三峡水库香溪河鱼类资源现状及渔业管理建议

于2012—2013年对香溪河鱼类组成及资源量进行了周年季度调查,结合历史资料,分析了三峡水库成库前后香溪河鱼类资源的变动情况,以期为保护和利用三峡库区的鱼类资源提供依据。共采集鱼类48种,隶属于3目8科35属,以湖泊定居性鱼类为主;发现香溪河鱼类优势种是光泽黄颡鱼、鳙、鲢、达氏鲌、贝氏、大眼鳜、翘嘴鲌、瓦氏黄颡鱼、银、蛇;肉食性鱼类(达氏鲌、翘嘴鲌、大眼鳜等)占总渔获量的31.54%,生物量相对较高;对单位捕捞努力渔获量的调查显示,夏季日均单船渔获量最高,达到(69.45±46.61)kg/(船·d)。与历史记录比较,三峡水库成库后,香溪河的鱼类群落组成已经发生了显著变化,湖泊定居性鱼类成为优势种群。基于此次调查结果,文章提出了禁渔期调整、小型鱼类资源利用和肉食性鱼类合理放养等渔业管理建议。     

三峡库区木洞江段翘嘴鲌早期生长特征研究

2013年9—10月在三峡库区木洞江段采集翘嘴鲌(Culter alburnus)幼鱼,摘取微耳石进行耳石微结构分析,推算了翘嘴鲌幼鱼的日龄及孵化日期,探讨其早期生活史阶段的生长特征。结果显示,采集97尾翘嘴鲌幼鱼,体长范围为40—98 mm。翘嘴鲌幼鱼的微耳石形状为不规则扁椭球形,耳石横截面磨片上具有一个核和一个原基。耳石原基的直径为11.6—27.8μm,平均值为(18.6±3.8)μm。耳石核中心到第一个生长轮的距离为(13.0±4.7)μm。翘嘴鲌幼鱼的日龄为44—104d,推算其孵化日期为2013年6月9日至8月17日,高峰期为2013年7月9日至7月22日。耳石半径与体长、日龄与体长之间均呈显著的线性关系(P0.05)。耳石日轮宽度随着日龄的增加不断变化显示,三峡库区翘嘴鲌早期生活史阶段的生长速率不断变化,日平均生长率为0.774 mm/d。     

武昌东湖蒙古红鲌和翘嘴红鲌的食性及其种群控制问题的研究

本文主要报道蒙古红鲌和翘嘴红鲌对放养鳙、鲢鱼种的危害性及控制其种群发展的途径。通过肠道内食物的检查,发现不同大小的蒙古红鲌和翘嘴红鲌与所吞食“家鱼”鱼种规格的大小有一定的相关,根据所得的数据分别求出这两种凶猛鱼的全长与被吃鱼种全长的迥归方程式及95％的可信限,确定不同大小的蒙古红鲌和翘嘴红鲌危害不同规格鱼种的范围。并通过对东湖这两种凶猛鱼种群长度的调查,提出鳙、鲢鱼种放养的合理规格。蒙古红鲌和翘嘴红鲌全年各月的摄食强度随着水温的不同和生殖季节的来临而有所改变,根据这种情况,对于什么时间放养鱼种较为有利也进行了探讨。从两种鱼的食物组成和摄食强度来看,它们对鳙、鲢的危害性是很明显的。为了遏制其种群发展,进行了围捕产卵群体、药物杀卵和投放棕榈皮鱼巢诱其产卵等试验。试验证明,在生殖季节当它们大量集群时进行围捕,效果较为显著。近年来这两种凶猛鱼的产量和种群的长度组成都有所下降。文中附有不同长度的蒙古红鲌和翘嘴红鲌吞食不同鳙鱼种的范围表,供有关单位参考。     

武昌东湖蒙古红(鱼白)和翘嘴红(鱼白)的食性及其种群控制问题的研究

本文主要报道蒙古红鲌和翘嘴红鲌对放养鳙、鲢鱼种的危害性及控制其种群发展的途径。通过肠道内食物的检查,发现不同大小的蒙古红鲌和翘嘴红鲌与所吞食“家鱼”鱼种规格的大小有一定的相关,根据所得的数据分别求出这两种凶猛鱼的全长与被吃鱼种全长的迴归方程式及95%的可信限,确定不同大小的蒙古红鲌和翘嘴红鲌危害不同规格鱼种的范围。并通过对东湖这两种凶猛鱼种群长度的调查,提出鳙、鲢鱼种放养的合理规格。蒙古红鲌和翘嘴红鲌全年各月的摄食强度随着水温的不同和生殖季节的来临而有所改变,根据这种情况,对于什么时间放养鱼种较为有利也进行了探讨。从两种鱼的食物组成和摄食强度来看,它们对鳙、鲢的危害性是很明显的。为了遏制其种群发展,进行了围捕产卵群体、药物杀卵和投放棕榈皮鱼巢诱其产卵等试验。试验证明,在生殖季节当它们大量集群时进行围捕,效果较为显著。近年来这两种凶猛鱼的产量和种群的长度组成都有所下降。文中附有不同长度的蒙古红鲌和翘嘴红鲌吞食不同鳙鱼种的范围表,供有关单位参考。     

斑鳜种内遗传多态性以及与翘嘴鳜的分子鉴别

鳜鱼属鲈形目、酯科、酯亚科,种类繁多。有长体鳜、波纹鳜、斑鳜、无斑鳜、暗鳜、大眼鳜、翘嘴鳜等,是淡水鱼类中的名贵鱼类[1],肉质纯白细嫩,味道鲜美可口。对其报道多集中在水产养殖方面,而从遗传学和DNA角度进行分析的报道较少,本文用RAPD技术对斑鳜(Siniperca scherzeriSte     

四种鲤科鱼肠道中高血糖素免疫活性内分泌细胞的研究

应用过氧化物酶抗过氧化物酶(PAP)免疫组织化学技术,用4种哺乳动物中培育出的抗血清对草鱼、青鱼、鲤和翘嘴红鲌4种鲤科鱼的肠内分泌细胞进行免疫、组织化学的鉴别和定位.证实了高血糖素免疫活性内分泌细胞在草鱼整个肠道中均呈阳性反应;在鲤、青鱼前肠中仅有少量阳性反应;在翘嘴红鲌肠道中未见阳性反应。胃蛋白酶原(Pepsinogen)、凝乳酶(Prochymosin)和神经特异烯醇酶(Neuron specific enolase)3种抗血清在4种鱼的肠道中均未发现阳性反应.本文重点描述草鱼高血糖素免疫活性内分泌细胞在肠道各段的分布,密度及其形态学特征,还就其可能的生理功能与草食性哺乳动物胃肠道中该类内分泌细胞进行比较和讨论。     

“太湖鲂鲌”及其亲本肌肉营养成分的分析与评价

为评价新型杂交鱼“太湖鲂鲌”(翘嘴鲌Culter alburnus♀×三角鲂Megalobrama terminalis♂)的肌肉营养价值, 采用生化测定法比较分析了“太湖鲂鲌”、翘嘴鲌和三角鲂的肌肉营养成分, 结果表明: (1)“太湖鲂鲌”肌肉水分含量显著低于翘嘴鲌和三角鲂(P<0.05), 而肌肉粗蛋白质含量较高(P<0.05)。(2)“太湖鲂鲌”的必需氨基酸(EAA)含量显著高于三角鲂(P<0.05); 3种鱼的第一限制性氨基酸均为含硫氨基酸(蛋氨酸+胱氨酸)。(3)“太湖鲂鲌”肌肉脂肪酸中的不饱和脂肪酸(UFA)含量显著高于翘嘴鲌和三角鲂(P<0.05)。(4)3种鱼肌肉矿物质元素铁、铜、锰、锌含量均无显著差异(P>0.05)。综上所述, “太湖鲂鲌”肌肉营养继承并综合了双亲的优良性状, 是一种富含蛋白质、EAA和UFA的优良养殖品种, 具有推广价值。     

十二种淡水鱼类血红蛋白与窒息点的相关分析

为了解鱼类耐低氧能力与血红蛋白的相关性,测定了大口鲇(Silurus meridionalis)、乌鳢(Channa argus)、加洲鲈(Micropterus salmoides)、斑点叉尾(Ictalurus punetaus)、黄颡鱼(Pelteobagrus fulvidraco)、泥鳅(Misgurnus anguillicaudatus)、黄鳝(Monopterus albus)、草鱼(Ctenopharyngodon idellus)、翘嘴红鲌(Erythroculter ilishaeformis)、鲢(Hypophthalmichthys molitrix)、鳙(Aristichthys nobilis)和鳜(Siniperca chuatsi)12种鱼的窒息点,同时分别对其血红蛋白进行电泳分析。12种鱼的血红蛋白电泳图谱各不相同,大口鲇、乌鳢、加洲鲈、斑点叉尾、黄颡鱼、泥鳅、黄鳝、草鱼、翘嘴红鲌、鲢、鳙、鳜的血红蛋白分子量加权平均值分别为92.93、93.91、94.61、97.78、98.66、98.95、101.34、104.10、104.73、108.06、108.23、111.84 ku,窒息点分别为0.15、0.18、0.30、0.27、0.36、0.26、0.24、0.39、0.42、0.51、0.46、0.59 mg/L。分析发现,这12种鱼类的窒息点与血红蛋白分子量呈极显著正相关(r=0.925,P0.01)。     

学习记忆通路抑制剂T-5224和KN-62对翘嘴鳜c-fos及味觉受体t1r1表达的影响

为探究翘嘴鳜 (Siniperca chuatsi) 中原癌基因c-Fos (proto-oncogene c-Fos)对摄食相关的味觉受体t1r1(taste receptor type 1 member 1, t1r1)的调控作用, 研究采用学习记忆通路相关抑制剂T-5224、KN-62处理鳜脑细胞, 通过不同浓度抑制剂处理发现T-5224对c-fos的起负调控作用而KN-62对c-fos起正调控作用, 同时筛选出适合的处理时间及浓度。30 μmol/L T-5224处理24h, 鳜脑中c-fos及t1r1的mRNA表达显著降低(P<0.05), 而200 nmol/L KN-62处理2h, 鳜脑中c-fos及t1r1的mRNA表达却极显著升高(P<0.05)。此外, 研究还分析了抑制剂处理翘嘴鳜脑细胞后, t1r1基因DNA甲基化变化。然而在两种抑制剂处理后, 鳜脑中t1r1的甲基化水平无显著变化(P>0.05)。以上结果说明, 翘嘴鳜脑细胞味觉受体t1r1转录水平变化, 可能是通过学习记忆因子c-fos基因调控, 而c-fos可能通过其他途径调控t1r1的转录, 但不是DNA甲基化。同时为翘嘴鳜驯化后摄食偏好变化提供理论依据。     

翘嘴红鲌雌雄基因组差异及太湖野生群体遗传多样性现状的AFLP分析

为发展翘嘴红鲌Erythroculter ilishaeformis(Bleeker)性别控制育种和单性养殖技术, 利用AFLP技术对翘嘴红鲌太湖野生群体中雌、雄各20个个体的基因组进行了遗传多样性和雌雄差异分析。用筛选出的8对AFLP多态性引物在太湖野生群体基因组中共检测到319个位点, 其中多态性位点185个。通过对所有多态性位点在个体中的分布进行分析, 发现一个只在雄性个体中稳定存在、在雌性个体中缺失的差异位点。在人工雌核发育翘嘴红鲌群体只有雌性个体, 其基因组中也检测不到该差异位点的存在。这些结果表明翘嘴红鲌性别分化可能受到严格的遗传调控, 该差异位点是雄性特有的性别分子标记。翘嘴红鲌太湖野生群体目前的多态位点比率P=57.99%, 观测等位基因数N_a=1.5799±0.4943, 有效等位基因数N_e=1.3859±0.3971, Shannon’s信息指数I=0.3221±0.2987。这些统计分析结果与10年前对该群体的AFLP研究结果(P=51.21%, N_a=1.512±0.500,N_e=1.252±0.371,I=0.218±0.275)相比没有显著差别(P>0.05), 说明该群体目前还具有适度的遗传多样性。     

鳜类系统发育的线粒体Cytb基因全序列分析

测定了鳜、大眼鳜、斑鳜、暗鳜、波纹鳜、长体鳜、中国少鳞鳜等7种鳜类12个个体的线粒体细胞色素b基因全序列。结合GenBank中的同源序列,共分析了9种鳜类的系统发育关系。序列分析表明,鳜属鱼类属内种间的遗传距离(0.015～0.093)明显小于少鳞鳜属鱼类属内种间的遗传距离(0.152～0.178)。在分子系统发育树上,长体鳜与鳜属的鳜、大眼鳜、斑鳜、波纹鳜、暗鳜聚合成一分支,少鳞鳜属的种类聚成另一分支;支持将长体鳜归入鳜属,鳜类分为鳜属和少鳞鳜属等二个属的分类处理。在鳜属鱼类中,鳜和大眼鳜亲缘关系十分密切;斑鳜与波纹鳜亲缘较近;长体鳜与鳜属其它5个种的亲缘关系较远。在少鳞鳜属鱼类中,中国少鳞鳜和日本少鳞鳜的亲缘关系较远,韩国少鳞鳜的系统位置较不明确。鳜类的单系性及其鳜类的系统位置仍有待进一步研究。     

两种(鱼尝)科鱼类在长江和珠江流域Cytb基因序列变异性分析

采用PCR技术获得了长江和珠江流域的两种鲿科鱼类1137bp Cytb基因的片段,进行了序列测定,并用Mega软件进行了序列分析。研究发现两种鲿科鱼类的全序列从第十位碱基起有一个三联体密码子的缺失,推测为鲇形目鱼类Cytb序列所特有特征。黄颡鱼和大鳍鳠种群间的序列差异分别为0．4％和1．6％,介于一般淡水鱼类mtDNA种内序列的变异范围,而高于洄游鱼类序列变异。黄颡鱼属和鲮属Cytb基因序列间的差异为17．6％-18．0％,大大高于种间的序列差异率,也从分子水平上证实了二者属级分类单元的有效性。依据分子进化速率推测,长江和珠江两水系间大鳍鳠的分歧时间为距今27万年左右的更新世中晚期,黄颡鱼的分歧时间在距今7万年左右的更新世末期。推测造成二者有着不同分歧时间的可能原因是：大鳍鳠属暖水性鱼类,在第四纪冰川期间,由于全球性气候变冷,大鳍鳠退至长江以南,并在各水系间产生隔离,各自独立分化至今。而黄颡鱼具有很强的适应性,在第四纪数次冰川期间可能进行过广泛的交流。     

Phylogenetic studies of three sinipercid fishes (Perciformes: Sinipercidae) based on complete mitochondrial DNA sequences

The sinipercids are a group of 12 species of freshwater percoid fish endemic to East Asia and their phylogenetic placements have perplexed generations of taxonomists. We cloned and sequenced the complete mitochondrial DNA (mtDNA) of three sinipercid fishes (Siniperca chuatsi, S. kneri, and S. scherzeri) to characterize and compare their mitochondrial genomes. The mitochondrial genomes of S. chuatsi, S. kneri, and S. scherzeri were 16,496, 17,002, and 16,585?bp in length, respectively. The organization of the three mitochondrial genomes is similar to those reported from other fish mitochondrial genomes, which contains 37 genes (13 protein-coding genes, 2 ribosomal RNAs, and 22 transfer RNAs) and a major non-coding control region. Among the 13 protein-coding genes of all the three sinipercid fishes, three reading-frame overlaps were found on the same strand. There is an 81-bp tandem repeat cluster at the end of CSB-3 in the S. scherzeri control region. The complete mitochondrial genomes of the three sinipercids should be useful for the evolutionary studies of sinipercids and other vertebrate species.     

Development of endocrine pancreatic islets in embryos of the grass snake Natrix natrix (Lepidosauria,Serpentes)

Differentiation of the pancreatic islets in grass snake Natrix natrix embryos, was analyzed using light, transmission electron microscopy, and immuno-gold labeling. The study focuses on the origin of islets, mode of islet formation, and cell arrangement within islets. Two waves of pancreatic islet formation in grass snake embryos were described. The first wave begins just after egg laying when precursors of endocrine cells located within large cell agglomerates in the dorsal pancreatic bud differentiate. The large cell agglomerates were divided by mesenchymal cells thus forming the first islets. This mode of islet formation is described as fission. During the second wave of pancreatic islet formation which is related to the formation of the duct mantle, we observed four phases of islet formation: (a) differentiation of individual endocrine cells from the progenitor layer of duct walls (budding) and their incomplete delamination; (b) formation of two types of small groups of endocrine cells (A/D and B) in the wall of pancreatic ducts; (c) joining groups of cells emerging from neighboring ducts (fusion) and rearrangement of cells within islets; (d) differentiated pancreatic islets with characteristic arrangement of endocrine cells. Mature pancreatic islets of the grass snake contained mainly A endocrine cells. Single B and D or PP–cells were present at the periphery of the islets. This arrangement of endocrine cells within pancreatic islets of the grass snake differs from that reported from most others vertebrate species. Endocrine cells in the pancreas of grass snake embryos were also present in the walls of intralobular and intercalated ducts. At hatching, some endocrine cells were in contact with the lumen of the pancreatic ducts.     

诱导大鳍鱯和长吻鮠排卵过程中血清GTH水平的变化

繁殖期从嘉陵江收集性成熟的大鳍■ 和长吻 野生亲鱼,用Ｌｉｎｐｅ方法（即ＬＨＲＨ－Ａ加多巴胺Ｄ２受体拮抗剂地欧酮）或传统的ＬＨＲＨ—Ａ加脑垂体的方法进行催产,定时取血样,用放射免疫方法测定催产过程中血清ＧＴＨ水平的变化,进一步证实鲇形目鱼类ＧＴＨ的分泌受到下丘脑分泌的促性腺激素释放激素ＧｎＲＨ和多巴胺的双重调节;排卵和产卵也是以血清ＧＴＨ的急剧升高为先导的,而最终能否排卵还有赖于血清ＧＴＨ峰是否超过“排卵阈值”。尽管催产后的大鳍 和长吻 雄鱼血清ＧＴＨ水平也有一个高峰出现,但血清ＧＴＨ水平升高幅度都大大低于雌鱼,这种现象在硬骨鱼类可能具有普遍性。     

Fetoacinar pancreatic protein in the developing human pancreas

The distribution of the 110-kilodalton fetoacinar pancreatic (FAP) protein was examined in 56 pancreases obtained from human embryos and fetuses (ranging 6 from weeks of gestation to full term) and 10 normal adult pancreases. This recently discovered protein is a concanavalin-A-binding glycoprotein that is specific for acinar cells of the pancreas. Using a murine monoclonal antibody for either immunoperoxidase or immunofluorescence procedures, FAP-protein expression was not found in embryos at less than 9 weeks of gestation. At 9-10 weeks, a clear staining was observed in the terminal portions of dilated buds in primitive pancreatic tubular structures (i.e., the site of the first development of the future acinus). At 11-12 weeks, acinar structuration began, and FAP-protein expression increased as shown by the higher number of stained acini and the greater staining intensity. Maximal expression occurred at 15-22 weeks and then gradually decreased; from 28 to 32 weeks until full term, the pancreas was almost negative for this protein. In the adult pancreases, the protein was either absent or only present in acinar cells surrounding the islets of Langerhans. The pancreatic ducts and endocrine cells remained negative throughout gestation and in adults. FAP-protein thus appears to be a marker of acinar-cell differentiation. Its function remains unknown at present. Its close association with the growth and development of the pancreas together with the fact that, in a previous study, it was found to be re-expressed in pancreatitis and in cancer, suggest that it may play a role in developmental regenerative and neoplastic processes in the pancreas.     

Glucokinase activation repairs defective bioenergetics of islets of Langerhans isolated from type 2 diabetics

It was reported previously that isolated human islets from individuals with type 2 diabetes mellitus (T2DM) show reduced glucose-stimulated insulin release. To assess the possibility that impaired bioenergetics may contribute to this defect, glucose-stimulated respiration (Vo(2)), glucose usage and oxidation, intracellular Ca(2+), and insulin secretion (IS) were measured in pancreatic islets isolated from three healthy and three type 2 diabetic organ donors. Isolated mouse and rat islets were studied for comparison. Islets were exposed to a "staircase" glucose stimulus, whereas IR and Vo(2) were measured. Vo(2) of human islets from normals and diabetics increased sigmoidally from equal baselines of 0.25 nmol/100 islets/min as a function of glucose concentration. Maximal Vo(2) of normal islets at 24 mM glucose was 0.40 ± 0.02 nmol·min(-1)·100 islets(-1), and the glucose S(0.5) was 4.39 ± 0.10 mM. The glucose stimulation of respiration of islets from diabetics was lower, V(max) of 0.32 ± 0.01 nmol·min(-1)·100 islets(-1), and the S(0.5) shifted to 5.43 ± 0.13 mM. Glucose-stimulated IS and the rise of intracellular Ca(2+) were also reduced in diabetic islets. A clinically effective glucokinase activator normalized the defective Vo(2), IR, and free calcium responses during glucose stimulation in islets from type 2 diabetics. The body of data shows that there is a clear relationship between the pancreatic islet energy (ATP) production rate and IS. This relationship was similar for normal human, mouse, and rat islets and the data for all species fitted a single sigmoidal curve. The shared threshold rate for IS was ～13 pmol·min(-1)·islet(-1). Exendin-4, a GLP-1 analog, shifted the ATP production-IS curve to the left and greatly potentiated IS with an ATP production rate threshold of ～10 pmol·min(-1)·islet(-1). Our data suggest that impaired β-cell bioenergetics resulting in greatly reduced ATP production is critical in the molecular pathogenesis of type 2 diabetes mellitus.     

倒刺鲃两极虫的宿主新记录及其分子系统学研究

为弄清倒刺鲃两极虫(Myxidium spinibarba)的宿主多样性和胭脂鱼(Myxocyprinus asiaticus)寄生黏孢子虫的种类组成, 研究基于形态和分子数据, 比较分析了寄生于不同宿主的倒刺鲃两极虫的形态学和形态计量学特征及分子系统发育关系。结果显示: 寄生于胭脂鱼和中华倒刺鲃的倒刺鲃两极虫株系在形态学和形态计量学上未出现显著性差异, 18S rDNA序列相似度为99.9%—100.0%, 遗传距离为0.000—0.001, 符合种内变异; 寄生于不同宿主倒刺鲃两极虫的株系在系统发育树中嵌合聚支, 且寄生于胭脂鱼的倒刺鲃两极虫株系先分化。以上结果表明: 研究中两株系与倒刺鲃两极虫为同一物种, 但在分子水平已经出现分化; 这是首次在胭脂鱼中检获到黏孢子虫, 胭脂鱼是倒刺鲃两极虫的新宿主。     

Development of the islets, exocrine pancreas, and related ducts in the Nile tilapia, Oreochromis niloticus (Pisces: Cichlidae)

Pancreatic development and the relationship of the islets with the pancreatic, hepatic, and bile ducts were studied in the Nile tilapia, Oreochromis niloticus, from hatching to the onset of maturity at 7 months. The number of islets formed during development was counted, using either serial sections or dithizone staining of isolated islets. There was a general increase in islet number with both age and size. Tilapia housed in individual tanks grew more quickly and had more islets than siblings of the same age left in crowded conditions. The pancreas is a compact organ in early development, and at 1 day posthatch (dph) a single principal islet, positive for all hormones tested (insulin, SST-14, SST-28, glucagon, and PYY), is partially surrounded by exocrine pancreas. However, the exocrine pancreas becomes more disseminated in older fish, following blood vessels along the mesenteries and entering the liver to form a hepatopancreas. The epithelium of the pancreatic duct system from the intercalated ducts to the main duct entering the duodenum was positive for glucagon and SST-14 in 8 and 16 dph tilapia. Individual insulin-immunopositive cells were found in one specimen. At this early stage in development, therefore, the pancreatic duct epithelial cells appear to be pluripotent and may give rise to the small islets found near the pancreatic ducts in 16-37 dph tilapia. Glucagon, SST-14, and some PPY-positive enteroendocrine cells were present in the intestine of the 8 dph larva and in the first part of the intestine of the 16 dph juvenile. Glucagon and SST-14-positive inclusions were found in the apical cytoplasm of the mid-gut epithelium of the 16 dph tilapia. These hormones may have been absorbed from the gut lumen, since they are produced in both the pancreatic ducts and the enteroendocrine cells. At least three hepatic ducts join the cystic duct to form the bile duct, which runs alongside the pancreatic duct to the duodenum.     

Pancreatic Duct Obstruction in the Pig: Light Microscopy of Chronic Pancreatitis

Morphological changes of pancreatic tissue in young pigs caused by surgical ligation of the main pancreatic duct are described. Nineteen animals from 6 to 7 weeks in age were operated on and necropsied 3 or 6 to 8 weeks later. Twelve pigs developed a pronounced chronic pancreatitis with complete exocrine insufficiency. Of the 7 animals failing to develop ectasia of pancreatic ducts, 2 died due to surgical complications. In addition, 3 pigs were sham-operated and served as controls. In macroscopical studies it was observed that in the pronounced pancreatitis cases the ligated duct was greatly dilated by a clear watery fluid. Only remnants of pale and firm grandular tissues were seen around the ectatic ducts. Microscopically, typical changes of chronic pancreatitis were noted. Complete disappearance of acini was followed by ductular cell proliferations. Glandular tissues were divided into lobuli by fibrotic tissues and fat cells. The wall of the main pancreatic duct was greatly thickened and fibrotic, presenting intensely proliferating ductular cells and round cell infiltrates. Furthermore, enlarged endocrine islets surrounded by connective tissue fibres were seen.