Synthesis Of Digestive Enzymes Research Articles

147 The ‘horse-side’ of host-microbe interactions and gastrointestinal homeostasis in the equine hindgut

Abstract Homeostasis is a complex physiological process that enables biological systems to maintain balanced internal environments in response to internal and external stimuli. In the equine gastrointestinal (GI) tract, homeostasis involves a network of factors that regulate gene expression, maintain the integrity of the mucosal barrier, and modulate immune responses to pathogenic microorganisms while supporting commensal bacteria that provide benefits to the host (Figure 1). These factors work together and respond to changes in diet, environment, external stress, and challenges by infectious agents or toxins. Proper gastrointestinal function is dependent on maintaining homeostasis in the system, and the dynamic interactions between the microbial population (the microbiota) and the equine host are central to this equilibrium. The regulation and interplay between the equine host and GI microbiota are evident in the distribution of distinct microbial communities within the various compartments of the equine hindgut. The contributions of each compartment to digestive physiology and the overlap with various stages of microbial fermentation in the equine hindgut are well-researched. What remains to be documented is gene expression in tissues of the equine GI and the underlying role this might play in the processes of digestion, physiology, and homeostasis in the GI. To better understand the roles that host gene expression plays in the interactions with the microbiota, it is critical that we investigate gene expression in the different tissues along the intestinal tract. Protein-coding genes are crucial in maintaining the health of the gastrointestinal tract. They direct the synthesis of various structural elements, molecular transporters, and digestive enzymes, which support digestion, nutrient absorption, and gut integrity. Non-coding genes also play an important role in regulating protein-coding gene expression, modulating immune responses, and maintaining gut barrier function. Moreover, there is evidence that non-coding transcripts regulate the composition of microbial communities in the GI tract. The presentation will focus on the current research and future directions for investigating protein-coding and non-coding gene expression to understand the mechanisms involved in the host-microbe interaction in the equine hindgut and their potential role in maintaining GI homeostasis.

A closed-loop negative feedback model for the pancreas: A new paradigm and pathway to a cure.

To develop a model that describes how the pancreas functions, how the rate of synthesis of digestive enzymes is regulated, and finally what puts the pancreas to rest between meals. We applied the principals of control theory to previously published canine data to develop a model for how the canine pancreas functions. Using this model, we then describe the steps needed to apply this model to the human pancreas. This new closed-loop negative feedback model describes what regulates digestive enzyme synthesis. This model is based on basolateral exocytosis of butyrylcholinesterase (BCHE) into the interstitial space. It is this level of BCHE * BCHE activity that controls the rate of canine pancreas digestive enzyme synthesis, and in the absence of stimulation from the vagus nerve, puts the pancreas to rest between meals. Finding secretagogue-specific inhibitory enzymes in the human pancreas that are analogous to BCHE in the canine, and blocking its associated receptors, may lead to a cure for human pancreatitis.

Breaking Down Cachexia: A Narrative Review on the Prevalence of Cachexia in Cancer Patients and Its Associated Risk Factors.

Cachexia is an irreversible condition that involves a significant loss of body weight, muscle mass, and adipose tissue. It is a complex condition that involves a variety of metabolic, hormonal, and immune-related factors, with the precise mechanisms not yet fully understood. In this review, the prevalence of cachexia in different types of cancer as well as the potential risk factors was evaluated from literature retrieved from databases such as ScienceDirect, PubMed and Scopus. Potential risk factors evaluated here include tumor-related factors such as location, and stage of the cancer, as well as patient-related factors such as age, gender, and comorbidities. Several findings were observed where cachexia is more prevalent in male cancer patients than females, with higher incidences of weight loss and poorer outcomes. This may be due to the different muscle compositions between gender. Additionally, cachexia is more prevalent at the later stages, which may be brought about by the late-stage diagnosis of certain cancers. The anatomical location of certain cancers such as the pancreas and stomach may play a significant factor in their high prevalence of cachexia. These are sites of the synthesis of digestive enzymes and hormones regulating appetite. Cachexia is an issue faced by cancer patients which could affect their recovery. However, it is poorly understood, which limit therapeutic options. Hence, understanding this disease from different perspectives (clinical and pre-clinical), and bridging those findings could further improve our comprehension and consequently improve therapeutic options.

HPTLC Method Development and quantification of marker compound Gallic acid and Piperine in Ayurvedic Polyherbal formulations: Avipattikar Churna

Ayurvedic medications are becoming more and more well-liked and accepted globally because they are inexpensive and have no negative side effects. There is a chance that original medications will be adulterated with substances that chemically or physically mimic raw pharmaceuticals because of the increasing demand for herbal raw materials for the production of various classical as well as phytoformulation. Avipattikar Churna is an excellent Ayurvedic formulation for treating health issues resulting from an imbalance of Pitta dosha, such as acidity, heartburn, and indigestion. These issues might arise from bad eating habits, a sedentary lifestyle, or a lack of physical activity. Avipattikar Churna is also beneficial for ailments affecting the digestive and excretory systems' ability to operate normally. It counteracts the gastrointestinal tract's acid secretion and encourages the synthesis of digestive enzymes, which facilitate food absorption. Acid dyspepsia, often known as indigestion, is a condition marked by burning and sour vomit, nausea, heartburn (retrosternal burning), and burning in the throat. Avipattikar Churna is beneficial in treating these symptoms. The standardisation process, which can be carried out using a variety of methods and advanced techniques, conforms the identity, quality, and purity of herbal pharmaceuticals. The HPTLC method is superior to other methods since it may be used with herbal medications and is inexpensive, simple to use, and repeatable. For the purpose of evaluating the quality of Avipattikar Churna and identifying any changes made to the drug's composition, an HPTLC method has been devised. The existence and quantity of the marker compound in the sample are confirmed by the overlap of all relevant spectra with the marker. A gramme of Avipattikar Churna (AVC) methanolic extract contained 2.51 mg of piperine and 2.70 mg of gallic acid, the marker compounds.

Starvation induces hepatopancreas atrophy in Chinese mitten crab (Eriocheir sinensis) by inhibiting angiogenesis

BackgroundThe hepatopancreas of crustaceans serves as a significant organ for both the synthesis and secretion of digestive enzymes, as well as energy storage. In the event of food shortage, the hepatopancreas can provide energy for survival. To investigate the potential regulatory mechanisms of the hepatopancreas in response to starvation in Eriocheir Sinensis, transcriptome analysis, histological study and qRT-PCR were performed.ResultsThe results showed that starvation caused a decrease in the hepatopancreas index of E. sinensis, which had certain effects on the tissue structure, metabolism and angiogenesis in the hepatopancreas. In addition, WGCNA and linear regression analysis showed that the genes significantly related to the hepatopancreas index were mainly enriched in the angiogenesis pathway, in which AKT signaling played an important role. Starvation may inhibit AKT signaling pathway by reducing the expression of TGFBI, HSP27, HHEX, and EsPVF1, thereby hindering angiogenesis, promoting apoptosis, and leading to hepatopancreas atrophy.ConclusionThese results indicate that AKT plays an important role in the angiogenesis pathway and apoptosis of the starvation induced hepatopancreas index reduction, which is beneficial to further understand the effect of starvation stress on hepatopancreas of Chinese mitten crab.

Impact of gut microbiota composition on black cutworm, Agrotis ipsilon (hufnagel) metabolic indices and pesticide degradation

Endosymbionts are known to have significant effects on their insect hosts, including nutrition, reproduction, and immunity. Insects gut microbiota is a critical component that affects their physiological and behavioral characteristics. The black cutworm (BCW), Agrotis ipsilon, is an economically important lepidopteran pest that has a diverse gut microbiome composed of nine species belonging to three phyla: Proteobacteria, Actinobacteria, and Firmicutes. This study was conducted to investigate the diversity of gut bacteria isolated from BCW larvae and moths and their effects on metabolism and pesticide degradation. The bacterial isolates were identified using the 16 S rRNA gene. The study showed that the gut microbiome composition significantly affected the metabolism of BCW larvae. Based on the screening results of synthesis of digestive enzymes and pesticide degradation, Brachybacterium conglomeratum and Glutamicibacter sp were selected to perform the remaining experiments as single isolates and consortium. The consortium-fed larvae showed high metabolic indices compared to antibiotic-fed larvae and the control. The gut bacteria were also shown to degrade three pesticide groups. Concerns regarding the health risk of chlorpyrifos have been raised due to its extensive use in agriculture. The isolated B. conglomeratum was more effective in chlorpyrifos degradation than the consortium. Furthermore, the study also examined the presence of sex related endosymbionts (Wolbachia, Spiroplasma, and Rickettsia) in the reproductive tissues of adults. The outcomes demonstrated that none of the examined endosymbionts existed. In conclusion, the study highlights the importance of the gut microbiome in insect physiology and behavior and its potential applications in biotechnology. It provides insights into developing eco-friendly pest control and bioremediation strategies using gut bacteria.

Relationship between the behavioral type of American mink males and the activity of digestive enzymes

The domestication of the American mink (Neovison vison) leads to the manifestation of such a trait as “tame” behavior. The selection of animals on this basis seems to be very attractive from the standpoint of commodity production. Since work with predators is rather complicated, selection for the “tame” behavior of animals seems relevant. Assuming that the genes that control behavior, due to their pleiotropic action, can be involved in the synthesis of digestive enzymes, which can lead to a decrease in productivity characteristics. In this respect, experiments were carried out to determine the enzymatic activity of proteases, lipases, and α-amylases in aggressive and tame animals. It has been established that the activity of proteases and lipases is higher in aggressive lines of American mink males than in the tame ones, while the amylolytic activity in tame animals is higher than in theaggressive ones.

The endoplasmic reticulum acetyl-CoA transporter AT-1 plays a role in the protective unfolded protein response in the exocrine pancreas

Pancreatic acinar cells are responsible for the synthesis and secretion of digestive enzymes. In order to sustain high rates of secretory protein production, acinar cells rely on adaptive mechanisms to mitigate endoplasmic reticulum (ER) stress and maintain secretory homeostasis. The adaptive unfolded protein response (UPR), mediated by the IRE1-XBP1s axis, is essential for acinar function and protects against cellular injury. Recent work has demonstrated that the ER acetyl-CoA transporter, AT-1, is necessary for nascent secretory protein acetylation and export out of the ER and is regulated by IRE1-XBP1s. Furthermore, AT-1 is rapidly downregulated during experimental pancreatitis. To investigate the role of AT-1 in exocrine pancreas function, we generated inducible, acinar-specific AT-1 knockout mice (Ela-Cre AT-1-/-). Loss of AT-1 produced a chronic pancreatitis phenotype characterized by inflammation, immune cell infiltration, tissue fibrosis, and aberrant intracellular activation of the proteolytic digestive enzyme trypsin. Despite the histological and biochemical dysfunction observed, Ela-Cre AT-1-/- mice grow normally, have typical lifespans, and do not lose pancreatic mass. Interestingly, XBP1s expression is significantly upregulated in Ela-Cre AT-1-/- and may confer a protective effect with loss of AT-1. Our data suggests a role for AT-1 in the IRE1-XBP1s axis and highlights the previously undescribed role of protein acetylation in exocrine pancreas physiology. Given the numerous potential downstream effects of dysregulated acetyl-CoA transport, this model will advance our understanding of pancreatic function and disease. NIH This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Probiotics Based on Lactic Acid Bacteria for Aquaculture

Aquaculture (especially fish farming) provides billions of people with nutrients: amino acids, vitamins, minerals, and proteins. Aquaculture of commercial species (rainbow trout, common carp, grass carp, pacific white-legged shrimp, etc.) are growing rapidly and accounts for about a third of the global fish production. It is a major alternative to reducing wild populations that are unable to meet growing food demand. Lactic acid bacteria (LAB) of the genera Lactococcus, Lactobacillus, Lactiplantibacillus, Enterococcus, Leuconostoc, Pediococcus, Streptococcus, Carnobacterium, and Weissella belong to the normobiota of the gastrointestinal (GI) tract of most fish. They play an important role as they stimulate the synthesis of digestive enzymes, prevent intestinal disorders, improve the immune response of the macroorganism, increase the barrier capacity of the mucous membrane due to the colonization of the fish GI tract, activate the resistance to the development of bacterial and viral infections due to the production of a wide range of antimicrobial substances (bacteriocins, organic acids, hydrogen peroxide, etc.). Therefore, Lactobacilli are classified as potential probiotic strains for aquaculture. The combined use of lactic acid bacteria with feed increases their nutritional value, as microorganisms produce a wide range of digestive enzymes that actively participate in the process of digestion and decomposition of feed, as well as positively affect the growth of individuals and stimulate their reproductive activity, which undoubtedly contributes to the active introduction of commercial probiotics based on LAB strains. As a result of growing aquaculture, there are many problems such as stocking density, infectious diseases, excessive use of antibiotics, water pollution, which can be solved with the help of probiotic lactic acid bacteria. Therefore, the review presents current literature data on the use of lactic acid bacteria strains as probiotic preparations for aquaculture, their species composition, probiotic effect on the host, the mechanism of action of probiotics on aquaculture, and the methods for delivery to the macroorganism.

Termite exocrine systems: a review of current knowledge

AbstractIn this review, we summarize the 22 exocrine glands hitherto described for termites (Isoptera), highlighting their distribution, morphological features, and likely function. The secretion from such glands displays a very important role in termite communication, but is also attributed to many other activities performed by these insects, including defense, building, and foraging, as well as physiological processes such as the synthesis of digestive enzymes, and antiseptic and lubricant compounds. Here, glands are divided into those associated with termite mouthparts and other head appendages, tegumentary glands with epithelial arrangement, those related to the reproductive apparatus, and glands which do not fit into these divisions. The exocrine systems in termites may be composed of classes 1, 2, and 3 secretory cells, which differ in how the glandular secretion is released. Moreover, they may exhibit a varied composition of secretory cell classes. Different glands may be involved in specific tasks and therefore produce specific compounds, although there are cases in which the same content is secreted by different glands, suggesting a functional plasticity. The chemical nature of these secretions and their role are well known for some glands, such as the frontal, salivary, tergal, and sternal ones. On the other hand, such aspects remain speculative or completely unknown for other glands. The number of termite exocrine glands is extremely low when compared to those described for eusocial Hymenoptera, and is a likely consequence of the higher diversity of species and chemical communication in the latter group. Moreover, vibroacoustic signals represent an important type of communication in termites. Further studies are encouraged to provide new insights into the occurrence and function of the exocrine systems in termites and how they modulate the different activities displayed by them.

Changes in the Intestinal Microbiota in Patients with Chronic Pancreatitis: Systematizing Literature Data

The purpose of the review. To systematize literature data on changes in the structure of the intestinal microbiota in patients with chronic pancreatitis (CP).Key findings. The human intestinal microbiota is a dynamically changing system that is constantly undergoing qualitative and quantitative changes, especially in several pathological conditions of the digestive system. At present, the differences in the intestinal microbiota in pancreatic diseases are poorly understood. The severe CP is associated with impaired synthesis of antimicrobial peptides, bicarbonates, and digestive enzymes by the pancreas, which is a risk factor for dysbiotic changes in the intestinal microbiota, consisting in the development of small intestinal bacterial overgrowth (SIBO) and gut dysbiosis. The results of two large meta-analyses show that about a third of CP patients have SIBO. The colonic microbiota in patients with CP is also characterized by dysbiotic disorders, primarily in the reduction of alpha-diversity. Some studies have shown that these patients have an increase in Firmicutes, while Bacteroides and Faecalibacterium are reduced. In addition, as a rule, in patients with CP, the growth of Escherichia, Shigella and Streptococcus is recorded.Conclusion. In general, scientific papers have revealed significant heterogeneity in the profiles of the intestinal microbiota in patients with CP. Thus, several questions remain open, prioritizing the further study of the intestinal microbiota in patients with CP for identifying the specifics of its structure that can personalize the selection of enzyme replacement therapy and restrict the unreasonable prescription of additional pharmacotherapy (the use of proton pump inhibitors and / or antibacterial drugs).

Estrogen-Related Receptor γ Maintains Pancreatic Acinar Cell Function and Identity by Regulating Cellular Metabolism

Mitochondrial dysfunction disrupts the synthesis and secretion of digestive enzymes in pancreatic acinar cells and plays a primary role in the etiology of exocrine pancreas disorders. However, the transcriptional mechanisms that regulate mitochondrial function to support acinar cell physiology are poorly understood. Here, we aim to elucidate the function of estrogen-related receptor γ (ERRγ) in pancreatic acinar cell mitochondrial homeostasis and energy production. Two models of ERRγ inhibition, GSK5182-treated wild-type mice and ERRγ conditional knock-out (cKO) mice, were established to investigate ERRγ function in the exocrine pancreas. To identify the functional role of ERRγ in pancreatic acinar cells, we performed histologic and transcriptome analysis with the pancreas isolated from ERRγ cKO mice. To determine the relevance of these findings for human disease, we analyzed transcriptome data from multiple independent human cohorts and conducted genetic association studies for ESRRG variants in 2 distinct human pancreatitis cohorts. Blocking ERRγ function in mice by genetic deletion or inverse agonist treatment results in striking pancreatitis-like phenotypes accompanied by inflammation, fibrosis, and cell death. Mechanistically, loss of ERRγ in primary acini abrogates messenger RNA expression and protein levels of mitochondrial oxidative phosphorylation complex genes, resulting in defective acinar cell energetics. Mitochondrial dysfunction due to ERRγ deletion further triggers autophagy dysfunction, endoplasmic reticulum stress, and production of reactive oxygen species, ultimately leading to cell death. Interestingly, ERRγ-deficient acinar cells that escape cell death acquire ductal cell characteristics, indicating a role for ERRγ in acinar-to-ductal metaplasia. Consistent with our findings in ERRγ cKO mice, ERRγ expression was significantly reduced inpatients with chronic pancreatitis compared with normal subjects. Furthermore, candidate locus region genetic association studies revealed multiple single nucleotide variants for ERRγ that are associated with chronic pancreatitis. Collectively, our findings highlight an essential role for ERRγ in maintaining the transcriptional program that supports acinar cell mitochondrial function and organellar homeostasis and provide a novel molecular link between ERRγ and exocrine pancreas disorders.

Shrimp and microplastics: A case study with the Atlantic ditch shrimp Palaemon varians

Many invertebrate species inhabit coastal areas where loads of plastic debris and microplastics are high. In the current case study, we exemplarily illustrate the principal processes taking place in the Atlantic ditch shrimp, Palaemon varians, upon ingestion of microplastics. In the laboratory, shrimp readily ingested fluorescent polystyrene microbeads of 0.1–9.9 µm, which could be tracked within the widely translucent body. Ingested food items as well as micro-particles cumulate in the stomach where they are macerated and mixed with digestive enzymes. Inside the stomach, ingested particles are segregated by size by a complex fine-meshed filter system. Liquids and some of the smallest particles (0.1 µm) pass the filter and enter the midgut gland where resorption of nutrients as well as synthesis and release of digestive enzymes take place. Large particles and most of the small particles are egested with the feces through the hindgut. Small particles, which enter the midgut gland, may interact with the epithelial cells and induce oxidative stress, as indicated by elevated activities of superoxide dismutase and cellular markers of reactive oxygen species. The shrimp indiscriminately ingest microparticles but possess efficient mechanisms to protect their organs from overloading with microplastics and other indigestible particles. These include an efficient sorting mechanism within the stomach and the protection of the midgut gland by the pyloric filter. Formation of detrimental radical oxygen species is counteracted by the induction of enzymatic antioxidants.

Growth of Pancreas and Intestinal Enzyme Activities in Growing Goats: Influence of a Low-Protein Diet

A dependence between dietary protein and starch levels flowing to the duodenum has been characterized in monogastric animals for optimal enzymatic secretions of the pancreas, but those in ruminants remain unclarified. The present experiment was conveyed to assess the pancreas growth and mRNA expression of the small intestine enzymes in growing goats fed a low-protein diet. Twenty-four Liuyang goats (19.55 ± 3.55 of body weight (BW)) and aged approximately 8 months were randomly assigned to either a control protein diet (NP: 10.77% CP) or a low-protein diet (LP: 5.52% CP) for 70 days. The results show that no statistical differences (p > 0.05) were observed in the pancreas growth indices between the groups. Pancreas and small intestine α-amylase and lipase activities were unaffected (p > 0.05) by the LP diet, while activities of trypsin and chymotrypsin were decreased (p < 0.05). The LP diet reduced (p < 0.05) the mRNA expressions of trypsin and chymotrypsin in the duodenum and jejunum, and had no effects (p > 0.05) on the mRNA expressions of α-amylase and lipase. Goats fed with the LP diet had higher (p < 0.05) concentrations of cholecystokinin and insulin than those fed with the NP diet. In conclusion, feeding an LP diet (5.52% CP) had no profound influence on pancreas growth and digestive enzyme synthesis in goats.

The Benefit and The Content of Lactic Acid Bacteria “Lactobacillus casei Shirota Strain” in Yakult

The purpose of this article is to determine the content of lactic acid bacteria in a probiotic beverage (Yakult) with a starter fermentation of Lactobacillus casei Shirota strain and to find out its benefits for digestion. In this study, the library research method was used by obtaining data and materials from journals. The author tries to describe the content of lactic acid bacteria “L. casei Shirota strain” in Yakult and its benefits for the digestive system. The results showed that the levels of L. casei Shirota strain in fermented milk were 1.27-1.70% with an average of 1.42%. In the Indonesian National Standard 01-2891-2009, the lactic acid bacteria content of L. casei Shirota in fermented milk was 0.5-2.0%. L. casei Shirota can produce lactic acid and acetic acid, so that, it can decrease intestinal pH and prevent pathogens bacteria’s growth. Probiotic beverage from fermented milk using L. casei is beneficial for consumption for its ability in inhibiting the growth and development of pathogenic bacteria in the gastrointestinal tract, help the absorption of vitamins and antioxidants, eliminate toxic components contained in food, as well as producing several vitamins through the synthesis of digestive enzymes.

Dietary Protein and Amino Acid Deficiency Inhibit Pancreatic Digestive Enzyme mRNA Translation by Multiple Mechanisms.

Background & AimsChronic amino acid (AA) deficiency, as in kwashiorkor, reduces the size of the pancreas through an effect on mammalian target of rapamycin complex 1 (mTORC1). Because of the physiological importance of AAs and their role as a substrate, a stimulant of mTORC1, and protein synthesis, we studied the effect of acute protein and AA deficiency on the response to feeding.MethodsICR/CD-1 mice were fasted overnight and refed for 2 hours with 4 different isocaloric diets: control (20% Prot); Protein-free (0% Prot); control (AA-based diet), and a leucine-free (No Leu). Protein synthesis, polysomal profiling, and the activation of several protein translation factors were analyzed in pancreas samples.ResultsAll diets stimulated the Protein Kinase-B (Akt)/mTORC1 pathway, increasing the phosphorylation of the kinase Akt, the ribosomal protein S6 (S6) and the formation of the eukaryotic initiation factor 4F (eIF4F) complex. Total protein synthesis and polysome formation were inhibited in the 0% Prot and No Leu groups to a similar extent, compared with the 20% Prot group. The 0% Prot diet partially reduced the Akt/mTORC1 pathway and the activity of the guanine nucleotide exchange factor eIF2B, without affecting eIF2α phosphorylation. The No Leu diet increased the phosphorylation of eIF2α and general control nonderepressible 2, and also inhibited eIF2B activity, without affecting mTORC1. Essential and nonessential AA levels in plasma and pancreas indicated a complex regulation of their cellular transport mechanisms and their specific effect on the synthesis of digestive enzymes.ConclusionsThese studies show that dietary AAs are important regulators of postprandial digestive enzyme synthesis, and their deficiency could induce pancreatic insufficiency and malnutrition.

Fine structure of Aldrovanda vesiculosa L: the peculiar lifestyle of an aquatic carnivorous plant elucidated by electron microscopy using cryo-techniques.

The aquatic carnivorous plant Aldrovanda vesiculosa L. is critically endangered worldwide; its peculiar lifestyle raises many questions and poses problems both intriguing on their own and relevant to conservation. While establishing a culture system for its propagation and restoring its natural habitat in Hozoji pond in Saitama, Japan, we conducted ultrastructural observations to examine the various aspects of Aldrovanda's way of life. Electron microscopic observation in combination with cryo-techniques produced novel information which could not be obtained by other methods. Some of the results are: phosphorous is stored in petiole cells of turions during winter; mucilaginous guides are provided for pollen tubes in parietal placental ovaries; storage of potassium in the vicinity of the midrib of carnivorous leaves may contribute to the rapid closing of the carnivorous leaves; dynamic sequential changes of the ultrastructure of digestive glands are involved in the synthesis and secretion of digestive enzymes, including protease and acid phosphatase. These results should contribute significantly to our understanding of Aldrovanda and the detailed mechanisms of its life.

Leucine Regulates the Exocrine Function in Pancreatic Tissue of Dairy Goats In Vitro.

This study aimed to investigate the effects of leucine (Leu) on the synthesis and secretion of digestive enzymes in cultured pancreatic tissue of dairy goats and on the signaling molecules. Fresh pancreatic tissue from dairy goats was cut into approximately 2 mm × 2 mm pieces and incubated in oxygenated Krebs-Ringer bicarbonate buffer containing 0 (the control), 0.40, 0.80, or 1.60 mM Leu at 39°C in a CO2 incubator for 180 min. The results showed that Leu increased the release of α-amylase, trypsin, and chymotrypsin in the buffer and tissue, as well as the total activity (P < 0.05), especially at 0.40 and 0.80 mM. Compared with the control, 1.60 mM Leu increased the release of α-amylase and the total activity of trypsin and chymotrypsin (P < 0.05) but had no effect on the tissue concentration of α-amylase, trypsin, and chymotrypsin or the total activity of α-amylase (P > 0.05). Leu improved the mRNA expression of α-amylase, trypsin, and chymotrypsin (P < 0.05), especially at 0.80 and 1.60 mM. The activity and mRNA expression of lipase were not affected (P > 0.05). Compared with the control, 0.40 and 0.80 mM Leu increased the expression of the γ isoform of 4EBP1 (P < 0.05), implying increased phosphorylation of 4EBP1. Leu increased the phosphorylation of S6K1 (P < 0.05). Compared with the control, 0.40 and 0.80 mM Leu decreased the eEF2 phosphorylation level (P < 0.05). Conclusively, these results suggested that Leu could regulate the synthesis of pancreatic enzymes by increasing the mRNA expression and phosphorylation level of protein factors in the mammalian target of rapamycin pathway and the optimal Leu level in this experiment was 0.80 mM.

Structure, function and development of the digestive system in malacostracan crustaceans and adaptation to different lifestyles.

The digestive system of the malacostracan crustaceans, namely the decapods, isopods, amphipods and mysids, is among the most complex organ systems of the animal kingdom serving multiple functions such as food processing, absorption and storage of nutrients, synthesis of digestive enzymes and blood proteins, detoxification of xenobiotics and osmoregulation. It is rather well investigated compared to other invertebrates because the Malacostraca include many ecological keystone species and food items for humans. The Decapoda and Peracarida share food processing with chewing and filtering structures of the stomach but differ with respect to morphology and ultrastructure of the digestive glands. In the Peracarida, the digestive glands are composed of few, relatively large lateral caeca, whereas in the Decapoda, hundreds to thousands of blindly ending tubules form a voluminous hepatopancreas. Morphogenesis and onset of functionality of the digestive system strongly depend on the mode of development. The digestive system is early developed in species with feeding planktonic larvae and appears late in species with direct lecithotrophic development. Some structures of the digestive system like the stomach ossicles are rather constant in higher taxa and are of taxonomic value, whereas others like the chewing structures are to some degree adapted to the feeding strategy. The nutrient absorbing and storing cells of the digestive glands show considerable ultrastructural variation during moult cycle, vitellogenesis and starvation. Some of the various functions of the digestive system are already assigned to specific sections of the digestive tract and cell types, but others still await precise localization.

Isoleucine Regulates the Synthesis of Pancreatic Enzymes via the Activation of mRNA Expression and Phosphorylation in the Mammalian Target of Rapamycin Signalling Pathways in Pancreatic Tissues.

This study aimed to investigate the effects of isoleucine (Ile) on the synthesis and secretion of digestive enzymes and cellular signalling in the pancreatic tissue of dairy goats. The pancreatic tissues were incubated in buffer containing 0, 0.40, 0.80, and 1.60 mM Ile. High levels of Ile significantly increased the buffer release and total concentration of ɑ-amylase in the tissues (P < 0.001). The total trypsin and chymotrypsin concentrations in each of the Ile groups were significantly higher than those in the control group (P < 0.05); however, lipase was not affected. High levels of Ile significantly increased ɑ-amylase mRNA expression (P < 0.001) but had no effect on the mRNA expression of trypsin, chymotrypsin, or lipase. Ile did not affect S6K1 phosphorylation levels. High levels of Ile significantly increased the expression of the γ isoform of 4EBP1 (P < 0.001), which indicated that the phosphorylation of 4EBP1 was significantly increased. The phosphorylation level of eEF2 gradually decreased with the addition of Ile (P < 0.001). These results suggested that high doses of Ile can regulate the excretion of enzymes, especially ɑ-amylase, in the pancreatic tissues of dairy goats by modulating mTOR signalling, and this regulation is independent of the mTOR-S6K1 pathway.