RESUMO
Objective: To investigate pathological features and differential diagnosis in the gonads with disorder of sex development. Methods: Thirty-six cases of clinically diagnosed hermaphroditism with gonadal biopsy in the Department of Pathology, the Seventh Medical Center of People's Liberation Army General Hospital from April 2007 to July 2021, were collected. All biopsy pathological sections were reviewed, and the gonadal cases with abnormal pathological morphology were screened out. The clinical and imaging data and karyotype of these cases were reviewed. Additional immunohistochemical staining was performed and relevant literature was reviewed. Results: Seven cases of ovotesticular disorder of sex development (OTDSD) were identified, which were characterized by the presence of testicular and ovarian differentiation in the same individual. All patients were under 15 years old and presented with abnormal appearance of external genitalia, and the ratio of male to female was 2â¶5. Ultrasonography showed testicular structure in all female patients and cryptorchidism in all male patients. The most common karyotype was 46, XX. One case with undifferentiated gonadal tissue (UGT) and one case with streak gonads were screened out. UGT germ cells were neither in seminiferous tubules nor in follicles, but randomly distributed in an ovarial-type interstitial background, sometimes accompanied by immature sex cords. Streak gonads resembled UGT without germ cells. FOXL2 was positive in granulosa cells, but negative in Sertoli cells. SOX9 expression was opposite. OCT4 was weakly positively/negatively expressed in oocytes and positively expressed in the germ nuclei of UGT. Conclusions: Four differentiation patterns need to be identified in the gonadal biopsy: ovarian differentiation, testicular differentiation, undifferentiated gonadal tissue and streak gonad. The positive expression of SOX9 indicates testicular differentiation, while the positive expression of FOXL2 confirms ovarian differentiation, and the expression of both markers in the same tissue indicates ovotestis differentiation. It is very important to identify UGT, because that has a high probability of developing into gonadoblastoma in the future.
Assuntos
Transtornos do Desenvolvimento Sexual , Gônadas , Humanos , Masculino , Feminino , Adolescente , Gônadas/patologia , Transtornos do Desenvolvimento Sexual/genética , Transtornos do Desenvolvimento Sexual/patologia , Testículo/patologia , Ovário/patologia , CariotipagemRESUMO
Objective: To observe the effects of exosomes derived from human umbilical cord mesenchymal stem cells on the proliferation and invasion of pancreatic cancer cells, and to analyze the contents of exosomes and explore the mechanisms affecting pancreatic cancer cells. Methods: Exosomes extracted from human umbilical cord mesenchymal stem cells were added to pancreatic cancer cells BxPC3, Panc-1 and mouse models of pancreatic cancer, respectively. The proliferative activity and invasion abilities of BxPC3 and Panc-1 cells were measured by cell counting kit-8 (CCK-8) and Transwell assays. The expressions of miRNAs in exosomes were detected by high-throughput sequencing. GO and KEGG were used to analyze the related functions and the main metabolic pathways of target genes with high expressions of miRNAs. Results: The results of CCK-8 cell proliferation assay showed that the absorbance of BxPC3 and Panc-1 cells in the hucMSCs-exo group was significantly higher than that in the control group [(4.68±0.09) vs. (3.68±0.01), P<0.05; (5.20±0.20) vs. (3.45±0.17), P<0.05]. Transwell test results showed that the number of invasion cells of BxPC3 and Panc-1 in hucMSCs-exo group was significantly higher than that in the control group (129.40±6.02) vs. (89.40±4.39), P<0.05; (134.40±7.02) vs. (97.00±6.08), P<0.05. In vivo experimental results showed that the tumor volume and weight in the exosomes derived from human umbilical cord mesenchymal stem cells (hucMSCs-exo) group were significantly greater than that in the control group [(884.57±59.70) mm(3) vs. (695.09±57.81) mm(3), P<0.05; (0.94±0.21) g vs. (0.60±0.13) g, P<0.05]. High-throughput sequencing results showed that miR-148a-3p, miR-100-5p, miR-143-3p, miR-21-5p and miR-92a-3p were highly expressed. GO and KEGG analysis showed that the target genes of these miRNAs were mainly involved in the regulation of glucosaldehylation, and the main metabolic pathways were ascorbic acid and aldehyde acid metabolism, which were closely related to the development of pancreatic cancer. Conclusion: Exosomes derived from human umbilical cord mesenchymal stem cells can promote the growth of pancreatic cancer cells and the mechanism is related to miRNAs that are highly expressed in exosomes.
Assuntos
Carcinoma Ductal Pancreático , Exossomos , Células-Tronco Mesenquimais , MicroRNAs , Neoplasias Pancreáticas , Camundongos , Animais , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Exossomos/genética , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Carcinoma Ductal Pancreático/genética , Células-Tronco Mesenquimais/metabolismo , Cordão Umbilical , Neoplasias PancreáticasRESUMO
In order to discuss the necessity of repeated renal arteriography in the treatment of severe bleeding after percutaneous nephrolithotomy, this study retrospectively analyzed the clinical data of patients with severe bleeding after percutaneous nephrolithotomy in the Department of Urology Surgery of the First Hospital of China Medical University from August 2010 to July 2020, summarily analyzing treatments, outcomes and follow-up results of 27 patients who were treated by renal arteriography more than twice. Of these 27 patients who underwent repeated renal arteriography, 23 of them were treated by two times, 4 by three times, all of whom were diagnosed as renal vascular injury. And 15 of them were diagnosed as pseudoaneurysm, 4 of them renal arteriovenous fistula, and 8 of them pseudoaneurysm combined with renal arteriovenous fistula. After clear diagnosis, all these patients were performed with renal artery embolization, after which the symptoms of hematuria and lumbar discomfort were relieved or disappeared immediately. These patients were followed up from 6 months to 5 years, without corresponding symptoms recurring and with the renal function equivalent to that before embolization. The results showed that repeated renal arteriography was of great significance in the treatment of patients with severe bleeding after percutaneous nephrolithotomy, helping to clarify the cause of bleeding and giving appropriate and timely treatment.
Assuntos
Nefrolitotomia Percutânea , Nefrostomia Percutânea , Angiografia , Hemorragia , Humanos , Nefrolitotomia Percutânea/efeitos adversos , Estudos RetrospectivosRESUMO
OBJECTIVES: This study aimed to evaluate associations between mental distress and COVID-19-related changes in behavioral outcomes and potential modifiers (age, gender, educational attainment) of such associations. STUDY DESIGN: This was a cross-sectional study. METHODS: An online survey using anonymous network sampling was conducted in China from April to May 2020 using a 74-item questionnaire. A national sample of 10,545 adults in 31 provinces provided data on sociodemographic characteristics, COVID-19-related mental distress, and changes in behavioral outcomes. Structural equation models were used for data analyses. RESULTS: After adjusting for covariates, greater mental distress was associated with increased smoking (odds ratio [OR] = 1.42, 95% confidence interval [CI]: 1.20-1.68 and OR = 1.54, 95% CI: 1.31-1.82 per one standard deviation [SD] increase in mental distress) and alcohol consumption (OR = 1.67, 95% CI: 1.45-1.92 and OR = 1.47, 95% CI: 1.24-1.75 per one SD increase in mental distress) among current smokers and drinkers and with both increased and decreased physical activity (ORs ranged from 1.32 to 1.56). Underweight adults were more likely to lose body weight (≥1 kg; OR = 1.63, 95% CI: 1.30-2.04), whereas overweight adults were more likely to gain weight (OR = 1.61, 95% CI: 1.46-1.78) by the same amount. Association between mental distress and change in physical activity was stronger in adults aged ≥40 years (ORs ranged from 1.43 to 2.05) and those with high education (ORs ranged from 1.43 to 1.77). Mental distress was associated with increased smoking in males (OR = 1.60, 95% CI: 1.37-1.87) but not females (OR = 1.11, 95% CI: 0.82-1.51). CONCLUSIONS: Greater mental distress was associated with some positive and negative changes in behavioral outcomes during the pandemic. These findings inform the design of tailored public health interventions aimed to mitigate long-term negative consequences of mental distress on outcomes.
Assuntos
COVID-19 , Pandemias , Adulto , China/epidemiologia , Estudos Transversais , Humanos , Masculino , SARS-CoV-2RESUMO
OBJECTIVE: RBBP6 is identified to be a cancer-associated gene by bioinformatics analysis. This study aims to explore the role of RBBP6 in regulating proliferation and metastasis in ovarian cancer, thus providing theoretical references for ovarian cancer treatment. PATIENTS AND METHODS: Differential expressions of RBBP6 in ovarian cancer and normal ones were detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The relationship between RBBP6 and prognosis in ovarian cancer patients was analyzed. The interaction between RBBP6 and PIK3R6 was detected by bioinformatics analysis and Dual-Luciferase reporter assay. Moreover, regulatory effects of RBBP6 and PIK3R6 on proliferative and migratory potentials in A2780 and CAOV3 cells were examined by Cell Counting Kit-8 (CCK-8) and transwell assay, respectively. Finally, tumorigenicity assay was conducted in nude mice to illustrate the in vivo regulations of PBBP6 and PIK3R6 on ovarian cancer growth. RESULTS: RBBP6 was upregulated in ovarian cancer tissues than normal ones. RBBP6 was irrelevant to age, tumor size and tumor node metastasis (TNM) staging in ovarian cancer patients, but correlated to lymphatic metastasis and distant metastasis. RBBP6 was abundantly expressed in ovarian cancer cells, and among the tested cell lines, CAOV3 and A2780 expressed the highest level of RBBP6. Knockdown of RBBP6 attenuated in vitro proliferative and migratory potentials in CAOV3 and A2780 cells. PIK3R6 was the target gene binding RBBP6, which was positively regulated by RBBP6. Overexpression of PIK3R6 could abolish the inhibited proliferative and migratory potentials in ovarian cancer cells with RBBP6 knockdown. In addition, the knockdown of RBBP6 slowed the in vivo growth of ovarian cancer in nude mice, and the alleviated cancer progression was reversed by overexpression of PIK3R6. CONCLUSIONS: RBBP6 is highly expressed in ovarian cancer cases, which stimulates proliferative and migratory potentials by targeting PIK3R6. RBBP6 may be a novel therapeutic target for ovarian cancer.
Assuntos
Classe Ib de Fosfatidilinositol 3-Quinase/metabolismo , Proteínas de Ligação a DNA/metabolismo , Neoplasias Ovarianas/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Animais , Linhagem Celular , Movimento Celular , Proliferação de Células , Classe Ib de Fosfatidilinositol 3-Quinase/genética , Proteínas de Ligação a DNA/genética , Feminino , Humanos , Masculino , Camundongos , Camundongos Nus , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Neoplasias Ovarianas/patologia , Ubiquitina-Proteína Ligases/genéticaRESUMO
The aim of this study was to investigate the quantitative association between active/passive maximum mouth opening (AMMO/PMMO) and the severity of simulated temporomandibular joint (TMJ) bony ankylosis. Twenty-eight male sheep were divided randomly and equally into surgical and control groups. Surgical group animals underwent bilateral TMJ osteotomy during which left lateral pterygoid muscle function was blocked. Control animals did not undergo surgery. Body weight, AMMO/PMMO, and TMJ morphological features were evaluated preoperatively and at 12 and 24 weeks post-surgery. In the surgical group, only the right TMJ complexes with maintained lateral pterygoid muscle function developed TMJ bony ankylosis. The AMMO/PMMO and end-feel distance in the surgical group were significantly lower than those in the control group (P < 0.001, both) at 12 and 24 weeks post-surgery. Moreover, AMMO (r = -0.940 and -0.952, P < 0.001, both) and PMMO (r = -0.944 and -0.953, P < 0.001, both) were negatively correlated with the area (mm2) of bony fusion post-surgery. These findings may be useful for the clinical treatment of early mandibular condyle fracture, with the use of occlusal pads/open-mouth plates to relax the lateral pterygoid muscle and block its function. When bony ankylosis developed in the TMJ, the greater the area of bony fusion, the more limited were AMMO/PMMO.
Assuntos
Anquilose , Transtornos da Articulação Temporomandibular , Animais , Masculino , Côndilo Mandibular , Boca , Ovinos , Articulação TemporomandibularRESUMO
Parkinson's disease (PD), a common degenerative disease in humans, is known to result from loss of dopamine neurons in the substantia nigra and is characterized by severe motor symptoms of tremor, rigidity, bradykinsia and postural instability. Although levodopa administration, surgical neural lesion, and deep brain stimulation have been shown to be effective in improving parkinsonian symptoms, cell replacement therapy such as transplantation of dopamine neurons or neural stem cells has shed new light on an alternative treatment strategy for PD. While the difficulty in securing donor dopamine neurons and the immuno-rejection of neural transplants largely hinder application of neural transplants in clinical treatment, induced pluripotent stem cells (iPS cells) derived from somatic cells may represent a powerful tool for studying the pathogenesis of PD and provide a source for replacement therapies in this neurodegenerative disease. Yamanaka et al. [2006, 2007] first succeeded in generating iPS cells by reprogramming fibroblasts with four transcription factors, Oct4, Sox2, Klf4, and c-Myc in both mouse and human. Animal studies have further shown that iPS cells from fibroblasts could be induced into dopamine neurons and transplantation of these cells within the central nervous system improved motor symptoms in the 6-OHDA model of PD. More interestingly, neural stem cells or fibroblasts from patients can be efficiently reprogrammed and subsequently differentiated into dopamine neurons. Derivation of patient-specific iPS cells and subsequent differentiation into dopamine neurons would provide a disease-specific in vitro model for disease pathology, drug screening and personalized stem cell therapy for PD. This review summarizes current methods and modifications in producing iPS cells from somatic cells as well as safety concerns of reprogramming procedures. Novel reprogramming strategies that deter abnormal permanent genetic and epigenetic alterations are essential for propagating clinically-qualified iPS cells. Future investigations into cell transforming and reprogramming processes are needed to generate the disease-specific iPS cells for personalized regeneration medicine of PD patients by disclosing detailed reprogramming mechanisms.
Assuntos
Células-Tronco Pluripotentes Induzidas/fisiologia , Células-Tronco Neurais/fisiologia , Doença de Parkinson/terapia , Transplante de Células-Tronco , Fatores de Transcrição/fisiologia , Animais , Terapia Baseada em Transplante de Células e Tecidos/métodos , Reprogramação Celular/fisiologia , Fibroblastos/fisiologia , Humanos , Células-Tronco Pluripotentes Induzidas/transplante , Fator 4 Semelhante a Kruppel , Células-Tronco Neurais/transplante , Doença de Parkinson/genética , Células-Tronco Pluripotentes/fisiologia , Fatores de Transcrição/genéticaRESUMO
OBJECTIVE: To study specific diagnosis of Spirometra erinaceieuropaei. METHODS: An enzyme-linked immunosorbent assay (ELISA) was studied using highly pure gene engineering antigen expressed by the recombination of the cloned cysteine proteinase gene of Spirametra erinaceieuropaei with expression vector pMAL-c2. Six sera from patient infected with Spirometra erinaceieuropaei were detected using this method. RESULTS AND CONCLUSION: The results showed that the gene engineering antigen reacted strongly with the sera from Spirometra erinaceieuropaei-infected patients, but did not with the sera from Cysticercus cellulosae-infected patients.
Assuntos
Anticorpos Anti-Helmínticos/sangue , Infecções por Cestoides/diagnóstico , Spirometra/imunologia , Animais , Antígenos de Helmintos/imunologia , Infecções por Cestoides/parasitologia , Ensaio de Imunoadsorção Enzimática/métodos , Humanos , Sensibilidade e EspecificidadeRESUMO
Previous work from this laboratory demonstrated that arachidonic acid activates c-jun NH(2)-terminal kinase (JNK) through oxidative intermediates in a Ca(2+)-independent manner (Cui X and Douglas JG. Arachidonic acid activates c-jun N-terminal kinase through NADPH oxidase in rabbit proximal tubular epithelial cells. Proc Natl Acad Sci USA 94: 3771-3776, 1997.). We now report that JNK can also be activated via a Ca(2+)-dependent mechanism by agents that increase the cytosolic Ca(2+) concentration (Ca(2+) ionophore A(23187), Ca(2+)-ATPase inhibitor thapsigargin) or deplete intracellular Ca(2+) stores [intracellular Ca(2+) chelator 1, 2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA)-AM]. The activation of JNK by BAPTA-AM occurs despite a decrease in cytosolic Ca(2+) concentration as detected by the indicator dye fura 2, but appears to be related to Ca(2+) metabolism, because modification of BAPTA with two methyl groups increases not only the chelation affinity for Ca(2+), but also the potency for JNK activation. BAPTA-AM stimulates Ca(2+) influx across the plasma membrane, and the resulting local Ca(2+) increases are probably involved in activation of JNK because Ca(2+) influx inhibitors (SKF-96365, nifedipine) and lowering of the free extracellular Ca(2+) concentration with EGTA reduce the BAPTA-induced JNK activation.
Assuntos
Cálcio/metabolismo , Células Epiteliais/metabolismo , Túbulos Renais Proximais/metabolismo , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Animais , Quelantes/farmacologia , Ácido Egtázico/análogos & derivados , Ácido Egtázico/farmacologia , Ativação Enzimática , Células Epiteliais/efeitos dos fármacos , Proteínas Quinases JNK Ativadas por Mitógeno , Túbulos Renais Proximais/efeitos dos fármacos , Proteínas Quinases Ativadas por Mitógeno/efeitos dos fármacos , CoelhosRESUMO
The effects of position change on respiration and circulation of 42 patients during spinal operations were investigated in this study. The results showed that, if the patient was placed on the operation position following the administration of the anesthesia, the changes of respiration (f, VT, MV) and circulation (SBP, HR) were significant (P < 0.01, 0.05). On the contrary, if the patient was placed in the operation position and then started the anesthesia, the respiratory and circulatory changes were comparatively stable (P > 0.05). The authors concluded that: 1. for the cases undergoing spinal operations, it is advisable to place the patient in the operation position first and then start the anesthesia; 2. for the critical cases, a tolerable position should be adopted; 3. during the adjustment of the position of the patient, the clavicle and the ilium should be used as the fulcrum so as to avoid driect contact of the chest and abdoment with the operation table, thus to minimze interference on the respiratory and circulatory functions.
Assuntos
Circulação Sanguínea/fisiologia , Postura/fisiologia , Respiração/fisiologia , Doenças da Coluna Vertebral/cirurgia , Adulto , Anestesia , Feminino , Humanos , Período Intraoperatório , Masculino , Pessoa de Meia-IdadeRESUMO
AIM: To study effects of the Fuzheng Huoxue anticancer prescription (Traditional Chinese Medicine) in treatment of gastric cancer. METHODS: Sixty-nine patients with histologically confirmed mid- or late-stage gastric cancer were assigned to two groups. The treatment group included 35 cases (26 males and 9 females; 2 patients aged 33-40 years, 18 patients aged 41-60 years, and 15 patients aged 61-75 years; mean group age = 58.4 years). The control group included 34 cases (23 males and 11 females; 4 patients aged 33-40 years, 16 patients aged 41-60 years, and 14 patients aged 61-75 years; mean group age = 56.8 years. The two groups were not significantly different in sex, age, their clinical and pathological stages of disease or operation mode. The two groups of patients were given similar treatments; however, patients in the treatment group were given the Fuzheng Huoxue anticancer prescription. In animal studies, SGC-7901 gastric cancers cells were inoculated into the backs of 30 nude mice under sterile conditions. After inoculation, the nude mice were randomly allocated to a control group, a traditional Chinese medicine group, and a chemotherapy group (n = 10 mice per group). The total weight of the 10 mice in each group was similar. Each nude mouse in the control group received 0.5 mL of saline solution each day. Mice in the traditional Chinese medicine group received 0.5 mL of the Fuzheng Huoxue anticancer prescription (containing 1.5 g crude drug) each day, while mice in the chemotherapy group were intraperitoneally injected with 1 mg of 5-Fu once a week for 8 wk. RESULTS: Prior to treatment, the mean OKT8 percentage among gastric patients in the treatment group was 45.94% ± 8.45%, the mean OKT4/OKT8 ratio was 0.89 ± 0.19, the mean AT-III concentration was 29.9 ± 7.9 mg/dL, the mean Fa value was 50.4% ± 24.4%, and the mean ß-TG concentration was 91.0 ± 25.9 ng/dL. Prior to treatment, the mean percentage of OKT8 cells among patients in the control group was 49.21% ± 6.60%, the OKT4/OKT8 ratio was 0.94 ± 0.20, the AT-III concentration was 32.3 ± 7.2 mg/dL, the mean Fa value was 57.3% ± 24.6%, and the mean ß-TG concentration was 87.5 ± 34.2 ng/dL. After treatment, the mean OKT8 percentage among patients in the treatment group was 33.52% ± 7.80%, the mean OKT4/OKT8 ratio was 1.47 ± 0.51, the mean AT-III concentration was 38.8 ± 5.5 mg/dL, the mean Fa value was 102.6% ± 31.6%, and the mean ß-TG concentration was 62.3 ± 15.1 ng/dL. After treatment, the mean OKT8 percentage among patients in the control group was 42.22% ± 7.07%, the mean OKT4/OKT8 ratio was 1.12 ± 0.24, the mean AT-III concentration was 30.9 ± 8.0 mg/dL, the mean Fa value was 64.6% ± 26.9%, and the mean ß-TG concentration was 67.0 ± 42.1 ng/dL. These data indicate that after treatment, the immunologic function of the T lymphocytes of gastric cancer patients in the treatment group was significantly improved (P < 0.01). Additionally, the hypercoagulability in the treatment group was also improved (P < 0.001), and the mean OKT4/OKT8 ratio, antithrombin III (AT-III) concentration, and fibrinolytic activity, etc. had all beome normalized. The one-year (86%), 3-year (69%), and 5-year (40%) survival rates in the treatment group were all higher than those in the control group (P < 0.05). The mean tumor weights in the control, traditional medicine, and chemotherapy groups were 0.895 ± 0.289 g, 0.433 ± 0.177 g, and 0.357 ± 0.142 g, respectively. The tumor-inhibition rates in the traditional Chinese medicine group and chemotherapeutic group (51.6% and 60.1%, respectively) were significantly better than that in the control group (P < 0.001). The mean tumor weight in the traditional Chinese medicine group (24.68 ± 1.93 g) was significantly higher than that in both the treatment group (22.96 ± 1.87 g) and control group (22.47 ± 2.18 g). CONCLUSION: The Fuzheng Huoxue anticancer prescription can not only replenish vital functions (Zhengqi), correct a hypercoagulatory state, improve immunologic function, and extend patient survival times, but may also directly inhibit gastric tumor growth without producing toxic side effects.
RESUMO
Fuzheng Huoxue Anticancer prescription (FZHXAC) showed better clinical effect in treating 35 cases of postoperative patients with gastric cancer in middle or late stage as compared with 35 cases of controls. After treatment, the immune function of T-lymphocytes enhanced significantly, the hypercoagulability improved, the criteria such as OKT4/OKT8 ratio, antithrombase III (AT-III), fibrinolytic activity, etc were all normalized, the one year, 3 year and 5 year suvival rate of patient were elevated. FZHXAC showed obvious inhibitory action on tumor growth in nude mice with transplanted human gastric cancer, as compared with control, the difference was significant, P < 0.001. In comparing with chemotherapeutic drug 5-fluorouracil, FZHXAC showed no significant toxicity, it didn't influence the normal growth of body weight. These results suggested that FZHXAC could not only replenish the Zheng-Qi, improve blood circulation, improve immune function and extend the survival period of patient, but also might have direct inhibiting, killing action on gastric tumor cells, this problem is expecting for further research.
Assuntos
Neoplasias Gástricas/tratamento farmacológico , Adulto , Idoso , Animais , Antitrombina III/metabolismo , Gastrectomia , Humanos , Masculino , Camundongos , Camundongos Nus , Pessoa de Meia-Idade , Transplante de Neoplasias , Período Pós-Operatório , Neoplasias Gástricas/mortalidade , Neoplasias Gástricas/cirurgia , Taxa de SobrevidaRESUMO
The difference in pulmonary vascular response to hypoxia between Hilltop Sprague-Dawley (HT) rats and Wistar (W) rats was studied. Effects of inhibitor of leukotriene (LT) synthesis or prostaglandin (PG) synthesis on hypoxic pulmonary vasoconstriction (HPV) and chronic pulmonary hypertension were observed, and variations in plasma TXB2 and 6-keto-PGF1 alpha during hypoxia were determined. The results showed that in rats of both strains LTs are the major mediator of HPV, which is also mediated by vasoconstrictive PGs in HT rats, while modulated by vasodilative PGs in W rats. This might be the crucial mechanism responsible for the higher pulmonary vascular responsiveness in HT rats. Differences in the modulating effect of histamine and in the structural feature of pulmonary arteriole might be contributing factors as well.