ObjectiveTo investigate the potential mechanism of Yiqi Yangyin Huoxue Formula （益气养阴活血方， YYHF） in the treatment of membranous nephropathy （MN） based on the NOX4-mediated stromal cell-derived factor-1α（SDF-1α）/CXC chemokine receptor 4 （CXCR4） signaling pathway. MethodsA total of 42 male SD rats were randomly divided into blank group （n=6） and modeling group （n=36）. The modeling rats were given a single injection of sheep antirat Fx1A （6 ml/kg） serum into the tail vein to establish MN model. Thirty-six rats with successful modeling were further divided into model group （normal saline， 10 ml/kg）， benazepril group （10 mg·kg^-1·d^-1）， the medium-dose YYHF group （11.0 g·kg^-1·d^-1） and high-dose YYHF group （22.0 g·kg^-1·d^-1）， with 9 rats in each group. All groups received daily intragastric administration for 6 consecutive weeks. During the experimental period， the general condition of rats in each group was observed. After gavage administration finished， a fully automated biochemical analyzer was used to measure the 24-hour urine total protein （24 h-UTP） and serum biochemical parameters， including albumin （ALB）， aspartate aminotransferase （AST）， blood urea nitrogen （BUN）， serum creatinine （SCr）， total cholesterol （TC）， and triglyceride （TG）. Hematoxylin-eosin （HE） staining and periodic acid-silver metheramine （PASM） staining were used to observe the histopathological changes of renal tissues in each group of rats. The levels of superoxide dismutase （SOD） and malondialdehyde （MDA） in renal tissues were detected by ELISA. The protein expression levels of NOX4， SDF-1α， CXCR4， Nrf2， nuclear factor kappa B subunit p65 （NF-κB p65） and podocyte slit diaphragm protein nephrin in rat renal tissues were detected by Western Blotting. The mRNA expressions of NOX4， SDF-1α， CXCR4， Nrf2， NF-κB p65 and Nephrin in renal tissues were detected by real-time fluorescence quantitative polymerase chain reaction （RT-PCR）. ResultsCompared to the blank group， rats in the model group exhibited typical features of MN， including lethargy， reduced activity， dull and coarse fur， marked edema， and massive proteinuria. Compared to the model group， these abnormal conditions were improved to varying degrees in all treatment groups. The high-dose YYHF group showed a level of improvement comparable to that of the benazepril group， with overall recovery superior to that of the medium-dose YYHF group. Compared to the blank group， the model group showed increased levels of 24 h-UTP， BUN， SCr， TC and TG， decreased level of ALB， increased levels of MDA and protein and mRNA expressions of NOX4， SDF-1α， CXCR4 and NF-κB p65 in renal tissue， along with decreased levels of SOD and protein and mRNA expressions of Nrf2， Nephrin （P＜0.01）， accompanied by severe renal pathological damage. Compared to the model group， the benazepril and the medium- and high-dose YYHF groups showed significant improvements in the above indicators （P＜0.01）， along with alleviation of renal pathological injury. The 24 h-UTP level in the high-dose YYHF group was lower than that in the medium-dose group （P＜0.01）， while no statistically significant difference was observed among the other treatment groups （P＞0.01）. ConclusionYYHF may alleviate oxidative stress and inflammatory responses by down-regulating the expression of NOX4 and inhibiting the SDF-1α/CXCR4-Nrf2 signaling pathway， thereby improving podocyte damage and protecting renal function.

G protein-coupled receptor kinase 2 (GRK2) participates in the phosphorylation and desensitization of G protein-coupled receptor (GPCR), impacting various biological processes such as inflammation and cell proliferation. Dysregulated expression and activity of GRK2 have been reported in multiple cells in rheumatoid arthritis (RA). However, whether and how GRK2 regulates synovial hyperplasia and fibroblast-like synoviocytes (FLSs) proliferation is poorly understood. In this study, we investigated the regulation of GRK2 and its biological function in RA. We found that GRK2 transmembrane activity was increased in FLSs of RA patients and collagen-induced arthritis (CIA) rats. Additionally, we noted a positive correlation between high GRK2 expression on the cell membrane and serological markers associated with RA and CIA. Immunoprecipitation-mass spectrometry and pull-down analyses revealed tumor necrosis factor receptor-associated factor 2 (TRAF2) as a novel substrate of GRK2. Furthermore, surface plasmon resonance (SPR) and molecular docking assays determined that the C-terminus of GRK2 binds to the C-terminus of TRAF2 at the Gln340 residue. GRK2 knockdown and the GRK2 inhibitor CP-25 attenuated synovial hyperplasia and FLS proliferation in CIA both in vitro and in vivo by decreasing GRK2 membrane expression and activity. Mechanistically, increased GRK2 transmembrane activity contributed to the recruitment of TRAF2 on the cell membrane, promoting GRK2-TRAF2 interactions that facilitate the recruitment of the E3 ubiquitin ligase TRIM47 to TRAF2. This enhanced TRAF2 Lys63 polyubiquitylation and induced nuclear factor (NF)-κB activation, leading to synovial hyperplasia and abnormal proliferation of FLSs. Our study provides a mechanistic and preclinical rationale for further evaluation of GRK2 as a therapeutic target for RA.

Objective To investigate the differences in cortical activation and functional connectivity during speech under different cognitive loads in young individuals.Methods Twenty-one participants(mean age 21.9±1.33 years)were instructed to read short sentences embedded with color words under both congruent(where the color words matched the font color)and incongruent(where the color words did not match the font color)condi-tions.The color words required reading the font color instead of the word itself.Functional near-infrared spectros-copy(fNIRS)was utilized to analyze differences in cortical activation(changes in HbO concentration)and functional connectivity(Pearson correlation of HbO between brain regions)in the dorsolateral prefrontal cortex(DLPFC)and supplementary motor area(SMA)bilaterally.Results The fNIRS results revealed significant increase in HbO con-centration changes in the RDLPFC(t=3.4,P=0.003),LDLPFC(t=2.58,P=0.019),RSMA(t=3.59,P=0.002),and LSMA(t=4.06,P=0.001)under the incongruent condition compared to the congruent condition.Additionally,there was a significant enhancement in the correlation between RDLPFC and LDLPFC(t=2.44,P=0.025).However,the differences in correlation between left and right SMA,as well as between SMA and DLPFC,were not statistically significant(P＞0.05).Conclusion These findings suggest that during speech under incongru-ent conditions,increased cognitive load leads to elevated cortical activation in the DLPFC and SMA,along with in-creased functional connectivity between the left and right DLPFC.

Objective:To assess the efficacy and safety of Gongxuening Capsules in reducing post-abortion bleeding following artificial abortion.Methods:A multicenter, randomized, double-blind study was conducted. From May 31, 2022 to March 31, 2023, 484 women who underwent vacuum aspiration abortion for early intrauterine pregnancy were enrolled in 11 centers and randomly assigned to control group and the study group at a 1∶1 ratio using a center-block randomization method. Control group were administered a placebo of Gongxuening Capsules for 9 d, while the study group received the actual Gongxuening Capsules for the same duration. The outcomes measured included vaginal bleeding volume, duration of vaginal bleeding, endometrial thickness, time to menstrual recovery, and complications.Results:1) A total of 484 subjects were enrolled, and 472 completed the study. Totally 450 subjects were included in the efficacy analysis set, with 224 in control group and 226 in the study group; 468 subjects were included in the safety analysis set, with 236 in control group and 232 in the study group. The baseline characteristics of the two groups were comparable (all P>0.05). 2) The vaginal bleeding volume was lower in the study group [(13.30±12.14) mL] than in control group [(19.00±17.67) mL, P<0.001]. The proportion of subjects in the study group with bleeding days less than 4 d [29.65% (67/226)] was higher than that in control group [19.20% (43/224), P=0.010]. 3) No significant differences were observed between the two groups in terms of time to menstrual recovery and endometrial thickness (all P>0.05). 4) In the study group, 3 subjects experienced non-therapeutic-related complications, while 11 subjects in control group. The incidence of complications was lower in the study group [1.29% (3/232)] than in control group [4.66% (11/236), P=0.033]. Conclusion:The administration of Gongxuening Capsules to women following artificial abortion significantly reduced vaginal bleeding volume and was associated with good safety, with the treatment being well-tolerated by the subjects.

Objective:To explore the inhibitory effect of protocatechuic acid (PCA) on the growth of ovarian cancer cell line A2780 and its mechanism.Methods:A2780 cells were cultured in vitro and randomly divided into a control group and protocatechuic acid-treated groups with concentrations of 5 μM and 10 μM. Cell proliferation was detected using the MTT assay; Cell migration ability was assessed through wound healing experiments; Cell cycle and apoptosis were analyzed using flow cytometry; Protein expression of apoptosis-related proteins was examined using Western blot.Results:Compared with the control group, the absorbance of the protocatechuic acid groups (5 μM, 10 μM) decreased after 48 hours, and protocatechuic acid significantly inhibited cell proliferation ( P<0.05) . In the 5 μM protocatechuic acid treatment group, the proportion of cells in the G2/M phase increased to 25.26%, and in the 10 μM treatment group, the proportion of cells in the G2/M phase increased to 24.99%. Protocatechuic acid groups could arrest the cell cycle of the human ovarian cancer cell line A2780 at the G2/M phase. Protocatechuic acid groups could also promote the increase of early and late apoptosis rates of A2780 cells, leading to the upregulation of the expression levels of related apoptotic proteins CASPASE-3 and Bax, while the expression level of the anti-apoptotic protein Bcl2 was downregulated. Conclusions:Protocatechuic acid can inhibit proliferation and migration of A2780 ovarian cancer cells, arrest the cell cycle of A2780 cells, and promote apoptosis. The mechanism of action may be related to the upregulation of apoptosis-related proteins BAX and caspase3.

Objective:To assess the efficacy and safety of Gongxuening Capsules in reducing post-abortion bleeding following artificial abortion.Methods:A multicenter, randomized, double-blind study was conducted. From May 31, 2022 to March 31, 2023, 484 women who underwent vacuum aspiration abortion for early intrauterine pregnancy were enrolled in 11 centers and randomly assigned to control group and the study group at a 1∶1 ratio using a center-block randomization method. Control group were administered a placebo of Gongxuening Capsules for 9 d, while the study group received the actual Gongxuening Capsules for the same duration. The outcomes measured included vaginal bleeding volume, duration of vaginal bleeding, endometrial thickness, time to menstrual recovery, and complications.Results:1) A total of 484 subjects were enrolled, and 472 completed the study. Totally 450 subjects were included in the efficacy analysis set, with 224 in control group and 226 in the study group; 468 subjects were included in the safety analysis set, with 236 in control group and 232 in the study group. The baseline characteristics of the two groups were comparable (all P>0.05). 2) The vaginal bleeding volume was lower in the study group [(13.30±12.14) mL] than in control group [(19.00±17.67) mL, P<0.001]. The proportion of subjects in the study group with bleeding days less than 4 d [29.65% (67/226)] was higher than that in control group [19.20% (43/224), P=0.010]. 3) No significant differences were observed between the two groups in terms of time to menstrual recovery and endometrial thickness (all P>0.05). 4) In the study group, 3 subjects experienced non-therapeutic-related complications, while 11 subjects in control group. The incidence of complications was lower in the study group [1.29% (3/232)] than in control group [4.66% (11/236), P=0.033]. Conclusion:The administration of Gongxuening Capsules to women following artificial abortion significantly reduced vaginal bleeding volume and was associated with good safety, with the treatment being well-tolerated by the subjects.

Objective:To explore the inhibitory effect of protocatechuic acid (PCA) on the growth of ovarian cancer cell line A2780 and its mechanism.Methods:A2780 cells were cultured in vitro and randomly divided into a control group and protocatechuic acid-treated groups with concentrations of 5 μM and 10 μM. Cell proliferation was detected using the MTT assay; Cell migration ability was assessed through wound healing experiments; Cell cycle and apoptosis were analyzed using flow cytometry; Protein expression of apoptosis-related proteins was examined using Western blot.Results:Compared with the control group, the absorbance of the protocatechuic acid groups (5 μM, 10 μM) decreased after 48 hours, and protocatechuic acid significantly inhibited cell proliferation ( P<0.05) . In the 5 μM protocatechuic acid treatment group, the proportion of cells in the G2/M phase increased to 25.26%, and in the 10 μM treatment group, the proportion of cells in the G2/M phase increased to 24.99%. Protocatechuic acid groups could arrest the cell cycle of the human ovarian cancer cell line A2780 at the G2/M phase. Protocatechuic acid groups could also promote the increase of early and late apoptosis rates of A2780 cells, leading to the upregulation of the expression levels of related apoptotic proteins CASPASE-3 and Bax, while the expression level of the anti-apoptotic protein Bcl2 was downregulated. Conclusions:Protocatechuic acid can inhibit proliferation and migration of A2780 ovarian cancer cells, arrest the cell cycle of A2780 cells, and promote apoptosis. The mechanism of action may be related to the upregulation of apoptosis-related proteins BAX and caspase3.

Objective To explore the therapeutic effect and mechanism of electroacupuncture on depressive model mice based on the phosphatase and tensin homolog-induced kinase 1(PINK1)/Parkin pathway.Methods Specific pathogen-free grade male C57BL/6J mice were used.For experiment 1,60 mice were randomly divided into blank,model,sham electroacupuncture,and electroacupuncture groups using the random number table method,with 15 rats per group.For experiment 2,30 mice were randomly divided into normal,cyclosporine A(CsA),and electroacupuncture+CsA groups using the same method,with 10 rats per group.The chronic restraint stress(CRS)was used to establish a depression model.After successful modeling,CRS was continued to maintain model stability.After modeling,1 h before daily CRS stimulation,the electroacupuncture and electroacupuncture+CsA groups received electroacupuncture interventions at the"Baihui"(GV20)and"Zusanli"(ST36)acupoints,using continuous wave stimulation at a frequency of 2 Hz and an intensity of 1 mA for 20 min,once daily for 7 consecutive days.Mice in the sham electroacupuncture group received superficial needling at non-meridian,non-acupoint locations under the axilla 1 h before CRS,with the electroacupuncture device connected but not powered on once a day for 7 consecutive days.Mice in the CsA and electroacupuncture+CsA groups received an intraperitoneal injection of CsA solution(0.2 mg/g)30 min before electroacupuncture intervention,once daily for 7 consecutive days.In experiment 1,depressive-like behavior was assessed using the open field,tail suspension,and sucrose preference tests.The spontaneous excitatory postsynaptic currents(sEPSC)and spontaneous inhibitory postsynaptic currents(sIPSC)parameters of hippocampal neurons were evaluated using brain slice patch clamp techniques.Western blotting was conducted to measure the expression levels of mitochondrial autophagy-related proteins PINK 1,phosphorylated PINK1(p-PINK1),Parkin,microtubule-associated protein 1A/1B-light chain 3-Ⅱ/Ⅰ(LC3-Ⅱ/Ⅰ),ubiquitin-binding protein(p62),and mitochondrial markers,including translocase of outer mitochondrial membrane 20(TOMM20),heat shock protein 60(HSP 60),and cytochrome c oxidase Ⅳ(COX Ⅳ).Immunofluorescence was used to detect PINK1 protein expression in the CA3 region of the hippocampus.Transmission electron microscopy was used to examine the ultrastructure of mitochondria in hippocampal neurons.On the basis of experiment 1,experiment 2 evaluated depressive-like behavior in mice using sucrose preference,open field,and tail suspension tests;Western blotting was used to detect the expressions of PINK1,p-PINK1,Parkin,LC3-Ⅱ/Ⅰ,p62,TOMM20,HSP 60,and COX Ⅳ proteins of hippocampus in mice.The mitochondrial ultrastructure was observed in hippocampal neurons using transmission electron microscopy.Results In experiment 1,compared with the blank group,the model and sham electroacupuncture groups exhibited a decrease in sucrose consumption rate,a decrease in the time spent in the center area,a reduced proportion of distance moved in the center area,and an increase in immobility time of tail suspension(P＜0.05).The sEPSC and sIPSC in hippocampal neurons decreased in both amplitude and frequency(P＜0.05).p-PINK1,Parkin,LC3-Ⅱ/Ⅰ,TOMM20,HSP 60,and COXⅣ expression levels in the hippocampus were reduced,whereas the p62 expression level was increased(P＜0.05).The average fluorescence intensity of PINK1 in the CA3 region of the hippocampus decreased(P＜0.05).The number of healthy mitochondria in hippocampal neurons was reduced,with numerous damaged mitochondrial structures observed.Compared to the model and sham electroacupuncture groups,the electroacupuncture group showed an increased in the time spent in the center area,a higher proportion of distance moved in the center area,and an elevated sucrose consumption rate.In contrast,the immobility time in the tail suspension test decreased(P＜0.05),whereas the amplitude and frequency of sEPSC and sIPSC in hippocampal neurons increased(P＜0.05).p-PINK1,Parkin,LC3-Ⅱ/Ⅰ,TOMM20,HSP 60,and COXⅣ expression levels in the hippocampus increased,whereas the p62 expression level decreased(P＜0.05).The average fluorescence intensity of PINK1 in the CA3 region of the hippocampus increased(P＜0.05).Additionally,mitochondrial damage in hippocampal neurons was alleviated,and a notable presence of autophagosomes mitophagy lysosomes was observed.In experiment 2,compared with the normal group,the mice in the CsA and electroacupuncture+CsA groups showed a decrease in the time spent in the center area and the proportion of distance moved in the center area,a decrease in sucrose consumption rate,and an increase in the immobility time in the tail suspension test(P＜0.05).p-PINK1,Parkin,LC3-Ⅱ/Ⅰ,TOMM20,HSP 60,and COX Ⅳ expression levels in the hippocampus decreased,whereas p62 expression increased(P＜0.05).Many damaged mitochondria were observed in hippocampal neurons.Conclusion Electroacupuncture may exert its antidepressant effects by promoting PINK1/Parkin pathway-mediated mitophagy to eliminate damaged mitochondria,thereby restoring the function of hippocampal neurons in depressive model mice.

Objective To explore the therapeutic effect and mechanism of electroacupuncture on depressive model mice based on the phosphatase and tensin homolog-induced kinase 1(PINK1)/Parkin pathway.Methods Specific pathogen-free grade male C57BL/6J mice were used.For experiment 1,60 mice were randomly divided into blank,model,sham electroacupuncture,and electroacupuncture groups using the random number table method,with 15 rats per group.For experiment 2,30 mice were randomly divided into normal,cyclosporine A(CsA),and electroacupuncture+CsA groups using the same method,with 10 rats per group.The chronic restraint stress(CRS)was used to establish a depression model.After successful modeling,CRS was continued to maintain model stability.After modeling,1 h before daily CRS stimulation,the electroacupuncture and electroacupuncture+CsA groups received electroacupuncture interventions at the"Baihui"(GV20)and"Zusanli"(ST36)acupoints,using continuous wave stimulation at a frequency of 2 Hz and an intensity of 1 mA for 20 min,once daily for 7 consecutive days.Mice in the sham electroacupuncture group received superficial needling at non-meridian,non-acupoint locations under the axilla 1 h before CRS,with the electroacupuncture device connected but not powered on once a day for 7 consecutive days.Mice in the CsA and electroacupuncture+CsA groups received an intraperitoneal injection of CsA solution(0.2 mg/g)30 min before electroacupuncture intervention,once daily for 7 consecutive days.In experiment 1,depressive-like behavior was assessed using the open field,tail suspension,and sucrose preference tests.The spontaneous excitatory postsynaptic currents(sEPSC)and spontaneous inhibitory postsynaptic currents(sIPSC)parameters of hippocampal neurons were evaluated using brain slice patch clamp techniques.Western blotting was conducted to measure the expression levels of mitochondrial autophagy-related proteins PINK 1,phosphorylated PINK1(p-PINK1),Parkin,microtubule-associated protein 1A/1B-light chain 3-Ⅱ/Ⅰ(LC3-Ⅱ/Ⅰ),ubiquitin-binding protein(p62),and mitochondrial markers,including translocase of outer mitochondrial membrane 20(TOMM20),heat shock protein 60(HSP 60),and cytochrome c oxidase Ⅳ(COX Ⅳ).Immunofluorescence was used to detect PINK1 protein expression in the CA3 region of the hippocampus.Transmission electron microscopy was used to examine the ultrastructure of mitochondria in hippocampal neurons.On the basis of experiment 1,experiment 2 evaluated depressive-like behavior in mice using sucrose preference,open field,and tail suspension tests;Western blotting was used to detect the expressions of PINK1,p-PINK1,Parkin,LC3-Ⅱ/Ⅰ,p62,TOMM20,HSP 60,and COX Ⅳ proteins of hippocampus in mice.The mitochondrial ultrastructure was observed in hippocampal neurons using transmission electron microscopy.Results In experiment 1,compared with the blank group,the model and sham electroacupuncture groups exhibited a decrease in sucrose consumption rate,a decrease in the time spent in the center area,a reduced proportion of distance moved in the center area,and an increase in immobility time of tail suspension(P＜0.05).The sEPSC and sIPSC in hippocampal neurons decreased in both amplitude and frequency(P＜0.05).p-PINK1,Parkin,LC3-Ⅱ/Ⅰ,TOMM20,HSP 60,and COXⅣ expression levels in the hippocampus were reduced,whereas the p62 expression level was increased(P＜0.05).The average fluorescence intensity of PINK1 in the CA3 region of the hippocampus decreased(P＜0.05).The number of healthy mitochondria in hippocampal neurons was reduced,with numerous damaged mitochondrial structures observed.Compared to the model and sham electroacupuncture groups,the electroacupuncture group showed an increased in the time spent in the center area,a higher proportion of distance moved in the center area,and an elevated sucrose consumption rate.In contrast,the immobility time in the tail suspension test decreased(P＜0.05),whereas the amplitude and frequency of sEPSC and sIPSC in hippocampal neurons increased(P＜0.05).p-PINK1,Parkin,LC3-Ⅱ/Ⅰ,TOMM20,HSP 60,and COXⅣ expression levels in the hippocampus increased,whereas the p62 expression level decreased(P＜0.05).The average fluorescence intensity of PINK1 in the CA3 region of the hippocampus increased(P＜0.05).Additionally,mitochondrial damage in hippocampal neurons was alleviated,and a notable presence of autophagosomes mitophagy lysosomes was observed.In experiment 2,compared with the normal group,the mice in the CsA and electroacupuncture+CsA groups showed a decrease in the time spent in the center area and the proportion of distance moved in the center area,a decrease in sucrose consumption rate,and an increase in the immobility time in the tail suspension test(P＜0.05).p-PINK1,Parkin,LC3-Ⅱ/Ⅰ,TOMM20,HSP 60,and COX Ⅳ expression levels in the hippocampus decreased,whereas p62 expression increased(P＜0.05).Many damaged mitochondria were observed in hippocampal neurons.Conclusion Electroacupuncture may exert its antidepressant effects by promoting PINK1/Parkin pathway-mediated mitophagy to eliminate damaged mitochondria,thereby restoring the function of hippocampal neurons in depressive model mice.

ObjectiveTo establish background data for a 90-day feeding trial of SD rats to ensure the reliability of research data. MethodsBackground data from six independent 90-day feeding trials of SD rats conducted by the National Center for Safety Evaluation of Drugs from 2020 to 2023 were summarized. These studies involved a blank control group of 120 SPF-grade 4-week-old SD rats, with an equal number of males and females, which were only given standard full-nutrient pelleted rat feed. After the quarantine period, the animals were observed for an additional 90 days, followed by intraperitoneal injection of Zoletil (50 mg/mL) for anesthesia, blood sampling, euthanasia, and necropsy. By analyzing the data from the blank control group, a relevant background database for SD rats was established. ResultsBoth male and female rats exhibited steady weight gain, with a more pronounced increase in male rats. Within 90 days, the average body weight of male and female rats increased to over 500 g and 300 g, respectively. Three weeks later, the average daily food intake of male rats stabilized at approximately 25~28 g per rat, while that of female rats remained stable at approximately 16~19 g per rat. The food utilization rate of all animals gradually decreased from the first week of the experiment. In the white blood cell (WBC) differential count results, significant differences were observed in the counts of WBCs, neutrophils (Neut), lymphocytes (Lymph), and monocytes (Mono) between males and females (P<0.001). However, there were no significant differences in the percentages of neutrophil (%Neut), lymphocyte (%Lymph), and monocyte (%Mono) between the sexes (P>0.05). The average red blood cell count (RBC), hemoglobin concentration (HGB), hematocrit (HCT), platelet count (PLT), prothrombin time (PT), and activated partial thromboplastin time (APTT) were higher in male animals than in female animals (P<0.05). The average values of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), creatine phosphokinase (CK), lactate dehydrogenase (LDH), glucose (GLU), and triglyceride (TG) in male rats were higher than those in female rats (P<0.05). The urinary pH range for male animals was 5.0 to 8.5, while for female animals it was 6.5 to 9.0. The majority of male animals had a urinary specific gravity lower than 1.020, and the majority of female animals had a urinary specific gravity lower than 1.015. The weights of various organs (excluding the adrenal glands and reproductive organs) in male animals were heavier than those in female animals (P<0.001), while the organ/body weight ratios (excluding the kidneys and reproductive organs) of female animals were higher than those of male animals (P<0.001). ConclusionThis study summarizes the background reference ranges for body weight, food intake, hematology, and serum biochemistry indicators in SPF-grade SD rats in the untreated control group from six 90-day feeding trials conducted by the National Center for Safety Evaluation of Drugs. It provides important reference data for related research. By summarizing the background and spontaneous histopathological changes in rats, this study aids in the standardization and normalization of subsequent research, as well as in the evaluation and analysis of abnormal results.