Introduction: Iron and molybdenum are essential trace elements for cell metabolism. They are involved in maintaining proper functions of enzymes, cell proliferation, and metabolism of DNA. Material and Methods: BALB/3T3 and HepG2 cells were incubated with iron chloride or molybdenum trioxide at concentrations from 100 to 1,400 µM. The cells were also incubated in mixtures of iron chloride at 200 μM plus molybdenum trioxide at 1,000 μM or iron chloride at 1,000 μM plus molybdenum trioxide at 200 μM. Cell viability was determined with MTT reduction, LHD release, and NRU tests. Results: A decrease in cell viability was observed after incubating both cell lines with iron chloride or molybdenum trioxide. In cells incubated with mixtures of these trace elements, a decrease in cell viability was observed, assessed by all the used assays. Conclusions: Iron (III) and molybdenum (III) decrease cell viability in normal and cancer cells. A synergistic effect of the mixture of these elements was observed.

The major difficulty in analysis of nitrofurans in feed, feed water, and food of animal origin is that nitrofurans have low molecular weights and fast metabolism. The principal goal of this study was to prepare a procedure for the determination of nitrofurans and their metabolites by a single method in different types of feed, feed water, and food of animal origin. Two-gram samples were subjected to hydrolysis and derivatisation processes by addition of hydrochloric acid and 2-nitrobenzaldehyde. After incubation the sample was purified by solid phase extraction technique. Nitrofurans were analysed using ultra-high-pressure liquid chromatography-MS/MS (UHPLC-MS/MS). The results of validation fulfil the requirement of the confirmatory criteria according to the European Commission Decision 2002/657/EC regarding apparent recoveries (88.9%–107.3%), repeatability (2.9%–9.4%) and within-laboratory reproducibility (4.4%–10.7%). The method can be successfully applied to monitor nitrofurans and their metabolites in different matrices.

Maintaining mineral homeostasis as well as the secretion and metabolism of mineralotropic hormones is important for healthy of periparturient dairy cows. To increase the activity of mineralotropic hormones, blood pH can be adjusted. The purpose of this study was to investigate changes in blood pH and the mechanism of action of this change in induced hypercalcaemic cows. Six non-lactating Holstein cows were used in a 2 × 2 crossover design. To induce hypercalcaemia, calcium borogluconate was administered subcutaneously to experimental cows and normal saline was administered subcutaneously to control cows. Blood and urine samples were collected serially after administration. Whole blood without any anticoagulant was processed with a portable blood gas analyser. Plasma concentration and urinary excretion of calcium were measured. In hypercalcaemic cows, both blood and urine calcium levels were significantly increased at 8 h compared to those at 0 h (P < 0.05), and a spontaneous increase in blood pH was also observed. The calcium concentration in plasma was highest at 2 h after administration (3.02 ± 0.27 mmol/L). The change in pH correlated with that in bicarbonate (r = 0.781, P < 0.001) rather than that in partial pressure of CO₂ (r = 0.085, P = 0.424). Hypercalcaemia induced a spontaneous change in blood pH through the bicarbonate buffer system and this system may be a maintainer of calcium homeostasis.

Introduction: Nickel and iron are very commonly occurring metals. Nickel is used in industry, but nowadays it is also used in medical biomaterials. Iron is an element necessary for cell metabolism and is used in diet supplements and biomaterials, whence it may be released along with nickel. Material and Methods: BALB/3T3 and HepG2 cells were incubated with iron chloride or nickel chloride at concentrations ranging from 100 to 1,400 µM. The following mixtures were used: iron chloride 200 µM plus nickel chloride 1,000 µM, or iron chloride 1,000 µM plus nickel chloride 200 µM. The cell viability was determined with MTT, LHD, and NRU tests. Results: A decrease in cell viability was observed after incubating the BALB/3T3 and HepG2 cells with iron chloride or nickel chloride. A synergistic effect was observed after iron chloride 1,000 μM plus nickel chloride 200 μM treatment in all assays. Moreover, the same effect was observed in the pair iron chloride 200 μM plus nickel chloride 1,000 μM in the LDH and NRU assays. Conclusions: Iron (III) and nickel (II) decrease cell viability. Iron chloride at a concentration of 200 µM protects mitochondria from nickel chloride toxicity.

Some azo dyes, including Sudans I–IV and Para Red, are genotoxic and may be biotransformed to cancerogenic aromatic amines. They are banned as food and feed additives, but their presence has been detected in food. Aromatic amines are also considered potentially toxic. Online EC–MS is a promising tool to study the transformation mechanisms of xenobiotics such as azo dyes. The aim of the study was to investigate emulation of how azo dyes are enzymatically transformed to amines with EC–MS. The reduction reactions of five azo dyes (Sudans I–IV and Para Red) were conducted using a glassy carbon working electrode and 0.1% formic acid in acetonitrile. Reduction results were compared with the literature and in silico to select preliminary candidates for metabolites. The LC-MS/MS method was used to confirm results obtained by electrochemical reactor. A limited number of pre-selected compounds were confirmed as azo dyes metabolites – aniline for Sudan I, aniline and 4-aminoazobenzene for Sudan III, o-toluidine for Sudan IV, and 4-nitroaniline for Para Red. No metabolites were found for Sudan II. Electrochemistry–mass spectrometry was successfully applied to azo dyes. This approach may be used to mimic the metabolism of azo dyes, and therefore predict products of biotransformation.

Introduction: The aim of this study was to evaluate the effect of lipoprotein fraction isolated from ostrich egg yolk (LPFo) on the metabolic activity of boar spermatozoa following liquid semen storage in different extenders and temperatures. Material and Methods: Boar ejaculates were extended in Androhep, Beltsville thawing solution (BTS), and Martín-Rillo and Alias (MR-A) without (control) or with the addition of LPFo and stored for three days at either 5°C or 16°C. The analysed sperm parameters included total motility (TMOT), plasma membrane integrity (PMI), mitochondrial membrane potential (MMP), oxygen consumption, and adenosine triphosphate (ATP) production. Results: The sperm metabolic activity seemed to be higher in the LPFo-based extenders following storage for three days, irrespective of the storage temperature. Compared with the LPFo-free extenders, significantly higher (P < 0.05) sperm PMI and MMP were observed in BTS and MR-A extenders supplemented with LPFo during storage for three days at 5°C. Spermatozoa stored in the BTS-LPFo extender exhibited higher (P < 0.05) TMOT and oxygen consumption, whereas higher (P < 0.05) PMI was observed in spermatozoa stored in Androhep-LPFo and MR-A-LPFo for three days at 16°C. No significant differences (P > 0.05) in ATP content were observed between the LPFo-free and LPFo-based extenders during storage. Conclusions: Supplementation of LPFo to semen extenders had varying effects on the metabolic activity of boar spermatozoa stored at different temperatures. It can be suggested that the interactions of various components of the extenders and seminal plasma with LPFo exert beneficial effects on the sperm metabolic activity during liquid storage of boar semen.

Sulfur-induced polioencephalomalacia (PEM) is an important disease affecting cattle in certain geographical regions. However, the pathogenesis of brain damage is not completely understood. We previously observed that excess dietary sulfur may influence thiamine status and altered thiamine metabolism may be involved in the pathogenesis of sulfur-induced PEM in cattle. In this study, we evaluated the activities of thiamine-dependent enzymes [α-ketogluterate dehydrogenase (α-KGDH) and pyruvate dehydrogenase (PDH)] and cytochrome c oxidase (COX) in the cerebral cortex of sulfur-induced PEM-affected cattle (n = 9) and clinically normal cattle (n = 8, each group) exposed to low or high dietary sulfur [LS = 0.30% versus HS = 0.67% sulfur on a dry matter (DM) basis]. Enzyme activities in PEM brains were measured from the brain tissue regions and examined using ultraviolent (UV) light illumination to show fluorescence or non-fluorescence regions. No gross changes under regular or UV light, or histopathological changes indicative of PEM were detected in the brains of cattle exposed to LS or HS diets. The PDH, α-KGDH, and COX activities did not differ between LS and HS brains, but all enzymes showed significantly lower (P < 0.05) activities in UV-positive region of PEM brains compared with LS and HS brains. The UV-negative regions of PEM brain had similar PDH activities to LS and HS brains, but the activities of α-KGDH and COX were significantly lower than in LS and HS brains. The results of this study suggest that reduced enzyme activities of brain PHD, α-KGDH, and COX are associated with the pathogenesis of sulfur-induced PEM.

Objective: To measure and compare insulin secretion and sensitivity in healthy alpacas and llamas via glucose clamping techniques. Animals: 8 llamas and 8 alpacas. Procedures: Hyperinsulinemic euglycemic clamping (HEC) and hyperglycemic clamping (HGC) were performed on each camelid in a crossover design with a minimum 48-hour washout period between clamping procedures. The HEC technique was performed to measure insulin sensitivity. Insulin was infused IV at 6 mU/min/kg for 4 hours, and an IV infusion of glucose was adjusted to maintain blood glucose concentration at 150 mg/dL. Concentrations of blood glucose and plasma insulin were determined throughout. The HGC technique was performed to assess insulin secretion in response to exogenous glucose infusion. An IV infusion of glucose was administered to maintain blood glucose concentration at 320 mg/dL for 3 hours, and concentrations of blood glucose and plasma insulin were determined throughout. Results: Alpacas and llamas were not significantly different with respect to whole-body insulin sensitivity during HEC or in pancreatic β-cell response during HGC. Alpacas and llamas had markedly lower insulin sensitivity during HEC and markedly lower pancreatic β-cell response during HGC, in comparison with many other species. Conclusions and Clinical Relevance: New World camelids had lower glucose-induced insulin secretion and marked insulin resistance in comparison with other species. This likely contributes to the disorders of fat and glucose metabolism that are common to camelids.

Objective-To assess effects of in vitro meloxicam exposure on metabolism in articular chondrocytes from dogs with naturally occurring osteoarthritis Sample-Femoral head cartilage from 16 dogs undergoing total hip replacement Procedures-Articular cartilage samples were obtained. Tissue sulfated glycosaminoglycan (SGAG), collagen, and DNA concentrations were measured. Collagen, SGAG, chondroitin sulfate 846, NO, prostaglandin E2 (PGE2), and matrix metalloproteinase (MMP)-2, MMP-3, MMP-9, and MMP-13 concentrations in culture medium were analyzed. Aggrecan, collagen II, MMP-2, MMP-3, MMP-9, MMP-13, ADAM metallopeptidase with thrombospondin type 1 motif (ADAMTS)-4, ADAMTS-5, tissue inhibitor of metalloproteinase (TIMP)-1, TIMP-2, TIMP-3, interleukin-1β, tumor necrosis factor-α, cyclooxygenase-1, cyclooxygenase-2, and nducible nitric oxide synthase gene expression were evaluated. Comparisons between tissues cultured without (control) and with meloxicam at concentrations of 0.3, 3.0, and 30.0 μg/mL for up to 30 days were performed by means of repeated-measures analysis. Results-Meloxicam had no effect on chondrocyte SGAG, collagen, or DNA concentrations. Expression of ADAMTS-5 was significantly decreased in all groups on all days, compared with the day 0 value. On day 3, culture medium PGE2 concentrations were significantly lower in all meloxicam-treated groups, compared with values for controls, and values remained low. Culture medium MMP-3 concentrations were significantly lower on day 30 than on day 3 in all meloxicam-treated groups. Conclusions and Clinical Relevance-Results suggested that in vitro meloxicam treatment of osteoarthritic canine cartilage for up to 30 days did not induce matrix degradation or stimulate MMP production. Meloxicam lowered PGE2 release from this tissue, and effects on tissue chondrocyte content and matrix composition were neutral.

Objective: To compare the effects of autologous equine serum (AES) and autologous conditioned serum (ACS) on equine articular chondrocyte metabolism when stimulated with recombinant human (rh) interleukin (IL)-1β. Sample: Articular cartilage and nonconditioned and conditioned serum from 6 young adult horses. Procedures: Cartilage samples were digested, and chondrocytes were isolated and formed into pellets. Chondrocyte pellets were treated with each of the following: 10% AES, 10% AES and rhIL-1β, 20% AES and rhIL-1β, 10% ACS and rhIL-1β, and 20% ACS and rhIL-1β, and various effects of these treatments were measured. Results: Recombinant human IL-1β treatment led to a decrease in chondrocyte glycosaminoglycan synthesis and collagen II mRNA expression and an increase in medium matrix metalloproteinase-3 activity and cyclooxygenase-2 mRNA expression. When results of ACS and rhIL-1β treatment were compared with those of AES and rhIL-1β treatment, no difference was evident in glycosaminoglycan release, total glycosaminoglycan concentration, total DNA content, or matrix metalloproteinase-3 activity. A significant increase was found in chondrocyte glycosaminoglycan synthesis with 20% AES and rhIL-1β versus 10% ACS and rhIL-1β. The medium from ACS and rhIL-1β treatment had a higher concentration of IL-1β receptor antagonist, compared with medium from AES and rhIL-1β treatment. Treatment with 20% ACS and rhIL-1β resulted in a higher medium insulin-like growth factor-I concentration than did treatment with 10% AES and rhIL-1β. No difference in mRNA expression was found between ACS and rhIL-1β treatment and AES and rhIL-1β treatment. Conclusions and Clinical Relevance: Minimal beneficial effects of ACS treatment on proteoglycan matrix metabolism in equine chonrocytes were evident, compared with the effects of AES treatment.