Aquaporin Research Articles

A Step Forward in Understanding the Expression of Classical Aquaporins in the Male Reproductive Tract: Study Findings in Cattle (Bos taurus).

Aquaporins (AQPs), also known as water channels, appear to be particularly promising in maintaining male reproductive potential. Therefore, this study aimed to determine the presence of classical AQPs in the bovine (Bos taurus) reproductive system and analyze changes in their expression with age using immunohistochemistry and Western blotting. Of the six classical AQPs, AQP0, AQP1, AQP4, AQP5 and AQP6 were detected, while AQP2 was absent. In the testis, AQP0 was visible in Leydig cells in selected animals, while AQP1 was found in myoid cells surrounding the seminiferous tubules of mature individuals. This characteristic expression patterns of AQP0, limited only to certain bulls, is difficult to explain unequivocally. It is possible that AQP0 expression in cattle is subject to individual variability or changes in response to specific physiological conditions. In the caput and corpus epididymis, AQP0 showed weak expression in epithelial cells of immature animals and stronger expression in basal and principal cells of reproductive bulls. In all animals, AQP1 was present on the apical surface of epithelial cells in the initial segment of the caput epididymis. AQP4, AQP5 and AQP6 were identified in principal and basal cells along the entire epididymis of reproductive bulls. The abundance of AQP4 and AQP6 increased from the caput to the cauda epididymis with the growth and development of the animals. In all males, AQP4, AQP5 and AQP6 were observed in epithelial cells of the vas deferens, and their expression in this section increased with age. In conclusion, the abundance and distribution of the classical AQPs in various cell types and parts of the male reproductive system indicate their crucial role in maintaining water homeostasis, which is essential for normal reproductive function in cattle.

Shy–bold behaviours in dragonfly larvae: syndromes or personality?

Abstract Researchers have recently focused efforts on the study of animal personality and behavioural syndromes, exploring consistent behaviour variations and correlations. Dragonflies, with their diverse behaviours, have become good models to improve our knowledge on animal behaviour. Here, we addressed whether dragonfly larvae exhibit shy–bold behaviours, akin to personality traits or behavioural syndromes. We made a series of experiments where we restrained larvae and noted their behaviour — some larvae exhibited thanatosis, playing dead when touched, while others boldly reacted with aggression. Later, we tested how active the larvae were in a water channel by analysing their movement. These experiments were made in three trials with 15 days apart. Our results show that larvae display consistent behaviours over time, hence, they exhibit personalities in terms of predator avoidance behaviour. Nevertheless, we found little evidence for behavioural syndromes. The boldness of larvae was only partially correlated with larval activity in the experimental channel. In conclusion, dragonflies emerge as a potential model for insect personality, prompting future studies on how cognition and personality impact fitness in different environments. Unravelling whether behavioural syndromes are a true phenomenon in these insects awaits further investigation.

Efficient generation of a stable CHO-K1 cell line overexpressing the human water channel aquaporin-5 as tool to generate therapeutic antibodies

Aquaporins (AQPs) are a family of water permeable channels expressed on the plasma membrane with AQP5 being the major channel expressed in several human tissues including salivary and lacrimal glands. Anti-AQP5 autoantibodies have been observed in patients with Sjögren’s syndrome who are characterised by dryness of both salivary and lacrimal glands, and they have been implicated in the underlying mechanisms of glandular dysfunction. AQP5 is formed by six transmembrane helices linked with three extracellular and two intracellular loops. Develop antibodies against membrane protein extracellular loops can be a challenge due to the difficulty in maintaining these proteins as recombinant in their native form. Therefore, in this work we aimed to generate an efficient stable-transfected cell line overexpressing human AQP5 (CHO-K1/AQP5) to perform primarily cell-based phage display biopanning experiments to develop new potential recombinant antibodies targeting AQP5. We also showed that the new CHO-K1/AQP5 cell line can be used to study molecular mechanisms of AQP5 sub-cellular trafficking making these cells a useful tool for functional studies.

Toward A Micrometeorological Assessment Of Agrivoltaic Farms: A Feature Tracking Velocimetry-Based Analysis

We investigate the flow dynamics around a model of an array of photovoltaic panels via laboratory experiments conducted in a water channel. The model farm consists of transparent polycarbonate panels with varying tilt angles, simulating different configurations typical of agrivoltaic systems. Velocities are measured using a feature tracking velocimetry technique. Results reveal distinct flow structures depending on the tilt angle of the panels and the distance between them, with varying numbers of recirculation regions observed. An increase in the distance between panels stretches the recirculation regions along the streamwise direction. Turbulent kinetic energy is more intense with negative tilt angles, and upstream turbulence penetrates more between panels. These findings suggest different transport and heat transfer properties, particularly relevant for tracker PV arrays that adjust tilt angles throughout the day. Understanding these dynamics is crucial for optimizing the design and operation of agrivoltaic farms to maximize energy production while minimizing impacts on agricultural productivity and the surrounding environment.

Microfiber Rotational Dynamics In Turbulence

We measure the effect of turbulence on spinning and tumbling rates of microfibers in wall-bounded turbulence. The measurements are performed in a turbulent water channel at Reτ 720. Fibres are 1.2 mm long and 10 m in diameter (aspect ratio 120). Their length ranges from 4 to 12 Kolmogorov length scales. They are neutrally buoyant, inertial-less, and rigid in these flow conditions. Six high-speed cameras image the fibres at the channel centre and in a near-wall region. We employ and further refine a technique of tomographic fibre reconstruction and tracking. Their curved shape is used to define a fibre-fixed reference frame and measure its time-resolved orientation. Thus measurements of tumbling and spinning rates are enabled. We provide a discussion about the uncertainty on the rotation rates based on their shape and angular displacement between time-steps. Based on converged statistics, we observed that the mean and mean square spinning are higher than tumbling rates at both channel centre and near-wall region. In addition, our study reveals that slender, curved fibres behave akin to straight rods, yet their curved shape provides a unique advantage: this curvature allows us to measure all rotational components.

The Effect of Removal of External Proteins PsbO, PsbP and PsbQ on Flash-Induced Molecular Oxygen Evolution and Its Biphasicity in Tobacco PSII.

The oxygen evolution within photosystem II (PSII) is one of the most enigmatic processes occurring in nature. It is suggested that external proteins surrounding the oxygen-evolving complex (OEC) not only stabilize it and provide an appropriate ionic environment but also create water channels, which could be involved in triggering the ingress of water and the removal of O2 and protons outside the system. To investigate the influence of these proteins on the rate of oxygen release and the efficiency of OEC function, we developed a measurement protocol for the direct measurement of the kinetics of oxygen release from PSII using a Joliot-type electrode. PSII-enriched tobacco thylakoids were used in the experiments. The results revealed the existence of slow and fast modes of oxygen evolution. This observation is model-independent and requires no specific assumptions about the initial distribution of the OEC states. The gradual removal of exogenous proteins resulted in a slowdown of the rapid phase (~ms) of O2 release and its gradual disappearance while the slow phase (~tens of ms) accelerated. The role of external proteins in regulating the biphasicity and efficiency of oxygen release is discussed based on observed phenomena and current knowledge.

Unexpected Self-Assembly of Nanographene Oxide Membranes upon Electron Beam Irradiation for Ultrafast Ion Sieving.

Nanographene oxide (nGO) flakes-graphene oxide with a lateral size of ≈100nm or less-hold great promise for superior flux and energy-efficient nanofiltration membranes for desalination and precise ionic sieving owing to their unique high-density water channels with less tortuousness. However, their potential usage is currently limited by several challenges, including the tricky self-assembly of nano-sized flakes on substrates with micron-sized pores, severe swelling in aqueous solutions, and mechanical instability. Herein, the successful fabrication of a robust membrane stacked with nGO flakes on a substrate with a pore size of 0.22µm by vacuum filtration is reported. This membrane achieved an unprecedented water permeance above 819.1 LMH bar-1, with a high rejection rate of 99.7% for multivalent metal ions. The nGO flakes prepared using an electron beam irradiation method, have uniquely pure hydroxyl groups and abundant aromatic regions. The calculations revealed the strong hydrogen bonds between two nGO flakes, which arise from hydroxyl groups, coupled with hydrophobic aromatic regions, greatly enhance the stability of stacked flakes in aqueous solutions and increase their effective lateral size. The research presents a simple yet effective approach toward the fabrication of advanced 2D nanographene membranes with superior performance for ion sieving applications.

Kármán Street-Boundary Layer Interactions In Turbulent Flow

Understanding the intricate interplay between turbulent boundary layers and wake structures caused by obstacles in the flow is key to assessing the local shear stress fields as well as the drag. These types of flows can be relevant to natural phenomena including sediment and nutrient transport. While existing literature predominantly explores the flow downstream of cylinders mounted perpendicular to bounding surfaces or downstream of cylinders positioned outside the boundary layer region, this work experimentally studies the turbulent boundary layer passing over a cylindrical obstacle positioned near and parallel to the surface of an underlying solid wall. Planar particle image velocimetry (PIV) was performed in an open recirculating water channel for three test cases at a friction Reynolds number Reτ = 1320. Key parameters investigated include the cylinder diameter relative to the boundary layer thickness (D/δ = 0.09 and 0.01) and the gap between the cylinder and the wall (G/δ = 0.09), where the range of D/δ used is smaller than most examples found in the literature. Instantaneous and averaged velocity and vorticity fields are examined based on the PIV measurements. The results in Fig. 1 show how von Kármán vortex streets and turbulent boundary layer structures interact to form unique flow features. The larger cylinder generates a clear separation downstream of its axis as well as a wake that remains coherent over a distance δ downstream. The smaller cylinder with D/δ = 0.01 generates a much narrower and weaker wake, but still shows a clear influence on time-averaged velocity profile. Future experiments will evaluate flow conditions further downstream as well as additional values of G/δ for the same D/δ values.

Effects of dissolved organic matter on distribution characteristics of heavy metals and their interactions with microorganisms in soil under long-term exogenous effects

Long-term waste accumulation (LTWA) in soil not only alters its physical and chemical properties but also affects heavy metals and microorganisms in polluted soil through the dissolved organic matter (DOM) it produces. However, research on the impact of DOM from LTWA on heavy metals and microorganisms in polluted soil is limited, which has resulted in an incomplete understanding of the mechanisms involved in LTWA soils remediation. This study focuses on the DOM generated by waste accumulation and analyses the physicochemical properties, microbial community structure, and vertical distribution of heavy metals in four types of LTWA soils at different depths (0–100 cm). A causal analysis is conducted using structural equation modelling. The results indicate that due to the retention effect of the soil and microorganisms, heavy metal pollution is concentrated on the soil surface layer (>30 cm). With increasing depth, there is a decrease in heavy metal concentration and an increase in microbial diversity and abundance. DOM plays a significant role in regulating the concentration of soil heavy metals and the diversity and abundance of microorganisms. The DOM from different soils gradually transforms into substances dominated by tyrosine, tryptophan, and fulvic acid, which sustain the normal life activities and gene expression of microorganisms. Bacteria such as Pseudarthrobacter, Desulfurivibrio, Thiobacillus, and Sulfurimonas, which are involved in energy transformation, along with genes such as water channel protein and YDIF, which enhance heavy metal metabolism, ensure that microbial communities can maintain basic life processes in polluted environments and gradually select for dominant species that are adapted to heavy metal pollution. These novel discoveries illuminate the potential for modulating the composition of DOM to amplify microbial activity, while concurrently offering insights into the migration patterns of various long-term exogenous pollutants. This foundational knowledge provides a foundation for the development of efficacious remediation strategies.

Structural and functional analysis of aquaporins in Bombus terrestris

Bombus terrestris are efficient pollinators in forestry and agriculture, with higher cold tolerance than other bees. Yet, their cold tolerance mechanism remains unclear. Aquaporins (AQPs) function as cell membrane proteins facilitating rapid water flow, aiding in osmoregulation. Recent studies highlight the importance of insect AQPs in dehydration and cold stress. Comparative transcriptome analysis of B. terrestris under cold stress revealed up-regulation of four AQPs, indicating their potential role in cold tolerance. Seven AQPs—Eglp1, Eglp2, Eglp3, DRIP, PRIP, Bib, and AQP12L—have been identified in B. terrestris. These are widely expressed in various tissues, particularly in the alimentary canal and Malpighian tubules. Functional analysis of BterAQPs in the Xenopus laevis oocytes expressing system showed distinct water and glycerol selectivity, with BterDrip exhibiting the highest water permeability. Molecular modeling of BterDrip revealed six transmembrane domains, two NPA motifs, and an ar/R constriction region (Phe131, His256, Ser265, and Arg271), likely contributing to its water selectivity. Silencing BterDRIP accelerated mortality in B. terrestris under cold stress, highlighting the crucial role of BterDRIP in their cold tolerance and providing a molecular mechanism for their cold adaptation.

An insight into physicochemical properties of hexagonal lyotropic liquid crystal templates from amphiphiles for mesoporous structural administration

Hexagonal lyotropic liquid crystals (HLLC) provide an ideal template for the fabrication of nanofiltration membranes without the flux-selectivity trade-off problem. Amphiphiles, the core components of the columnar micelles in the HLLC system, play a key role in regulating the nanostructure, their effects on dimensional stability and physicochemical properties of the system however have not been explored well. In this research, we compared the dimensional stability and physicochemical properties of HLLC templates prepared from amphiphiles with various head groups and tail lengths. The amphiphiles with charged head groups (dodecyl trimethylammonium bromide, DTAB, and hexadecyl trimethylammonium bromide, CTAB) enable more monomers to be introduced and a much smaller (∼ 1/2) pore size than that with uncharged ones (polyethylene glycol hexadecyl ether, Brij56). The tail length however mainly regulates the width of water channels with CTAB being 23.27 Å and DTAB about 17.06 Å when the head groups are identical. Although the HLLC systems with CTAB and DTAB present a little bit higher phase transition temperature, the dynamic mechanical stability is much better than that with Brij56 at room temperature, facilitating the reorientation process under an electric force with the order parameter reaching to about 0.9 and the retention of the aligned nanostructure with the absence of the force at room temperature. The study enables a better understanding of the effects of amphiphiles on HLLC templates and their tunability for advanced nanofiltration membranes.

Effects of atmospheric pressure plasma treatment on the quality and cellulose modification of brown rice

This study investigates the effect of atmospheric pressure dielectric barrier pulsed discharge plasma treatment on cooking quality and cellulose modification of brown rice. The results showed that 15 min of plasma treatment reduced the cooking time, hardness, and chewiness of brown rice by 27.40%, 30.68%, and 40.23%, respectively, compared to the control. The etching of the brown rice skin and the formation of water channels lead to increased water absorption. This led to a significant increase in palatability of the treated brown rice. In addition, the crystallinity and average particle size (Dhkl) of the treated brown rice were reduced to 10.93% and 42.85% of the initial level, respectively, and the cellulose solubility increased from 8.20% to 55.20%. The surface microstructure was also found to fracture and destroy of the cellulose structure. These findings suggest that plasma made the originally dense fiber structure of brown rice epidermis loose through the etching effect, thus improving the cooking quality of brown rice. The present conclusions offer fundamental insights into the interaction between plasma treatment and brown rice, which should be beneficial for applying plasma in whole-grain processing.

Leveraging the genetic diversity of trout in the rivers of the British Isles and northern France to understand the movements of sea trout (Salmo trutta L.) around the English Channel.

Populations of anadromous brown trout, also known as sea trout, have suffered recent marked declines in abundance due to multiple factors, including climate change and human activities. While much is known about their freshwater phase, less is known about the species' marine feeding migrations. This situation is hindering the effective management and conservation of anadromous trout in the marine environment. Using a panel of 95 single nucleotide polymorphism markers we developed a genetic baseline, which demonstrated strong regional structuring of genetic diversity in trout populations around the English Channel and adjacent waters. Extensive baseline testing showed this structuring allowed high-confidence assignment of known-origin individuals to region of origin. This study presents new data on the movements of anadromous trout in the English Channel and southern North Sea. Assignment of anadromous trout sampled from 12 marine and estuarine localities highlighted contrasting results for these areas. The majority of these fisheries are composed predominately of stocks local to the sampling location. However, there were multiple cases of long-distance movements of anadromous trout, with several individuals originating from rivers in northeast England being caught in the English Channel and southern North Sea, in some cases more than 1000 km from their natal region. These results have implications for the management of sea trout in inshore waters around the English Channel and southern North Sea.

Study on the effect of marine propeller wake on sediment siltation in a shallow water channel

Study on the effect of marine propeller wake on sediment siltation in a shallow water channel

Tissue-free water tritium and non-exchangeable organically bound tritium concentrations in fish near coastline during and after operation of Japan's first nuclear fuel reprocessing facility

The risks from radioactive wastewater release from nuclear facilities into the ocean are a global concern. Radioactive contaminants, such as tritium (3H), in both forms of tissue free water tritium (TFWT) and non-exchangeable organically bound tritium (NE-OBT), can be incorporated into marine biota and cause radiation doses to biota and future consumers. However, no studies have been conducted to measure both forms of 3H in marine fish as well as evaluate the residence time in the vicinity of a nuclear fuel reprocessing facility. Here, fish from a brackish lake and from the Pacific Ocean coastline of Japan, which are near such a facility, were collected between 2006 and 2021. The reprocessing facility was operational between 2006 and 2009, during which time about 300 times more tritiated water was discharged per year into the ocean compared to the period when the facility was not operational. During operation the annual release was 30 times higher than the treated water released annually from Fukushima Daiichi. As expected, TFWT and NE-OBT concentrations increased in marine fish during operations and had peak values of 3.59 ± 0.03 and 0.56 ± 0.03 Bq/L, respectively. Total dose rates to the fish were 36,000 times lower than the 10 μGy h−1 benchmark. Concentrations gradually decreased to pre-operational levels as the facility was turned off with NE-OBT taking twice as long. Fish sampled from the brackish lake tended to have more incorporated TFWT and NE-OBT concentrations than ocean fish. This indicates that ocean tides might have contributed to the accumulation of discharged tritiated water in the lake via a narrow water channel, which highlights the importance of examining all marine ecosystems in future operations. In both marine environments, the estimated committed effective dose using the highest observed data through ingestion was well below public limits (91,000 times lower).

The Evaluation of the Quality of Local Water Company Tirta Anoa Processed Water in the Community of West Kendari District, Kendari City

Backgrounds: The government has the task of collecting, purifying and distributing clean water from water terminals via water channels, pipes or tank cars (in administrative management units with economic activities) to homes, industrial companies or other commercial uses. For this reason, Local water company has the responsibility to provide clean water for all groups of people in an area. Methods: This type of research is observational research with a descriptive approach to get an overview of the quality of Local water company Tirta Anoa's processed water. Water quality sampling was carried out in 9 sub-districts in West Kendari District, which is the sub-district with the largest population of 44,290 people. Results: The results of the pollution index analysis for TDS parameters show that river waters in the study study area at 7 monitoring points are still classified as meeting water quality standards, namely still below 1,000 mg/L. The highest TDS content was found at station 5 (AB.03 = 611 mg/L) and station 6 (AB.04 = 614 mg/L), while the lowest TDS value was at station 2 (AB.02 = 193 mg/L). And the concentration of TSS parameters is still below the quality standard, namely monitoring point 1 (AP.01 to 5 (AB.05) respectively 4.7 mg/L; 3.4 mg/L; 2.6 mg/L ; 3.7 mg/L; 3.9 mg/L; Conclusion: There is water quality (physics, chemistry, biology) from Local water company Tirta Anoa processed water which has been consumed by the community in West Kendari.

Adaptation of Wetland Farming Communities to Modernization: Case Study in Jelapat 1 Village, Indonesia

Modernization can bring progress on the one hand, but on the other hand, modernization may not provide the expected benefits, such as increasing dependence on expensive agricultural inputs and climate change which has an impact on agricultural practices. The main theme of the research is wetland farming communities facing the flow of modernization to outline farming community strategies in adapting wetland farming practices. This research uses a qualitative approach with a case study method based on considering the specificity of the theme according to the characteristics of the research area in Jelapat 1 Village, Tamban District, Barito Kuala Regency. Informants were selected purposively using the criteria of character, membership of farmer groups, and willingness to become informants. Data was collected using observation methods, in-depth interviews, and documentation to obtain valid and varied data. Data were analyzed through data reduction, data presentation, and conclusion drawing stages. For data credibility, triangulation techniques were used. The research results show that farmers in Jelapat 1 Village face water conditions that always inundate agricultural land, which is difficult to control due to strong natural factors. The challenges faced by farmers besides pasang pandit are also dwarf pests and birds. Concerning modernization, it can be concluded that farmers in Jelapat 1 Village use traditional knowledge in adapting agricultural practices in wetlands, namely, arranging planting patterns, making simple water channels, selecting superior seeds that suit wetland criteria, and using organic fertilizer. This phenomenon indicates the conservation of local wisdom in wetland farming in Jelapat 1 Village by the farming community.

Pathological remodeling of reactive astrocytes: Involvement of DNA methylation and downregulation of homeostatic genes.

Astrocytes provide metabolic support to neurons, maintain ionic and water homeostasis, and uptake and recycle neurotransmitters. After exposure to the prototypical PAMP lipopolysaccharide (LPS), reactive astrocytes increase the expression of pro-inflammatory genes, facilitating neurodegeneration. In this study, we analyzed the expression of homeostatic genes in astrocytes exposed to LPS and identified the epigenetic factors contributing to the suppression of homeostatic genes in reactive astrocytes. Primary astrocytic cultures were acutely exposed to LPS and allowed to recover for 24, 72 h, and 7 days. As expected, LPS exposure induced reactive astrogliosis and increased the expression of pro-inflammatory IL-1B and IL-6. Interestingly, the acute exposure resulted in persistent hypermethylation of astroglial DNA. Similar hypermethylation was observed in highly reactive astrocytes from the traumatic brain injury (TBI) penumbra invivo. Hypermethylation was accompanied by decreased expression of homeostatic genes including LDHA and Scl16a1 (MCT1) both involved in the lactate shuttle to neurons; glutamine synthase (GS) responsible for glutamate processing; Kcnj10 (Kir4.1) important for K+ homeostasis, and the water channel aquaporin-4 (Aqp4). Furthermore, the master regulator of DNA methylation, MAFG-1, as well as DNA methyl transferases DNMT1 and DNMT3a were overexpressed. The downregulation of homeostatic genes correlated with increased methylation of CpG islands in their promoters, as assessed by methylation-sensitive PCR and increased DNMT3a binding to the GS promoter. Treatment with decitabine, a DNMT inhibitor, prevented the LPS- and the HMGB-1-induced downregulation of homeostatic genes. Decitabine treatment also prevented the neurotoxic effects of these astrocytes in primary cortical cultures. In summary, our findings reveal that the pathological remodeling of reactive astrocytes encompasses not only the pro-inflammatory response but, significantly, also entails a long-term suppression of homeostatic gene expression with methylation of crucial CpG islands within their promoters.

Monitoring of the Icing Process and Simulation of Its Formation Mechanism in the Cut Slope of Beihei Highway

Icing in cut slopes is a serious risk to transportation safety in cold regions. Research on the occurrence process and mechanism of icing is a prerequisite for proposing effective management measures. We took the cut slopes of the K162 section of the Beihei Highway as the research object. We used a combination of field investigation, geological exploration, monitoring, and simulation to study and analyze the power source, occurrence process, and triggering mechanism of icing in cut slopes. The results show that the geologic type of this cut slope is a mudstone–sandstone interaction stratum. Abundant shallow groundwater is the source of water for icing. The excavation of cut slopes extends the effect of negative temperatures on groundwater flow during the winter period. The process of ice formation in cut slopes can be described as follows: As the environmental temperature drops, the surface soil begins to freeze, resulting in a gradual narrowing of the water channel; then, the groundwater flow is blocked, so that the internal pressure begins to rise. When the internal pressure of the pressurized groundwater exceeds the strength of the frozen soil, groundwater overflows from the sandstone layer to the surface, forming icing. The high pore water pressure inside the cut slope is the precursor for the occurrence of icing. The dynamic pressure of the pore water pressure is the main driving force for the formation of icing in cut slopes. The obstruction of the water channel due to ground freezing is the triggering condition for ice formation in cut slopes.

Development and experimental validation of analytical models for water and mud inrushes through a filled karst conduit

Water or mud inrush has become a common geological disaster during tunnel construction in karst areas. To study forming process and mechanism of water and mud inrushes through a filled karst conduit, water inrush and mud inrush model tests were carried out with a self-developed 3D model test system. The results show that the forming processes of water inrush and mud inrush have different forming modes. For water inrush, the forming process follows: flowing instability of filling material particles—formation of water inrush channel—water inrush occurring; while for mud inrush, the forming process follows: stability—sliding instability of the whole filling material suddenly—mud inrush occurring. Accordingly, a local instability model of critical hydraulic pressure causing water inrush and an integral sliding instability model of critical hydraulic pressure causing mud inrush were established respectively. The two analytical models reveal the mechanism of water inrush and mud inrush experiments to an extent. The calculated critical hydraulic pressures for water inrush and mud inrush are in good agreement with the test results. The distinguishment of water inrush and mud inrush through a karst conduit was discussed based on the critical hydraulic pressure and the evolution law of seepage water pressure in tests, and a criterion was given. The research results might provide guidance for the forecast of water and mud inrush disasters during the construction of tunnels in karst area.