误次数以及记忆障碍模型大鼠的上台前总路程和潜伏期,试验结果与模型组相比具有显著性差异(P﹤0.05),治疗效果优于脑复新或与之相当。结论:金针菇多糖可有效改善氢溴酸东莨菪碱诱导的记忆障碍模型小鼠、大鼠的学习记忆能力,治疗效果优于脑复新或与之相当。     

茶多酚对大鼠泌乳性能及抗氧化能力的影响

通过在不同能量条件下,研究茶多酚(TP)对泌乳期大鼠泌乳性能、血液生化指标及抗氧化能力的影响。选取40只SD孕鼠,随机分为4组,每组10个重复,每个重复1只。采用2×2拉丁方设计,分别饲喂:高能日粮(HE),低能日粮(LE),高能日粮+500mg茶多酚/kg饲料(HE-TP),低能日粮+500mg茶多酚/kg饲料(LE-TP),实验期40d。结果表明:添加TP显著提高大鼠的泌乳量及乳腺组织中催乳素(PRL)、雌激素(E2)水平(p<0.05),对采食量没有显著作用。在日粮中添加TP,均可显著降低HE和LE组大鼠血浆TG、GLU和UN水平(p<0.05)。添加TP,HE和LE组大鼠血浆T-AOC、CAT活力显著提高(p<0.05),SOD活力均提高但不显著(p>0.05),MDA水平显著降低(p<0.05)。结论:茶多酚通过提高母鼠的抗氧化能力,减少体内氧化产物,同时调节了泌乳激素水平从而提高了母鼠泌乳性能。     

Prolactin in bovine milk near the time of calving and its relationship to premature induction of lactogenesis

Twenty-three primiparous heifers and pluriparous cows were milked once daily beginning 3 to 10 days before parturition. Retrospectively, they were divided into groups representing either successful or unsuccessful premature induction of lactogenesis, depending on milk production prior to calving. Successfully induced animals had prepartum milk yields greater than 4 kg/milking and unsuccessful animals yielded less. Ten of 23 animals satisfied the criterion for successful premature induction at 2.6 +/- .4 days before calving and 3.6 +/- .8 days after first milking and had peak prepartum yields of 7.9 +/- .7 kg/milking. Total number of prepartum days milked did not differ between successful and unsuccessful groups. Greater milk yield prepartum was significantly associated with higher milk prolactin concentration on days -6 to -4. Heifers had less milk yield than cows but did not differ in milk prolactin concentration or in total prolactin per milking. Premature induction of lactogenesis did not confer significant lactational benefits for more than 1 day postpartum or over the first 35 days postpartum. Premature induction of lactogenesis as a result of prepartum milking did not, as hypothesized, decrease the ability of mammary secretions to accumulate prolactin in large amounts. All groups rapidly lost this ability after parturition, suggesting that the hormonal environment of late pregnancy may promote the transfer of prolactin from blood into milk when there is regular removal of prepartum milk.     

Lactational response of dairy cows to oral administration of a synthetic glucocorticoid.

Effects of oral administration of 0, 5, 10, or 20 mug of 6 alpha, 9 alpha-difluoro-16alpha-methyl-prednisolone (Flumethasone) daily on milk and milk component yields, udder health reproductive performance, and body weight change were measured. With 24 Holstein cows in a randomized block design, daily Flumethasone administration was initiated 4 days postpartum and continued until milk secretion ceased or the completion of 305 days on treatment. Mature equivalent yields (adjusted for days open) of milk, solids-not-fat, and milk fat were higher for cows receiving 5 or 10 mug Flumethasone than for cows receiving 0 or 20 mug Flumethasone daily. Lactations for cows receiving 20 mug Flumethasone were 37 to 48 days shorter than lactations for cows in other treatment groups. There were no differences between treatment groups for measures of udder health, reproductive efficiency, and body weight changes. A second experiment of 45 Holstein cows in their second or third lactations included treatments 0, 5, or 10 mug Flumethasone daily for 25 days followed by a 5 day withdrawal. Treatments were begun between day 210 and day 270 of lactation. During the 30 days, Flumethasone failed to alter milk production. These experiments indicate that Flumethasone given continuously increased milk components and milk yield but had no significant effect on milk yield when given only during the latter stage of lactation.     

Endotoxin mastitis in cows milked four times daily

As part of a project to identify the pathophysiological cause or causes of mastitic hypogalactia, midlactation cows were infused in two homolateral quarters with 10 micrograms of endotoxin while being milked four times daily to resolve better the temporal changes in mammary synthetic activity during endotoxin mastitis. Milk fat was decreased by the first milking (5 h) postinfusion and then recovered rapidly. In contrast, milk yield and the yields of protein and lactose were not significantly inhibited until the second milking, and these yields recovered slowly thereafter. The decline in milk yield by infused quarters was only 20% greater than the decline by uninfused quarters in this experiment. Mammary inflammation developed rapidly in infused quarters as milk serum albumin concentration was maximal at the first milking. Milk SCC and NAGase were also elevated at this time, and maximal levels occurred at milkings 2 to 4. Increased temperature, increased cortisol, and a mild anorexia were apparent at the first milking only. Endotoxin treatment had no effect on serum prolactin or glucose. These data suggest that the delayed hypogalactia is consequent to the mammary inflammation and systemic responses following endotoxin infusion. The results indicate that different pathophysiological events may inhibit synthesis of the different milk components.     

Short communication: Circulating serotonin (5-HT) concentrations on day 1 of lactation as a potential predictor of transition-related disorders

The monoamine serotonin (5-hydroxytryptamine; 5-HT) has been described as a homeostatic regulator of lactation. Recently, our laboratory determined that 5-HT is involved in the regulation of calcium and glucose homeostasis during the transition period in rodents. More specifically, we demonstrate that 5-HT is responsible for calcium mobilization from bone and upregulation of hepatic gluconeogenic enzymes and mammary gland glucose transporters. Our objective was to investigate the correlation between circulating 5-HT concentrations and circulating ionized calcium, parathyroid hormone-related protein (PTHrP), and glucose concentrations on d 1 postpartum. We also investigated the correlation between circulating 5-HT and milk fever and ketosis incidence and severity in multiparous Holstein cows at the onset of lactation. Blood samples were collected from 42 multiparous cows on d 1 of lactation and analyzed for 5-HT, calcium, glucose, and PTHrP. Milk fever (determined subjectively for each cow on d 1 postpartum) and ketosis incidence and severity (scale 1 to 4, determined objectively for each cow during the first 10 d postpartum) were recorded for all animals. Serum 5-HT was positively correlated with serum calcium and with plasma PTHrP (r > 0.37). Serum 5-HT was negatively correlated with milk fever incidence and with ketosis severity (most severe ketosis incidence recorded during the first 10 d postpartum; r < -0.33). Serum calcium and plasma glucose concentrations were negatively correlated with milk fever and ketosis severity, respectively (r < -0.39). These data indicate that 5-HT potentially plays a role in the regulation of calcium and glucose homeostasis during the transition period in cattle, which we previously demonstrated in rodents. Increased circulating concentrations of 5-HT might decrease milk fever at the onset of lactation and ketosis severity during the first 10 d postpartum in dairy cows. Understanding this physiological axis could help describe the underlying mechanisms associated with these periparturient metabolic disorders in dairy cows.     

Increased serum serotonin improves parturient calcium homeostasis in dairy cows

Hypocalcemia in dairy cows is caused by the sudden increase in calcium demand by the mammary gland for milk production at the onset of lactation. Serotonin (5-HT) is a key factor for calcium homeostasis, modulating calcium concentration in blood. Therefore, it is hypothesized that administration of 5-hydroxy-l-tryptophan (5-HTP), a 5-HT precursor, can increase 5-HT concentrations in blood and, in turn, induce an increase in blood calcium concentration. In this study, 20 Holstein dairy cows were randomly assigned to 2 experimental groups. Both groups received a daily i.v. infusion of 1 L of either 0.9% NaCl (C group; n = 10) or 0.9% NaCl containing 1 mg of 5-HTP/kg of BW (5-HTP group, n = 10). Infusions started d 10 before the estimated parturition and ceased the day of parturition, resulting in at least 4 d of infusion (8.37 ± 0.74 d of infusion). Until parturition, blood samples were collected every morning before the infusions, after parturition samples were taken daily until d 7, and a final sample was collected on d 30. Milk yield was recorded during this period. No differences between groups were observed for blood glucose, magnesium, and β-hydroxybutyrate. Cows receiving the 5-HTP infusion showed an increase in fatty acid concentrations from d ?3 to ?1 before parturition. Serum 5-HT concentrations were increased at d ?4 related to parturition until d 5 postpartum in the 5-HTP group compared with the C group. In addition, cows from the 5-HTP group had increased 5-HT concentrations in colostrum, but not in mature milk, on d 7 postpartum. Serum calcium concentrations decreased in both groups around parturition; however, calcium remained higher in the 5-HTP group than in controls, with a significant difference between groups on d 1 (1.62 ± 0.08 vs. 1.93 ± 0.09 mmol/L in control and 5-HTP groups, respectively) and d 2 (1.83 ± 0.06 vs. 2.07 ± 0.07 mmol/L in control and 5-HTP groups, respectively). Additionally, colostrum yield (first milking) was lower in the 5-HTP group compared with the C group, but without consequences on colostrum IgG concentrations. Milk yield did not differ between groups during the rest of the experiment. The study data were consistent with the concept that infusion of 5-HTP to dairy cows increases blood 5-HT concentrations, which in turn is a significant regulatory component in the chain of effectors that affect calcium status around parturition, hence the occurrence of clinical or subclinical hypocalcemia.     

Temporary alterations to postpartum milking frequency affect whole-lactation milk production and the energy status of pasture-grazed dairy cows

This study investigated the immediate and long-term effects of temporary alterations to postpartum milking frequency (MF) on milk production, body condition score (BCS), and indicators of energy status in pasture-grazed cows supplemented with concentrates. Multiparous Holstein-Friesian cows (n = 150) were randomly assigned to 1 of 5 groups at calving: milked twice daily (2×) throughout lactation (control), or milked either once daily (1×) or 3 times daily (3×) for 3 or 6 wk immediately postpartum, and then 2× for the remainder of lactation. During wk 1 to 3 postpartum, cows milked 1× produced 15% less milk and 17% less energy-corrected milk (ECM) than cows milked 2×. This immediate production loss increased to 20% less milk and 22% less ECM during wk 4 to 6 postpartum for cows that remained on 1× milking; these animals also produced less than 1× cows switched to 2× milking after 3 wk. During wk 8 to 32, when all cows were milked 2×, those previously milked 1× had sustained reductions in milk (−6%) and ECM (−8%) yields, which were not affected by the duration of reduced postpartum MF. In contrast, cows milked 3× postpartum had 7% greater milk yields during wk 1 to 6 compared with 2× controls, irrespective of the duration of increased MF. Milk yields also remained numerically greater (+5%) during wk 8 to 32 in cows previously milked 3×. Nevertheless, yields of ECM were not increased by 3× milking, because of lower milk fat and protein contents that persisted for the rest of lactation. In addition, indicators of cow energy status reflected an increasing state of negative energy balance with increasing MF. Cows milked 1× postpartum had greater plasma glucose and lower plasma nonesterified fatty acid concentrations during the reduced MF, and plasma glucose remained lower for 2 wk after cows had switched to 2× milking. Moreover, BCS was improved relative to 2× controls from wk 5 to 6. In contrast, cows milked 3× had lower plasma glucose concentrations, greater plasma nonesterified fatty acid concentrations, and greater BCS loss during wk 1 to 3; however, greater body fat mobilization was not sustained, indicating that additional energy supplements may be required to achieve better milk production responses. In conclusion, temporary 1× milking had lactation-long negative effects on milk and milk component yields but improved cow energy status and BCS, whereas temporary 3× milking immediately increased milk yield but did not improve milk fat and protein yields in pasture-grazed cows.     

Endocrine and metabolic changes in transition dairy cows are affected by prepartum infusions of a serotonin precursor

Serotonin (5-HT) has been shown to be involved in calcium homeostasis, modulating calcium concentration in blood. In addition, 5-HT participates in a variety of metabolic pathways, mainly through the modulation of glucose and lipid metabolism. The hypothesis of the present study was that the prepartum administration of 5-hydroxy-l-tryptophan (5-HTP), a 5-HT precursor, would affect endocrine systems related to calcium homeostasis, and interact with other endocrine and metabolic pathways during the transition period. In this study, 20 Holstein dairy cows were randomly assigned to 2 experimental groups. Both groups received a daily i.v. infusion of 1 L of either 0.9% NaCl (control group; n = 10) or 0.9% NaCl containing 1 mg of 5-HTP/kg of BW (5-HTP group, n = 10). Infusions started d 10 before estimated parturition date and ended the day of parturition, resulting in a minimum of 4 d of infusion (8.4 ± 0.7 d of infusion). Until parturition, blood samples were collected before the daily infusions, and postpartum daily until d 7, and on d 30. Plasma concentrations of parathyroid hormone (PTH) were transiently increased at parturition and on d 1 in control cows. In the 5-HTP group PTH remained unchanged. The concentration of pyridinoline (PYD), an established marker for calcium release from the bone to the bloodstream, increased on d 1 postpartum only in the 5-HTP group. In control cows, PYD concentrations did not change on d 1 postpartum. Melatonin concentrations were slightly but significantly increased in the 5-HTP group compared with the control group. Insulin concentrations decreased in both groups postpartum. Before parturition, leptin concentrations decreased in both groups and remained at this level until d 30 postpartum. Plasma IgG concentrations decreased in both groups on d ?1 postpartum. Haptoglobin increased in both groups on d ?1 and remained at this level until d 7 postpartum. No differences between groups were observed for insulin, glucagon, IgG, leptin, adiponectin, and haptoglobin concentrations. The results obtained in the present study evidenced that 5-HT is regulating calcium homeostasis independent of PTH. The lack of treatment effects on IgG and on other hormones and metabolites indicates that 5-HTP did not affect these other metabolic pathways and the IgG concentration during the transition period.     

色氨酸对慢性应激小鼠行为的影响

研究色氨酸对慢性应激小鼠行为的影响及与下丘脑5-HT的关系。将60只小鼠随机分为空白组(NC)、慢性应激模型组(CUS)、慢性应激模型+高剂量色氨酸(CUS-H)、慢性应激模型+低色氨酸(CUS-L),对CUS、CUS-H、CUS-L建立慢性应激模型,同时分别对CUS-H、CUS-L组灌胃高、低剂量的色氨酸,建模第5周开始进行旷场实验、悬尾实验、糖水消耗实验、强迫游泳实验及水迷宫实验等行为学实验,测定行为学指标,并采用ELISA法检测下丘脑5-HT含量。CUS-H组旷场实验得分显著高于CUS组与NC组(p<0.05),悬尾实验静止时间与CUS与NC组相比极显著地缩短(p<0.01),CUS-H组糖水偏好程度极显著低于CUS组(p<0.01),其强迫游泳静止时间极显著低于NC组(p<0.01);灌胃色氨酸对应激动物的学习和记忆能力有一定增强作用,但作用不显著;灌胃色氨酸可极显著地提高下丘脑5-HT含量(p<0.01)。研究结果表明,灌胃色氨酸能促进下丘脑5-HT的合成并有效增强动物的抗应激能力。抗应激能力的增强可能与下丘脑5-HT含量的提高有关。     

酸枣仁茯苓粉、大豆肽粉对失眠模型小鼠的改善睡眠作用

目的:研究酸枣仁茯苓粉和大豆肽粉对对氯苯丙氨酸(PCPA)诱导的失眠模型小鼠的睡眠改善作用。方法:180只SPF级雄性BALB/c小鼠,先选取90只随机分为6组(正常对照组,模型对照组,酸枣仁茯苓粉低、中、高剂量组,大豆肽粉组),进行戊巴比妥钠诱导小鼠睡眠实验,另选90只随机分为6组(分组同上),进行旷场实验并测定下丘脑5-羟色胺(5-HT)、5-羟吲哚乙酸(5-HIAA)、去甲肾上腺素(NE)以及海马中的γ-氨基丁酸(GABA)和谷氨酸(Glu)的含量。正常对照组和模型对照组均灌胃无菌水;酸枣仁茯苓粉低、中、高剂量组分别灌胃0.67、1.33、4.00 g/kg BW的受试物;大豆肽粉组灌胃1.15 g/kg BW的受试物,小鼠的灌胃体积均为20 mL/kg BW。睡眠实验共计灌胃36 d,矿场实验共计灌胃37 d。在灌胃的第29和30 d时,除正常对照组外,其余小鼠通过腹腔注射PCPA(350 mg/kg BW)诱导失眠模型,之后两批动物分别再继续灌胃6、7 d。结果:与模型对照组相比酸枣仁茯苓粉能显著缩短戊巴比妥钠诱导的睡眠潜伏期,延长睡眠时间,降低失眠模型小鼠自主活动能力,包括...