This study aims to explore the auditory response characteristics of the thalamic reticular nucleus (TRN) in awake mice during auditory information processing, so as to deepen the understanding of TRN and explore its role in the auditory system. By in vivo electrophysiological single cell attached recording of TRN neurons in 18 SPF C57BL/6J mice, we observed the responses of 314 recorded neurons to two kinds of auditory stimuli, noise and tone, applied to mice. The results showed that TRN received projections from layer six of the primary auditory cortex (A1). Among 314 TRN neurons, 56.05% responded silently, 21.02% responded only to noise and 22.93% responded to both noise and tone. The neurons with noise response can be divided into three patterns according to their response time: onset, sustain and long-lasting, accounting for 73.19%, 14.49% and 12.32%, respectively. The response threshold of the sustain pattern neurons was lower than those of the other two types. Under noise stimulation, compared with A1 layer six, TRN neurons showed unstable auditory response (P < 0.001), higher spontaneous firing rate (P < 0.001), and longer response latency (P < 0.001). Under tone stimulation, TRN's response continuity was poor, and the frequency tuning was greatly different from that of A1 layer six (P < 0.001), but their sensitivity to tone was similar (P > 0.05), and TRN's tone response threshold was much higher than that of A1 layer six (P < 0.001). The above results demonstrate that TRN mainly undertakes the task of information transmission in the auditory system. The noise response of TRN is more extensive than the tone response. Generally, TRN prefers high-intensity acoustic stimulation.
Rats ; Mice ; Animals ; Wakefulness ; Auditory Pathways/physiology* ; Rats, Wistar ; Mice, Inbred C57BL ; Thalamus/physiology*

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

OBJECTIVE: To investigate the effects of umbilical moxibustion therapy on phobic behavior and the contents of norepinephrine (NE), dopamine (DA) and 5-hydroxytryptamine (5-HT) in different brain regions of the stress-model rats and explore the potential mechanism of umbilical moxibustion on phobic behavior. METHODS: Among 50 Wistar male rats, 45 rates were selected and randomly divided into a control group, a model group and an umbilical moxibustion group, 15 rats in each one; and the rest 5 rats were used for preparing the model of electric shock. The bystander electroshock method was adopted to prepare phobic stress model in the model group and the umbilical moxibustion group. After modeling, the intervention with umbilical moxibustion started in the umbilical moxibustion group, in which, the ginger-isolated moxibustion was applied at "Shenque" (CV 8), once daily, 2 cones for 20 min each time, for consecutively 21 days. After modeling and intervention completed, the rats in each group were subjected to the open field test to evaluate the state of fear. After intervention, the Morris water maze test and fear conditioning test were performed to evaluate the changes in learning and memory ability and the state of fear. Using high performance liquid chromatography (HPLC), the contents of NE, DA and 5-HT in the hippocampus, prefrontal cortex and hypothalamus were determined. RESULTS: Compared with the control group, the horizontal and vertical activity scores were lower (P<0.01), the number of stool particles was increased (P<0.01), the escape latency was prolonged (P<0.01), the times of target quadrant were reduced (P<0.01), and the freezing time was prolonged (P<0.05) in the rats of the model group. The horizontal and vertical activity scores were increased (P<0.05), the number of stool particles was reduced (P<0.05), the escape latency was shortened (P<0.05, P<0.01), the times of target quadrant were increased (P<0.05), and the freezing time was shortened (P<0.05) in the rats of the umbilical moxibustion group when compared with the model group. The trend search strategy was adopted in the control group and the umbilical moxibustion group, while the random search strategy was used in rats of the model group. Compared with the control group, the contents of NE, DA and 5-HT in the hippocampus, prefrontal cortex and hypothalamus were reduced (P<0.01) in the model group. In the umbilical moxibustion group, the contents of NE, DA and 5-HT in the hippocampus, prefrontal cortex and hypothalamus were increased (P<0.05, P<0.01) when compared with the model group. CONCLUSION Umbilical moxibustion can effectively relieve the state of fear and learning and memory impairment of phobic stress model rats, which may be related to the up-regulation of contents of brain neurotransmitters, i.e. NE, DA, and 5-HT.
Rats ; Male ; Animals ; Moxibustion ; Rats, Sprague-Dawley ; Rats, Wistar ; Serotonin ; Hippocampus ; Dopamine ; Norepinephrine ; Neurotransmitter Agents

OBJECTIVE: To observe the effects of moxibustion on the ultrastructure of synovial cells of knee joint and serum cytokines in adjuvant arthritis (AA) rats, and to explore the potential mechanism of moxibustion in treatment of rheumatoid arthritis. METHODS: Forty-five Wistar male rats were randomly divided into a normal group, a model group and a moxibustion group, with 15 rats in each group. In the model group and the moxibustion group, the AA model was replicated under wind, cold and humid environment and by injection with complete freund's adjuvant. In the moxibustion group, moxibustion at "Zusanli" (ST 36) and "Shenshu" (BL 23) was used, 20 min each time, once daily, for consecutive 21 days. In the normal group and the model group, no intervention was processed. The scores of the knee joint swelling degree (JSD) and arthritis index (AI) were compared among groups. The ultrastructure of synovial cells of knee joint were observed under transmission electron microscope (TEM). The levels of serum cytokines such as tumor necrosis factor-α (TNF-α), interieukin (IL)-1β, IL-6 and IL-10 were detected using ELISA method. RESULTS: Compared with the normal group, JSD and AI scores, the levels of TNF-α, IL-1β and IL-6 were increased (P<0.01), while IL-10 was reduced (P<0.01) in the model group after intervention. JSD and AI scores, and the levels of TNF-α, IL-1β and IL-6 were lower (P<0.05, P<0.01), while the level of IL-10 was higher (P<0.01) in the moxibustion group compared with the model group. Compared with the normal group, the ultrastructure of synovial cell was obviously damaged in the model group, and the damage was attenuated in the moxibustion group compared with the model group. CONCLUSION Moxibustion can reduce the symptoms of arthritis in AA rats, which may be related to the improvement of the ultrastructure of synovial cells and the regulation of cytokines.
Male ; Rats ; Animals ; Cytokines ; Interleukin-10 ; Arthritis, Experimental ; Tumor Necrosis Factor-alpha ; Interleukin-6 ; Moxibustion ; Rats, Wistar ; Knee Joint

This study assessed the effects of a simulated high-altitude environment on the reproductive system of prepubertal male rats and the reversibility of these effects upon return to a normal environment. Three-week-old male Wistar rats were randomly allocated to 4 groups that were exposed to different conditions: a normal environment for 6 weeks and 12 weeks, respectively, hypobaric hypoxia for 6 weeks, and hypobaric hypoxia for 6 weeks followed by a normal environment for 6 weeks. Multiple pathophysiological parameters were evaluated at the histological, endocrine, and molecular levels. Hypobaric hypoxia exposure for 6 weeks during the prepubertal phase significantly altered physiological parameters, body functions, blood indices, and reproductive potential. Six weeks after returning to a normal environment, the damaged reproductive functions partially recovered due to compensatory mechanisms. However, several changes were not reversed after returning to a normal environment for 6 weeks, including disorders of body development and metabolism, increased red blood cells, increased fasting blood glucose, abnormal blood lipid metabolism, decreased testicular and epididymis weights, abnormal reproductive hormone levels, excessive apoptosis of reproductive cells, and decreased sperm concentration. In summary, a hypobaric hypoxic environment significantly impaired the reproductive function of prepubertal male rats, and a return to normal conditions during the postpubertal phase did not fully recover these impairments.
Rats ; Male ; Animals ; Rats, Wistar ; Altitude ; Semen/metabolism* ; Hypoxia/pathology* ; Genitalia, Male

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 systematically study the anti-fibrotic effect of N-acetyl-seryl-as partyl-lysyl-proline (Ac-SDKP) on pulmonary fibrosis. Methods: In May 2021, a computer search was performed on CNKI, Wanfang Knowledge Service Platform, VIP.com, China Biomedical Literature Database, Pubmed, OVID and other databases. The retrieval time was from January 2008 to May 2021. Randomized controlled experiments on the inhibition of pulmonary fibrosis by Ac-SDKP were screened. The control group was the pulmonary fibrosis model group and the experimental group was the Ac-SDKP treatment group. The quality of the literature was assessed using the syrcle risk of bias assessment tool, and data were extracted. Data analysis was Performed using revman 5.4 software. Results: 18 papers were included, with a total of 428 animal models. The results of meta analysis showed that the contents of α-smooth muscle actin (α-SMA), type I collagen, type Ⅲ collagen, transforming growth factor-β (TGF-β) and Nodule area in the exPerimental group were lower than those in the control grouP. [SMD=-2.44, 95%CI (-3.71--1.17), P=0.000][SMD=-5.36, 95%CI (-7.13--3.59), P=0.000] [SMD=-3.07, 95%CI (-4.13--2.02), P<0.000][SMD=-2.88, 95%CI (-3.63--2.14), P=0.000] [SMD=-1.80, 95%CI (-2.42--1.18), P=0.000], the content of hydroxy proline in the experimental group was higher than that in the control group [SMD=7.62, 95%CI (4.90-10.33), P=0.000], all indexes included in the literature were statistically significant. Conclusion: Ac-SDKP has obvious inhibitory effect on the process of pulmonary fibrosis, and may become a new clinical drug for the treatment of pulmonary fibrosis.
Rats ; Animals ; Pulmonary Fibrosis ; Rats, Wistar ; Fibrosis ; Disease Models, Animal ; Proline

Objective: To construct paraquat (PQ) poisoning rat model and to explore the effect of pirfenidone (PFD) on PQ-induced pulmonary fibrosis. Methods: In April 2017, male 6-8 week-old Wistar rats were selected, and PQ was administered intraperitoneally at one time. PFD was administered by gavage 2 hours after poisoning. The daily gavage doses were 100, 200 and 300 mg/kg, and the rats were divided into physiological saline group, PQ group, PQ+PFD 100 group, PQ+PFD 200 group, PQ+PFD 300 group, with 10 rats in each group at each observation time point. The pathological changes of lung tissue at different time points (the 1st, 3rd, 7th, 14th, 28th, 42nd and 56th days) after poisoning and the effect of PFD intervention with different dose on PQ-induced pulmonary fibrosis were observed. Pathological evaluation of lung tissue was performed by Ashcroft scale method. The PQ+PFD 200 group was selected to further explore the pathological changes of lung tissue, the contents of hydroxyproline and malondialdehyde in lung tissue were determined.And the tumor necrosis factor (TNF) -α, interleukin (IL) -6, transforming growth factor (TGF) -β1, fibroblast growth factor (FGF) -B, platelet-derived growth factor (PDGF) -AB, insulin-like growth factor (IGF) -1 and PQ concentrations in serum and lung tissue were determined. Results: On the 1st to 7th day after PQ exposure, rats developed lung inflammation, which was aggravated on the 7th to 14th day, and pulmonary fibrosis appeared on the 14th to 56th day. Compared with PQ group, the Ashcroft scores of lung fibrosis in PQ+PFD 200 group and PQ+PDF 300 group decreased significantly in 7th and 28th day (P<0.05), while the Ashcroft score of lung fibrosis in PQ+PFD 100 group had no significant difference (P>0.05). After PQ exposure, the content of hydroxyproline in lung tissue increased gradually and reached the peak value on the 28th day. Compared with the PQ group, the contents of hydroxyproline in the PQ+PFD 200 group decreased at the 7th, 14th and 28th day, and the contents of malondialdehyde decreased at the 3rd and 7th day, the differences were statistically significant (P<0.05). The levels of TNF-α, IL-6 in rat serum and lung tissue reached the peak value on the 7th day after PQ exposure, and the levels of TGF-β1, FGF-B and IGF-1 in rat serum and lung tissue reached the peak value on the 14th day after PQ exposure, and the level of PDGF-AB in rat serum and lung tissue reached the peak value on the 28th day after PQ exposure. Compared with PQ group, the level of serum IL-6 in PQ+PFD 200 group decreased significantly on the 7th day, and serum TGF-β1, FGF-B, PDGF-AB and IGF-1 on the 14th and 28th day were decreased significantly (P<0.05). The levels of TNF-α, IL-6 in lung tissue of rats in PQ+PFD 200 group on the 7th day decreased significantly, and the levels of TGF-β1, FGF-B and IGF-1 in lung tissue of rats on the 14th day were significantly decreased, and the level of PDGF-AB in lung tissue of rats on the 28th day were significantly decreased (P<0.05) . Conclusion: PFD partially alleviates the PQ-induced lung inflammation and fibrosis by inhibiting oxidative stress, reducing the levels of pro-inflammatory and pro-fibrotic cytokines in serum and lung tissue, but does not affect the concentrations of PQ in serum and lung tissue.
Male ; Rats ; Animals ; Pulmonary Fibrosis/chemically induced* ; Insulin-Like Growth Factor I ; Paraquat ; Transforming Growth Factor beta1 ; Hydroxyproline ; Interleukin-6 ; Tumor Necrosis Factor-alpha ; Rats, Wistar ; Malondialdehyde

OBJECTIVE: To explore the effect of electroacupuncture (EA) intervention on the vasoconstriction of cerebral artery smooth muscle cells after cerebral infarction. METHODS: Male Wistar rats were randomly divided into 3 groups by a random number table: the model group (n=24), the EA group (n=24), and the normal group (n=6). The model and the EA groups were divided into different time subgroups at 0.5, 1, 3, and 6 h after middle cerebral artery occlusion (MCAO), with 6 rats in each subgroup. MCAO model was established using intraluminal suture occlusion method. The EA group was given EA treatment at acupoint Shuigou (GV 26) instantly after MCAO for 20 min. The contents of cerebrovascular smooth muscle MLCK, the 3 subunits of myosin light chain phosphatase (MLCP) MYPT1, PP1c-δ and M20, as well as myosin-ATPase activity were detected using immunohistochemistry and Western blotting. RESULTS: The overall expression level of the MYPT1 and PP1c-δ in the model group was significantly higher (P<0.01). After EA intervention, the 0.5 h group expression level was close to that of the normal group (P>0.05), and the other subgroups were still significantly higher than the normal group (P<0.01). After EA intervention, the expression level of each subgroup was significantly lower than the corresponding model group. There was a significant difference between the 0.5 and 1 h subgroups (P<0.01), while a difference was also observed between the 3 and 6 h subgroups (P<0.05). The dynamic change rule gradually increased with the prolongation of infarction time within 6 h after infarction. CONCLUSION EA intervention can inhibit contraction of cerebral vascular smooth muscle cells and regulate smooth muscle relaxation by regulating MLCK pathway.
Rats ; Male ; Animals ; Rats, Wistar ; Electroacupuncture ; Cerebral Infarction/metabolism* ; Muscle, Smooth ; Acupuncture Points ; Brain Ischemia/therapy*

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*