Anatomical features in the kidney involved in water conservation through urine concentration in dromedaries (Camelus dromedarius)

A Comparative Study on Kidney Morphology of Anatolian Ground Squirrels, Rabbits, and Rats

In this study, the kidneys of ground squirrels (hibernated and nonhibernated), rabbits, and rats were examined macro and microanatomically. Kidney morphology was investigated by stereo microscopy, light microscopy, and scanning electron microscopy. Triple and immunohistochemical staining were performed for light microscopic examinations. Cold crushing and takilon injection into the renal arteries were performed for scanning electron microscopic examinations. The course and branching of intrarenal capillaries and morphologic features from glomeruli to foramina papillaria were demonstrated. The location, position, shape, weight, and size of the kidneys of the three species studied were determined. Relative medullary thickness (RMT) and kidney index (Ki) values were calculated from the measurements. Based on the RMT values of the three species, it was concluded that they are mammals belonging to the semiarid and humid habitat category. The number of nephrons with long segments was high in the kidneys of all three species. Structural findings suggested that the rat may produce more concentrated urine than the ground squirrel, and the ground squirrel may produce more concentrated urine than the rabbit. The mean diameter of the renal corpuscles was 112.5 μm in the hibernated ground squirrel, 137.6 μm in the nonhibernated ground squirrel, 138.1 μm in the rabbit, and 137.8 μm in the rat. In hibernated ground squirrels, a narrowing of the cavum glomeruli and a decrease in renal corpuscle diameters were found. In contrast to ground squirrel and rat kidneys, rabbit kidneys showed the presence of species-specific subcapsular glomeruli. Immunohistochemistry (antinestin antibody) staining and scanning electron microscope (SEM) images revealed the structure of podocytes in detail. Species-specific area cribrosa configurations were detected in the renal papillae of the kidneys we examined. With this study, new renal morphological findings were obtained in ground squirrels, rabbits, and rats.

Serum Starvation Enhances the Antitumor Activity of Natural Matrices: Insights into Bioactive Molecules from Dromedary Urine Extracts

Natural matrices have historically been a cornerstone in drug discovery, offering a rich source of structurally diverse and biologically active compounds. However, research on natural products often faces significant challenges due to the complexity of natural matrices, such as urine, and the limitations of bioactivity assessment assays. To ensure reliable insights, it is crucial to optimize experimental conditions to reveal the bioactive potential of samples, thereby improving the validity of statistical analyses. Approaches in metabolomics further strengthen this process by identifying and focusing on the most promising compounds within natural matrices, enhancing the precision of bioactive metabolite prioritization. In this study, we assessed the bioactivity of 17 dromedary urine samples on human renal cells under serum-reduced conditions (1%FBS) in order to minimize possible FBS-derived interfering factors. Using viability assays and Annexin V/PI staining, we found that the tumor renal cell lines Caki-1 and RCC-Shaw were more sensitive to the cytotoxic effects of the small molecules present in dromedary urine compared to non-tumor HK-2 cells. Employing NMR metabolomics analysis combined with detected in vitro activity, our statistical model highlights the presence of bioactive compounds in dromedary urine, such as azelaic acid and phenylacetyl glycine, underscoring its potential as a sustainable source of bioactive molecules within the framework of green chemistry and circular economy initiatives.

Review on camel genetic diversity: ecological and economic perspectives

Camels, known as the "Ship of the Desert," play a vital role in the ecosystems and economies of arid and semi-arid regions. They provide meat, milk, transportation, and other essential services, and their resilience to harsh environments makes them invaluable. Despite their similarities, camel breeds exhibit notable differences in size, color, and structure, with over 40 million camels worldwide. This number is projected to increase, underscoring their growing significance. Economically, camels are crucial for food production, tourism, and trade, with camel racing being particularly significant in Arab countries. Their unique physiological traits, such as low disease susceptibility and efficient water conservation, further enhance their value. Camel products, especially meat and milk, offer substantial nutritional and therapeutic benefits, contributing to their high demand. Genetic diversity studies have advanced our understanding of camels' adaptation to extreme environments. Functional genomics and whole-genome sequencing have identified genes responsible for these adaptations, aiding breeding programs and conservation efforts. High-throughput sequencing has revealed genetic markers linked to traits like milk production and disease resistance. The development of SNP chips has revolutionized genetic studies by providing a cost-effective alternative to whole-genome sequencing. These tools facilitate large-scale genotyping, essential for conserving genetic diversity and improving breeding strategies. To prevent the depletion of camel genetic diversity, it is crucial to streamline in situ and ex situ conservation efforts to maintain their ecological and economic value. A comprehensive approach to camel conservation and genetic preservation, involving advanced genomic technologies, reproductive biotechniques, and sustainable management practices, will ensure their continued contribution to human societies.

Factors influencing the bioactivity of natural matrices: The case of osmolarity-dependent modulation of cell viability by different dilutions of camel urines

The widespread practice of dromedary urinotherapy as a remedy for various illnesses, including cancer, is well-established in traditional dromedary countries. Researchers attempted to demonstrate anticancer properties of camel urine through in vitro experiments with debated outcomes. Notably, two critical aspects remained unexplored in those assays: (i) the osmolarity of tested urines, which can significantly influence in vitro results; (ii) the potential morphological changes of cells, following exposure to camel urines. In this study, we addressed these gaps by evaluating the osmolarity-dependent modulation of cell viability in human renal cell lines. In this regard, we assessed the impact of hyperosmolar mannitol-based solutions and dromedary urine on the viability and morphology of human non-tumor (HK2) and tumor renal cells (Caki-1). The results indicate that cell viability or morphology in both HK2 and Caki-1 cells are not significantly affected only if mannitol-induced hyperosmolarity is lower than 500 mOsm/L. Notably, when exposed to urine solution, diluted to <500 mOsm/L, statistically significant antiproliferative effects were observed primarily in Caki-1 cells (in presence of two out of ten tested urine samples). Conversely, alterations in cell morphology were observed exclusively in HK2 cells when exposed to the same diluted camel urines. In order to investigate, at molecular level, the observed antiproliferative effects, a preliminary metabolomics analysis of the tested urine samples was performed to identify potential bioactive compounds. The Nuclear Magnetic Resonance (NMR) metabolic profiling revealed the presence of three antioxidant compounds, namely trigonelline, pyruvic acid and N-acetylglucosamine. In conclusion, our results highlight the importance of considering the critical role of osmolarity when evaluating the bioactive properties of camel urine in vitro, which should not be used to treat any illness as it is. Conversely, it can be considered the possibility to use camel urines as a source of bioactive compounds.

Welfare assessment of dromedary camels kept under pastoralism in Pakistan

Standardized welfare assessment protocols are crucial to enhance animal welfare; up to date, there is no data on the level of welfare of camels kept under pastoralism. A tailored protocol for measuring welfare in dromedary camels kept under nomadic pastoralist conditions was recently developed, drawing from the currently available welfare protocol for dromedary camels kept in intensive systems. This study, therefore, aimed to apply the newly developed tailored protocol and assess the welfare of dromedary camels kept under pastoralism in the Southern Punjab Province of Pakistan. A total of 44 welfare indicators (animal-, resource, and management-based measures) aligning with animal welfare principles ("Good Feeding", "Good Housing", "Good Health", and "Appropriate Behavior") were gathered into two assessment levels: "Caretaker-Herd level" and "Animal level". Data were collected in 2023 in the Cholistan desert in the southern Punjab province. Fifty-four herds were evaluated for a total population of 1,186 camels, of which 510 (495 females and 15 males; average age: 5-6 years old) were assessed at the animal level. The indicators were scored and aggregated to obtain Principle Aggregated Indexes (PAIs) and a total Welfare Index (TWI). Using the PAIs classification, 4 herds were categorized as excellent, 42 satisfactory, and 8 unsatisfactory. Total Welfare Index (TWI) varied from 55.7 to 82.2, and the thresholds for classification into tertiles were 65.4 and 70.6. Good feeding and Good housing were the most problematic PAIs, with Good feeding as the most influential variable for classification into welfare categories. As expected, camels kept under pastoralism had a higher level of welfare than those reported in the literature for intensive systems, especially concerning the Appropriate Behavior principle. Our findings are a first step in proposing welfare standards for dromedary in Pakistan and worldwide.

The ultrastructure of peroxisomes in the kidney of the camel (Camelus dromedarius)

Dromedary camels can survive and reproduce in desert areas. The unique anatomical structure of the kidney enables the camel to prevent water loss. The present study aimed to investigate the ultrastructure of the peroxisomes in the normal kidney of the adult dromedary camel. Tissue samples were taken from the cortex and outer medulla of the kidney of eight camels. The samples were then processed for histological and ultrastructural investigations. The epithelial cells of the proximal tubules displayed peroxisomes with varying sizes and shapes. The peroxisomes were observed in either dispersed or clustered arrangement. Each peroxisome exhibited a homogenous matrix enveloped by a single membrane. Several peroxisomes exhibited one or more dark marginal plates that were always strongly associated with the smooth endoplasmic reticulum. The intensity of the peroxisomal matrix differed significantly, either within the same cell or across different cells. The intensity was light or dark, with a few peroxisomes presenting a similar intensity to that of the mitochondria. Some peroxisomes contained nucleoids within their matrix. The peroxisomes in the first and second sections of proximal convoluted tubules were scattered and primarily located in the region between the microvilli and the underlying mitochondria. The peroxisomes in the third region were abundant and frequently aggregated in clusters throughout the cytoplasm. In the fourth region, the number of peroxisomes was low. The proximal straight tubule had a limited quantity of peroxisomes. In conclusion, peroxisomes in the proximal tubule in kidney of normal dromedary camel were similar in shape and size to other mammals; however, heterogeneity exists as a result of differences in species-specific peroxisomal proteins. Peroxisomes are suggested to be a major source of metabolic energy and act as hydrogen peroxide (H2O2) scavengers, resulting in the release of water and oxygen.

Renal adaptation in relation to insectivorous feeding habit in the greater mouse-eared bat, Myotis myotis (Chiroptera: Vespertilionidae)

We examined the histological structure of the kidneys of Myotis myotis to better understand their structural adaptations to dietary habits. M. myotis is an insectivorous bat species that belongs to the family Vespertilionidae. The kidneys of M. myotis are unilobular, bean-shaped, and surrounded by a renal capsule. The two parts are distinguished by a thin cortex and a thicker medulla. Renal corpuscles consist of the glomerulus and Bowman's capsule. The proximal tubule consists of cubic cells with a well-developed brush border, whereas the distal tubule is lined with a simple cubic epithelium without a brush border. The Henle's loop, located in the medullary region, was composed of flat cells. The microvilli of proximal tubule epithelial cells and basal lamina of proximal and distal tubule epithelial cells were periodic acid Schiff (PAS)-positive. The PAS-positive reaction of the microvilli of proximal tubular epithelial cells and basal lamina of proximal and distal tubule epithelial cells is due to the presence of glycogen, which may be used as an energy substrate during absorption. The presence of acidic glycoconjugates in the papilla was demonstrated by Alcian blue (pH 2.5)-PAS staining. According to the result of silver impregnation staining, it was determined that reticular fibers form a dense fibrillary network in the kidney parenchymal tissue. Reticular fibers are responsible for demarcating and supporting the borders of cells by forming a thin network of fibrils beneath the basal lamina of the cells. Structural features in the kidney, such as a thin cortex and thicker medulla, long conical papilla, and division of the thick medulla into inner and outer regions, of M. myotis may be an adaptation to produce concentrated urine, thereby reducing water loss associated with insectivorous feeding habits.

Assessment of different dietary alfalfa hay to alfalfa silage ratios for dromedary camel feeding

Two in vivo experiments studied the effects of different alfalfa hay (AH) to alfalfa silage (AS) ratios including 100:0 (AH100), 50:50 (AH50:AS50) and 0:100 (AS100) in total mixed rations (TMR) of dromedary camels. In experiment (Exp.) 1, a total of 18 multiparous Baluchi dairy camel [100 ± 5 days in milk (DIM); 3.65 ± 0.539 kg milk yield] were randomly allocated to one of the three groups (n = 6) for 42 d of experimental period. Dry matter intake (DMI) and milk yield were recorded daily, and blood samples were collected on days 0, 21 and 42. In Exp. 2, 18 male Baluchi camel calves [275 ± 14 days of old; 105 ± 8 kg BW] were housed in individual shaded pens for 150 days. DMI was recorded daily and individual weights of camels were recorded monthly. Blood samples were collected on days 0, 75 and 150. In Exp.1, feeding different dietary AH:AS ratios altered neither DMI (p = 0.351) nor milk yield (p = 0.667). Of all milk components, only the milk urea nitrogen (MUN) was increased (p = 0.015) by AS feeding (both AH50:AS50 and/or AS100). AS feeding tended to increase AST (p = 0.099) and ALT (p = 0.092) levels in lactating camels. In Exp. 2, DMI (p = 0.845), average daily gain (ADG; p = 0.092) and return per kg BW gain (p = 0.710) of silage-fed camels were similar to those of hay-fed group. The plasma concentration of BUN (p = 0.014) and AST (p = 0.014) were increased in camels fed AS100. Overall, the results suggest that both AS and/or AH could be used in dromedary camel diets based on the climatic condition, season and available facilities; however, the long-term use of AS (as sole forage) should done with caution due to the potential risk of impaired liver function. Further studies needed to explore the impact of hay versus silage feeding on digestibility, rumen function and nitrogen pollution in camel feeding.

Comparative physiological, morphological, histological, and AQP2 immunohistochemical analysis of the Arabian camels (Camelus dromedarius) and oxen kidney: Effects of adaptation to arid environments

Compared to other mammals, Arabian camels are ideal models for exploring the structural adaptations that enable camels to survive in arid environments. Thus, this study aimed to explore how evolutionary adaptation to arid conditions modifies the characteristics of the kidneys in Arabian camels (Camelus dromedarius) compared to oxen. Urine samples were physically and chemically analyzed. Harvested kidneys were subjected to topographical and fast spin echo magnetic resonance (FSE-MR) imaging. Histology, histomorphometry, and Aquaporin-2 (AQP2) expression by immunohistochemistry were also performed. Here, in dromedaries, sodium and potassium values in the urine were much higher (p=0.001, for both), whereas chloride was much lower (p=0.004) than the values of oxen. Compared with oxen, the level of the hormone aldosterone in serum was significantly lower (p=0.002), whereas creatinine and urea were significantly higher (p=0.005 and p=0.001, respectively). Uric acid in dromedaries and oxen did not differ significantly (p=0.349). Like sodium levels (p=0.001) in dromedary serum, chloride was also much higher (p=0.002) than in oxen. The average value of potassium was much lower (p=0.009) than that of oxen. Morphologically, anatomical and FSE MRI studies revealed that minor and major calyces were not found in dromedary kidneys. The renal pelvis was not found in oxen, and the major calyx was directly connected to the ureter. The dromedary kidney contained a wider medullary portion as well as increased diameters for renal corpuscles (RCs), proximal convoluted tubules (PCTs), and collecting tubules (CTs, p&lt;0.05) compared with the oxen. We also noted that AQP2 was significantly expressed in dromedary nephron components, except for RCs, compared with oxen as shown by immunohistochemistry. Overall, these data strongly suggest that the dromedary has a greater ability to adapt to harsh desert conditions in terms of producing highly concentrated urine than oxen.

NLRP3 inflammasome is involved in the mechanism of the mitigative effect of lycopene on sulfamethoxazole-induced inflammatory damage in grass carp kidneys

Freshwater environmental antibiotic pollution is becoming more severe because of the irregular use of sulfonamide antibiotics. Sulfamethoxazole (SMZ) is a kind of antibiotic that can cause harm to the urinary systems of organisms. However, the toxic impacts of environment-related concentrations of antibiotics in fish have not been thoroughly studied. Lycopene (LYC) has the property of alleviating antibiotic toxicity by diminishing oxidative stress and inflammation. This investigation is intended to examine the instrument of the mitigative part of LYC on SMZ-caused renal inflammatory injury in grass carp. Grass carp were born with SMZ (0. 3 μg L^-1) and LYC (10 mg/kg body weight) for 30 days. Serum was used to measure creatinine (CREA) and urea nitrogen (BUN) contents; what is more, kidneys were used to measure histological structure, oxidative stress indicators, relative expressions of cytokines, and inflammatory factors. We found that SMZ exposure significantly increased oxidative stress, characterized by decreased catalase activity (CAT) and superoxide dismutase (SOD). In addition, inflammation-related factors: interleukin (IL-18, IL-6, and IL-1β), an apoptotic speck-containing protein with a card (ASC), NOD-like receptor protein3 (NLRP3), cysteinyl aspartate specific proteinase-1 (caspase-1), tumor necrosis factor-α (TNF-α), and nuclear factor-activated B cells (NF-κB) expression increased significantly contrasted with those control group. Inflammatory reactions and ultrastructural changes accompany. LYC administration alleviated the changes mentioned above. In conclusion, In conclusion, these results suggest a protective effect of LYC dietary supplements against kidney damage caused by SMZ. LYC is expected to prevent and treat oxidative stress and chronic inflammation caused by antibiotics as a critical component in the fish breeding diet.

Multiomic analysis of the Arabian camel (Camelus dromedarius) kidney reveals a role for cholesterol in water conservation

The Arabian camel (Camelus dromedarius) is the most important livestock animal in arid and semi-arid regions and provides basic necessities to millions of people. In the current context of climate change, there is renewed interest in the mechanisms that enable camelids to survive in arid conditions. Recent investigations described genomic signatures revealing evolutionary adaptations to desert environments. We now present a comprehensive catalogue of the transcriptomes and proteomes of the dromedary kidney and describe how gene expression is modulated as a consequence of chronic dehydration and acute rehydration. Our analyses suggested an enrichment of the cholesterol biosynthetic process and an overrepresentation of categories related to ion transport. Thus, we further validated differentially expressed genes with known roles in water conservation which are affected by changes in cholesterol levels. Our datasets suggest that suppression of cholesterol biosynthesis may facilitate water retention in the kidney by indirectly facilitating the AQP2-mediated water reabsorption.