Dehydrogenase activity in small intestine mucosa in experimental coccidiosis in suckling pigs]

The activities of 3-beta-hydroxybutyrate dehydrogenase (EC. 1.1.1.30.; HBD) and isocitrate dehydrogenase (EC. 1.1.1.41; ICD) were evaluated microdensitometrically in the mucosa of duodenum, jejunum and ileum of 19 conventional piglets infected on the first day after parturition (DAP) with oocysts of Eimeria debliecki coccidium (infection dose of 200,000 oocysts). The two investigated enzymes are deposited in mitochondria which are dispersed in the supra-, para- and infranuclear region of absorption cells (Fig. 1). The synthesis of the two dehydrogenases was investigated in the small intestine mucosa in the period of 1st to 10th day after infection (DAI). The HBD and ICD activities were also followed in the small intestine of four control conventional piglets at the age of 2-5 days (Tab. I). The two dehydrogenases could be characterized by a topographic gradient; it means that their activity was increasing in the small intestine mucosa through duodenum in an aboral direction. The ICD activity is higher in the intestinal mucosa of healthy piglets (Figs. 2 and 3), where its topic concentration was more marked while the HBD activity is dispersed in enterocytes (Fig. 4). In infected piglets the density of the two enzymes was demonstrated to decrease already in the starting period of experimental infection, and it reaches the lowest values for the first time on DAI 5-6 (Fig. 5, Tab. II), then on DAIs 9 (HBD; Fig. 6, graph 11)) or 8 (ICD, Fig. 7 and 10). In the period of experimental infection no statistically significant predisposition to the hypoactivity of target dehydrogenases nor its marked shift were observed. Somewhat rapid resumption of synthesis was demonstrated as soon as on DAI 8 in ICD (Fig. 8); its activity on DAI 10 in the intestinal mucosa corresponded to the 93% activity of this dehydrogenase recorded in the small intestine of control piglets. The density of HBD to the same day (DAI 10) reached in the intestinal mucosa of infected piglets the values making only 44.7% of those demonstrated in the intestinal mucosa of the control group of animals.     

Densitometric analysis of aminopeptidase M activity in small intestine mucosa in piglets experimentally infected with Isospora suis

In gnotobiotical and conventional piglets infected a day post partum (DPP) with oocysts of the coccidium Isospora suis, densitometrical analysis of the activity of aminopeptidase M (EC.3.4.11.2; APM) was performed in the area of microvillous zone of the small intestine. Piglets were infected with different infection doses of oocysts (100,000 oocysts) in gnotobiotical piglets and 200,000 oocysts in conventional piglets). In infected gnotobiotical piglets, the APM activity was studied in the period from the 3rd to 11th day after infection (DAI) and in infected conventional piglets in the period of to the 2nd to 10th day after infection (DAI). Control piglets, in the group of the gnotobiotical animals at the age of 2 to 5 days in the group of the conventional animals at the age of 4 to 7 days, had different APM activity in the microvillous zone of the intestinal mucosa. It was stated that the microvillous zone of the intestinal mucosa gained higher values in control conventional piglets (+7.01 mean values of density). In infected gnotobiotical piglets the density fall of the reaction product of APM was demonstrated already on the third day with further marked reduction of APM density on the 4th day after infection in the whole small intestine with predominance of the persisting APM activity in ileum. Even despite the slight increase in the density of the reaction product of APM in the period from the 5th to 7th DAI (the highest increase in APM density on the 6th DAI), a further decrease of the activity was recorded again on the 8th and namely the 9th DAI in the whole small intestine (the lowest value of density was found in the rear jejunum), the ileum mucosa being affected, too. A slightly higher density of the reaction product of APM was found in the duodenum. On the 10th DAI the APM density started to change and on the 11th DAI in the duodenum and in the middle jejunum it even reached higher values in comparison with the control data. Some differences were proved in the infected conventional piglets in comparison with the development of the APM activity in the small intestine mucosa in the infected gnotobiotical piglets. On the 3rd and 4th DAI APM defect occurred in the whole small intestine, with APM density prevailing in the ileum mucosa (like in the group of infected gnotobiotical piglets). The second period of decrease in APM activity lasted for almost four days (6th to 9th DAI).(ABSTRACT TRUNCATED AT 400 WORDS)     

Synthesis of nonspecific esterase in small intestine enterocytes during experimental coccidiosis in suckling pigs]

The activity of nonspecific esterase (EC. 3.1.1.1.) was evaluated in the small intestine mucosa of 21 conventional piglets infected on day 5 after parturition (DAP) with oocysts of the Eimeria debliecki coccidium (infection dose of 200,000 oocysts) for this evaluation a microdensitometric analysis at the level of enterocytes was used. The same examination was also performed in the small intestine mucosa of four control conventional piglets at the age of 2-5 days (Tab. I). The synthesis of nonspecific esterase in the experimentally infected piglets was followed on day 1 to day 10 after infection (DAI). The activity of nonspecific esterase in the small intestine mucosa was found to decrease in a direction from duodenum absorption cells (D mean 34.15) to caudal ones (Fig. 1); ileum enterocytes have the optical density of the enzyme by 8.2% lower (D mean 31.38). The deposition of nonspecific esterase is localized mainly in the supranuclear zone of enterocytes while in the para- and infranuclear zones of absorption cells its concentration is only minute. In the experimentally infected piglets a marked increase in the optical density of nonspecific esterase of enterocytes was observed as soon as on day 1 after infection when the enzyme concentration increased by 19.4% (Tab. II). The maximum increase in the activity of nonspecific esterase of absorption cells was recorded on DAI 9 when the enzyme D mean value was higher by 165% in comparison with the activity of nonspecific esterase demonstrated in the control piglets (Fig. 2, 3, 4). But at the end of experimental infection (DAI 10) the total density of nonspecific esterase of enterocytes decreased by 38.2%.(ABSTRACT TRUNCATED AT 250 WORDS)     

Alkaline phosphatase activity in goblet cells in the small intestine of piglets experimentally infected with the coccidium Isospora suis

Alkaline phosphatase activity (EC. 3.1.3.1.) in goblet cells was investigated in the small intestine of 16 gnotobiotic piglets infected one day after delivery (DAD) by different rates of oocysts of Isospora suis coccidia. At a high infection rate of I. suis (750,000) the goblet cells were found to be highly positive to alkaline phosphatase on day 3 to day 4 after infection (DAI). In piglets infected by a low infection rate of I. suis oocysts (100,000) the activity of alkaline phosphatase activity in goblet cells was proved on days 4 to 10 after infection. In the first group of piglets, the positive goblet cells prevailed in the middle region of jejunum, with the peak on 4th DAI. It the second group of piglets a marked increase in the alkaline phosphatase activity was recorded in the goblet cells in the posterior part of jejunum on days 4 to 5 after infection and on 10th DAI. No alkaline phosphatase activity in the goblet cells was demonstrated in the control gnotobiotic piglets at the age of two to seven days.     

Activity of mucosubstances and the goblet cell count in the large intestine of piglets infected with the coccidium, Isospora suis

In a group of conventional and gnotobiotic piglets experimentally infected with the Isospora suis coccidia the quantitative presence of acid and neutral mucous substances in the large intestine and the counts of goblet cells in the surface mucosa and in Lieberkühnis crypts (in the following text called just the crypts) were investigated. In conventional piglets infected with the dose of 200,000 oocysts of I. suis coccidia the lowest content of acid mucous substances was recorded from the eighth to tenth day after infection (DAI). A decrease in the activity of neutral mucous substances was somewhat slower. The lowest count of goblet cells was found on DAI 9, especially on the surface mucosa (4.89 to 4.91 goblet cells per 10 enterocytes). There was observed no difference in the piglets infected the first and fifth day after parturition (DAP). Gnotobiotic piglets infected with the dose of 100,000 oocysts of I. suis coccidia on DAP 1 showed the lowest content of mucous substances in the large intestine from the ninth to tenth day after infection. Unlike the conventional piglets, in gnotobiotic piglets there was recorded a decrease in the content of acid and neutral mucous substances. The gnotobiotic piglets had the lowest counts of goblet cells in the surface mucosa (10:4.57) and in the crypts (10:7.71) on DAI 9. As to the quantitative proportions, in the conventional and gnotobiotic piglets neutral mucous substances prevailed on the other days (DAI 3-7 and DAI 11), similarly like on DAI 8. The results of this investigation revealed a functional disease of the large intestine in conventional and gnotobiotic piglets infected experimentally with the Isospora suis coccidia.     

Histochemistry of selected peptidases in small intestine mucosa in piglets experimentally infected with Isospora suis

In the small intestine mucosa of 24 gnotobiotical piglets experimentally infected the first day post partum with oocysts of the coccidium Isospora suis, the activities of dipeptidylpeptidase IV (EC.3.4.14.5.; DAP IV) and gamma-glutamyl transferase (EC.2.3.2.2.; GGT) in the microvillous zone of enterocytes were evaluated by scanning densitometry. The tissue of the small intestine in piglets infected with a dose of 100,000 oocysts of the coccidia of I. suis was examined in the period from the first till the eleventh day post infection (DPI). In the control piglets at the age of 2-5 days it was found that most of the DAP IV activity was located in the microvillous zone of the enterocytes of the middle jejunum, rear jejunum and ileum. The DAP IV activity of duodenum mucosa was lower; as compared with the activity in the mucosa of the jejunum and ileum it reached 53-57%. In the case of GGT activity, the highest density values of the reaction product were recorded in the microvillous zone of enterocytes of the duodenum and the whole jejunum, the lowest in the ileum mucosa (86-89%) of the activity found in the duodenum and jejunum). During the experimental infection the infected piglets had a significant deficit of both peptidases, especially DAP IV (the whole studied period). The development of GGT activity was slightly different with the onset of the marked decline of the enzyme activity only on the fifth DPI. The lower GGT activity persisted till the eighth DPI. The density of the GGT reaction product began to return to the normal on the ninth to eleventh DPI. No predisposition in the location of the deficit was observed in the peptidases studied during the infection. The decline of the activity of both enzymes influenced also the mucosa of all studied parts of the small intenstine. The difference lay in the relevance of lowering of the density of reaction product of DAP IV and GGT on other DPI and in the different intensities of the return of the activity to the physiological normal.     

Lysosomal activity in enterocytes in the small intestine in piglets experimentally infected with Isospora suis

The lysosomal activity of enterocytes of the small intestine mucosa was investigated in gnotobiotic and conventional piglets experimentally infected on the first day after birth (DAB) by the oocysts of the coccidia Isospora suis. A method of the proof of beta-D-glucuronidase (EC.3.2.1.31.) activity was used to demonstrate lysosomes. The piglets were infected by different infection doses of oocysts (100,000 oocysts in gnotobiotic piglets and 200,000 oocysts in conventional piglets). In the gnotobiotic infected piglets the activity of beta-D-glucuronidase in enterocyte lysosomes was investigated in the period from day 3 to day 11 after infection (DAI) and in the infected conventional piglets in the period from day 2 to day 10 after infection. Comparing the control piglets, the group of gnotobiotic piglets at the age of 2-5 days and the group of conventional piglets at the age of 4-7 days, the higher activity of beta-D-glucuronidase was demonstrated in the lysosomes of intestinal mucosa enterocytes in the gnotobiotic control piglets (+5.30 of the average density value, Dx). In the infected gnotobiotic and conventional piglets the pattern of beta-D-glucuronidase activity was found to have three stages in the course of this infection. Two stages can be characterized by a great increase in the enzyme activity (DAI 3-9 in gnotobiotic piglets, DAI 2-3 and 7-9 in conventional piglets. The third stage, which is manifest mainly in the conventional infected piglets, is characterized by a marked decrease in the activity of beta-D-glucuronidase, reaching the level of control findings (DAI 10 and mainly 11 in gnotobiotic piglets. DAI 4-6 and 10 in conventional piglets). A topographical picture shows that the two stages of increase and the stage of beta-D-glucuronidase activity decrease occur in the whole small intestine without any predisposition defect of the enzyme in the different sections of the small intestine.     

Density of selected enzymes in the goblet cells of the small intestine in piglets experimentally infected with the coccidium Isospora suis

The density of selected enzymes in the goblet cells of the mucous membrane of the small intestine was studied in a group of 12 gnotobiotic piglets experimentally infected with the coccidium Isospora suis one day after parturition (DPP), using the Vickers M-786 scanning and integrating microdensity meter. At an infecting dose of 100,000 oocysts of I. suis, the histochemistry of the goblet cells of the mucous membrane of the piglets changed significantly in the period of 4 to 10 days after infection (DPI). Increases occur in the density of non-specific esterase (EC. 3.1.1.1.) and acid phosphatase (EC. 3.13.2.). The density of acid and neutral muco-substances declines and the densities of alkaline phosphatase (EC. 3.1.3.1.) and aminopeptidase M (EC. 3.4.11.2) are significantly high. The goblet cells of the mid and posterior parts of jejunum are very similar in their histochemistry in the experimentally infected gnotobiotic piglets. In the duodenum and ileum the histochemical picture of the goblet cells shows no substantial difference from the data recorded in the goblet cells of the mucous membrane of the small intestine of the four control piglets at an age of two to seven days.     

Morphometric analysis of the activity of alkaline phosphatase in the small intestine of piglets infected with the coccidium Isospora suis

Gnotobiotical one-day-old piglets were infected with 100,000 Isospora suis coccidia oocysts, and were immediately killed. In piglets killed on the 3rd to 11th day after infection (DAI), the morphometric analysis of alkaline phosphatase activity was performed in the area of the microvillus zone of small intestine. In the control 2-7 days old animals, the small intestine was not equally supplied with alkaline phosphatase. In duodenum the activity reached 88.37 per cent of the active length of absorbent surface (% LAac), in the middle jejunum 95.98 per cent LAac, in the dorsal jejunum 78.63% LAac and the ileum 90.55 % LAac. The width of the active area was more balanced and ranged from 5.003 microM in the ileum to 6.129 microM in the dorsal jejunum. In infected gnotobiotical piglets the lowest activity was found out on the 3rd to 4th DAI, with a greater decline on the 9th day after infection. The range from 25.99 to 40.50 per cent LAac with minimum in the duodenum and maximum in the ileum was observed on the 3rd DAI. In the middle and dorsal ileum the activity was nearly equal (28.34 and 27.69 per cent LAac). nI the dorsal jejunum a moderate increasing was up to 47.13% LAac on the 4th DAI, with the exception of the ileum, where the activity of alkaline phosphatase decreased to 24.96% LAac. On the 9th DAI the activity of alkaline phosphatase was nearly equal in the whole small intestine (from 55.70 to 60.01% LAac) with the maximum in the middle jejunum. In the width of the reaction product a direct dependence on the total activity of alkaline phosphatase was evident only in the segment of the middle and dorsal jejunum and ileum, but merely on the period of the 3rd to 4th DAI. The lowest values were measured in the middle jejunum (0.982 micron on the 3rd DAI and 0.709 micron on the 4th DAI). No dependence was observed between the total activity and the reaction product in the middle jejunum (0.982 micron on the 3rd DAI and 0.709 micron on the 4th DAI), there was no general stabilisation of the activity of alkaline phosphatase.     

Synthesis of glucose-6-phosphatase in small intestine mucosa during experimental coccidiosis in suckling piglets]

Glucoso-6-phosphatase activity (EC. 3.1.3.9.) was evaluated microdensitometrically in the small intestine mucosa of 19 conventional piglets infected with Eimeria debliecki coccidium oocysts (infection dose of 200,000 oocysts) on day 1 after delivery (DAD). The synthesis of the observed hydrolase was followed within days 1 to 10 after infection (DAI). The activity of the same enzyme was also determined in four control conventional piglets at the age of two to five days. The small intestine mucosa of healthy piglets was found to have relatively balanced glucoso-6-phosphatase concentrations in all observed sections (duodenum, middle and posterior jejunum and ileum). The topographic gradient failed to be demonstrated in control piglets. In piglets experimentally infected with E. debliecki coccidium the glucoso-6-phosphatase activity was decreasing during infection already since DAI 1. The enzyme hypoactivity was still lower in the following days and reached the minimum value at the end of the target period (DAI 10), when its value made only 33% of the concentration recorded in the intestine mucosa of control piglets. The topographic predisposition to the lower activity of glucoso-6-phosphatase was not found to be high. The only exception are DAI 6 and 7, when the lowest enzyme concentration was observed in the duodenum mucosa (52% on DAI 6; 54% on DAI 7). The activity of the observed enzyme was higher in the other sections of small intestine (57% on DAI 6; 62% on DAI 7).     

beta-D-glucosidase in the microvillous zone of small intestine enterocytes in experimental coccidiosis in suckling piglets]

In the small intestine mucosa of 24 gnotobiotic farrows experimentally infected with the oocysts of coccidiosis of Isospora suis (infection administration--100,000 oocysts) on the first day after the delivery, we carried out the microdensitometric evaluation of the activity of beta-D-glucosidase (phlorizin-hydrolase; hetero-beta-galactosidase; lactase-beta-glucosidase complex; EC. 3.2.1.21). Great attention was paid to the topochemistry of enzyme, deposited in a microvillous zone of enterocytes. We studied likewise the activity of beta-D-glucosidase in the striped fringe of enterocytes of the four control gnotobiotic farrows, in the age from 2 to 5 days. We found out that in healthy farrows the reaction product of studied disaccharidase is located in high concentrations in the microvillous zone of absorptive cells of the whole small intestine. We proved a topographic gradient at which the beta-D-glucosidase activity decreases in control farrows the duodenum mucosa in the aboral direction. When using the choice substrate for beta-D-glucosidase (5-Br-4-Cl-beta-indolyl-3-D-glucoside) we did not prove the enzyme deposition in the small intestine wall. The negative enteral effect of coccidiosis I. suis was provable in the farrows experimentally infected already on the first day after the infection (DPI) when the beta-D-glucosidase activity decreased within the whole small intestine by 15% (ileum) and even by 23% (middle jejunum). The activity reduction had been deepening since the first after the infection and it reached its maximum on the 9th day after the infection when the enzyme concentration in the microvillous zone of absorptive cells reached only 11% of the activity level found in control farrows. On the 10th and 11th day after the infection we registered the increase of the density of beta-D-glucosidase reaction product, however the microvillous zone was even in that final stage of experimental infection significantly deficient (31% of intestine mucosa activity of control farrows).     

Histochemistry of nucleoside phosphatases and phosphoglucomutase in the small intestine during coccidiosis in piglets]

The first day after birth, 22 conventional piglets were experimentally infected with the oocysts of the coccidia of I. suis (infection dose 200,000 oocysts). The activity of 5-nucleotidase (5-ribonucleotide phosphohydrolase, EC.3.1.3.5) and phosphoglucomutase (alpha-D-glucoso-1-phosphate phosphotransferase, EC.5.4.2.2) was densitometrically assessed in the mucosa of the small intestines of these piglets. Enzyme activities were studied in the infected piglets during the 2nd to 10th day after infection. The same histochemical examination was simultaneously performed in the intestinal mucosa of five control conventional piglets at an age of 2-14 days. 5-nucleotidase and phosphoglucomutase were found to have a high density in the mucosa of the small intestine of the control piglets: the high-density locations of these enzymes include, first of all, the supranuclear area of the absorption cells, the microvillous zone of enterocytes and the smooth muscle elements of lamina muscularis mucosae. The experimentally infected piglets showed a marked decline of the density of both enzymes during the infection. The deficit affected, for a transient period, the microvillous zone and the supranuclear region of enterocytes; the musculature of the mucous layer was affected permanently. The inactivity was more protracted in the case phosphoglutamase (especially 5 to 9 days after infection). The density of 5-nucleotidase showed a partial return to the normal already the 7th day after infection, with an interruption of resumption of activity on the 10th day. Resumption of enzyme activity in the lamina muscularis mucosae was not recorded during the infection. In the three locations under study, the density of none of the enzymes did reach parameters comparable with the controls at the end of the trial (10 days after infection).     

超微粉中药对保育猪腹泻及肠黏膜免疫细胞的影响

为研制安全、高效环保型保育猪中药添加剂,将72头体重相近的28日龄杜长大断奶仔猪随机分为4组,每组3个重复,每个重复6头猪,分别饲喂基础饲粮、基础饲粮＋抗生素、基础饲粮＋1%中草药组方Ⅰ、基础饲粮＋1%中草药组方Ⅱ,进行为期28 d的饲养试验,统计腹泻频率及腹泻指数、测定肠黏膜免疫细胞。结果显示,中药Ⅱ组效果优于中药Ⅰ组和抗生素组。中药Ⅱ组腹泻持续时间最短、腹泻频率及腹泻指数最低;与对照组相比,对回肠段杯状细胞数量影响最大的是抗生素组,提高14.29%（P〉0.05）。对其它肠黏膜免疫细胞数量影响最大的是中药Ⅱ组,提高十二指肠、空肠及回肠段上皮内淋巴细胞数量分别达23.37%（P〈0.01）、16.33%（P〈0.01）、14.52%（P〈0.01）;提高十二指肠及空肠段杯状细胞数量分别达31.82%（P〈0.01）、26.92%（P〈0.01）;提高十二指肠、空肠及回肠段肥大细胞数量分别达17.99%（P〈0.01）、23.87%（P〈0.01）、18.71%（P〈0.01）。     

Impact of Yersinia enterocolitica enteritis on disaccharidase activity and small intestinal morphology in colostrum-deprived newborn piglets

The effect of enteritis on the development of the small intestine was examined in newborn, colostrum-deprived piglets infected with a human isolate of Y. enterocolitica (serotype 0:3, biotype 4) soon after birth. The piglets were killed 3 days (n = 6) or 5 days (n = 8) after infection, or antibiotic therapy was commenced on day 5 and the animals killed on day 14 (n = 5). Compared with the non-infected controls, infected animals had reduced mucosal lactase and sucrase, but not maltase activity, while after antibiotic therapy, previously infected piglets had a lower lactase and a higher maltase and sucrase activity. Lactase activity was significantly reduced in the duodenum and jejunum, and mean values were lower in the ileum, but the difference did not reach significance; maltase activity was greater at all ages from the distal jejunum to the mid-ileum; sucrase activity was reduced in all segments up to day 5 but after antibiotic therapy was increased in the jejunum and appeared early in the ileum. Enzyme profiles were more mature along the crypt-villus axis in some segments of the intestine in previously infected piglets. Sodium-potassium-ATPase activity was unchanged. There was a reduced villus height:crypt depth ratio, crypt hyperplasia and increased crypt cell proliferation. Morphological maturation, indicated by loss of vacuoles and location of the nucleus at the base of the enterocyte, proceeded distally from the duodenum to ileum from 3 to 14 days of age when only the ileum remained immature. In infected piglets, there was reduced vacuolation and earlier location of the nucleus at the base of the cell in the distal intestine. Accelerated maturity of specific disaccharidases and enterocyte morphology in infected piglets appears to be due to physical damage to the mucosa resulting in faster proliferation of crypt cells and migration of enterocytes. It is suggested that this may reduce macromolecular internalisation and impair the ability to utilise dietary carbohydrate and may have long-term effects on growth and immunological responses of the gut.     

妊娠后期母猪和仔猪补饲外源精胺对初生和28日龄仔猪肠道形态结构及二糖酶活性的影响

本文通过研究妊娠后期母猪和仔猪补饲外源精胺对初生和28日龄仔猪肠道形态结构和二糖酶活性的影响,初步探讨干预“仔猪早期断奶综合征”的技术措施.试验第1阶段,选择6头体重和膘情相近、胎次为3、已怀孕91 d的健康“长×大”母猪,随机分为Ⅰ、Ⅱ和Ⅲ3个组,每个组设2个重复,每个重复1头母猪.Ⅰ、Ⅱ和Ⅲ组妊娠母猪饲粮中外源精胺的添加量为0、1.5和3.0 mg/kg,饲喂至分娩结束;第2阶段,分娩后母猪采食同一种不含外源精胺的饲粮,Ⅰ、Ⅱ和Ⅲ组哺乳仔猪于7日龄起相应补饲外源精胺添加量为0、3.0和6.0 mg/kg的哺乳仔猪饲粮至28日龄.在仔猪初生和28日龄时,分别从每窝仔猪中选1头接近平均体重的健康仔猪进行屠宰,用于胃肠发育指标的测定.结果表明:与未添加外源精胺相比,妊娠母猪饲粮添加3.0 mg/kg外源精胺显著提高了初生仔猪十二指肠和回肠的柱状细胞数量、十二指肠和空肠的杯状细胞数量(P＜0.05),显著增加了空肠隐窝深度(P＜0.05),显著提高了麦芽糖酶和蔗糖酶比活力(P＜0.05);哺乳仔猪饲粮添加6.0 mg/kg外源精胺显著增加了28日龄仔猪空肠黏膜重(P＜0.05),显著提高了十二指肠和空肠的麦芽糖酶和蔗糖酶比活力(P＜0.05),极显著增加了空肠柱状细胞和杯状细胞数量(P＜0.01),极显著增加了十二指肠和空肠隐窝深度(P＜0.01).因此,在妊娠后期母猪和哺乳仔猪饲粮中添加外源精胺有利于初生和28日龄仔猪肠道形态结构的改善和二糖酶活性的提高.     

Effect of weaning on small intestinal structure and function in the piglet.

Fifty-four piglets were selected from 12 litters weaned at 17 (Treatment 1), 21 (Treatment 2), 28 (Treatment 3) and 35 (Treatment 4) days old, respectively, to determine the effect of weaning age on small intestinal villus morphology, immunology and histochemistry. From proximal duodenum, proximal jejunum, distal jejunum and middle ileum, intestinal samples with three replicates (piglets) in each treatment were taken at 18, 22, 28 and 36; 22, 28, 36 and 43; 28, 36, 43, and 50; and 18, 22, 28, 36, 43 and 50 d of age in Treatment 1, 2, 3 and 4, respectively. This was equivalent to 12 h, 3 d, 1 week, 2 week postweaning in Treatment 1; 12 h, 1 week, 2 week, 3 week postweaning in Treatment 2 and 3, and all the same age in Treatment 4 as in Treatment 1, 2, 3, respectively. The results showed that villous height of duodenum and proximal jejunum decreased significantly in Treatment 1 and 3. Crypt depth in the duodenum, proximal jejunum and ileum also decreased significantly in Treatment 1. Date had significant effect on villous height of the duodenum, distal jejunum and ileum with the shortest on day 29 and crypt depth of all positions increased with piglet age except the crypt depth in proximal jejunum decreased on day 50. Weaning age and day of age had significant effects on intraepithelial lymphocyte (IEL) number and goblet cell (GC) number at all positions of small intestinal mucosa in piglets. The number of IEL at all segments of small intestinal mucosa in Treatment 3 increased significantly compared to those in other treatments, but IEL number at all locations of small intestinal mucosa in Treatment 2 decreased significantly compared to those in other treatments. The number of GC in small intestinal mucosa increased significantly in early-weaned (< day 21) piglets. It appears that providing fluid milk replacer for a few days postweaning could dramatically reduce the negative impact of weaning on villous morphology and digestive and absorptive function, especially in pigs weaned prior to 3 week of age. Finally, as weaning age was reduced, GC had a greater role in intestinal duct protection.     

The ratio of enterocytes and goblet cells in the mucosa of the small intestine in experimental infection of piglets with the coccidium Isospora suis

The proportions of cup-shaped cells and enterocytes were studied in piglets infected the first and fifth day after birth with 200,000 oocysts of Isospora suis. The greatest imbalance was found in the ratio of the cells of the intestinal mucous membrane in the region of middle and lower jejunum (ratio of 10:1.75)--this was recorded the third to fourth day after infection when the ratio made 10:0.62, whereas in the control animals it was 10:5.7. On the eighth to ninth day after infection the number of cup-shaped cells began to increase, the ratio reaching the values of 10:2.62. Even the 13th day after infection the ratio remained far from normal (10:2.50).     

地衣芽孢杆菌对脂多糖应激仔猪肠道形态、肠黏膜抗氧化能力和免疫力的影响

本试验旨在研究地衣芽孢杆菌对脂多糖(LPS)应激仔猪肠道形态、肠黏膜抗氧化能力和免疫力的影响。试验选用35日龄、平均体重为(10.0±0.5)kg的苏山猪90头,随机分成3组(对照组、LPS组和BL+LPS组),每组3个重复,每个重复10头仔猪。其中,对照组和LPS组仔猪均饲喂基础饲粮;BL+LPS组仔猪饲喂添加500 mg/kg地衣芽孢杆菌的基础饲粮。预试期3 d,正试期21 d,于正试期第21天从每个重复中选2头仔猪腹腔注射LPS(LPS组和BL+LPS组)或等量的灭菌生理盐水(对照组),注射24 h后屠宰取样。结果显示:1)与对照组相比,LPS应激显著降低了仔猪十二指肠二胺氧化酶(DAO)、空肠一氧化氮合成酶(NOS)活性及空肠一氧化氮(NO)含量(P<0.05),显著提高了血浆中NO含量和NOS活性(P<0.05);显著降低了空肠绒毛高度和绒隐比、回肠绒隐比(P<0.05);显著降低了十二指肠、空肠和回肠谷胱甘肽过氧化物酶(GSH⁃Px)、十二指肠和回肠超氧化物歧化酶(SOD)活性(P<0.05);显著降低了空肠上皮细胞中淋巴细胞、空肠和回肠上皮细胞中杯状细胞数量(P<0.05);显著降低了血清免疫球蛋白G(IgG)含量,提高了回肠黏膜白细胞介素-6(IL⁃6)和白细胞介素-1β(IL⁃1β)含量(P<0.05)。2)与LPS组相比,饲粮添加地衣芽孢杆菌显著提高了LPS应激仔猪回肠DAO和NOS活性(P<0.05);显著提高了空肠黏膜GSH⁃Px活性显著提高(P<0.05),显著降低了十二指肠黏膜丙二醛(MDA)含量(P<0.05);显著提高了血清IgG含量(P<0.05)。由此可见,LPS应激导致仔猪肠黏膜损伤,在饲粮中添加地衣芽孢杆菌可提高LPS应激仔猪的肠黏膜抗氧化能力和免疫力,一定程度上促进肠道形态的修复,减缓LPS应激导致的肠道损伤。     

Decreased activity of brush border membrane-bound digestive enzymes in small intestines from pigs experimentally infected with porcine epidemic diarrhea virus

Brush border membrane-bound digestive enzymes such as disaccharidases (lactase, sucrase, and maltase), leucine aminopeptidase N, and alkaline phosphatase were measured in jejunum from pigs experimentally infected with porcine epidemic diarrhea virus (PEDV). Three piglets from the infected and control groups were euthanized by electrocution and subjected to necropsy at 24, 36, 48, 60, and 72 hours post-inoculation (hpi). The infection of PEDV to jejunum resulted in significant decreases in brush border membrane-bound digestive enzymes such as disaccharidases (lactase, sucrase, and maltase), leucine aminopeptidase N, and alkaline phosphatase. PEDV replication results in massive destruction of villous enterocytes leading to a marked reduction of intestinal epithelial surface and brush border membrane-bound digestive enzyme activity. Reduced enzymatic activity and villous atrophy in the small intestine is thought to result in a maldigestive and malabsorptive diarrhea.