针刺足三里对FD胃排空及血清Motilin和Ghrelin的影响

目的:观察针刺穴位足三里对功能性消化不良(Functional Dyspepsia,FD)促进胃排空的治疗作用及对照研究血清Motilin和Ghrelin的变化。方法:采用适度夹尾刺激法复制FD大鼠模型,分别予电针刺激足三里穴位及对照性西药治疗,测定各组大鼠摄食量、体重、胃残留率、碳末推进率及血清Motilin和Ghrelin浓度。结果:模型组、西药组和针刺组摄食量与空白组比较均显著下降;西药组与针刺组胃残留率减少;西药组和针刺组相应的碳末推进率较空白组显著升高;模型组大鼠血清Motilin浓度显著下降;模型组大鼠血清Ghrelin相对升高,但无统计学意义。结论:中医手法针刺足三里对胃肠动力有促进作用,可能与恢复功能性消化不良大鼠的Moti-lin、Ghrelin水平有相关性。

餐后不适综合征患者血浆Motilin与Ghrelin水平的测定

目的探讨血浆中Motilin与Ghrelin含量的变化与餐后不适综合征(Postprandial Distress Syndrome,PDS)型功能性消化不良的关系。方法将32例餐后不适综合征患者进行临床症状积分评价,分为轻、中、重三组。采用ELISA法测定32例餐后不适综合征患者血浆中Motilin与Ghrelin的含量,判断血浆中Motilin和Ghrelin的含量与餐后不适综合征发病及疾病严重程度的关系。结果餐后不适综合征患者血浆中Motilin与Ghrelin水平显著低于正常对照组(P<0.01),且临床症状积分高者明显低于临床症状积分低者(P<0.05)。结论餐后不适综合征患者血浆Motilin与Ghrelin水平降低,并与临床症状的严重程度密切负相关。

The distribution of motilin receptor in the amygdala of rats and its role in migrating myoelectric complex

Objective:To investigate the distribution of the motilin receptor in the amygdala of rats and its role in regulating the duodenal migrating myoelectric complex(MMC).Methods:The distribution of motilin receptor in the amygdala in adult SD rats was detected by immunohistochemistry methods,and the duodenal interdigestive MMC was recorded via the electrodes implanted in the duodenum and analyzed us- ing a multichannel recorder.Results:Motilin receptor was observed in the amygdala of rats.The great amount of motilin receptor was found in the medial amygdaloid nucleus,which was also abundant in the basolateral nucleus but less abundant in the basomedial amygdaloid nucleus,the central amygdaloid nucle- us and the lateral amygdaloid nucleus.The shortening of the duodenal MMC cycle duration and the in- crease of the amplitude and the frequency of phase $ were recorded after motilin receptors being bound with exogenous motilin in the amygdala.The effects could be completely blocked by the subdiaphragmatic vagotomy but not by the intravenous injections of atropine,phentolamine or propranolol.Anti-motilin serum could partially block these effects,and the destruction of the basolateral nucleus of the amygdala had no significant effects on the duodenal MMC.Conclusion:Motilin receptor is present in all the subnu- clei of the amygdala,with the greatest amount of motilin receptor present in the medial amygdaloid nucle- us.Microinjections of motilin in the amygdala can shorten the duodenal MMC cycle duration and increase the amplitude and the frequency of phaseⅢ.These effects might be accomplished via the amygdala-hy- pothalamus-brainstem-vagus pathway,indicating the important role of the amygdala motilin receptor in the duodenal MMC regulation.

Effect of motilin and erythromycin on intracellular Ca2+ mobilization in rat myenteric neurons in culture

Objective: To investigate the effects of motilin and erythromycin on intracellular Ca2+ mobi-lization in cultured myenteric neurons of rats. Methods: The cultured myenteric neurons were identified with immunofluorescence staining technique. Motilin-induced and erythromycin-induced intracellular Ca2+ mobilization was studied in primary cultures of myenteric neurons using the ratiometric Ca2+ indicator Furo3/AM, with a laser confocal microscope. Results: The effects of motilin and erythromycin on intracellular Ca2+ mobilization were as follows: (1)In Hank's solution, 10 -8, 10-7, 10-6 mol/L motilin could elevate intracellular Ca2+ concentration ([Ca2+]i)in a dose-dependent manner. (2) In Hank's solution, 10μg/ ml erythromycin also could induce the elevation of [Ca2+]i. (3) After pretreatment with antibody against the motilin receptor in Hank's solution, the Ca2+ response to erythromycin was almost restricted. Conclusion: It is suggested that motilin could increase [Ca2+]i in myenteric neurons in a dose-dependent manner, and erythromycin may also have this effectivenesss by binding to the motilin receptor.

Expression of motilin in the hypothalamus and the effect of central eryth-romycin on gastric motility in diabetic rats

Objective To investigate the expression of motilin-immunoreactive neurons in the hypothalamus and the effect of central administration of erythromycin （EM） on the regulation of gastric motility in diabetic rats. Methods The motilin immunoreactive neurons in the hypothalamus and the hippocampus were detected by immunohistochemistry with rabbit anti-motilin polyclonal antibody. To measure the gastric motility, force transducers were surgically affixed to the gastric serosa. A microinjection syringe was connected via a plastic tube to an injection cannula, which was connected with a stainless steel guide cannula. The syringe was inserted into the right lateral cerebral ventricle for microinjecting the chemicals. Results Diabetic mellitus was successfully induced in cohorts of rats. Motilin-immunoreactive neurons significantly increased in the paraventricular （PVN） and supraoptic nuclei （SON） of the hypothalamus in the diabetic rats. Intracerebroventricular （i.c.v.） administration of EM, a motilin receptor agonist, stimulated the gastric motility of diabetic rats. EM （91.56 nmol, i.c.v.） dose-dependently increased the amplitude by （174.82±48.62）% （P 〈 0.05）, and increased the frequency by （70.43±27.11）% （P 〈 0.05） in 5 min. The stimulatory effect lasted more than 15 min to the end of the measurement, and can be blocked partially by the prior treatment of motilin receptor antagonist GM-109. Conclusion Motilin-immunoreactive neurons are increased in the PVN and SON of the hypothalamus in diabetic rats. Centrally administered EM may regulate gastric motility by binding to the central motilin receptors, and central motilin might be involved in regulation of gastric motility in diabetic rats.

Simotang enhances gastrointestinal motility,motilin and cholecystokinin expression in chronically stressed mice

AIM:To investigate the effect of Simotang(Decoction of Four Powered Drugs) on gastrointestinal motility,motilin and cholecystokinin expression in chronically stressed mice.METHODS:Forty mice were randomly divided into control group,stress group(model group),mosapride group and Simotang group,10 in each group.A variety of unpredictable stimulations were used to induce chronic stress in mice.Then,the mice were treated with distilled water,mosapride or Simotang for 7 d.Gastric emptying and intestinal propulsion function were detected.Serum level of motilin was measured by enzyme-linked immunosorbent assay.Expression of cholecystokinin(CCK) in intestine,spinal cord and brain of mice was detected by immunohistochemistry and semi-quantitative reverse transcription polymerase chain reaction,respectively.RESULTS:Simotang improved the gastric emptying and intestinal propulsion in chronically stressed mice.Furthermore,the serum motilin level was significantly higher and the expression levels of CCK-positive cells and genes were significantly lower in intestine,spinal cord and brain of Simotang group than in those of model group(P<0.05).No significant difference was found in serum motilin level and expression levels of CCK-positive cells and genes between the mosapride and Simotang groups.CONCLUSION:Simotang enhances the gastrointestinal motility in chronically stressed mice by regulating the serum motilin level and the expression of cholecystokinin.

Sphincter of Oddi hypomotility and its relationship with duodenal-biliary reflux,plasma motilin and serum gastrin

AIM: To detect whether patients with a T tube after cholecystectomy and choledochotomy have duodenal-biliary reflux by measuring the radioactivity of Tc99m-labeled diethylene triamine penta-acetic acid (DTPA) in the bile and whether the patients with duodenal-biliary reflux have sphincter of Oddi hypomotility, by mea-suring the level of plasma and serum gastrin of the patients. Finally to if there is close relationship among sphincter of Oddi hypomotility, duodenal-biliary reflux and gastrointestinal peptides. METHODS: Forty-five patients with a T tube after cholecystectomy and choledochotomy were divided into reflux group and control group. The level of plasma and serum gastrin of the patients and of 12 healthy volunteers were measured by radioimmunoas-say. Thirty-four were selected randomly to undergo choledochoscope manometry. Sphincter of Oddi basal pressure (SOBP), amplitude (SOCA), frequency of con-tractions (SOF), duration of contractions (SOD), duo-denal pressure (DP) and common bile duct pressure (CBDP) were scored and analyzed. RESULTS: Sixteen (35.6%) patients were detected to have duodenal-biliary reflux. SOBP, SOCA and CBDP in the reflux group were much lower than the controlgroup (t = 5.254, 3.438 and 3.527, P < 0.001). SOD of the reflux group was shorter than the control group (t = 2.049, P < 0.05). The level of serum gastrin and plasma motilin of the reflux group was much lower than the control group (t = -2.230 and -2.235, P < 0.05). There was positive correlation between the level of plasma motilin and SOBP and between the level of serum gastrin and SOBP and CBDP. CONCLUSION: About 35.9% of the patients with a T tube after cholecystectomy and choledochotomy have duodenal-biliary reflux. Most of them have sphincter of Oddi hypomotility and the decreased level of plasma motilin and serum gastrin. The disorder of gastroin-testinal hormone secretion may result in sphincter of Oddi dysfunction. There is a close relationship between sphincter of Oddi hypomotility and duodenal-biliary re-flux.

Differences and significance of motilin,vasoactive intestinal peptide and gastrin in blood and gallbladder tissues of patients with gallstones

BACKGROUND: The disorders of gallbladder motility may play an important role in the formation of gallstones. Many neural and hormonal factors and their interactions regulate gallbladder motility and bile flow into the duodenum. Further study in these factors may help to reveal the etiology of gallbladder diseases. This study was undertaken to assess the relationship of the levels of motilin, vasoactive intestinal peptide (VIP) and gastrin in blood and gallbladder tissues with the formation of cholelithiasis. METHODS: The levels of motilin, gastrin and VIP in blood and gallbladder tissues of 36 patients with gallbladder stones, 14 patients with gallbladder polyps, 10 healthy volunteers and 10 patients with common bile duct stones were measured by radioimmunoassay. RESULTS: The level of motilin in plasma and gallbladder tissues of the gallbladder stone group was higher than that of the control and gallbladder polyp groups (P<0.05). The levels of plasma VIP and serum gastrin were much higher than those of the other three groups (P<0.01). The level of VIP in gallbladder tissues was higher than that of the control and gallbladder polyp groups (P<0.01). CONCLUSIONS: The abnormal excretion of hormonal factors is closely related to gallstone formation. The high level of VIP in gallbladder tissues may be an important cause of gallbladder hypomotility. The abnormal level of serum gastrin may be related to the gastrointestinal symptoms of patients with gallstones.

Effects of erythromycin on pressure in pyloric antrum and plasma motilin and somatostatin content in dogs

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猪Motilin和Ghrelin基因克隆及其真核载体的构建与体外表达

目的:克隆Motilin和ghrelin基因,构建表达Motilin的pDsRed-Express-motilin载体和表达ghrelin的pEGFP-ghrelin载体,并检测它们能否在真核细胞中表达及表达量的变化。方法:用RT-PCR方法分别从猪小肠和胃的cDNA上扩Motilin和ghrelin基因片段,并分别克隆到pDsRed-Express-N1载体和pEGFP-N1载体上,用脂质体法转染RIBS2细胞系(来自于肾),并用半定量RT-PCR和荧光成像法检测目的基因的表达。结果:构建了表达Motilin的pDsRed-Express-motilin和表达ghrelin基因的pEGFP-ghrelin载体,并能在真核细胞中超表达目的基因,为进一步相关研究提供了实验基础。

Preclinical and clinical studies on motilin

In the paper,we review our preclinical and clinical studies on motilin (MTL) in recentyears.Our studies have demonstrated for the first time that MTL was widely distributed in hu-man body fluids,fetal cerebrospinal fluid and digestive tract and have revealed that both humanand rabbit Mo cells(MTL-secreting cells)did secret intracavitarily.The endogenous MTL hadan accelerating effect on small bowel transmit time.Wheaten food taking could inhibit the releaseof MTL into plasma,and acupuncturing in certain acupoints could promote its secretion.The ris-es of plasma MTL levels were found in patients with liver cirrhosis,pregnant hypertension syn-drome or in stress state.MTL levels in plasma and gastroduodenal juices of gastric cancer pa-tients were elevated significantly;MTL levels in plasma were decreased in patients with non-ul-cer dyspepsia,bile-regurgitational gastritis or leukemia.We also probed into the phys-iopathological significance of changes in MTL levels in other human body fluids.

Plasma motilin concentration in the second and third trimesters of pregnancy and postpartum

Plasma motilin concentrations were measured in 135 women during the second and third trimesters of pregnancy and 3～5 d after delivery and the results were compared with those of 20 healthy nonpregnant women.The mean plasma motilin concentration (323.96± 125.10 ng/L) in women during the second trimester of pregnancy was lower than in healthy nonpregnant women (366.12±96.23 ng/L) (P<0.05),but that was significantly higher than in women during the third trimester of pregnancy (121.04±27.00 ng/L) (P<0.01);the plasma motilin concentration in women during 3～5d after delivery (443.05±140.79 ng/L) was significantly higher than that in pregnant women (P<0.01).The results showed that pregnancy appears to have a profound inhibitory effect on plasma motilin,and this may partly be responsible for the gastrointestinal hypomotility associated with pregnancy.

Effect of motilin on the contractility of gastric smooth muscle via NO pathway in guinea pigs

This study investigates the gastroprokinetic effects of motilin and erythromycin A （EM-A） and its potential mechanism in guinea pigs Carla porcellus in vitro. Guinea pig stomach strips were mounted under organ baths containing Krebs solution. Motilin, EM-A, Nω-Nitro-L-arginine （L-NNA）, L-arginine （L-AA） were added to the bathing solution in a non-cumulative way. Then the effects of motilin and EM-A was studied during electrical field stimulation （EFS） in the absence and presence of L-NNA and L-AA in the gastric anturm and fundus of guinea pigs. In addition, we observed the co-expression of motilin receptors and neuronal nitric oxide synthase （nNOS） in the gastric myenteric plexus of guinea pigs by fluo-immunohistochemistry. The results showed that the circular muscle tissues of the gastric fundus generated on-relaxations and off-contractions with the frequency of 1 - 16 Hz. The on-responses induced a relaxation, partially mediated by the release of nitric oxide （NO） because addition of L-NNA turned the relaxations into cholinergically mediated contractions. The off-contractions were also cholinergically mediated as they disappeared under non-adrenergic, non-cholinergic （NANC） conditions using atropine and guanethidine. In fundic strips, motilin and EM-A induced on-relaxation and off-contraction and both motilin （1 μmol/L） and EM-A （100 μmol/L） may significantly increased on-response and reduced off-response （P 〈 0.05）. And the effects of motilin on strip responses were significantly enhanced compared with EM-A. The on-responses could be reversed into a cholinergically mediated contraction by addition of NOS inhibitors L-NNA. In contrast, administration of substrate of NOS, L-AA, significantly increased on-relaxations and reduced cholinergic motor responses which were induced by motilin or EM-A. However D-arginine （D-AA） did not change the above response induced by motilin or EM-A. In the antral strips, motilin and EM-A only increased off-contractions. The response to motilin and EM-A in the presence of L-NNA did differ from that obtained with L-NNA alone. It showed that both motilin and EM- A could enhance off-contractions induced by L-NNA （P 〈 0.05）. Immunohistochemistry study showed that motilin receptor immunoreactive positive neurons were co-localized with nNOS positive neurons in the gastric myenteric plexus of the guinea pigs. These results suggested that motilin or EM-A modulates gastrointestinal motility which was mediated by activating gastric nervous and NO pathways in guinea pigs gastro-intestinal tract.

Effects of motilin in the hippocampus on the interdigestive migrating motor complex in rats

Objective ：To explore the effects of motilin in the hippocampus on the interdigestive migrating motor complex （MMC） in rats. Methods： Adult SD rats of either sex were used; 0.5 μl motilin （0. 74 retool/L） was injected into the guide cannula which was stereotaxically implanted into the hippocampus previously. Then the MMC was recorded by a RM6240B multilead physiological recording system. Resuits： （1）MMC characteristics of normal rats＇ duodenum： the frequency of phase Ⅲ was （18. 1±0. 4） bursts/min; the amplitude of phase Ⅲ was （260.5±42.3）μV; the duration of phase Ⅲ was （354.1±21.6） s; MMC cycle duration was （690.2±58.7）s. （2） After motilin was injected into the hippocampus, the duodenal MMC cycle duration was decreased significantly. However, the amplitude of phase Ⅲ and the frequency of phase Ⅲ were increased. But there were no effects on the duration of phase Ⅲ . Frequency of phase Ⅲ percentage change was much more than amplitude of phase Ⅲ percentage change （57.2±2.8 vs 39.3±5. 2）. （3） Effects of motilin in the hippocampus on MMC were completely abolished by subdiaphragmal vagotomy. （4） Effects of motilin in the hippocampus on MMC were unaffected by intravenously injected atropine, phentolamine or propranolol. （5） The anti-motilin serum partly abolished the effects of motilin in the hippocampus on MMC. Conclusion： Motilin in the hippocampus has effects on the duodenal MMC cycle duration, the amplitude of phase Ⅲ and the frequency of phase Ⅲ. Motilin in the hippocampus plays an important role in duodenal MMC.

梅山猪Ghrelin和Motilin基因克隆、结构分析及组织表达谱

分析克隆梅山猪Ghrelin和M otilin基因全编码序列并分析其核苷酸和氨基酸序列,系统研究它们的组织表达分布;用RT-PCR方法克隆梅山猪M otilin和Ghrelin基因全编码序列,并利用生物信息学和分子生物学技术相结合的方法分析它们的核苷酸和氨基酸序列;采用半定量RT-PCR技术检测梅山猪不同组织M otilin和GhrelinmRNA的相对丰度;显示,梅山猪Ghrelin和M otilin基因具有编码区cDNA单核甘酸多肽性(cSNPs);Gh-relin和M otilin基因呈广泛分布,在所取组织中均有不同程度的Ghrelin和M otilinmRNA表达。

基因重复在基因选配(gene co-option)过程中的重要作用:对motilin/ghrelin荷尔蒙基因家族及其受体基因家族的进化研究

原先存在的基因经过一些改良可能获得新的属性从而承担新的功能.在分子遗传的层次,这个过程通常伴随基因重复以及基因重复后旁系同源基因的功能分化.本研究探索了基因重复后荷尔蒙、受体间特异性相互作用的演化形成.尽管对这个问题已有相关研究报道,但针对更多个案的研究能帮助我们更好地理解此前已经提出的进化模型的普遍性,可能还有助于发现新的进化模式.基于生物信息学的手段,结合比较基因组学、系统发育学的方法,本研究揭示,ghrelin前体基因和motilin前体基因是由一个祖先基因重复而来,基因重复发生在羊膜动物与两栖动物刚刚分歧之后.与此形成鲜明对照,它们各自的特异性受体却呈现了很不一样的进化历史.GPR39最先分化出来,而后一个祖先基因经连续的基因重复分化为鱼类特异的进化支A,GHSR和MLNR,基因重复发生在射线鳍鱼(ray-finned fish)与四足动物分化之前.ghrelin/GHSR信号系统的功能从鱼类到哺乳动物的进化过程中始终保守.motilin-MLNR之间的特异性相互作用是荷尔蒙基因重复后,MLN与GHRL基因分化之后,在羊膜动物世系中配体与受体协同进化而形成的.该结果提示,在分子水平上,基于保守的分子元件,新的神经内分泌响应模式能够通过基因重复后的基因选配过程形成.基因重复既节俭又极具创造力,为生物多样性的演化提供了物质基础.

Motilin and ghrelin gene experienced episodic evolution during primitive placental mammal evolution

Motilin and ghrelin,members of a structure-function-related hormone family,play important roles in gastrointestinal function,regulation of energy homeostasis and growth hormone secretion.We observed episodic evolution in both of their prehormone gene sequences during primitive placental mammal evolution,during which most of the nonsynonymous changes result in radical substitution.Of note,a functional obestatin hormone might have only originated after this episodic evolution event.Early in placental mammal evolution,a series of biology complexities evolved.At the same time the motilin and ghrelin prehormone genes,which play important roles in several of these processes,experienced episodic evolution with dramatic changes in their coding sequences.These observations suggest that some of the lineage-specific physiological adaptations are due to episodic evolution of the motilin and ghrelin genes.

motilin,ghrelin基因在哺乳动物进化早期经历插曲式的快速进化

motilin,ghrelin是一对结构相似,功能相关的多肽类荷尔蒙.尽管彼此有所区别,二者都在胃肠消化道行使功能,参与调控能量动态平衡和生长激素的释放.研究发现,编码这两种荷尔蒙前体的基因在哺乳动物进化的早期经历了插曲式的快速进化,期间积累了许多改变氨基酸性质(电荷、极性、及空间容量)的非同义替换.值得注意的是,有功能活性的obestatin多肽荷尔蒙很可能是这一插曲式快速进化后才演化出现的.在哺乳动物进化的早期,发生了一系列复杂的变化,与此同时,我们观察到在相关过程中承担重要功能的motilin,ghrelin基因编码区经历了插曲式的快速进化,提示这可能对世系特异的适应性变化有所贡献.

Gene duplication plays a major role in gene co-option: Studies into the evolution of the motilin/ghrelin family and their receptors

Extant genes can be modified, or 'tinkered with', to provide new roles or new characteristics of these genes. At the genetic level, this often involves gene duplication and specialization of the resulting genes into particular functions. We investigate how ligand-receptor partnerships evolve after gene duplication. While significant work has been conducted in this area, the examination of additional models should help us better understand the proposed models and potentially reveal novel evolutionary patterns and dynamics. We use bioinformatics, comparative genomics and phylogenetic analyses to show that preproghrelin and prepromotilin descended from a common ancestor and that a gene duplication generated these two genes shortly after the divergence of amphibians and amniotes. The evolutionary history of the receptor family differs from that of their cognate ligands. GPR39 diverges first, and an ancestral receptor gives rise to receptors classified as fish-specific clade A, GHSR and MLNR by successive gene duplications occurring before the divergence of tetrapods and ray-finned fish. The ghrelin/GHSR system is maintained and functionally conserved from fish to mammals. Motilin-MLNR specificity must have arisen by ligand-receptor coevolution after the MLN hormone gene diverged from the GHRL gene in the amniote lineage. Conserved molecular machinery can give rise to new neuroendocrine response mechanisms by the co-option of duplicated genes. Gene duplication is both parsimonious and creative in producing elements for evolutionary tinkering and plays a major role in gene co-option, thus aiding the evolution of greater biological complexity.