洞庭湖区社鼠消化道长度和质量的季节变化

对洞庭湖区社鼠（Niviventer confucianus）自然种群四季的消化道各器官的长度和质量进行了测定。结果表明。消化道指标季节变化明显。总体消化道含内容鲜质量、净鲜质量与干质量均具有显著的季节变化。以冬、春季较高。夏、秋季较低。消化道各器官的变化与总消化道不尽相同。其中,以胃的变化相对比较稳定。仅长度的变化达显著水平,以冬季最短,夏、秋季较长。这是动物为适应繁殖季节能量需求而增加摄食量的反应,也与夏秋季食物丰富度有关。小肠、盲肠、大肠的长度和质量指标（内容鲜质量、净鲜质量和干质量）以冬、春季较高。夏、秋季较低。这是该鼠对冬、春季低温和食物匮乏的适应性反应。总体来说。洞庭湖区社鼠为适应夏、秋季繁殖盛期能量需求增加的主要对策是增加摄食量;而为适应冬、春季低温环境和食物数量和质量减少的主要对策是增大消化道。提高消化效率。     

Effect of fasting on the structure and function of the gastrointestinal tract of house sparrows (Passer domesticus)

Starvation is a condition that often affects animals in nature. The gastrointestinal tract is the organ system displaying the most rapid and dramatic changes in response to nutrient deprivation. To date, little is known about starvation phases and effects on the organ morphology and digestive function in small passerine birds. In this study, we determined the phases of starvation and examined the effect of final stage of starvation in the organ morphology and, intestinal histology and enzymatic function in the small intestine. Our results show the three phases of the classical model of fasting in a shorter period of time. The mass of heart, pancreas, stomach, small intestine and liver of long-term fasted birds was reduced between 20 and 47%. The mass decrease in small intestine was correlated with reduction in small intestinal histology: perimeter, mucosal thickness, villus height and width. In contrast, the enzyme activity of sucrase-isomaltase and aminopeptidase-N in enterocytes, all expressed per μg of protein, was higher in long-term fasted birds than fed animals. This suggest that, while autophagy of digestive organs is induced by starvation, consistent with phenotypic plasticity, the activity of sucrase-isomaltase and aminopeptidase-N remains high, probably as an anticipatory strategy to optimize digestion at re-feeding time.     

新疆干旱环境中褐家鼠消化道长度和重量的季节变化及其适应意义

动物消化道的形态与食性、食物质量以及动物对能量的需求密切关系。本文对新疆干旱环境中生存的褐家鼠在自然环境中消化道长度及重量进行了测定,结果表明,家栖的褐家鼠只有总消化道、小肠和大肠的长度有季节差异,冬、春季高于夏、秋季。同时发现捕自阿拉山口的褐家鼠胃长度和干重有季节差异。     

树麻雀代谢率和器官重量在季节驯化中表型的可塑性变化

动物能量代谢的生理生态特征与物种的分布和丰富度密切相关,基础代谢率(BMR)是内温动物能量预算的重要组成部分。北温带的小型鸟类,通过增加产热来适应低温环境。增加BMR的基础之一是中心器官(代谢机器)发生明显的变化。本研究中我们测定了树麻雀(Passermontanus)的BMR、体重和各器官的重量,分析了麻雀各器官的季节性变化及与BMR的关系。方差分析表明:麻雀的BMR存在明显的季节性变化,在冬季和秋季较高。麻雀内部器官的变化同样有明显的季节性,冬季和秋季麻雀的肝脏、心脏、肌胃、小肠、直肠和整体消化道的重量,都有明显的增加。相关分析表明:麻雀的BMR与肝脏、心脏和消化道等内部器官存在明显的相关性。我们的结果验证了“中心限制假说”,即麻雀体内存在着与BMR相关的“代谢机器”,中心器官是提高麻雀BMR的基础之一。     

Effect of fasting in the digestive system: Histological study of the small intestine in house sparrows

In birds and mammals the metabolic response to fasting has been studied and can be characterized by three consecutive phases reflecting metabolic and physiological adjustments. An effective way to minimize energy expenditure during food scarcity is to decrease the mass of the organs. As the digestive system is metabolically expensive to maintain, the small intestine and the liver are the most affected organs. We evaluated the effects of phase III starvation on the mass of the different organs and histological parameters on house sparrows, a small non-migrant bird. In a short period of time (34 h) we observed a larger reduction in the digestive organ mass when compared to the mass of the body and non-alimentary tissues. Furthermore, the intestinal mass was proportionally more reduced than its length and nominal surface area. A reduction on the intestinal mucosal layer also resulted in a shortening of villus (length and thickness) and crypt depth. Moreover, the morphology of the enterocytes changed from cylindrical to cubical, suggesting that the surface exposed to the lumen was conserved. This may indicate an adaptive response to the moment of refeeding. The nominal surface area/body mass remained constant in both groups and several histological parameters were reduced, suggesting that starving induces the atrophy of the small intestine. However, the goblet cells were conserved after fasting indicating a protective tendency.     

蛇雕消化系统形态学研究

对蛇雕消化系统进行了解剖观察,结果表明：蛇雕有锋利的喙,利于撕裂食物;舌根表面具有尖端指向后方的栉状突,可防止食物滑脱;粗大且收缩性较大的食管,嗉囊发达,肌胃不太发达,相对于体长而言肠管较短,但小肠较发达,具有不发达的双侧盲肠。并与部分食植物的鸟类作了比较。     

Seasonal acclimatization of metabolism in Eurasian tree sparrows (Passer montanus)

Acclimatization to winter conditions is an essential prerequisite for survival of small passerines of the northern temperate zone. Changes in photoperiod, ambient temperature and food availability trigger seasonal acclimatization in physiology and behavior of many birds. In the present study, seasonal adjustments in several physiological, hormonal, and biochemical markers were examined in wild-captured Eurasian tree sparrows (Passer montanus) from the Heilongjiang Province in China. In winter sparrows had higher body mass and basal metabolic rate (BMR). Consistently, the dry mass of liver, heart, gizzard, small intestine, large intestine and total digestive tract were higher in winter than in that in summer. The contents of mitochondrial protein in liver, and state-4 respiration and cytochrome c oxidase (COX) activity in liver and muscle increased significantly in winter. Circulating level of serum triiodothyronine (T₃) was significantly higher in winter than in summer. Together, these data suggest that tree sparrows mainly coped with cold by enhancing thermogenic capacities through increased organ masses and heightened activity of respiratory enzymes activities. The results support the view that prominent winter increases in BMR are manifestations of winter acclimatization in tree sparrows and that seasonal variation in metabolism in sparrows is similar to that in other small temperate-wintering birds.     

小鼠肠道组织结构在低温环境下的适应性调整

对长期(3个月)处于低温条件下的小鼠各肠道组织结构的适应性变化进行了比较研究。低温驯化后小鼠的体重(P0.05)、消化道总长度(P0.05)、小肠长度(P0.01)和盲肠长度(P0.05)显著增加,而十二指肠肠腔隙截面积未发生显著变化,提示小鼠的肠腔隙体积在低温环境下明显增加。同时,低温驯化小鼠十二指肠的肠道和肠壁组织截面积均显著降低(P0.05),而其绒毛高则显著增加(P0.001),提示其黏膜层厚度增加,而黏膜下层结构趋于萎缩,表明小鼠肠道组织的形态结构为应对低温条件已经产生了适应性调整,即通过增加消化道的长度和营养物质的吸收面积来增加食物摄取量、食物吸收速率和吸收效率等,进而满足低温条件下小鼠能量需求的增加。相比之下,低温鼠的胃大小、盲肠重量、大肠长度与重量、直肠组织结构均未产生显著变化,暗示这些肠道结构对外界温度变化的敏感性相对较低。研究结果表明,小型哺乳类主要通过增大消化道长度和吸收面积来提高其消化效率,通过改变消化道的形态和结构来提高消化和吸收效率,以便更好地去适应环境温度变化而导致的能量需求变化。     

Digestive flexibility in females of the subterranean rodent ctenomys talarum in their natural habitat

We studied the occurrence of digestive strategies at different levels in females of the subterranean herbivorous rodent Ctenomys talarum living in their natural habitat. We determined the dimensions of different parts of the gastrointestinal tract and organs along as the activity of key digestive enzymes(sucrase, maltase and N-aminopeptidase) in small intestine in females seasonally caught. Females of C. talarum did not show seasonal variations in the mass of the different parts of the gastrointestinal tract. In nonreproductive females large intestine was longer in autumn, whereas reproductive females did not show seasonal variations in the length of the different parts of the gut. Females of C. talarum exhibited a high sucrose, maltase and N-aminopeptidase activity in small intestine, although these activities were higher in small intestine of females caught in autumn (nonreproductive) than in females caught in winter (reproductive). The results show that C. talarum females exhibit characteristics in the gut at the morphological and biochemical level, which could represent digestive strategies to face the constraints imposed by their costly particular way of life.     

纵纹腹小鸮Athene noctua消化系统形态学研究

本文对纵纹腹小鸮Athene noctua的消化系统形态学结构进行了较为系统的解剖与观察。结果表明：纵纹腹小鹗舌根表面具有尖端指向后方的栉状突,可防止食物的滑脱;无嗉囊,食管相对比较宽阔,且粘膜褶发达;肌胃的结构适于其食肉特性,壁薄,内有粘膜褶,伸缩性较大,其作用除消化外,尚有储食功能;小肠发达;具两条末端膨大的盲肠。文中还与部分鸟类作了比较。     

社鼠和褐家鼠消化道长度和重量的季节变化

测定了浙江金华的社鼠和褐家鼠消化道长度和重量的季节变化。野生社鼠消化道各器官无论长度不审重量都有明显季差异,在寒冷的冬季具有相对较大的小肠、大肠、盲肠、雄性社鼠的消化道长度在秋季由于食物条件的改善而明显下降,但雌性社鼠由于在秋季仍有繁殖负担,其消化道长度下降不明显,而家栖的褐家鼠只有总消化道、小肠和大肠的长度有季节差异,冬、春季高于夏、秋季。消化道形态季节变化与温度、食物条件和繁殖有关。     

Morphometrics of the avian small intestine compared with that of nonflying mammals: a phylogenetic approach

Flying animals may experience a selective constraint on gut volume because the energetic cost of flight increases and maneuverability decreases with greater digesta load. The small intestine is the primary site of absorption of most nutrients (e.g., carbohydrates, proteins, fat) in both birds and mammals. Therefore, we used a phylogenetically informed approach to compare small intestine morphometric measurements of birds with those of nonflying mammals and to test for effects of diet within each clade. We also compared the fit of nonphylogenetic and phylogenetic models to test for phylogenetic signal after accounting for effects of body mass, clade, and/or diet. We provide a new MATLAB program (Regressionv2.m) that facilitates a flexible model-fitting approach in comparative studies. As compared with nonflying mammals, birds had 51% less nominal small intestine surface area (area of a smooth bore tube) and 32% less volume. For animals <365 g in body mass, birds also had significantly shorter small intestines (20%-33% shorter, depending on body mass). Diet was also a significant factor explaining variation in small intestine nominal surface area of both birds and nonflying mammals, small intestine mass of mammals, and small intestine volume of both birds and nonflying mammals. On the basis of the phylogenetic trees used in our analyses, small intestine length and nominal surface area exhibited statistically significant phylogenetic signal in birds but not in mammals. Thus, for birds, related species tended to be similar in small intestine length and nominal surface area, even after accounting for relations with body mass and diet. A reduced small intestine in birds may decrease the capacity for breakdown and active absorption of nutrients. Birds do not seem to compensate for reduced digestive and absorptive capacity via a longer gut retention time of food, but we found some evidence that birds have an increased mucosal surface area via a greater villus area, although not enough to compensate for reduced nominal surface area. We predict that without increased rate of enzyme hydrolysis and/or mediated transport and without increased passive absorption of water-soluble nutrients, birds may operate with a reduced digestive capacity, compared with that of nonflying mammals, to meet an increase in metabolic needs (i.e., a reduced spare capacity).     

黑斑侧褶蛙消化道重量及长度的性别和季节差异

消化道是联系脊椎动物能量摄入和能量支出之间关系的纽带,其重量和长度对外界环境具有高度的敏感性和弹性(flexibility)。以黑斑侧褶蛙(Pelophylax nigromaculata)为研究对象,测定了山东聊城地区2012年夏季(16只,8♀/8♂)、秋季(19只,9♀/10♂)及翌年春季(17只,8♀/9♂)其体重、体长、胴体湿重和干重系数、总消化道及各段(食道、胃、小肠和大肠)的湿重、干重和长度系数的性别和季节差异(双因素方差分析),对有性别差异的指标,用单因素方差分析分别比较了雌、雄蛙的季节差异。结果显示,1)雌蛙的体重、体长均高于雄蛙,都在秋季最高,春季或夏季最低;雄蛙的胴体湿重系数高于雌蛙,夏季高于秋季;胴体干重系数既无性别差异,也无季节差异。2)除食道湿重系数无性别差异外,雌蛙总消化道及各段的湿重系数均高于雄蛙;除胃湿重系数无季节差异外,春季或秋季的总消化道及各段的湿重系数都高于夏季;雌蛙的总消化道干重和胃干重系数高于雄蛙,食道、小肠和大肠的干重系数无性别差异,所有的干重系数均无季节性差异。3)除雌蛙的大肠长系数高于雄蛙外,总消化道及各段的长度系数均无性别差异,春季和秋季的总消化道长、食道长及胃长系数均高于夏季,小肠长和大肠长系数均无季节性差异。结果表明,随着季节更替,黑斑侧褶蛙消化道各段的重量和长度表现出一定的弹性特征,这与各器官的功能及其生活环境的多样性是相适应的。     

Histochemical changes in the fowl small intestine associated with enhanced absorption after feed restriction

Summary The morphology and histochemical enzyme pattern of the small intestine were investigated in chicks undergoing feed restriction. Corresponding intestinal sites were compared in both restricted birds and in control birds under normal feeding. Intestines from the restricted birds showed some atrophy, the villi being slightly shorter and thinner than normal after eight days restriction, and there was an increase in the activity of alkaline phosphatase, leucine naphthylamidase, acid phosphatase, -glucuronidase, non-specific esterase and succinic dehydrogenase in the absorptive cells.The significance of these findings has been discussed in relation to the enhanced absorptive capacity of the intestine during feed restriction and its similarity to other dietary stress factors that produce enhanced absorption. Possible mechanisms for the production of such mucosal changes have been considered. It was concluded that the enhanced absorption of nutrients in semi-starved animals is correlated with increased mucosal enzyme activities.     

长爪沙鼠肠道5-羟色胺细胞密度的季节变化

为探讨季节性环境对长爪沙鼠肠道5-羟色胺(5-hydroxytryptamine,5-HT)细胞密度动态的影响,于2003
年11 月(冬季)和2004 年7 月(夏季),采用卵白素-生物素-过氧化物酶复合物(avidin-biotin-peroxidase complex,
ABC)免疫组织化学法,对其肠道5-HT 细胞进行了定位研究。结果显示:5-HT 细胞主要分布于肠上皮基
底部和肠腺上皮中,多呈圆形或椭圆形,少数呈长棒状、锥体形或不规则形,其形态学特征无季节性差异。冬
季在小肠密度最高,十二指肠、盲肠和直肠其次,结肠最低;夏季在小肠和十二指肠密度最高,其它各段密度
相似,这可能与其食物质量的季节性变化有关。除十二指肠和结肠外,冬季肠道各段的密度都高于夏季,这有
利于提高处理和消化食物的能力,是对冬季食物质量和摄食量增加的适应。5-HT 细胞的形态学特征和季节动态
说明,长爪沙鼠肠道在细胞水平上可对环境条件的变化产生反应,具有适应性调节的能力。     

Protease and Amylase in the digestive tract ofBarbus paludinosus

1. Protease and amylase activity in the digestive system ofBarbus paludinosus Peters (Pisces, Cyprinidae) has been investigated.
2. Chromatographic analysis showed seven amino acids to be present in both the anterior and posterior intestine. Only leucine, phenylalanine, valine, glycine and aspartic acid were positively identified.
3. In the anterior intestine chromatography revealed two sugars, but only one in the posterior intestine which was identified as glucose.
4. The pH of the intestinal fluid was found to be 5.8 and 7.8 for the fore and hind gut respectively, This correlates well with the enzyme pH optima found in in vitro experiments.
5. Protease and amylase activity was found throughout the digestive tract. Maximum proteolytic activity being present in the anterior intestine. Amylase activity is similar in both regions of the gut.
6. Correlation between the digestive enzymes and the fishes diet is briefly discussed.

     

大绒鼠消化道形态的季节变化

为探讨栖息于横断山地区大绒鼠(Eothenomys miletus)的消化道特征与环境之间的适应关系,对自然环境中大绒鼠消化道各项指标进行了测定.实验分别测定了不同季节大绒鼠胃、小肠、大肠、盲肠的长度,及其含内容物重、去内容物重、干组织重.结果表明,大绒鼠消化道特征存在季节性变化,随着温度降低、食物质量下降,大绒鼠的小肠、盲肠长度增加;各器官重量均在6月份最大;大绒鼠在低温、食物质量下降、繁殖等胁迫因子作用下,通过增加食物摄入、调节消化道形态来满足能量需求的增加,维持正常的生理机能.大绒鼠的消化道在不同季节中表现出的变化模式,与其低纬度高海拔、年平均温度较低的生存环境有关,从一方面反映了该物种在温度胁迫下的生存机制和适应对策.     

根田鼠消化道长度和重量的变化及其适应意义

动物消化道的形态与食性、食物质量以及动物量的需求密切相关。本文对青海高原地区的根田鼠在自然环境中消化道各器官的长度及重量进行了测定,结果显示总消化道及各器官（胃、小肠、大肠和盲肠）的长度,含内容物重（鲜重和干重）在各物侯期间具显著的变化,各项指标均于环境条件较好的植物生长盛期最低,于条件较差（食物纤维素含量高及低温）的植物枯黄期或返青期较高。各器官所反应程度不同,其中小肠的反应最为强烈,表明消化道     

甘肃鼢鼠适应地下生活的消化道形态和结构的季节可塑性

甘肃鼢鼠(Myospalax cansus)是终生营地下生活的小型哺乳动物,为研究其在自然环境中的消化对策和调节,探讨地下鼠消化道的可塑性,测定了不同季节消化道各器官长度、重量及各器官的组织结构。结果显示,甘肃鼢鼠总消化道长度、各消化器官长度和含内容物总重量无显著季节差异。总消化道及各器官的鲜重和干重多在春季最高,含内容物重量于秋季较高。组织结构有显著性季节变化,黏膜层和肌层的厚度及肠道绒毛高度春季最高。结果表明,甘肃鼢鼠主要依靠肠道重量的增加和组织结构的可塑性变化来适应相对稳定的地下生活环境,无需增加消化器官长度满足其能量需求。