Liver Tissue Of Sprague-Dawley Rats Research Articles

Nod-like receptor protein 3 inflammasome-mediated pyroptosis contributes to chronic NaAsO2 exposure-induced fibrotic changes and dysfunction in the liver of SD rats

The metalloid arsenic, known for its toxic properties, is widespread presence in the environment. Our previous research has confirmed that prolonged exposure to arsenic can lead to liver fibrosis injury in rats, while the precise pathogenic mechanism still requires further investigation. In the past few years, the Nod-like receptor protein 3 (NLRP3) inflammasome has been found to play a pivotal role in the occurrence and development of liver injury. In this study, we administered varying doses of sodium arsenite (NaAsO2) and 10 mg/kg.bw MCC950 (a particular tiny molecular inhibitor targeting NLRP3) to Sprague-Dawley (SD) rats for 36 weeks to explore the involvement of NLRP3 inflammasome in NaAsO2-induced liver injury. The findings suggested that prolonged exposure to NaAsO2 resulted in pyroptosis in liver tissue of SD rats, accompanied by the fibrotic injury, extracellular matrix (ECM) deposition and liver dysfunction. Moreover, long-term NaAsO2 exposure activated NLRP3 inflammasome, leading to the release of pro-inflammatory cytokines in liver tissue. After treatment with MCC950, the induction of NLRP3-mediated pyroptosis and release of pro-inflammatory cytokines were significantly attenuated, leading to a decrease in the severity of liver fibrosis and an improvement in liver function. To summarize, those results clearly indicate that hepatic fibrosis and liver dysfunction induced by NaAsO2 occur through the activation of NLRP3 inflammasome-mediated pyroptosis, shedding new light on the potential mechanisms underlying arsenic-induced liver damage.

Determination of coumarin-3-carboxylic acid in the liver and heart tissue of Sprague-Dawley rats after intragastric administration of extractive of leaves of F. virens var. sublanceolata by HPLC

AbstractThe study was aimed to validate and optimize high performance liquid chromatographic (HPLC) method for the determination of coumarin-3-carboxylic acid (C3A) in the heart and liver issue of Sprague-Dawley (SD) rats after intragastric administration of extractive of leaves of Ficus virens var sublanceolata. And simple ADME and target prediction analyses were performed for C3A. Ethyl acetate was employed to precipitate protein with appropriate sensitivity and acceptable matrix effects. The satisfactory separation was developed on an ODS2 column (4.6 mm × 250 mm, 5 μm) by gradient elution with a methanol-acetic acid solution (pH = 3.0) as the mobile phase. The flow rate was 1.0 mL min−1, the column temperature was maintained at 30 ± 2 °C, the injection volume was 20 μL, and the detection wavelength was set as 309 nm. The method was fully validated in terms of selectivity, linearity, accuracy, precision, extraction recovery and stability. The results of the ADME analysis found that C3A has excellent characteristics of drug-likeness, consistent with good bio-absorption. And the predicted 12 target protein belongs to the amine oxidoreductase and carbonic anhydrase target class. This method is simple, rapid, sensitive, and accurate for the determination of coumarin-3-carboxylic acid in the heart and liver tissue of SD rats.

Effect and mechanism of gdolinium chloride on hepatic ischemia/reperfusion injury in Sprague Dawley rats

Objective To analyze the effect and mechanism of gadolinium chloride on hepatic ischemia-reperfusion injury (HIRI) in Sprague Dawley (SD) rats. Methods Thirty six eight weeks special pathogen free SD rats, were included in the project. The body weight ranged from 200 to 250 g. Thirty six rats were randomly divided into sham operation group, model group and gadolinium chloride group with 12 rats/group. Model of ischemia-reperfusion injury was generated in the rats of model group; In the gadolinium chloride group, preoperative intraperitoneal injection of gadolinium chloride was performed before the model of HIRI was established; In the sham operation group, only the abdomen was opened and closed and the hilum was dissected. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were detected in the three groups. The relative expression of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1 β (IL-1β) mRNA were detected by Q-PCR. Western blot was used to detect the expression of markers involved in the Toll like receptor 2/myeloid differentiation factor 88 (MyD88) signaling pathway. Immunohistochemistry staining was used to detect the expression of Fas and Fas ligands in hilar bile duct epithelial cells. Results ALT and AST were (55±8) U/L, (92±22) U/L in sham operation group, lower than those in model group (1 247±62) U/L, (1 117±60) U/L, respectively, and ALT and AST in gadolinium chloride group were (622±50) U/L and (552±41) U/L, lower than those in model group (all P<0.05). Compared with the sham operation group, the relative expression of TNF-α, IL-1 β, IL-6 mRNA in the model group was significantly higher (all P<0.05), but the expression of those markers were higher than gadolinium chloride group (all P<0.05). Gadolinium chloride down-regulated the expression of Toll like receptor 2/MyD88 signaling pathway in rat with liver ischemia-reperfusion. The percentage of Fas protein positive cells in model group was (40.2±3.8)%, and the percentage of Fas ligand positive cells was (36.9±2.9)%, which was higher than those in gadolinium chloride group (29.7±2.3)% and (23.6±2.1)% with statistically significant differences (all P<0.05). Conclusion Gadolinium chloride can reduce the injury of liver function and inhibit the expression of inflammatory factors in liver tissue of SD rats with hepatic ischemia-reperfusion, which may play a protective role by down regulating the expression of relative protein in Toll like receptor 2/MyD88 signaling pathway. Key words: Reperfusion injury; Gdolinium chloride; Liver; Toll-like receptor 2; Myeloid differentiation factor 88

Erratum: “Role of Sensitivity of Zinc Oxide Nanorods (ZnO-NRs) Based Photosensitizers in Hepatocellular Site of Biological Tissue”

Zinc oxide nanorods (ZnO-NRs) with high surface to volume ratio and bio compatibility are used as an efficient photosensitizer carrier system for achievement of Hepatocellular cancer cell (HepG2) necrosis within few minutes. Present study highlights the role of effectiveness of ZnO-NRs in photodynamic therapy (PDT). We have grown the ZnO-NRs on the tip of borosilicate glass capillaries (0.5 μm diameter). The grown ZnO-NRs were conjugated using Photofrin® and ALA for the efficient intracellular drug delivery, which produces reactive oxygen species (ROS) via photochemical reactions leading to cell death within few minutes after exposing UV light (240 nm). Viability of controlled and treated HepG2 cells with optimum dose of light (UV-visible) has been assessed by neutral red assay (NRA). The results were verified by staining of mitochondria using Mitotracker® red as an efficient dye as well as ROS detection. ZnO-NRs based Phogem® (PG) treated normal liver tissues of Sprague-Dawley rats were used as comparative experimental model. Morphological apoptotic changes in liver tissue of Sprague-Dawley rats before and after ZnO-NRs conjugated with photosensitizer (PS)-mediated PDT were investigated by microscopic examination.

Delta 22-Ursodeoxycholic acid, a unique metabolite of administered ursodeoxycholic acid in rats, indicating partial beta-oxidation as a major pathway for bile acid metabolism.

We describe for the first time the identification of 3 alpha, 7 beta-dihydroxy-5 beta-chol-22-en-24-oic acid (delta 22-UDCA) in the plasma, bile, intestinal contents, and liver tissue of Sprague-Dawley rats after intravenous and oral administration of ursodeoxycholic acid (UDCA). Infusion of [2,2,4,4-2H4]UDCA confirmed delta 22-UDCA to be a specific metabolite of UDCA. Definitive confirmation of this unique and major metabolite was established by liquid secondary ionization mass spectrometry and gas chromatography-mass spectrometry by comparison of the retention index and mass spectrum with an authentic standard of delta 22-UDCA. When rats were fed a diet containing 1.0% UDCA, high concentrations of delta 22-UDCA were found in the plasma (40.3 +/- 11.8 mumol/L) and liver tissue (300.9 +/- 64.2 nmol/g of tissue), and these represented 36% and 57%, respectively, of the UDCA concentration. In animals fed 0.4% and 1.0% UDCA, the mass of delta 22-UDCA in the jejunum was high (7.5 +/- 0.9 and 6.6 +/- 0.6 mg, respectively), accounting for 50-60% of the total UDCA, but diminished markedly along the intestine, accounting for < 3% of the total UDCA in the colon. Although delta 22-UDCA was not found in biological samples from control rats, delta 22-beta-muricholic and delta 22-omega-muricholic acids were normal constituents of plasma and intestinal contents and were major muricholate isomers in liver tissue and bile. Synthesis of delta 22-bile acids appears to be highly specific toward bile acids possessing a functional 7 beta-hydroxyl group. We presume that, in common with pathways for endogenous bile acid synthesis, partial side-chain oxidation of UDCA occurs in the peroxisome with formation of alpha/beta unsaturation; since UDCA has only a 5-carbon side chain, release of propionic or acetic acid is not possible, beta-oxidation proceeds no further, and delta 22-UDCA is formed. While the mechanism of formation and physiological significance of delta 22-bile acids remain to be established, our data indicate that partial beta-oxidation is a quantitatively important pathway for endogenous bile acid synthesis and for UDCA metabolism in this species.

Biotransformation enzymes in nasal mucosa and liver of Sprague-Dawley rats

The metabolism of hexamethylphosphoramide (HMPA), aminopyrine, ethoxycoumarin, ethoxyresorufin and pentoxyresorufin, by the monooxygenase cytochrome P-450-dependent system, was studied in microsomes from nasal epithelial membranes and liver tissue of Sprague-Dawley rats. Nasal metabolism rates for the different substrates ranged from 9% of liver values for aminopyrine to 83% for ethoxycoumarin. HMPA-demethylase activity followed Michaelis-Menten kinetics in nasal mucosa microsomes but was biphasic in those from liver. SKF 525A, metyrapone, dioxolane and α-naphthoflavone (ANF), inhibitors of various P-450 monooxygenases, were examined with regard to inhibition of nasal and liver ethoxycoumarin deethylase. In addition, activity of epoxide hydrolase, glutathione S-transferase, DT-diaphorase and UDP-glucuronyltransferase (UDP-GT) in nasal tissue homogenates were investigated. These activities were generally lower than those present in the liver. Various attempts to increase the activity of oxidative enzymes in nasal tissue by PB, 3-MC and ethanol failed, 3-MC and PB doubled the microsomal UDP-GT and the epoxide hydrolase activities. The results together with data from the literature suggest that the balance between P-450 isozymes and detoxifying enzymes differs in the nose compared with the liver. The activities of these enzymes in nasal tissue of different strains of rats also varies substantially with implications regarding the metabolic fate and activitation of inhaled xenobiotics.