ObjectiveThis paper aims to investigate the effects and mechanism of Mimenghua prescription in modulating the mitogen-activated protein kinase kinase （MEK）/rat sarcoma viral oncogene homolog （Ras）/rapidly accelerated fibrosarcoma kinase （Raf）/extracellular signal-regulated kinase （ERK） signaling pathway to inhibit inflammatory responses in a dry eye animal model. MethodsA total of 60 C57BL/6J mice （eight weeks old， half male and half female） were used in the experiment. Ten mice were randomly selected as the blank control group， while the remaining 50 were exposed to a controlled dry system and received instillation of 0.2% benzalkonium chloride （BAC） into the eyes for four weeks to establish a dry eye mouse model. After successful modeling， the mice were randomly divided into five groups： Model group， sodium hyaluronate group， and Mimenghua prescription groups with low dose （4.83 g·kg^-1）， medium dose （9.67 g·kg^-1）， and high dose （19.34 g·kg^-1）. The mice in the model group received an equal volume of normal saline via gavage for four weeks. The mice in the sodium hyaluronate group received instillation of sodium hyaluronate eye drops twice daily for 14 consecutive days. The tear secretion volume， tear film break-up time （TBUT）， and corneal fluorescein staining were evaluated once every two weeks. After four weeks of administration， mice were euthanized， and their lacrimal gland tissues and corneas were harvested. Hematoxylin-eosin （HE） staining was used to assess histopathological morphology. Western blot was performed to detect the protein expression levels of MEK， Ras， Raf， and ERK. Enzyme-linked immunosorbent assay （ELISA） was used to measure the contents and expressions of MEK， Ras， Raf， ERK， and interleukin （IL）-1β in lacrimal gland and corneal tissues of the mice in each group. Quantitative real-time polymerase chain reaction （Real-time PCR） was employed to determine mRNA expression levels of MEK， Ras， Raf， and ERK. ResultsThe Mimenghua prescription groups and the sodium hyaluronate group exhibited significantly increased tear secretion volume （P<0.05） and prolonged TBUT （P<0.05） after treatment. Ocular surface damage of mice was visibly recovered. Western blot results indicated that protein expression levels of MEK， Ras， Raf， and ERK in the lacrimal gland and corneal tissues were significantly downregulated in the sodium hyaluronate group and Mimenghua prescription group with high dose （P<0.05）. ELISA results showed that IL-1β levels were highest in the model group but significantly reduced in the sodium hyaluronate group and Mimenghua prescription groups （P<0.05）. Both ELISA and Real-time PCR results demonstrated that the expression levels of MEK， Ras， Raf， and ERK in the lacrimal glands and corneal tissues were significantly elevated in the model group （P<0.05）， but markedly downregulated in the sodium hyaluronate group and Mimenghua prescription groups （P<0.05）， suggesting that Mimenghua prescription can decrease the expressions of MEK， Ras， Raf， and ERK in the lacrimal glands and corneal tissues. ConclusionMimenghua prescription can reduce inflammatory responses， increase tear secretion， prolong TBUT， and promote corneal recovery by inhibiting the MEK， Ras， Raf， and ERK signaling pathways in lacrimal gland and corneal tissues.

BACKGROUND:Studies have shown that patients with premature ovarian failure have changes in the structure of intestinal flora and that imbalance of intestinal microbiota may be one of the important mechanisms in the development of premature ovarian failure. OBJECTIVE:To investigate the effect of Liuwei Dihuang Wan on oxidative stress and intestinal microbiota in premature ovarian failure mice induced by cyclophosphamide. METHODS:Forty-five female ICR mice were randomized into three groups:blank group(normal mice),model group(premature ovarian failure mice),and Liuwei Dihuang Wan group.A mouse model of premature ovarian failure was prepared by one-time intraperitoneal injection of cyclophosphamide(120 mg/kg)in the latter two groups.After successful modeling,the Liuwei Dihuang Wan group was intragastrically administered for 28 continuous days,and the other two groups were intragastrically administered with the same amount of normal saline for 28 days.Mouse body mass was recorded weekly and ovarian index was calculated.The development of mouse follicles was observed using hematoxylin-eosin staining.ELISA method was used to detect serum levels of anti-Mullerian hormone,estradiol,follicle stimulating hormone,superoxide dismutase,glutathione peroxidase,and malondialdehyde.Meanwhile,the gut microbiome of all mice was detected through 16S rDNA sequencing. RESULTS AND CONCLUSION:The mice in the model group had loose hair,decreased vigor and grip strength,almost no increase in body mass,and decreased ovarian index.Whereas,the mouse body mass and ovarian index were increased after treatment with Liuwei Dihuang Wan(P<0.05).The estrous cycle of mice in the model group was disorganized;Liuwei Dihuang Wan could restore the estrous cycle and reduce the number of atretic follicles in mice with premature ovarian failure.The serum levels of follicle stimulating hormone and malondialdehyde in the model group significantly increased(P<0.01),while the levels of estradiol,anti-Mullerian hormone,superoxide dismutase,and glutathione peroxidase significantly decreased(P<0.01).Liuwei Dihuang Wan could significantly decrease the serum levels of follicle stimulating hormone and malondialdehyde(P<0.01),and increase the levels of estradiol,anti-Mullerian hormone,superoxide dismutase,and glutathione peroxidase.According to the 16S rDNA sequencing results,Liuwei Dihuang Wan could regulate the abundance and diversity of intestinal microbiota,and increase the relative abundance of beneficial bacteria.KEGG pathway analysis showed that the intestinal microbiota and metabolic pathways,biosynthesis of secondary metabolites,microbial metabolism in different environments,and biosynthesis of amino acids were regulated by Liuwei Dihuang Wan.To conclude,the changes in the structure of intestinal microbiome may be one of the potential mechanisms of Liuwei Dihuang Wan in treating premature ovarian failure.Liuwei Dihuang Wan can regulate the structure of intestinal microbiome,increase the number of beneficial bacteria,reduce the number of harmful bacteria,and thus improve the balance of intestinal microbiota.This regulatory effect helps to reduce oxidative stress levels and further inhibit ovarian oxidative stress in mice with premature ovarian failure.

Objective To establish a chronic kidney disease-associated aortic calcification model in SD rats using different nephrectomy surgical methods, and to compare and evaluate surgical duration and survival time to explore a more optimized modeling method. Methods According to different surgical methods, the SD rats were divided into four groups: Group A: intraperitoneal resection of 2/3 of the left kidney followed by right total nephrectomy in the second stage; Group B: intraperitoneal resection of 2/3 of the left kidney and simultaneous right total nephrectomy; Group C: dorsal approach right total nephrectomy followed by resection of 2/3 of the left kidney in the second stage; Group D: dorsal approach resection of 2/3 of the left kidney followed by right total nephrectomy in the second stage. After comparing survival curves of SD rats undergoing intraperitoneal versus dorsal approaches, and staged versus single-stage nephrectomy, the optimal nephrectomy surgical method was determined. Then, twenty-four 8-week-old SPF-grade male SD rats were selected for nephrectomy combined with calcitriol-induced calcification. Experimental group (12 rats): the dorsal approach left 2/3 nephrectomy followed by right total nephrectomy, with intraperitoneal injection of 1 μg/kg calcitriol administered one week later to induce aortic calcification. Control group (12 rats): the intraperitoneal injection of 250 μL/kg physiological saline containing 1% DMSO one week after sham surgery. After intraperitoneal injection of drugs for 3 months, the survival status of rats in each group was observed. Under anesthesia, blood samples were collected from each group to measure serum phosphorus and calcium ion concentrations, as well as serum urea nitrogen and creatinine levels. After euthanizing the rats, a post-mortem examination was performed to observe the residual kidney morphology, and HE staining was used to observe the pathological changes in the coronal section of the kidney. Additionally, the entire aorta of each group was taken, and the degree of aortic calcification was observed by staining with Alizarin red S and von Kossa. Real-time fluorescence quantitative PCR was used to detect the gene expression of smooth muscle actin-associated protein alpha (Sm22), Runt-related transcription factor 2 (Runx2), and osteopontin (OPN) in rat aortic tissue to evaluate the effectiveness of the model. Results The exploratory optimization experiment of different surgical procedures found that the survival rate of group D rats,which underwent 2/3 left kidney resection followed by right whole kidney resection via the dorsal approach, was the highest, indicating that this surgical procedure was the best method for establishing a chronic kidney disease model with renal dysfunction. The experimental group rats treated with this surgical procedure combined with high-dose calcitriol injection had significantly lower serum calcium ion concentration than those in the sham-operated control group (P<0.05), while serum phosphorus ion concentration, serum creatinine, and serum urea nitrogen levels were significantly higher than those of the control group (P<0.05). HE staining of the kidneys showed significant organic changes in the kidneys of the experimental group rats, with a significant decrease in glomerular count compared to that of the control group (P<0.05), indicating the successful establishment of a renal failure model. Alizarin red S staining showed significant pigment deposition in the aortic media of the experimental group rats, while von Kossa staining showed significant silver nitrate deposition in the aortic media of the experimental group rats, which was consistent with the manifestation of aortic calcification in renal failure. Real-time fluorescence quantitative PCR showed that the expression level of Sm22 in the aortic tissue of the experimental group rats decreased (P<0.05), while the expression levels of OPN and Runx2 increased (P<0.05), indicating a transition of aortic smooth muscle cells from smooth muscle phenotype to bone-like phenotype and successful induction of an aortic calcification model. Conclusion The method of establishing an aortic calcification model of chronic kidney disease in SD rats by first removing two-thirds of the left kidney via the dorsal approach followed by right total nephrectomy, combined with high-dose calcitriol administration, shortens the surgical time, improves the success rate of modeling, and increases the animal survival rate.

Objective To establish a chronic kidney disease-associated aortic calcification model in SD rats using different nephrectomy surgical methods, and to compare and evaluate surgical duration and survival time to explore a more optimized modeling method. Methods According to different surgical methods, the SD rats were divided into four groups: Group A: intraperitoneal resection of 2/3 of the left kidney followed by right total nephrectomy in the second stage; Group B: intraperitoneal resection of 2/3 of the left kidney and simultaneous right total nephrectomy; Group C: dorsal approach right total nephrectomy followed by resection of 2/3 of the left kidney in the second stage; Group D: dorsal approach resection of 2/3 of the left kidney followed by right total nephrectomy in the second stage. After comparing survival curves of SD rats undergoing intraperitoneal versus dorsal approaches, and staged versus single-stage nephrectomy, the optimal nephrectomy surgical method was determined. Then, twenty-four 8-week-old SPF-grade male SD rats were selected for nephrectomy combined with calcitriol-induced calcification. Experimental group (12 rats): the dorsal approach left 2/3 nephrectomy followed by right total nephrectomy, with intraperitoneal injection of 1 μg/kg calcitriol administered one week later to induce aortic calcification. Control group (12 rats): the intraperitoneal injection of 250 μL/kg physiological saline containing 1% DMSO one week after sham surgery. After intraperitoneal injection of drugs for 3 months, the survival status of rats in each group was observed. Under anesthesia, blood samples were collected from each group to measure serum phosphorus and calcium ion concentrations, as well as serum urea nitrogen and creatinine levels. After euthanizing the rats, a post-mortem examination was performed to observe the residual kidney morphology, and HE staining was used to observe the pathological changes in the coronal section of the kidney. Additionally, the entire aorta of each group was taken, and the degree of aortic calcification was observed by staining with Alizarin red S and von Kossa. Real-time fluorescence quantitative PCR was used to detect the gene expression of smooth muscle actin-associated protein alpha (Sm22), Runt-related transcription factor 2 (Runx2), and osteopontin (OPN) in rat aortic tissue to evaluate the effectiveness of the model. Results The exploratory optimization experiment of different surgical procedures found that the survival rate of group D rats,which underwent 2/3 left kidney resection followed by right whole kidney resection via the dorsal approach, was the highest, indicating that this surgical procedure was the best method for establishing a chronic kidney disease model with renal dysfunction. The experimental group rats treated with this surgical procedure combined with high-dose calcitriol injection had significantly lower serum calcium ion concentration than those in the sham-operated control group (P<0.05), while serum phosphorus ion concentration, serum creatinine, and serum urea nitrogen levels were significantly higher than those of the control group (P<0.05). HE staining of the kidneys showed significant organic changes in the kidneys of the experimental group rats, with a significant decrease in glomerular count compared to that of the control group (P<0.05), indicating the successful establishment of a renal failure model. Alizarin red S staining showed significant pigment deposition in the aortic media of the experimental group rats, while von Kossa staining showed significant silver nitrate deposition in the aortic media of the experimental group rats, which was consistent with the manifestation of aortic calcification in renal failure. Real-time fluorescence quantitative PCR showed that the expression level of Sm22 in the aortic tissue of the experimental group rats decreased (P<0.05), while the expression levels of OPN and Runx2 increased (P<0.05), indicating a transition of aortic smooth muscle cells from smooth muscle phenotype to bone-like phenotype and successful induction of an aortic calcification model. Conclusion The method of establishing an aortic calcification model of chronic kidney disease in SD rats by first removing two-thirds of the left kidney via the dorsal approach followed by right total nephrectomy, combined with high-dose calcitriol administration, shortens the surgical time, improves the success rate of modeling, and increases the animal survival rate.

Objective: To investigate the association between medium to long term PM 2.5 exposure around school areas and overweight/obesity among primary and secondary school students in Guangxi, providing data support and theoretical foundations for scientifically addressing overweight and obesity in primary and secondary school students. Methods: From September to November 2023, a stratified cluster random sampling method was employed to select 251 183 students aged 7-18 years (grade 1 to grade 12) from 14 prefecture level cities (111 districts and counties) in Guangxi. PM 2.5 mass concentration data were obtained from the Tracking Air Pollution in China (TAP) dataset. Preliminary comparative analysis was conducted using the Mann-Whitney U test, while binary Logistic regression models were applied to quantify the relationship between PM 2.5 exposure and overweight/obesity. Restricted cubic spline analysis was further utilized to examine the nonlinear association between PM 2.5 concentration and overweight/obesity risk. Results: The detection rate of overweight/obesity among Guangxi students in 2023 was 19.5%. The median PM 2.5 concentration in the year prior to the study was higher in the overweight/obesity group (23.22 μg/m 3) compared to the non overweight/obesity group (22.63 μg/m 3) ( Z=-15.66, P <0.01), and consistent trends were observed across gender (male/female) and educational stage (primary/junior/senior high school) subgroups (all P <0.01). Binary Logistic regression revealed that for every 10 μg/m 3 increase in the annual average PM 2.5 concentration, the risk of overweight/obesity increased by 12% ( OR=1.12, 95%CI=1.09- 1.15 , P <0.01). Restricted cubic spline analysis indicated a nonlinear relationship between monthly PM 2.5 levels and overweight/obesity risk ( P trend <0.01). Below 22.68 μg/m 3, PM 2.5 exposure showed no significant association with obesity risk; above the threshold, the risk increased with rising PM 2.5 levels. Conclusion Medium to long term PM 2.5 exposure around school environments is significantly associated with overweight/obesity among primary and secondary school students.

ObjectiveTo establish a geographical origin identification model for Foeniculi Fructus from Haiyuan， providing a new technical reference for the protection of Haiyuan's geo-authentic medicinal materials and its designation as a national geographical indication agricultural product. MethodsSamples of Foeniculi Fructus were collected from eight producing areas， including Minqin （Gansu）， Bozhou （Anhui）， Qingdao （Shandong）， Dezhou （Shandong）， Urumqi （Xinjiang）， Nujiang （Yunnan）， Gutuo （Inner Mongolia）， and Haiyuan （Ningxia）. Gas chromatography-ion mobility spectrometry （GC-IMS） was used to detect the volatile organic compounds （VOCs） in samples from these geographic origins. VOCs were qualitatively analyzed through dual matching with the National Institute of Standards and Technology （NIST） mass spectral database and the IMS drift time database. Using the Reporter module and Gallery Plot visualization tools within the LAV analytical platform， VOC fingerprint profiles characterizing geographic origins were constructed. A non-targeted analytical strategy was adopted， and 97 VOCs detected via GC-IMS were subjected to principal component analysis （PCA） and partial least squares discriminant analysis （PLS-DA） based on their differential distribution patterns to construct an origin identification model for Foeniculi Fructus from Haiyuan region. Key discriminative markers were screened using variable importance in projection （VIP） values greater than 1. ResultsA total of 97 VOCs were identified， including alcohols， aldehydes， ketones， esters， organic acids， terpenoids， ethers， alkenes， and benzenes. The PLS-DA model， based on VOCs data obtained by GC-IMS， effectively distinguished Foeniculi Fructus in Haiyuan region from those of other origins. During cross-validation， the model achieved a prediction parameter （Q²） of 0.976 and a goodness-of-fit parameter （R²） of 0.936， with no overfitting observed in permutation testing. Twelve key flavor markers with VIP > 1 were identified as characteristic indicators of Haiyuan origin. ConclusionA stable and highly predictive origin identification model for Foeniculi Fructus from Haiyuan was successfully established using GC-IMS technology， PLS-DA， and VIP-based marker screening. This model provides a novel technical strategy for accurately distinguishing Foeniculi Fructus in Haiyuan region from other regional varieties and offers new technical support for its protection as a geo-authentic medicinal material and a nationally designated geographical indication agricultural product in China.

ObjectiveTo establish a geographical origin identification model for Foeniculi Fructus from Haiyuan， providing a new technical reference for the protection of Haiyuan's geo-authentic medicinal materials and its designation as a national geographical indication agricultural product. MethodsSamples of Foeniculi Fructus were collected from eight producing areas， including Minqin （Gansu）， Bozhou （Anhui）， Qingdao （Shandong）， Dezhou （Shandong）， Urumqi （Xinjiang）， Nujiang （Yunnan）， Gutuo （Inner Mongolia）， and Haiyuan （Ningxia）. Gas chromatography-ion mobility spectrometry （GC-IMS） was used to detect the volatile organic compounds （VOCs） in samples from these geographic origins. VOCs were qualitatively analyzed through dual matching with the National Institute of Standards and Technology （NIST） mass spectral database and the IMS drift time database. Using the Reporter module and Gallery Plot visualization tools within the LAV analytical platform， VOC fingerprint profiles characterizing geographic origins were constructed. A non-targeted analytical strategy was adopted， and 97 VOCs detected via GC-IMS were subjected to principal component analysis （PCA） and partial least squares discriminant analysis （PLS-DA） based on their differential distribution patterns to construct an origin identification model for Foeniculi Fructus from Haiyuan region. Key discriminative markers were screened using variable importance in projection （VIP） values greater than 1. ResultsA total of 97 VOCs were identified， including alcohols， aldehydes， ketones， esters， organic acids， terpenoids， ethers， alkenes， and benzenes. The PLS-DA model， based on VOCs data obtained by GC-IMS， effectively distinguished Foeniculi Fructus in Haiyuan region from those of other origins. During cross-validation， the model achieved a prediction parameter （Q²） of 0.976 and a goodness-of-fit parameter （R²） of 0.936， with no overfitting observed in permutation testing. Twelve key flavor markers with VIP > 1 were identified as characteristic indicators of Haiyuan origin. ConclusionA stable and highly predictive origin identification model for Foeniculi Fructus from Haiyuan was successfully established using GC-IMS technology， PLS-DA， and VIP-based marker screening. This model provides a novel technical strategy for accurately distinguishing Foeniculi Fructus in Haiyuan region from other regional varieties and offers new technical support for its protection as a geo-authentic medicinal material and a nationally designated geographical indication agricultural product in China.

Objective: To analyze the nucleic acid load of human parvovirus B19 in major commercially available blood products in China, including human albumin, human intravenous immunoglobulin, human rabies immunoglobulin and various coagulation factor products, aiming to provide evidence for improving blood product manufacturing processes and quality control of source plasma. Methods: A total of 98 batches of coagulation factor products were tested for human parvovirus B19 nucleic acid using real-time fluorescent quantitative PCR, including 42 batches of human prothrombin complex, 35 batches of human coagulation factor Ⅷ, and 21 batches of human fibrinogen. Additionally, 6 batches of human albumin, 6 batches of human intravenous immunoglobulin, and 38 batches of human rabies immunoglobulin were tested for human parvovirus B19 nucleic acid. Results: Human parvovirus B19 nucleic acid were undetectable in human albumin, human intravenous immunoglobulin and human rabies immunoglobulin. Among the 98 batches of coagulation factor products tested for human parvovirus B19 nucleic acid, B19 nucleic acid reactivity rate was 69.0% (29/42) for human prothrombin complex batches, but nucleic acid concentration were all significantly lower than 10 IU/mL. The reactivity rate of B19 nucleic acid in 35 batches of human coagulation factor Ⅷ was 48.6% (17/35), with nucleic acid concentration all below 10 IU/mL. The reactivity rate of B19 nucleic acid in 21 batches of human fibrinogen was 61.9% (13/21), with nucleic acid concentration all below 10 IU/mL. Conclusion: No human parvovirus B19 has been detected in human albumin, human intravenous immunoglobulin, or human rabies immunoglobulin. Human parvovirus B19 nucleic acid may exist in commercially available coagulation factor products, highlighting the need for enhanced screening of human parvovirus B19 nucleic acid in these products. It is also recommended that B19 viral nucleic acid testing be conducted on source plasma, particularly for coagulation factor products.

Objective: To analyze the nucleic acid load of human parvovirus B19 in major commercially available blood products in China, including human albumin, human intravenous immunoglobulin, human rabies immunoglobulin and various coagulation factor products, aiming to provide evidence for improving blood product manufacturing processes and quality control of source plasma. Methods: A total of 98 batches of coagulation factor products were tested for human parvovirus B19 nucleic acid using real-time fluorescent quantitative PCR, including 42 batches of human prothrombin complex, 35 batches of human coagulation factor Ⅷ, and 21 batches of human fibrinogen. Additionally, 6 batches of human albumin, 6 batches of human intravenous immunoglobulin, and 38 batches of human rabies immunoglobulin were tested for human parvovirus B19 nucleic acid. Results: Human parvovirus B19 nucleic acid were undetectable in human albumin, human intravenous immunoglobulin and human rabies immunoglobulin. Among the 98 batches of coagulation factor products tested for human parvovirus B19 nucleic acid, B19 nucleic acid reactivity rate was 69.0% (29/42) for human prothrombin complex batches, but nucleic acid concentration were all significantly lower than 10 IU/mL. The reactivity rate of B19 nucleic acid in 35 batches of human coagulation factor Ⅷ was 48.6% (17/35), with nucleic acid concentration all below 10 IU/mL. The reactivity rate of B19 nucleic acid in 21 batches of human fibrinogen was 61.9% (13/21), with nucleic acid concentration all below 10 IU/mL. Conclusion: No human parvovirus B19 has been detected in human albumin, human intravenous immunoglobulin, or human rabies immunoglobulin. Human parvovirus B19 nucleic acid may exist in commercially available coagulation factor products, highlighting the need for enhanced screening of human parvovirus B19 nucleic acid in these products. It is also recommended that B19 viral nucleic acid testing be conducted on source plasma, particularly for coagulation factor products.

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.