OBJECTIVE: To observe the effects of different suspension moxibustion methods on the syndrome characteristics and inflammatory factors of rats with rheumatoid arthritis (RA) of heat bi syndrome and to prove the concept of "moxibustion can be used for heat syndrome". METHODS: Among seventy Wistar rats, 12 rats were randomly selected as a normal group, and the remaining rats were induced by collagen combined with wind, dampness, and heat environmental stimulation to establish the RA model of heat bi syndrome. Forty-eight rats with successful model establishment were further randomly divided into a model group and three moxibustion groups (mild moxibustion group, rotating moxibustion group and sparrow-pecking moxibustion group), with 12 rats in each group. The acupoints "Quchi" (LI 11), "Dazhui" (GV 14) and ashi point were used in all moxibustion groups, with mild moxibustion, rotating moxibustion, and sparrow-pecking moxibustion intervention given respectively, each acupoint was treated with moxibustion for 10 min a day, and 6 days were considered one course of treatment, with a total of three courses. After the intervention, the arthritis index (AI), the Evans blue (EB) extravasated volume in the soft tissue of the right hind paw, and the levels of tumor necrosis factor (TNF)-α and interleukin (IL)-10 in the serum were measured by ELISA in each group. The volume of the bilateral hind paw was measured; the infrared thermal imaging was collected to analyze the temperature of the plantar area of the bilateral foot pads, and the reaction time of plantar heat pain was calculated before and after modeling, as well as after the 1st, 2nd and 3rd courses of interrention. The ankle dorsiflexion angle of the right hind foot was also measured before and after modeling, as well as after the intervention. RESULTS: After modeling, compared with the normal group, the rats in the model group had more high-temperature areas in the bilateral hind limbs, abnormal AI score, abnormal bilateral hind paw volume, abnormal temperature of the plantar area of the bilateral foot pads, abnormal foot pain response time, abnormal right hind ankle dorsiflexion angle, abnormal right hind paw soft tissue EB extravasation, and abnormal serum TNF-α and IL-10 levels (P<0.01, P<0.05). After the intervention, compared with the model group, the rats in each moxibustion group had decreased or disappeared high-temperature areas in the bilateral hind limbs, EB extravasated volume in the soft tissue of the right hind paw was reduced (P<0.05), and the right ankle dorsiflexion angle was increased (P<0.05), serum level of TNF-α was reduced, and level of IL-10 increased (P<0.05); the AI scores in the mild moxibustion group and the sparrow-pecking moxibustion group was decreased (P<0.01, P<0.05). After the 1st, 2nd and 3rd courses of intervention, compared with the model group, the bilateral hind paw volume of rats in each moxibustion group was decreased (P<0.05, P<0.01), and plantar heat pain reaction time was increased (P<0.05). After the 2nd course and the 3rd course of intervention, the temperature of the right hind paw pad area was decreased in each moribustion group (P<0.05); after the 3rd courses of intervention, the temperature of the left hind paw pad area was decreased in the mild moxibustion group (P<0.05). CONCLUSION Suspension moxibustion could adjust the serum levels of TNF-α and IL-10 to improve the syndrome characteristics of RA rats of heat bi syndrome, such as joint redness, swelling, heat, pain and activity restriction. The effect of mild moxibustion is the most prominent. The findings could provide scientific basis for "moxibustion can be used for heat syndrome".
Animals ; Rats ; Arthritis, Rheumatoid/therapy* ; Evans Blue ; Hot Temperature ; Interleukin-10/genetics* ; Moxibustion ; Rats, Wistar ; Tumor Necrosis Factor-alpha/genetics*

OBJECTIVE: In this study, the combined effect of two stressors, namely, electromagnetic fields (EMFs) from mobile phones and fructose consumption, on hypothalamic and hepatic master metabolic regulators of the AMPK/SIRT1-UCP2/FOXO1 pathway were elucidated to delineate the underlying molecular mechanisms of insulin resistance. METHODS: Weaned Wistar rats (28 days old) were divided into 4 groups: Normal, Exposure Only (ExpO), Fructose Only (FruO), and Exposure and Fructose (EF). Each group was provided standard laboratory chow ad libitum for 8 weeks . Additionally, the control groups, namely, the Normal and FruO groups, had unrestricted access to drinking water and fructose solution (15%), respectively. Furthermore, the respective treatment groups, namely, the ExpO and EF groups, received EMF exposure (1,760 MHz, 2 h/day x 8 weeks). In early adulthood, mitochondrial function, insulin receptor signaling, and oxidative stress signals in hypothalamic and hepatic tissues were assessed using western blotting and biochemical analysis. RESULT: In the hypothalamic tissue of EF, SIRT1, FOXO 1, p-PI3K, p-AKT, Complex III, UCP2, MnSOD, and catalase expressions and OXPHOS and GSH activities were significantly decreased ( P < 0.05) compared to the Normal, ExpO, and FruO groups. In hepatic tissue of EF, the p-AMPKα, SIRT1, FOXO1, IRS1, p-PI3K, Complex I, II, III, IV, V, UCP2, and MnSOD expressions and the activity of OXPHOS, SOD, catalase, and GSH were significantly reduced compared to the Normal group ( P < 0.05). CONCLUSION The findings suggest that the combination of EMF exposure and fructose consumption during childhood and adolescence in Wistar rats disrupts the closely interlinked and multi-regulated crosstalk of insulin receptor signals, mitochondrial OXPHOS, and the antioxidant defense system in the hypothalamus and liver.
Humans ; Rats ; Animals ; Adult ; Rats, Wistar ; Fructose/metabolism* ; Catalase ; Receptor, Insulin/metabolism* ; AMP-Activated Protein Kinases/metabolism* ; Electromagnetic Fields/adverse effects* ; Sirtuin 1/metabolism* ; Cell Phone ; Phosphatidylinositol 3-Kinases/metabolism* ; Forkhead Box Protein O1/metabolism* ; Uncoupling Protein 2

Objective To determine the optimal dosage and intervention duration of reserpine to establish a rat model of hypotension.Methods According to the body weight and systolic blood pressure (SBP),60 male Wistar rats were assigned to six groups (n=10),including a control group and five observation groups with different doses.The control group was administrated with 10 ml/kg 0.5% sodium carboxymethyl cellulose solution,and the observation groups with 0.016,0.032,0.064,0.128,and 0.160 mg/kg reserpine suspensions,respectively.All the groups were administrated by gavage twice a day,and the body weights of rats were monitored daily.SBP and heart rate (HR) were measured before modeling and 1-6 weeks after administration.After 6 weeks of administration,the blood samples of inner canthus were collected.The levels of lactate dehydrogenase (LDH),creatine kinase MB isoenzyme (CK-MB),alanine aminotransferase,aspartate aminotransferase (AST),serum creatinine,and blood urea nitrogen (BUN) were measured by an autoanalyzer.Three rats in each group were randomly selected for observation of the changes in SBP after drug withdrawal and the rest rats were sacrificed for measurement of the levels of norepinephrine and dopamine in the brain.Results Compared with the control group,different doses of reserpine lowered the SBP of rats (F=28.492,P<0.001).The decline in SBP increased in a concentration-dependent manner.SBP reached the lowest value after 1 week,rose slightly later,and was stable after 3 weeks of administration.There was no significant difference in SBP between 0.016 mg/kg reserpine group and the control group after the 5th week (P>0.05).The SBP levels of rats in 0.032,0.064,0.128,and 0.160 mg/kg reserpine groups showed no significant difference between each other (P=0.204) and were lower than that in the control group (all P<0.001).One week after drug withdrawal,the SBP of rats in the observation groups rose to the baseline level and remained stable.HR showed similar changes among groups,first increasing and then decreasing.There was no significant difference in HR among different groups at the same time point (F=0.922,P=0.475).Compared with the control group,reserpine of different doses reduced the norepinephrine content in the hippocampus (all P<0.001),and 0.128 mg/kg (P=0.045) and 0.160 mg/kg (P=0.042) reserpine lowered the dopamine level in the striatum,which showed no significant differences between different reserpine groups(P=0.343,P=0.301).The levels of LDH,CK-MB,and BUN in the serum increased with the increase in reserpine concentration,and the levels of LDH (P=0.001),CK-MB (P=0.020),AST (P=0.007),and BUN (P=0.001) in the 0.160 mg/kg reserpine group were significantly different from those in the control group.Conclusions The rat model of hypotension can be induced by gavage with reserpine.The gavage with reserpine at a dose of 0.032 mg/kg,twice a day for three consecutive weeks is the optimal scheme for the modeling.After the model establishment,continuous administration is essential to maintain the hypotension.
Male ; Rats ; Animals ; Reserpine ; Dopamine ; Rats, Wistar ; Hypotension/chemically induced* ; Norepinephrine

This study aims to investigate the mechanism of acacetin in protecting rats from cerebral ischemia-reperfusion injury via the Toll-like receptor 4(TLR4)/NOD-like receptor protein 3(NLRP3) signaling pathway. Wistar rats were randomized into sham, model, low-and high-dose acacetin, and nimodipine groups, with 10 rats in each group. The rat model of middle cerebral artery occlusion(MCAO) was established with the improved suture method in other groups except the sham group. The neurological deficit score and cerebral infarction volume of each group were evaluated 24 h after modeling. Enzyme-linked immunosorbent assay(ELISA) was employed to measure the levels of interleukin-1β(IL-1β), IL-6, tumor necrosis factor-α(TNF-α), malondialdehyde(MDA), supe-roxide dismutase(SOD), and glutathione(GSH). Western blot was employed to determine the expression levels of B-cell lymphonoma-2(Bcl-2), Bcl-2-associated X protein(Bax), and TLR4/NLRP3 signaling pathway-related proteins(TLR4, p-NF-κB/NF-κB, NLRP3, pro-caspase-1, cleaved caspase-1, pro-IL-1β, and cleaved IL-1β) in the rat brain tissue. Hematoxylin-eosin(HE) staining was employed to reveal the histopathological changes in the ischemic area. Compared with the sham group, the modeling of MCAO increased the neurological deficit score and cerebral infarction volume, elevated the IL-1β, IL-6, TNF-α, and MDA levels and lowered the SOD and GSH levels in the brain tissue(P<0.05). Compared with the MCAO model group, low-and high-dose acacetin and nimodipine decreased the neurological deficit score and cerebral infarction volume, lowered the IL-1β, IL-6, TNF-α, and MDA levels and elevated the SOD and GSH levels in the brain tissue(P<0.05). Compared with the sham group, the model group showed up-regulated protein levels of Bax, TLR4, p-NF-κB/NF-κB, NLRP3, pro-caspase-1, cleaved caspase-1, pro-IL-1β, and cleaved IL-1β and down-regulated protein level of Bcl-2 in the brain tissue(P<0.05). Compared with the MCAO model group, the acacetin and nimodipine groups showed down-regulated protein levels of Bax, TLR4, p-NF-κB/NF-κB, NLRP3, pro-caspase-1, cleaved caspase-1, pro-IL-1β, and cleaved IL-1β and up-regulated protein level of Bcl-2 in the brain tissue(P<0.05). In conclusion, acacetin regulates the TLR4/NLRP3 signaling pathway to inhibit neuroinflammatory response and oxidative stress, thus exerting the protective effect on cerebral ischemia-reperfusion injury in rats.
Rats ; Animals ; NF-kappa B/metabolism* ; bcl-2-Associated X Protein ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Rats, Sprague-Dawley ; Caspase 1/metabolism* ; Toll-Like Receptor 4/metabolism* ; Nimodipine/pharmacology* ; Interleukin-6 ; Rats, Wistar ; Signal Transduction ; Infarction, Middle Cerebral Artery ; Reperfusion Injury/prevention & control* ; Superoxide Dismutase/metabolism*

This study observed the effects of Guiqi Yiyuan Ointment(GQYY) on the left lung subjecting to bystander effect of right lung injury induced by ~(12)C~(6+) beam in rats and decipher the underlying mechanism from NOD-like receptor protein 3(NLRP3)/apoptosis-associated speck-like protein containing a CARD(ASC)/cysteinyl aspartate specific proteinase-1(caspase-1) pathway. Wistar rats were randomized into 7 groups: blank, model, inhibitor [200 mg·kg~(-1), N-acetylcysteine(NAC)], western drug [140 mg·kg~(-1) amifostine(AMI)], and high-, medium-, and low-dose(4.8, 2.4, and 1.2 g·kg~(-1), respectively) GQYY groups. The model of bystander effect damage was established by 4 Gy ~(12)C~(6+) beam irradiation of the right lung(with the other part shielded by a lead plate). The pathological changes in the lung tissue, the level of reactive oxygen species(ROS) in the lung tissue, and the levels of superoxide dismutase(SOD) and malondialdehyde(MDA) in the serum were observed and measured in each group. Furthermore, the mRNA and protein levels of NLRP3, ASC, caspase-1, and phosphorylated nuclear factor-κB p65(p-NF-κB p65)/nuclear factor-κB p65(NF-κB p65) were determined. Compared with the blank group, the model group showed thickened alveolar wall, narrowed alveolar cavity, and presence of massive red blood cells and inflammatory infiltration in the alveolar wall and alveolar cavity. In addition, the model group showed elevated ROS levels in both left and right lungs, elevated MDA level, lowered SOD level, and up-regulated mRNA and protein levels of NLRP3, ASC, caspase-1, and p-NF-κB p65/NF-κB p65. Compared with the model group, the drug administration in all the groups reduced inflammatory cell infiltration in the lung tissue. The inhibitor group and the western drug group showed enlarged alveolar cavity, thinned interstitium, and reduced inflammation. There was a small amount of alveolar wall rupture in the high-and medium-dose GQYY groups and reduced inflammatory cell infiltration in the low dose GQYY group. Compared with the model group, drug administration lowered level of ROS in the left and right lungs, lowered the MDA level, elevated the SOD level, and down-regulated the mRNA and protein levels of NLRP3, ASC, caspase-1, and p-NF-κB p65/NF-κB p65. GQYY can effectively reduce the damage caused by radiation and bystander effect, which may be associated with the ROS-mediated NLRP3 inflammasome activation.
Rats ; Animals ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; NF-kappa B/metabolism* ; Inflammasomes/metabolism* ; Lung Injury/genetics* ; Reactive Oxygen Species/metabolism* ; Bystander Effect ; Ointments ; Rats, Wistar ; Lung/metabolism* ; Caspase 1/metabolism* ; RNA, Messenger ; Superoxide Dismutase

Alzheimer's disease (AD) is a neurodegenerative disease characterized by cognitive impairment, with the predominant clinical diagnosis of spatial working memory (SWM) deficiency, which seriously affects the physical and mental health of patients. However, the current pharmacological therapies have unsatisfactory cure rates and other problems, so non-pharmacological physical therapies have gradually received widespread attention. Recently, a novel treatment using 40 Hz light flicker stimulation (40 Hz-LFS) to rescue the cognitive function of model animals with AD has made initial progress, but the neurophysiological mechanism remains unclear. Therefore, this paper will explore the potential neural mechanisms underlying the modulation of SWM by 40 Hz-LFS based on cross-frequency coupling (CFC). Ten adult Wistar rats were first subjected to acute LFS at frequencies of 20, 40, and 60 Hz. The entrainment effect of LFS with different frequency on neural oscillations in the hippocampus (HPC) and medial prefrontal cortex (mPFC) was analyzed. The results showed that acute 40 Hz-LFS was able to develop strong entrainment and significantly modulate the oscillation power of the low-frequency gamma (lγ) rhythms. The rats were then randomly divided into experimental and control groups of 5 rats each for a long-term 40 Hz-LFS (7 d). Their SWM function was assessed by a T-maze task, and the CFC changes in the HPC-mPFC circuit were analyzed by phase-amplitude coupling (PAC). The results showed that the behavioral performance of the experimental group was improved and the PAC of θ-lγ rhythm was enhanced, and the difference was statistically significant. The results of this paper suggested that the long-term 40 Hz-LFS effectively improved SWM function in rats, which may be attributed to its enhanced communication of different rhythmic oscillations in the relevant neural circuits. It is expected that the study in this paper will build a foundation for further research on the mechanism of 40 Hz-LFS to improve cognitive function and promote its clinical application in the future.
Humans ; Adult ; Rats ; Animals ; Memory, Short-Term/physiology* ; Rats, Wistar ; Neurodegenerative Diseases ; Hippocampus ; Prefrontal Cortex

OBJECTIVE: To explore the mechanism of effects of total saponin fraction from Dioscorea Nipponica Makino (TSDN) on M1/M2 polarization of monocytes/macrophages and arachidonic acid (AA) pathway in rats with gouty arthritis (GA). METHODS: Seventy-two Sprague Dawley rats were randomly divided into 4 groups (n=18 in each): normal, model, TSDN at 160 mg/kg, and celecoxib at 43.3 mg/kg. Monosodium urate crystal (MSU) was injected into the rats' ankle joints to induce an experimental GA model. Blood and tissue samples were collected on the 3rd, 5th, and 8th days of drug administration. Histopathological changes in the synovium of joints were observed via hematoxylin and eosin (HE) staining. The expression levels of arachidonic acid (AA) signaling pathway were assessed via real-time polymerase chain reaction (qPCR) and Western blot. Flow cytometry was used to determine the proportion of M1 and M2 macrophages in the peripheral blood. An enzyme-linked immunosorbent assay (ELISA) was used to detect interleukine (IL)-1 β, tumor necrosis factor-alpha (TNF-α), IL-4, IL-10, prostaglandin E₂ (PGE₂), and leukotriene B4 (LTB4). RESULTS: HE staining showed that TSDN improved the synovial tissue. qPCR and Western blot showed that on the 3rd, 5th and 8th days of drug administration, TSDN reduced the mRNA and protein expressions of cyclooxygenase (COX)2, microsomal prostaglandin E synthase-1 derived eicosanoids (mPGES-1), 5-lipoxygenase (5-LOX), recombinant human mothers against decapentaplegic homolog 3 (Smad3), nucleotide-binding oligomerization domain-like receptor protein 3 (NALP3), and inducible nitric oxide synthase (iNOS) in rats' ankle synovial tissues (P<0.01). TSDN decreased COX1 mRNA and protein expression on 3rd and 5th day of drug administration and raised it on the 8th day (both P<0.01). It lowered CD68 protein expression on days 3 (P<0.01), as well as mRNA and protein expression on days 5 and 8 (P<0.01). On the 3rd, 5th, and 8th days of drug administration, TSDN elevated the mRNA and protein expression of Arg1 and CD163 (P<0.01). Flow cytometry results showed that TSDN decreased the percentage of M1 macrophages while increasing the percentage of M2 in peripheral blood (P<0.05 or P<0.01). ELISA results showed that on the 3rd, 5th, and 8th days of drug administration, TSDN decreased serum levels of IL-1 β, TNF-α, and LTB4 (P<0.01), as well as PGE₂ levels on days 3rd and 8th days (P<0.05 or P<0.01); on day 8 of administration, TSDN increased IL-4 serum levels and enhanced IL-10 contents on days 5 and 8 (P<0.05 or P<0.01). CONCLUSION The anti-inflammatory effect of TSDN on rats with GA may be achieved by influencing M1/M2 polarization through AA signaling pathway.
Rats ; Humans ; Animals ; Arthritis, Gouty/drug therapy* ; Monocytes/pathology* ; Interleukin-10/metabolism* ; Arachidonic Acid/pharmacology* ; Dioscorea/chemistry* ; Rats, Wistar ; Tumor Necrosis Factor-alpha/metabolism* ; Saponins/therapeutic use* ; Interleukin-4/metabolism* ; Leukotriene B4/pharmacology* ; Rats, Sprague-Dawley ; Macrophages ; Signal Transduction ; RNA, Messenger/metabolism*

OBJECTIVE: To analyze the composition and metabolites of gut microbiota in septic rats by fecal 16s rRNA sequencing and untargeted metabolomics, and to preliminarily explore the effect and potential mechanism of gut microbiota and its metabolites on inflammatory response and multiple organ damage in sepsis. METHODS: Ten males healthy male Wistar rats were randomly divided into a sham operated group (Sham group) and sepsis model group (CLP group) using a random number table method, with 5 rats in each group. A rat sepsis model was established by cecal ligation and perforation (CLP) method. The animals were sacrificed 24 hours after modeling, the levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in peripheral blood were detected by enzyme-linked immunosorbent assay (ELISA). Hematoxylin-eosin (HE) staining was used to observe the pathological changes of lung and kidney tissues, and the pathological scores were evaluated. Fecal samples were collected, and 16s rRNA high-throughput sequencing and non-targeted metabolomics were used to screen microbiota, metabolites and potential signal pathways that may play an important role in disease outcomes. Spearman correlation analysis was conducted to jointly analyze the gut microbiota and non-targeted metabolism. RESULTS: Compared with the Sham group, the degree of pathological damage to lung and kidney tissues in the CLP group was significantly increased (lung tissue score: 3.60±0.80 vs. 0.00±0.00, kidney tissue score: 2.40±0.80 vs. 0.00±0.00, both P < 0.01), the level of IL-6 and TNF-α in peripheral blood significantly increased [TNF-α (ng/L): 248.12±55.98 vs. 143.28±36.57, IL-6 (ng/L): 260.26±39.47 vs. 116.01±26.43, both P < 0.05], the species diversity of intestinal flora of rats in the CLP group was significantly reduced, the relative abundance of Morganella, Bacteroides and Escherichia-Shigella were significantly increased, and the relative abundance of Lachnospiraceae NK4A136, Ruminococcus, Romboutsia and Roseburia were significantly reduced. In addition, the biosynthesis and bile secretion of phenylalanine, tyrosine, and tryptophan in the gut microbiota of the CLP group were significantly increased, while the biosynthesis of secondary bile acids was significantly reduced. There was a significant correlation between differential metabolites and differential microbiota. CONCLUSIONS Sepsis can cause significant changes in the characteristics of gut microbiota and fecal metabolites in rats, which provides a basis for translational research to seek new targets for the treatment of sepsis.
Rats ; Male ; Animals ; Tumor Necrosis Factor-alpha ; RNA, Ribosomal, 16S ; Gastrointestinal Microbiome ; Interleukin-6 ; Rats, Wistar ; Sepsis

OBJECTIVE: To observe the effect of amygdalin on liver fibrosis in a liver fibrosis mouse model, and the underlying mechanisms were partly dissected in vivo and in vitro. METHODS: Thirty-two male mice were randomly divided into 4 groups, including control, model, low- and high-dose amygdalin-treated groups, 8 mice in each group. Except the control group, mice in the other groups were injected intraperitoneally with 10% carbon tetrachloride (CCl₄)-olive oil solution 3 times a week for 6 weeks to induce liver fibrosis. At the first 3 weeks, amygdalin (1.35 and 2.7 mg/kg body weight) were administered by gavage once a day. Mice in the control group received equal quantities of subcutaneous olive oil and intragastric water from the fourth week. At the end of 6 weeks, liver tissue samples were harvested to detect the content of hydroxyproline (Hyp). Hematoxylin and eosin and Sirius red staining were used to observe the inflammation and fibrosis of liver tissue. The expressions of collagen I (Col-I), alpha-smooth muscle actin (α-SMA), CD31 and transforming growth factor β (TGF-β)/Smad signaling pathway were observed by immunohistochemistry, quantitative real-time polymerase chain reaction and Western blot, respectively. The activation models of hepatic stellate cells, JS-1 and LX-2 cells induced by TGF-β1 were used in vitro with or without different concentrations of amygdalin (0.1, 1, 10 µmol/L). LSECs. The effect of different concentrations of amygdalin on the expressions of liver sinusoidal endothelial cells (LSECs) dedifferentiation markers CD31 and CD44 were observed. RESULTS: High-dose of amygdalin significantly reduced the Hyp content and percentage of collagen positive area, and decreased the mRNA and protein expressions of Col-I, α-SMA, CD31 and p-Smad2/3 in liver tissues of mice compared to the model group (P<0.01). Amygdalin down-regulated the expressions of Col-I and α-SMA in JS-1 and LX-2 cells, and TGFβ R1, TGFβ R2 and p-Smad2/3 in LX-2 cells compared to the model group (P<0.05 or P<0.01). Moreover, 1 and 10 µmol/L amygdalin inhibited the mRNA and protein expressions of CD31 in LSECs and increased CD44 expression compared to the model group (P<0.05 or P<0.01). CONCLUSIONS Amygdalin can dramatically alleviate liver fibrosis induced by CCl₄ in mice and inhibit TGF-β/Smad signaling pathway, consequently suppressing HSCs activation and LSECs dedifferentiation to improve angiogenesis.
Rats ; Male ; Mice ; Animals ; Transforming Growth Factor beta/metabolism* ; Amygdalin/therapeutic use* ; Endothelial Cells/metabolism* ; Olive Oil/therapeutic use* ; Rats, Wistar ; Smad Proteins/metabolism* ; Liver Cirrhosis/metabolism* ; Liver ; Transforming Growth Factor beta1/metabolism* ; Signal Transduction ; Collagen Type I/metabolism* ; Carbon Tetrachloride ; Hepatic Stellate Cells

OBJECTIVE: To observe the toxicokinetic parameters, absorption characteristics and pathomorphological damage in different parts of the gastrointestinal tract of rats poisoned with different doses of diquat (DQ). METHODS: Ninety-six healthy male Wistar rats were randomly divided into a control group (six rats) and low (115.5 mg/kg), medium (231.0 mg/kg) and high (346.5 mg/kg) dose DQ poisoning groups (thirty rats in each dose group), and then the poisoning groups were randomly divided into 5 subgroups according to the time after exposure (15 minutes and 1, 3, 12, 36 hours; six rats in each subgroup). All rats in the exposure groups were given a single dose of DQ by gavage. Rats in the control group was given the same amount of saline by gavage. The general condition of the rats was recorded. Blood was collected from the inner canthus of the eye at 3 time points in each subgroup, and rats were sacrificed after the third blood collection to obtain gastrointestinal specimens. DQ concentrations in plasma and tissues were determined by ultra-high performance liquid chromatography and mass spectrometry (UPHLC-MS), and the toxic concentration-time curves were plotted to calculate the toxicokinetic parameters; the morphological structure of the intestine was observed under light microscopy, and the villi height and crypt depth were determined and the ratio (V/C) was calculated. RESULTS: DQ was detected in the plasma of the rats in the low, medium and high dose groups 5 minutes after exposure. The time to maximum plasma concentration (Tmax) was (0.85±0.22), (0.75±0.25) and (0.25±0.00) hours, respectively. The trend of plasma DQ concentration over time was similar in the three dose groups, but the plasma DQ concentration increased again at 36 hours in the high dose group. In terms of DQ concentration in gastrointestinal tissues, the highest concentrations of DQ were found in the stomach and small intestine from 15 minutes to 1 hour and in the colon at 3 hours. By 36 hours after poisoning, the concentrations of DQ in all parts of the stomach and intestine in the low and medium dose groups had decreased to lower levels. Gastrointestinal tissue (except jejunum) DQ concentrations in the high dose group tended to increase from 12 hours. Higher doses of DQ were still detectable [gastric, duodenal, ileal and colonic DQ concentrations of 6 400.0 (1 232.5), 4 889.0 (6 070.5), 10 300.0 (3 565.0) and 1 835.0 (202.5) mg/kg respectively]. Light microscopic observation of morphological and histopathological changes in the intestine shows that acute damage to the stomach, duodenum and jejunum of rats was observed 15 minutes after each dose of DQ, pathological lesions were observed in the ileum and colon 1 hour after exposure, the most severe gastrointestinal injury occurred at 12 hours, significant reduction in villi height, significant increase in crypt depth and lowest V/C ratio in all segments of the small intestine, damage begins to diminish by 36-hour post-intoxication. At the same time, morphological and histopathological damage to the intestine of rats at all time points increased significantly with increasing doses of the toxin. CONCLUSIONS The absorption of DQ in the digestive tract is rapid, and all segments of the gastrointestinal tract may absorb DQ. The toxicokinetics of DQ-tainted rats at different times and doses have different characteristics. In terms of timing, gastrointestinal damage was seen at 15 minutes after DQ, and began to diminish at 36 hours. In terms of dose, Tmax was advanced with the increase of dose and the peak time was shorter. The damage to the digestive system of DQ is closely related to the dose and retention time of the poison exposure.
Animals ; Male ; Rats ; Diquat/toxicity* ; Gastrointestinal Diseases ; Intestines ; Poisons ; Rats, Wistar ; Toxicokinetics