Middle Intestine Research Articles

Features of pathogenesis in sacbrood virus at honey bees (Apis mellifera L.)

Bees and their larvae are prone to various viral diseases, which lead to disruption of the vital activity of the bee colony and sometimes to its death. It is hazardous for the bee colony when a sac-like brood damages it. Sick families differ sharply from healthy ones in terms of their condition and productivity; they develop slowly in the spring and grow few offspring. Adult bees of sick families do not live long; they are not very active, weakly protect nests, fly sluggishly, and are unfriendly to collect honey. Therefore, the work aimed to identify physiological changes in the intestines of sexually mature ewes affected by cystic brood. The experimental part of the work was carried out in the conditions of the Stepan Gzhytskyi National University of Veterinary Medicine and Biotechnologies Lviv. The research was conducted during 2018–2020 at a farm in the Stryi district of the Lviv region. The farm's apiary consisted of 230 bee families. The subjects of the study were fertile uteri aged two years. Signs of virus damage were detected on the farm in 2018 and 2019. The diagnosis was confirmed based on epizootological data, clinical signs, and laboratory studies. By conducting histological studies, data on the pathogenesis of honey bees affected by the virus were supplemented. The data on physiological and morphological changes in the middle intestine of pregnant mothers are given. Histological studies were carried out in different parts of the mid intestine. Changes in the function of the peritrophic membrane were found in sick uteri compared to clinically healthy ones. An increase in the length of the midgut fold in the front part of the intestine by 23% was revealed (Р ˂ 0.001). Under the influence of the pathogenicity of the virus, there is an intensive proliferation of enterocytes in the middle part of the intestine. In the case of damage by a sac-like brood, the work of the membrane-associated with the motor, secretory and other functions of the midgut is disturbed. This, in turn, leads to dystrophic and inflammatory changes in the surface epithelium and also inhibits the regeneration process. Damage to the structural components of the mucous membrane is indicated by the absence of a hypertrophic membrane in the caudal direction of the midgut of sick mothers, where necrotic damage to the mucous membrane up to the basement membrane is revealed.

Ciprofloxacin Permanently Accelerates Gastrointestinal Transit in a Rodent Model of Fluoroquinolones Associated Disability

Fluoroquinolones (FQs) are a class of antibiotics intended to be prescribed for life‐threatening infections. However, they are often administered for less severe infections, which they are not meant to treat. In addition, studies suggest that FQs can lead to severe long‐lasting complications described as Fluoroquinolone Associated Disability (FQAD). Some of these permanent issues affect the central nervous system, cardiac, and musculoskeletal systems among others. Gastrointestinal issues have also been considered a possible side effect due to how FQs may negatively modulate the vagus nerve, which plays a major role in digestion and regulation of satiety. Indeed, the inhibitory neurotransmitter GABA regulates the motor portion of the vagus nerve, and FQs act as a selective inhibitor of GABAA receptors. This blockade of GABAA receptors is believed to contribute to the GI issues that seem to arise after taking FQs.To measure possible changes in digestion, Sprague Dawley rats were treated daily for 14 consecutive days with either 0.3ml of 0.9% saline (CTL n=6) or 20mg/kg of ciprofloxacin (CPX) via oral gavage. On experiment day (day 14 or 28; n=6 for both), rats were administered phenol red dye, sacrificed, and the stomach, proximal, middle, and distal small intestine were harvested to measure dye recovery via spectrophotometry as a measure of gastrointestinal transit. Results showed that both male and female rats in the 28 day group had significantly less dye recovered from their stomach compared to the 14 day and CTL group, with female rats being disproportionately affected compared to males (P<0.05). This data provides strong evidence that FQs lead to permanent acceleration in digestive patterns. Further experiments will analyze how the phenotype of enteric motor neurons, as well as the phenotype of neurons within the Dorsal Motor Nucleus of the vagus in the medulla oblongata, is affected by this drug. This will contribute to determining the mechanism underlying the observed digestion change in rats treated with ciprofloxacin.

Isolation and identification of Edwardsiellatardafrom the middle intestine of the(Asian catfish)Silurustriostegus(Heckel,1843

The present study represent a first record of the bacterium Edwardsiellatarda, Enterobacteriaceafrom the middle intestine of the Asian catfish, Silurustriostegus on native studies in Iraq.Twenty five fish were collected during December 2006 from the Garmat Ali River, Basrah City, using seine nets. Sampled fish ranged between 350-750g and250-650 mm. Tenisolates of were bacteriaEdwardsiellatardait is belong to.

The gastrointestinal tract histology of Eliomys quercinus and Glis glis

The Garden Dormouse (Eliomys quercinus) and the Edible Dormouse (Glis glis) differ in their omnivorous diet, with the first being more carnivorous and readily consuming small vertebrates and even poisonous invertebrates, while the latter consumes more plant-based foods. These differences could lead to histological differences in their gastrointestinal tract, which we wanted to test. Six animals of each species were caught in nature and fed the same diet for two weeks to diminish the impact of the short-term external factors. Tissue samples were taken of middle oesophagus, glandular stomach, middle small intestines and large intestines. They were stained with H&E for measuring the thickness of layers in oesophagus gastric mucosa and epithelial cell height in the intestines. Alcian blue - PAS stain was used for goblet cell count and type identification in the intestines, differentiating blue (acidic), lilac (neutral) and purple (mixed) cells. Results showed Eliomys quercinus having greater variance in oesophageal layer thicknesses, significantly thicker muscularis mucosae and thinner tunica muscularis in the oesophagus, and thicker gastric mucosa compared to Glis glis. Eliomys quercinus also had a significantly higher total goblet cell count in both intestines and a higher count of each type in the large intestine, although Glis glis had far more mixed and neutral goblet cells in the small intestine. Both showed intriguingly low numbers of neutral goblet cells in the small intestine. These results indicate interesting differences in gastrointestinal histology and goblet cell distribution in comparison with their distinct diets.

Barotrauma Telinga Tengah (Middle Ear Barotrauma)

The human ear consists of 3 main parts, there are the outer ear, middle ear and inner ear. One of the injuries that can affect the human ear is barotrauma. Barotrauma is an injury caused by a pressure difference between the inside of the body and the external space. Barotrauma can occur in any structure in the body where there is an enclosed space that can be occupied by air including the middle ear space, paranasal sinuses, lungs, stomach and intestines. However, barotrauma most commonly occurs in the middle ear, this is mainly due to the complexity of the function of the eustachian tube. Middle ear barotrauma occurs when the eustachian tube cannot open to balance air pressure. In various literatures it is reported that the incidence and prevalence of ear barotrauma ranges from 4.1 – 82%. Clinical manifestations of middle ear barotrauma include hearing loss, pain in the ear, autophony, a feeling of water in the ear and sometimes accompanied by tinnitus and vertigo.

Dietary lysine requirements of Colossoma macropomum (Cuvier, 1818) based on growth performance, hepatic and intestinal morphohistology and hematology.

This study aimed to determine the dietary lysine requirements of juvenile Colossoma macropomum tambaqui based growth performance, hepatic and intestinal morphohistology and hematology. Tambaqui were fed with levels of 6.60, 9.72, 12.84, 15.96, 19.08, and 22.20 g/kg of total lysine and those who received 15.96 g/kg dietary lysine showed higher final weight (p= 0.001) and optimized feed conversion ratio (p= 0.001). Morphohistological modifications (presence of fat droplets) were present in livers of fish fed with low levels of lysine. In the morphohistology of the intestine, the diets influenced the density of the intestinal, cell layers, height and perimeters of the villi and acid mucin secretion by the goblet cells. In the proximal intestine, mucosa layer density was greater at the level of 15.96 g/kg (p= 0.001). In the middle intestine, height (p= 0.001) and perimeter (p= 0.001) of the villi were greater at low levels of lysine (respectively, 9.72 and 12.84 g/kg dietary lysine). No differences were found for the hemoglobin, hematocrit, erythrocytes, MCV, MCH, MCHC, thrombocytes and leukocytes differentiated of fish fed with experimental diets (p>0.05). The biochemical responses were affected by the diet, both in plasma concentration (protein and cholesterol; p<0.05), and in muscle (ash and moisture; p<0.05). In conclusion, the dietary requirement for lysine for tambaqui juveniles was estimated to be 15.4 - 15.6 g/kg of diet (5.7% -5.8% dietary protein).

Effects of Mulberry (Morus alba L.) Leaf Extracts on Growth, Immune Response, and Antioxidant Functions in Nile Tilapia (Oreochromis niloticus)

Abstract This study evaluates how white mulberry (Morus alba L.) leaf extracts affect the growth, antioxidant activity, and immune response in Nile tilapia Oreochromis niloticus. Mulberry leaf extracts were obtained through aqueous extraction (AE) and ethanol extraction (EE). Powder of mulberry leaf (PML) was added directly to feed and compared with the effects of feeds supplemented with the different extracts. Fish were divided into eight groups for an 8-week feeding trial where they were fed the basal diet or supplemented with 10% PML, 10% AE, 20% AE, 40% AE, 10% EE, 20% EE, or 40% EE. The inclusion of mulberry leaf extract obtained with either method showed better effects on fish growth performance, antioxidant activities and acid phosphatase activity (ACP) in serum, immune cytokine expression, and intestinal morphology as compared with controls or fish fed the 10% PML diet. The specific growth rate was significantly higher in the 10% AE, 10% EE, and 20% EE groups compared with all other groups (P&lt;0.05). Catalase activity was significantly greater in most groups fed an extract, and in the 10% PML group, when compared with controls. Similarly, ACP, interleukin (IL)-1, and IL-2 expression was significantly increased in groups fed an extract, and in the 10% PML group, when compared with controls (P&lt;0.05). IL- 1, IL-2, IL-10, and Toll-like receptor 2 expression was significantly greater in the 10% EE group than in the 10% PML and 10% AE groups (P&lt;0.05). Villus length in the middle intestine was significantly increased in the 10% AE and 10% EE groups compared with controls and the 10% PML group (P&lt;0.05). Thus, 10% mulberry leaf ethanol extract added to feed is recommended for enhancing the growth rate and health of cultured Nile tilapia.

ВЛИЯНИЕ АНОМАЛЬНО ВЫСОКИХ ТЕМПЕРАТУР НА ПИТАНИЕ, ПИЩЕВЫЕ ВЗАИМООТНОШЕНИЯ И АНАТОМО-ГИСТОЛОГИЧЕСКУЮ ОРГАНИЗАЦИЮ ПЕРЕДНЕГО И СРЕДНЕГО ОТДЕЛОВ КИШЕЧНИКА САЗАНА (CYPRINUS CARPIO LINNAEUS, 1758) В УСЛОВИЯХ ЗАПАДНОГО ПОБЕРЕЖЬЯ СРЕДНЕГО КАСПИЯ

Conducted has been the study on the influence of abnormally high temperatures in the summer of 2021 on nutrition, nutritional interactions and anatomical and histological organization of the anterior and middle intestine of carp in the conditions of the Daghestan coast of the Caspian Sea. It is shown that under the influence of high temperatures in fish, nutrition is disrupted, destructive changes of the basement membrane and the plate of the intercellular substance have occurred in the midgut. In the anterior part, edema of the mucous layer and necrosis of individual parts of the intestine are observed. The disorders are reversible.

SATB.2 is a sensityive for well differentiated neuroendocrine tumors

Introduction: Neuroendocrine tumors (NET) constitute a heterogeneous group of rare neoplasms, with a sustained increase in incidence in recent years. They originate in neuroendocrine cells, the most common are those of the gastrointestinal system and most are sporadic, although they can be part of hereditary syndromes. Neuroendocrine neoplasms are divided into well-differentiated neuroendocrine tumors (WDNET) and poorly differentiated neuroendocrine carcinomas (PDNEC). Material and methods: We retrospectively evaluated 78 WDNET of the anterior, middle and posterior intestine, in a period of 20 years (01/01/2000 to 07/31/2020), with the SATB2 antibody, in which it is considered a diagnostic marker for WDNET of the hindgut tract. Results: Of the 40 WDNET of the anterior intestine, 2 (5%) tumors showed reactivity with SATB 2. Positive staining with SATB2 was observed in 1/17 (5.88%) of WDNET of the midgut. Among the 21 WDNET of the hindgut, we observed SATB2 staining in 19 (90.57%) of the tumors. Conclusion: Our results indicate that SATB2 is a sensitive marker for hindgut WDNET, although it is not specific. Keywords: STAB2 protein; Carcinoid tumors; Gastroenteropancreatic neuroendocrine tumors; Neuroendocrine tumor; Colorectal neuroendocrine tumors.

Pollen Diet-Properties and Impact on a Bee Colony.

Simple SummaryIn order to study the effects of malnutrition in bees, attention should be drawn to the dietary composition. A pollen diet plays an important role in the life of bees. A well-balanced diet influences the development of the larvae as well as the physiology, biochemistry, immunity and histology of the workers.Diet is an important factor in the proper development of the individual and the entire colony. A pollen diet affects honey bees in a number of ways. It can stimulate the number and type of hemocytes, the total number of proteins, carbohydrates and lipids, affect the histology of the middle intestine, and ensure the correct ontogenesis of the larvae. Moreover, selected single-flower diets can stimulate the development of the pharyngeal glands that produce royal jelly, thus conditioning the development of secretory immunity. Selected single-species pollen may also increase the phenol oxidase concentration, which contributes to the humoral response. A honey bee diet based on multi-flower pollen is more desirable than a mono-flower diet, but must be properly balanced.

Changes of the intestinal microbiota along the gut of Japanese Eel (Anguilla japonica).

Fish intestine contains different types of microbiomes, and bacteria are the dominant microbiota in fishes. Studies have identified various core gut bacteria in fishes. However, little is known about the composition and their relative functions of gut microbial community along the intestine. To explore this, the current study investigated the microbial community distribution along the gut in Anguilla japonica. By 16S rRNA gene sequencing, we profiled the gut microbiota in eel along the three regions (anterior intestine (AI), the middle intestine (MI) and the posterior intestine (PI)). Results suggested that the three regions did not have significant differences on the observed species and diversities. The cluster tree analysis showed that the bacteria community in MI was closer to PI than the AI. The dominant bacteria in AI were the Proteobacteria, in which the majority was graduated replaced by Bacteroidetes along the gut to PI region. Through PICRUSt analysis, shifts in the bacterial community along the gut were found to affect the genetic information processing pathways. Higher levels of translation and transcriptional pathway activities were found in MI and PI than in AI. The dominant bacterial species were different among the regions and contributed to various biological functions along the gut.

The delimitation of intestine segments of koi carp (Cyprinus carpio var. koi) based on histological features.

In this study, the delimitation of intestine segments of koi carp (Cyprinus carpio var. koi) was conducted using a histological approach with the measurements of height of mucosa folds (HF), width of mucosa folds (WF), thickness of muscularis (TM) and cross-sectional area (CSA). According to the change trends for these four parameters, the intestine of the koi carp was divided into anterior intestine, middle intestine and posterior intestine. The locations of the three intestine segments were defined, and their ratios along the entire intestine were accounted for 23.84±1.18%, 46.77±2.29% and 29.39±1.65%, respectively. The anterior intestine had a significantly higher HF, compared with the middle (p<.01) or posterior intestines (p<.01). The muscularis became thin gradually from the anterior intestine to posterior part. TM was significantly different among the anterior, middle and posterior intestines (p<.01). The anterior intestine had a significantly higher CSA, compared with the middle (p<.01) and posterior intestines (p<.01), and the latter two segments had similar CSA values (p>.05). The procedure of the delimitation of the koi carp intestine segments can offer useful information for future studies on other fish species. The presented results are meaningful for studies on differential functions of the different intestine segments in fish.

Dietary Marginal and Excess Selenium Increased Triglycerides Deposition, Induced Endoplasmic Reticulum Stress and Differentially Influenced Selenoproteins Expression in the Anterior and Middle Intestines of Yellow Catfish Pelteobagrus fulvidraco.

Selenium (Se) is an essential micro-mineral and plays important roles in antioxidant responses, and also influences lipid metabolism and selenoprotein expression in vertebrates, but the effects and mechanism remain unknown. The study was undertaken to decipher the insights into dietary Se influencing lipid metabolism and selenoprotein expression in the anterior and middle intestine (AI and MI) of yellow catfish Pelteobagrus fulvidraco. Yellow catfish (weight: 8.27 ± 0.03 g) were fed a 0.03- (M-Se), 0.25- (A-Se), or 6.39- (E-Se) mg Se/kg diet for 12 wk. AI and MI were analyzed for triglycerides (TGs) and Se concentrations, histochemistry and immunofluorescence, enzyme activities, and gene and protein levelsassociated with antioxidant responses, lipid metabolism, endoplasmic reticulum (ER) stress, and selenoproteome. Compared to the A-Se group, M-Se and E-Se diets significantly decreased weight gain (WG) and increased TGs concentration in the AI and MI. In the AI, compared with A-Se group, M-Se and E-Se diets significantly increased activities of fatty acid synthase, expression of lipogenic genes, and suppressed lipolysis. In the MI, compared to the A-Se group, M-Se and E-Se diets significantly increased activities of lipogenesis and expression of lipogenic genes. Compared with A-Se group, E-Se diet significantly increased glutathione peroxidase (GPX) activities in the AI and MI, and M-Se diet did not significantly reduce GPX activities in the AI and MI. Compared with the A- Se group, E-Se diet significantly increased glutathione peroxidase (GPX) activities in the plasma and liver, and M-Se diet significantly reduced GPX activities in the plasma and liver. Compared with the A-Se group, M-Se and E-Se groups also increased glucose-regulated protein 78 (GRP78, ER stress marker) protein expression of the intestine. Dietary Se supplementation also differentially influenced the expression of the 28 selenoproteins in the AI and MI, many of which possessed antioxidant characteristics. Compared with the A-Se group, the M-Se group significantly decreased mRNA levels of txnrd2 and txnrd3, but made no difference on mRNA levels of these seven GPX proteins in the MI. Moreover, we characterized sterol regulatory element binding protein 1c (SREBP1c) binding sites of three ER-resident proteins (selenom, selenon, and selenos) promoters, and found that Se positively controlled selenom, selenon, and selenos expression via SREBP1c binding to the selenom, selenon, and selenos promoter. Thus, dietary marginal and excess Se increased TGs deposition of yellow catfish P. fulvidraco, which might be mediated by ER-resident selenoproteins expression and ER stress.

Histological observations on the development of digestive tract in &amp;lt;italic&amp;gt;Tachypleus tridentatus&amp;lt;/italic&amp;gt;

In this study, paraffin sections and H-E staining were used to study the individual development of alimentary canal of <italic>T</italic>. <italic>tridentatus</italic> at 15 days old, 30 days old, 60 days old, the second instar and adult. Results showed that the structure of digestive tract of <italic>T</italic>. <italic>tridentatus</italic> at 15 days old was not clearly distinguished. The esophagus, stomach, midgut and rectum were similar in structure. Only mucous membrane was clear, and mucous folds were relatively short. When <italic>T</italic>. <italic>tridentatus</italic> was 30 days old, the mucous epithelium of esophagus and stomach showed dark bands, the muscle fibers of esophagus extended in a ring, and the muscle bundles of stomach were thickened. The mucous epithelium of the middle intestine and rectum had a striate border at the top, and the muscular fiber bundles were thickened. When <italic>T</italic>. <italic>tridentatus</italic> was 60 days old, the dark bands at the top of the mucosa epithelium of the esophagus and stomach developed into striate margins, with increased esophageal muscle fibers and thickened gastric myofilament bundles. The mucosa fold of the midgut and rectum increased in height and number, and the pigmentation of the striate border deepened. The digestive tract of the second instar <italic>T</italic>. <italic>tridentatus</italic> was composed of mucous layer, submucous , muscle layer and serosal layer, and the tissue structure was basically well-developed. With the gradual improvement of tissue structure, the number of folds of esophagus and gastric mucosa increased significantly to 9-15, and the striate border at the top of the mucosal epithelium developed into chitin layer. The number of folds in the mucosa of the middle intestine and rectum increased rapidly to 10-12, and the epithelial striatum of the mucosa of the middle intestine thickened, with little tin layer, and the epithelial striatum of the rectum developed into chitin layer. The structure of digestive tract of adult <italic>T</italic>. <italic>tridentatus</italic> was complete, and the mucous layer, submucous layer, muscle layer and serous membrane of digestive tract were obviously thicker than that of early stage. Results showed that the tissue structure of the alimentary canal of <italic>T</italic>. <italic>tridentatus</italic> was basically developed at the second instar, and the tissue structure of each layer was thickened with age, which was suitable for its living habit.

Effects of using vital wheat gluten in practical diets on growth, intestinal histopathology, proinflammation-related gene expression, and resistance of white seabream (Diplodus sargus) to Staphylococcus epidermidis infection

The current study was carried to assess the effects of using vital wheat gluten (VWG) as a fishmeal (FM) replacer in practical diets for white seabream, Diplodus sargus, juvenile. Five isonitrogenous (~ 40% CP) and isoenergetic (21 MJ/Kg diet) diets were formulated to replace FM protein by VWG protein at levels of 0.0 (CTR), 15 (VWG15), 30 (VWG30), 45 (VWG45), and 60% (VWG60). Fish (1.7 ± 0.1 g) were fed on the experimental diets in triplicated groups up to apparent satiety for 10 weeks. At the end of the feeding trial, fish of each treatment were intraperitoneally injected by pathogenic bacterium Staphylococcus epidermidis and observed for further 10 days. Results showed that only fish fed VWG45 and VWG 60 diets showed significant lower growth and feed intake relative to all other VWG groups. VWG at all inclusion levels did not significantly affect survival rate, proximate composition, or body morphometry of white seabream. The intestine architecture indicated that fish fed the VWG45 diet had mild alterations with abundant absorptive vacuole in the middle intestine, while mild to moderate pathological changes were observed in the distal portion. The intestine of fish fed VWG60 showed severe degeneration with signs of inflammation. Additionally, villi length/width and absorption area in foregut, midgut, and hindgut of white seabream were not significantly changed among CTR, VWG15, and VWG30 but these measurements were significantly lowest at the VWG60 treatment. Comparing with the CTR group, highest IL-1β and TNF-α gene expressions were observed in VWG60 followed by VWG45 groups. The phylogenetic tree indicated that VWG induced changes in muscles protein pattern especially at the VWG60 group. After the bacterial challenge, fish fed 15 and 30% VWG protein showed mild mortality as the control fish (43.3–46.7%); meanwhile fish fed the VWG60 diet were more susceptible to S. epidermidis infection showing highest mortality (63.3%). In conclusion, the present findings elucidated that the performance of white seabass was not significantly affected by partial replacement of 30% FM protein with VWG protein.

Characterization of the intestinal digesta and mucosal microbiome of the grass carp (Ctenopharyngodon idella)

The intestinal microbiome plays a pivotal role in the nutritional digestion and metabolism of the grass carp (Ctenopharyngodon idella). Here, we characterized the digesta and mucosal microbiome of the anterior, middle, and posterior intestine of the grass carp, using 16S rRNA next-generation sequencing. Based on 16S rRNA amplicon data, Proteobacteria, Firmicutes and Bacteroides were the dominant phyla in the intestine of grass carp. Our results also showed that microbial communities of the middle intestine exhibited higher alpha diversity indices compared with the anterior and posterior intestine. The clustering of microbial communities that had either colonized in the digesta or were attached to the mucosa, were significantly tighter in the posterior intestine, based on average unweighted Unifrac distances (P < 0.05). The digesta or mucosa of the anterior and middle intestines were similar in microbial composition, but were significantly different to the posterior intestine (P < 0.05). In digesta and mucosa samples from the posterior intestine, we observed a significantly increased abundance of cellulose-degrading microbiomes, such as Bacteroides, Clostridiales and Spirochaetia (P < 0.05). Our results suggested that the microbiomes of the posterior intestine, either attached to the mucosa or colonized in the digesta, were distinct from the microbiomes of the anterior and middle intestine in grass carp.

Length ratio, histological structure, feed composition, and enzyme activity in the gut of yellow rasbora (Rasbora lateristriata Blkr.)

A study of the ratio of gut length, histological structure, feed composition, and enzyme activity in the foregut had carried out to determine the feed category of yellow rasbora. The study used a survey method with sampling in the Banjaran River, Banyumas, Central Java. The research data had analyzed quantitatively and descriptively. The results showed that the gut length ratio of yellow rasbora ranged from 0.53 to 0.81. Gut histological showed no stomach structure with the relative height of the villi in the middle intestine approaching 0.5. Feed composition in the foregut showed that 60% was animal, and the rest were detritus and microalgae. Measurement of protease activity at foregut showed that no acidic protease activity but found alkaline proteases. In conclusion, yellow rasbora was an omnivorous fish with a short intestine and no functioning stomach.

Growth and metabolic responses of grouper juveniles (Epinephelus coioides) fed diets containing varying levels of leucine

We conducted an 8-week feeding trial to evaluate the effects of dietary leucine on growth performance, body and muscle composition, hepatic and plasma components, gut morphology, and relative expression levels of genes in the mTOR pathway. Six isonitrogenous and isolipidic diets with increasing levels of Leu (1.88%, 2.84%, 3.51%, 4.45%, 5.27%, and 6.06%, respectively) were formulated. Each diet was fed to 4-replicate groups of 20 groupers (average initial body weight of 35.0 g/fish) twice daily, to apparent satiety. Weight gain and specific growth rates; feed intake; body protein, lipid, and muscle protein content; and liver GOT and branched chain α-keto acid dehydrogenase kinase activities showed positive linear and/or quadratic responses to dietary Leu levels. In contrast, body moisture and ash content, liver triglyceride and total-cholesterol content, and plasma GOT and GTP activity had negative linear and/or quadratic responses to different dietary Leu levels. There were no differences in the feed conversion ratio and hepatosomatic index, condition factor, plasma GOT activity, and plasma triglyceride and total-cholesterol content among treatments. The mucosal fold number in three gut segments (proximal intestine (PI), middle intestine (MI), and distal intestine (DI)) and mucosal fold length and muscle layer thickness in the DI showed positive quadratic responses to dietary Leu levels. In addition, mucosal fold length and number, and muscle layer thickness in the PI were greater that those observed for the MI and DI. The mRNA level of SLC3A2, SLC7A5, RagC/D, Ragulator, Raptor, mTOR, mLST8, and Tel2 in the muscle and/or gut showed positive quadratic responses to dietary Leu levels, whereas negative quadratic responses were observed for mRNA levels of RagA/B and V-ATPase in the muscle and/or gut, and SLC7A5 in the liver. The optimal amount of Leu required for this fish was estimated to be 8.88% of the dietary protein content, based on the regression analysis of percent weight gains against dietary Leu levels. The results indicate that appropriate dietary Leu levels (range 3.51%–4.45%) could help to improve growth performance and nutrient deposition, maintain gut structural integrity and positively regulate genes in the mTOR signaling pathway in the fish.

Eubiotic effect of a dietary potassium diformate (KDF) and probiotic (Lactobacillus acidophilus) on growth, hemato-biochemical indices, antioxidant status and intestinal functional topography of cultured Nile tilapia Oreochromis niloticus fed diet free fishmeal

An 84 days experimental trial was undertaken to examine the influence of potassium diformate (KDF) and Lactobacillus acidophilus and their interaction on growth, biochemical of blood parameters, enzymes of antioxidant response and intestinal topography of Nile tilapia, Oreochromis niloticus, fingerlings fed fishmeal free diets. Six functional diets were formulated to contain two levels of L. acidophilus (0, 1.47 × 107 CFU kg−1), with each level being supplemented with 0, 5 g and 10 g KDF kg−1 diet, respectively. Fingerlings O. niloticus (n = 540; initial weight 4.29 ± 0.06 g) were randomly allocated into six groups (30 fish group−1 in triplicates). The results showed that the best values of growth, feed efficiency and biological parameters were recorded by fish fed diets containing 1.47 × 107 L. acidophilus CFU kg−1 and 10 g kg−1 KDF. Lower pH values in stomach and gut were noted in fish fed diet supplemented with 1.47 × 107 L. acidophilus CFU kg−1 and 10 g kg−1 KDF. Diets supplemented with L. acidophilus, KDF or in combination improved the hemoglobin, red blood cells and white blood cells count with insignificant differences among groups. The activities of serum alanine and aspartate aminotransferase decreased significantly (P < 0.05) by the addition of L. acidophilus and KDF in fish diets. Furthermore, addition of KDF and L. acidophilus significantly (P < 0.05) improved the serum total protein and albumin, but globulin not affected. The lowest value of uric acid was recorded in fish fed 5 g kg−1 KDF without addition of L. acidophilus, while there were no significant (P > 0.05) differences in creatinine content were found among treatments. Diets supplemented with L. acidophilus and/or KDF significantly (P < 0.05) improved phosphorus and calcium content. However, the activities of superoxide dismutase (SOD), total antioxidant capacity (T-AOC) and catalase (CAT) were highest in fish fed diet contained either 5 g or 10 g kg−1 KDF and 1.47 × 107 L. acidophilus CFU kg−1 (D4 and D6). Villi length and width in the middle intestine and number of goblet cell were shown to be promoted in fish fed diets 10 g KDF kg−1 or 10 g kg−1 KDF and 1.47 × 107 L. acidophilus CFU kg−1diet. In conclusion, the administration of a mixture of a probiotic and KDF is beneficial, as it effectively improves the gut morphology and the total antioxidant enzyme activity resulting in an overall enhancement of the fish growth performance.

Motilin- and ghrelin-induced contractions in isolated gastrointestinal strips from three species of frogs

Ghrelin (GHRL) and motilin (MLN), gut peptides isolated from the mucosa of the stomach and duodenum, respectively, stimulate gastrointestinal (GI) motility in mammals and birds. However, the functions of MLN and GHRL in amphibian GI tracts have not been examined in detail. To clarify the regulation of GI motility by the two peptides, the effects of human MLN and rat GHRL on contractility of isolated GI strips from three species of frogs, the black-spotted pond frog (pond frog; Pelophylax nigromaculata), bullfrog (Lithobates catesbeiana) and Western clawed frog (Xenopus; Xenopus tropicalis), were examined in in vitro experiments. The GI tract of each frog was divided into the stomach, upper intestine, middle intestine and lower intestine. Human MLN caused contractions of the stomach in the pond frog and upper intestine in the bullfrog and Xenopus, but other GI regions were insensitive to human MLN. Erythromycin did not cause contraction of the upper intestine of the bullfrog and Xenopus. Rat GHRL did not cause contraction of the stomach and small intestines in the pond frog and bullfrog, but it caused a concentration-dependent contraction in the stomach and upper intestine of Xenopus, while des-acyl rat GHRL did not cause any contraction of them. In conclusion, human MLN caused the contraction of the stomach or upper intestine in the three species of frogs, but GHRL was effective only in the stomach and upper intestine of Xenopus. On the basis of these data, MLN but not GHRL causes the GI region-dependent contractions in the frogs.