Surfactant Protein (SP) induces preterm birth by promoting oxidative stress via upregulating Storkhead-Box Protein 1

Abstract Preterm birth is the leading cause of infant mortality. The mechanisms that instigate preterm birth remain elusive and this makes it difficult to predict or prevent preterm birth. In this study, the authors found that SP-A induced pathological damage to the placenta and promoted preterm birth. Through mechanism, SP-A promoted the expression of STOX1 which further promoted the oxidative stress in the placenta by inhibiting the activities of a series of antioxidant enzymes including SOD, CAT and GSH-Px. SP-A also induced dysregulation of arginine metabolism by inhibiting NOS2 and ARG2. Overexpression of STOX1 aggravated SP-A induced oxidative stress, pathological damage, and preterm birth, whereas knockdown of STOX1 alleviated SP-A induced oxidative stress, pathological damage and preterm birth. The present study uncovers that SP-A induces preterm birth by promoting oxidative stress via upregulating STOX1, which provides new targets for the prediction and prevention of preterm birth.

Effects of Human Umbilical Cord Mesenchymal Stem Cells on Infected State of Human Alveolar type Ⅱ Epithelial Cells / 中山大学学报(医学科学版)

[Objective]To investigate the effect of human umbilical cord mesenchymal stem cells on infected state of human alve?olar type Ⅱ epithelial cells.[Methods]Human alveolar type Ⅱ epithelial cells A549(1×105/mL)2 mL and PA(3×104 CFU/mL)2 mL has grown after 6 hours,add hUCMSC(1 × 106/mL)2 mL as the experimental group,add equal amounts of phosphate buffer (PBS)for infection,A549 and PBS and the medium has grown as the control group. A549 cells morphological changes between the compared groups(Transmission electron microscope,TEM),A549 cell viability(new CCK-8 cell proliferation assay Kit),A549 cells apoptosis(Annexin V-FITC/PI double staining flow cytometry)and the expression of A549 pulmonary surfactant A(SP-A) (Western blot).[Results]Transmission electron microscope cell morphology observation displayed ,infection group A549 cell dam?aged obviously,cell quality appeared empty bubble degeneration,chromatin height agglutination,visible apoptosis bodies;experi?ment group cell package film structure full,nuclear film full,nucleolus obviously,nuclear chromatin electronic density low,chroma? tin uniform,no apoptotic bodies;control group A549 cell structure full,membrane surface micro-fluff rich,nuclear film full,nucle?ar week clearance structure normal,chromatin uniform;infection group and control group compared,Infection group A549 cell sur?vival significantly reduced[(70.35±2.89)% and(97.37±2.07)%,n=3,P<0.01],apoptosis rate significantly increased[(8.63%± 0.16)%and(2.55±0.11)%,n=3,P<0.01],In the infected group,PA could damage A549 cells and decrease the amount of SP-A ex?pression(n=5,P<0.05). In the experiment group,the protective effect of hUCMSC on the A549 cells after infection may increase the expression of SP-A(n=5,P<0.05);[Conclusions]HUCMSC inhibits the infection of A549 cells apoptosis and protection of A549 cells secrete SP-A.

Effects of pulmicort inhalation on serum sICAM-1, SP-A and IGF-1 levels in children with mycoplasma pneumonia / 中国生化药物杂志

Objective To observe the effect of atomized inhalation on the levels of serum sICAM-1, SP-A and IGF-1 in children with mycoplasma pneumonia.Methods 108 children with mycoplasma pneumonia in our hospital from January 2015 to September 2016 were selected as the study object, and they were randomly divided into control group and observation group with 54 cases in each group, the control group were treated with conventional treatment, the observation group were treated with pulmicort respules by aerosol inhalation on the basic treatment of control group , then the clinical effective rates and signs disappearing time of different severity degree, serum sICAM-1, SP-A and IGF-1 levels before and after the treatment of two groups were compared.Results The clinical effective rates of observation group with mild, moderate and severe disease were respectively 100.00%, 100.00% and 93.33%, and they were all higher than 84.21%, 80.00% and 73.33% of control group, and the cough, fever and pulmonary rales disappearing time were respectively (4.54 ±0.66)d, (1.84 ±0.18)d and (3.76 ±0.52)d, and they were all shorter than (7.10 ±0.82)d, (3.25 ± 0.30)d and (5.88 ±0.75)d of control group, the serum sICAM-1and SP-A at first, third and fifth day after the treatment were lower than those of control group, serum IGF-1 level were higher than those of control group, the difference was statistically significant (P<0.05), the differences were all significant.Conclusion The clinical effect of pulmicort respules by aerosol inhalation is better, and it has active adjustion role for the serum sICAM-1, SP-A and IGF-1.

Control Efficacy of Streptomyces sp. A501 against Ginseng Damping-off and Its Antifungal Substance

Ginseng damping-off, caused by the fungal pathogens Rhizoctonia solani and Pythium sp., is a critical disease in ginseng seedling. In a continuing effort to find microorganisms with the potential of acting as a biocontrol agent against Rhizoctonia damping-off, we found that a Streptomyces sp. A501 showed significant antifungal activity against Rhizoctonia solani. In field experiment to test the efficacy of Streptomyces sp. A501 in controlling ginseng damping-off, the incidence of damping-off disease was meaningfully reduced when ginseng seeds were soaked in the culture broth of Streptomyces sp. A501 before sowing. To perform characterization of the antifungal compound, we isolated it from the culture broth of strain A501 through Diaion HP-20 and silica gel column chromatographies and preparative high-performance liquid chromatography. The structure of the antifungal compound was assigned as fungichromin by spectroscopic methods, mainly nuclear magnetic resonance and electrospray ionization-mass analysis.

Thermostable chitinase from Cohnella sp. A01: isolation and product optimization

Abstract Twelve bacterial strains isolated from shrimp farming ponds were screened for their growth activity on chitin as the sole carbon source. The highly chitinolytic bacterial strain was detected by qualitative cup plate assay and tentatively identified to be Cohnella sp. A01 based on 16S rDNA sequencing and by matching the key morphological, physiological, and biochemical characteristics. The cultivation of Cohnella sp. A01 in the suitable liquid medium resulted in the production of high levels of enzyme. The colloidal chitin, peptone, and K2HPO4 represented the best carbon, nitrogen, and phosphorus sources, respectively. Enzyme production by Cohnella sp. A01 was optimized by the Taguchi method. Our results demonstrated that inoculation amount and temperature of incubation were the most significant factors influencing chitinase production. From the tested values, the best pH/temperature was obtained at pH 5 and 70 °C, with Km and V max values of chitinase to be 5.6 mg/mL and 0.87 µmol/min, respectively. Ag+, Co2+, iodoacetamide, and iodoacetic acid inhibited the enzyme activity, whereas Mn2+, Cu2+, Tweens (20 and 80), Triton X-100, and EDTA increased the same. In addition, the study of the morphological alteration of chitin treated by enzyme by SEM revealed cracks and pores on the chitin surface, indicating a potential application of this enzyme in several industries.

The diagnostic significance of KL-6, SP-A, SP-D and MMP-7 in IPF and its relationship with pulmonary function / 安徽医科大学学报

Objective To investigate the significance of serum krebs Yon den lungen-6(KL-6), surfactant protein A(SP-A), surfactant protein D(SP-D )and matrix metalloprotease 7(MMP-7) in the diagnosis of idiopathic pul-monary fibrosis (IPF) and its relationship with pulmonary function .Methods Serum levels of KL-6, SP-D, SP-A and MMP-7 were detected by ELISA in 38 patients with IPF and serum from 38 patients with pneumonia and 38 normal controls.Serum levels of markers were further analyzed by operating characteristic curve receiver (ROC), from which the ideal level of each serum marker was obtained , and the follow-up of 6 months in patients with IPF . Explore the significance of the diagnosis of IPF and its correlation with pulmonary function .Results The expres-sion of MMP-7, SP-A, SP-D and KL-6 in serum of IPF patients was higher than that in the control group and healthy control group ( P<0.05) .The optimal cutoff value of KL-6 was 723.0 U/ml, SP-A was 67.2 ng/ml, SP-D was 98.1 ng/ml, and MMP-7 was 10.1 ng/ml.The sensitivity of KL-6 was 71.1% and 98.7%, SP-A was 81.6%and 97.4%, SP-D was 81.6%and 97.4%, MMP-7 was 68.4%and 98.7%.The sensitivity of combined KL-6, SP-A, SP-D and MMP-7 four serum markers was 100%, compared with a single serum index , the P value was less than 0.05, with statistical significance .IPF patients serum SP-A, MMP-7 and forced vital capacity within 6 months were significantly correlated(r1 =-0.574,P1 <0.001;r2 =-0.465,P2 =0.003).Conclusion KL-6, SP-A, SP-D and MMP-7 were highly expressed in serum of patients with IPF , and in the diagnosis of IPF , com-bined detection of 4 serum markers can improve the early diagnosis of IPF patients .Combined serum SP-A and MMP-7 levels can improve the accuracy of the IPF patients with pulmonary function changes , the prediction of dis-ease progression has a certain significance .

Effect of Qinbai Qingfei Concentrated pellets on TGF-βand SP-A expression in lung tissue of rats infected by mycoplasmal pneumonia / 中国药理学通报

Aim To discuss the repairing mechanism of Qinbai Qingfei Concentrated pellets to lung tissue of rats infected by mycoplasma. Method 60 Wistar rats weighting 80~100 g, male to female:1 ∶ 1) were di-vided into six groups randomly ( 10 rats in each group): blank group, model group, positive group, the high、middle and low dose groups of Qinbai Qingfei Concentrated pellets. Rats were infected through nasal intubation drip of MP. After 10 days of administration, concentrations of IL-6 , IL-8 AND TNF-α in serum of MPP rats were detected. Left pulmonary tissues of rats were collected to observe the lung tissue pathological change by HE staining and right pulmonary tissues were used to detect the transforming growth factor-beta ( TGF-β) and surface activity related protein A( SP-A) mRNA expression level by real-time quantitative PCR ( RT-PCR) and TGF-βand SP-A protein expression by (Western blot. Result Qinbai Qingfei Concentrated) pellets significantly inhibited inflammation of lung tis-sue, reduced the expression of TGF-β and increased the expression of SP-A in the lung tissue of rats infec-ted by mycoplasma. Conclusion Qinbai Qingfei Con-centrated pellets can inhibit epithelial-mesenchymal transition ( EMT ) , of alveolar type Ⅱ epithelial cells by reducing the content of TGF-β and restore the nor-mal morphology and function of the lung by increasing the expression of SP-A.

Repair effect of Qinbai Qingfei concentrated pellets to AEC-Ⅱ of rats infected by Mycoplasmal pneumonia / 中国中药杂志

To discuss the repair mechanism of Qinbai Qingfei concentrated pellets to AEC-Ⅱ of rats infected by mycoplasma through the observation of the changes and distribution of TGF-β and SP-A in lungs, totally 60 Wistar rats that weighing 80-100 g were collected, with male and female in half. The rats were divided into six groups randomly, with 10 rats each group, namely blank group, model group, positive group and Qinbai Qingfei concentrated pellets high, middle and low dose groups. Rats were infected through nasal intubation drip of MP. After 10 days of administration, serum and bronchoalveolar lavage fluid (BALF) were collected to detect the concentration of surface activity related protein A (SP-A) by ELISA, left pulmonary tissues of rats were collected to observe the expression and distribution of transforming growth factor-beta (TGF-β) and SP-A by immunohistochemistry, and right pulmonary tissues were taken to detect TGF-β and SP-A mRNA expression level by real-time quantitative PCR (RT-PCR). Qinbai Qingfei concentrated pellets can reduce the expression of TGF-β and increase the expression of SP-A in the lung tissues of rats infected by mycoplasma. Specifically, TGF-β was mainly distributed among the lung interstitium, while SPAs were mainly distributed in AEC-II and parts of alveolar macrophage. The level of SP-A was reduced in serum and increased in BALF in rats in Qinbai Qingfei concentrated pellets groups. It was proved that Qinbai Qingfei concentrated pellets can restore the normal morphology and function of the lung by reducing the content of TGF-β to inhibit epithelial-mesenchymal transition (EMT) of alveolar type II epithelial cells and increasing the expression of SP-A. Qinbai Qingfei concentrated pellets have the repairing ability to capillary vessel damage caused by MP in lung tissues of rats.

Antifungal Substances from Streptomyces sp. A3265 Antagonistic to Plant Pathogenic Fungi

In a previous study, we identified a Streptomyces sp., A3265, as exhibiting potent antifungal activity against various plant pathogenic fungi, including Botrytis cinerea, Colletotrichum gloeosporioides, and Rhizoctonia solani. This strain also exhibited a biocontrolling effect against ginseng root rot and damping-off disease, common diseases of ginseng and other crops. In this study, we isolated two antifungal substances responsible for this biocontrolling effect via Diaion HP-20 and Sephadex LH-20 column chromatography, medium pressure liquid chromatography, and high-performance liquid chromatography. These compounds were identified as guanidylfungin A and methyl guanidylfungin A by spectroscopic methods. These compounds exhibited potent antimicrobial activity against various plant pathogenic fungi as well as against bacteria.

Relationship between expression of sesquiterpene synthase gene and sesquiterpene content in artificial agarwood induced by Fusarium sp. A2 / 中国药学杂志

OBJECTIVE: To explore the expression of sesquiterpene synthase (gene sesqui-TPS) and dynamic change of sesquiterpene content in the resin-deposited parts of the trunk of Aquilaria sinensis (Lour.) Gilg. induced by Fusarium sp. A2. METHODS: Artificial agarwoods from Aquilaria sinensis were induced by Fusarium sp. A2 using pinhole instillation. The heartwood of Aquilaria sinensis without or with resin were extracted before induction and at 7 time points within one year after induction. The expression of sesqui-TPS was detected by quantitative Real-time PCR. And then the dynamic change of sesquiterpene content in the tissues were analyzed by gas chromatography-mass spectrometry (GC-MS). RESULTS: The relative expression of sesqui-TPS gene in the artificial agarwoods induced by Fusarium sp. A2 from 2 to 12 months were 10.85, 0.793 1, 6.484, 611.4, 5 800, and 4 211 respectively. Sesquiterpene secondary metabolites were not detected in the trunk at 2 months before artificial induction. Fourteen sesquiterpene were detected from 4 to 12 months, with relative percentages of 21.40%, 25.52%, 36.44%, 32.40% and 55.70% at each time point. CONCLUSION: Sesqui-TPS gene is extremely sensitive to Fusarium sp. A2 treatment and responds to late damage. The expression of sesqui-TPS gene lags behind the accumulation of sesquiterpene component, which would provide a foundation for studies on regulation action of function gene for sesquiterpene biosynthase pathway during the formation of agarwood resin in A. sinensis.

The Alteration and Significance of Surfactant Protein A in Rats Chronically Exposed to Cigarette Smoke / 华中科技大学学报（医学）（英德文版）

In order to confirm the alteration and significance of cigarette smoke exposure on SP-A in rats, 20 Wistar rats were assigned randomly to two groups: an N group (n=10), and an S group (n=10). The ultra-structural change was observed by electron microscopy. The number of cells positive for SPA was by immunohistochemically measured. The mRNA expression in the lung tissues was deter-mined by reverse transcription polymerase chain reaction (RT-PCR). The number of cells positive for SPA of the S group (0.52±0.05) was lower than that of the N group (0.72±0.06) (P<0.05). The lev-els of mRNA of SPA in the lung tissues of the S group (0.3522±0.0512) was significantly lower than that of the N group (0.4432±0.05628) (P<0.05). It is concluded that cigarette smoke alone decreased the level of SP-A and that might have an important effect on surfactant metabolism and the host deense functions of surfactant in the peripheral airways, which might play a crucial role in the devel-opment of chronic obstructive lung disease.

The Expression of Cath D,SP-A,GLUT-1 of Bronchiogenic Carcinoma / 医学研究杂志

Objective To examine the expression of Cath D,SP-A and GLUT-1 in patients with bronchiogenic carcinoma.Methods A total of 41 patients were included in the study,10 of whom received the histological diagnosis of small cell lung cancer(SCLC).The other 28 were squamous cell carcinoma(SC) and 3 were inflammation.And all the samples were taken from the patients′ tunica mucosa bronchiorum through bronchofibroscope,then we detected the cathepsin D,SP-A and GLUT-1 following SP immunohistochemistry.Results ①Cath D: 6 samples(60%) in group SCLC were negtive expression(-6),4(40%)were moderately positive(++4),4(14%) were negative(-4),2(7%) were positive(+2),8(28%) were moderately positive(++8) and 14(50%) were intensive positive(+++14) in the other group.SCLC was significant different from SC in expressing cathepsin D(P

Modulation of Alveolar Surfactant after Lower Cervical Vagotomy / 대한해부학회지

Pulmonary surfactant prevents alveolar collapse by reducing alveolar surface tension and aids gaseous exchange in the lung. Since inadequate production of pulmonary surfactant is a key etiological process in ARDS, surfactant may play an important role in pathogenesis of ARDS. To provide a clue for establishing pathological mechanism of post-traumatic or neurogenic ARDS, we studied the influence of the vagal innervation on pulmonary surfactant metabolism. A total of 20 S-D rats (about 230 gm wt. each) were divided into two conditions: normal control and vagotomized groups. The vagotomized rats were subdivided into 3 hours, 8 hours and 24 hours groups. To preserve the superior cervical cardiac branches, both vagus nerves were cut at the lowest part of the carotid triangle. Cannula for adequate respiration and suction was fitted into the trachea. The lung tissue were processed for H&E, Masson's trichrome, Immunohistochemistry using anti-surfactant protein A (SP-A) and .anti-prosurfactant protein C (ProSP-C). The results were as follows; 1. The lungs of the vagotomized rats showed alveolar edema, fibrosis with infiltration of inflammatory cells and hyaline membrane formation. 2. In the lungs of the vagotomized rats, SP-A and ProSP-C immunoreactivity was decreased in proportion to postoperation time. Consequently, it can be postulated that autonomic disturbances caused by vagal interruption may induce ARDS-like pulmonary damage by modulating alveolar surfactant protein metabolism and by evoking the secondary inflammatory processes.

Association between the Human Surfactant Protein-A(SP-A) Gene Locus and Chronic Obstructive Pulmonary Disease in Korean Population / 결핵및호흡기질환

BACKGROUNDS: This study investigated whether or not a polymorphism in the gene encoding the surfactant protein A(SP-A) has any bearing on the individual susceptibility to the development of chronic obstructive pulmonary disease(COPD) in a genetically homogenous Korean population. METHODS: The genotypes of 19 COPD patients and 20 healthy neonates as controls were tested using a polymerase chain reaction followed by restriction fragment length polymorphism analysis for the SP-A gene. RESULTS: The specific frequencies of the 6A2 and 6A18 alleles of SP-A1 and the 1A2 allele of SP-A2 were much higher in the COPD group than control group (p<0.05). However, the frequencies of the 6A3 and 6A4 alleles of SP-A1 and the 1A0 allele of SP-A2 in the COPD group were significantly lower than the control group. In the COPD group, the frequencies of the +50 locus genotypes GG of SP-A1 and the +9 locus genotypes CC of SP-A2 were 85.0% and 60.6%, respectively, and 19.7% and 24.8% in the control group, respectively. The frequencies of the polymorphic genotypes or alleles showed a statistically significant difference between the COPD group and the control group (P<0.05). CONCLUSION: A genetic polymorphism in SP-A is associated with the development of COPD in the Korean population.

Differential Response of Surfactant Protein-A Genetic Variants to Dexamethasone Treatment

PURPOSE: Surfactant protein A(SP-A) is involved in surfactant physiology and structure, and plays a major role in innate host defense and inflammatory processes in the lung. Steroid therapy is widely used for mothers who threaten to deliver prematurely and also used commonly in the management of preterm infants with chronic lung disease. Two SP-A genes(SP-A1, SP-A2) and several alleles have been characterized for each SP-A gene in human. Preliminary evidence indicates that differences may exist among alleles in response to Dexamethasone(Dexa) and that the SP-A 3'UTR plays a role in this process. We studied whether 3'UTR-mediated differences exist among the most frequently found SP-A alleles in response to Dexa. METHODS: Constructs containing the 3'UTR from eight different SP-A alleles were made using luciferase as a the reporter gene. These constructs were driven by the SV40 promotor and were transfected along with a transfection control vector in H441 cells that express SP-A. The activity of the reporter gene in the presence or absence of Dexa(100 nM) treatment was measured. All the experiments for the eight SP-A alleles studied, were performed in triplicate and repeated five times. The results were normalized to the transfection control. RESULTS: Expression of alleles of 6A3, 6A, 1A were significantly decreased in response to Dexa. CONCLUSION: Three UTR mediated differences exist among human SP-A variants both in the basal expression and in response to Dexa. These genotype-dependent differences may point to a need for a careful consideration of individual use of steroid treatment in the prematurely born infant.

Allele Distribution and Frequency of Human Surfactant Protein-A2 in Korean Neonates

PURPOSE: We evaluated allele frequencies and distribution of surfactant protein A2(SP-A2) in Korean neonates in order to estimate the prevalence of RDS, to find out new SP-A alleles, and to establish new steroid therapy. METHODS: Genomic DNA was extracted from 71 neonates and served as a template in PCR for genotype analysis. SP-A gene-specific amplications and gene-specific allele determinations were performed using PCR-cRFLP methods. RESULTS: The distribution for the alleles of the SP-A2 gene in the study population was 1A, 1A0, 1A1, 1A2, 1A3, 1A5, 1A6, 1A7, 1A8, 1A9, 1A11, 1A12. The specific frequencies for the alleles of the SP- A2 gene in the study population were : 1A=11.3%, 1A0=38%, 1A1=12.7%, 1A2=9.2%, 1A5=15.5%, 1A7= 2.9%, 1A8=4.9%, 1A9=2.2%, others=3.3%. CONCLUSION: The frequency of 1A0 was higher than the other SP-A2 alleles in Korean neonates. This finding suggests that the prevalence of RDS in Korea may be low compared with other countries. However, this finding also suggests that Korean neonates have a high risk of infection.

Allele Distribution and Frequency of Human Surfactant Protein-A1 in Korean Neonates

PURPOSE: We evaluated allele frequencies and distribution of surfactant protein A1(SP-A1) in Korean neonates in order to estimate prevalence of RDS to find out new SP-A alleles, and to establish new steroid therapy. METHODS: Genomic DNA was extracted from 100 neonates and served as a template in PCR for genotype analysis. SP-A gene-specific amplications and gene-specific allele determinations were performed using PCR-RFLP methods. RESULTS: The distribution for the alleles of the SP-A1 gene in the study population were 6A, 6A(2), 6A(3), 6A(4), 6A(8), 6A(9), 6A(10), 6A(11), 6A(12), 6A(13), 6A(14), 6A(15), 6A(16), 6A(17), 6A(18), 6A(20). The specific frequencies for the alleles of the SP-A1 gene in the study population were: 6A(2)=21%, 6A(3)=45%, 6A(4)=11%, 6A(8)=9%, 6A(14)=8%. CONCLUSIONS: The frequency of 6A3 was higher than the other SP-A1 alleles in Korean neonates. This finding suggests that the prevalence of RDS in Korea may be low compared with other countries. However, this finding also suggests that Korean neonates have a high risk of infection.

Surfactant Protein SP-A, B, and C: Purification and Biochemical Characterization

PURPOSE: Several kinds of exogenous pulmonary surfactants (SF), either synthetic or animal- derived, are being used for the replacement therapy in respiratory distress syndrome (RDS) of newborn, especially in premature infants, and improved the neonatal mortality and morbidity. Because synthetic preparations are lack of surfactant protein (SP) and animal-derived preparations cause immunogenecity of heterogenous SP, there have been great necessity for the development of next generation of exogenous SF which made by new technology to produce new type of human SF (contained human synthetic SP). There are two methods to make next generation of SF (mixtures of phospholipids and human synthetic SP) which are using of recombinant SP or synthetic peptides of SP. For the synthesis of SP peptides and production of next generation of SF, at first step, we have isolated SP-A, B, and C from bovine lung SF, and studied the biochemical properties of these proteins. METHODS: Crude natural surfactant (CNS) and purified natural surfactant (PNS) were isolated from materials which extracted from the bovine lung lavage. The hydrophilic SP-A was purified from PNS by method of modified Hawgood, and hydrophobic SP-B, C were purified by Sephadex LH 60 column chromatography. The purities of the purified SP-A and SP-B, C were assessed by 12% SDS-polyacrylamide gel and tricine buffer SDS-polyacrylamide gel, respectively and the N-terminal amino acid sequences of these proteins were determined using Beckman PI-2090. The polyclonal anti-serum against SP-A was prepared by immunization of the purified SP-A into the mouse and the immunization of the purified SP-A into the mouse and the immunogenecity of SP-A was confirmed by indirect ELISA. RESULTS: Total 22 gm of CNS, 11 gm of PNS, and 2.5 mg of SP-B and 3.2 mg of SP-C/ 1 gm of CNS, were purified from one bovine both lungs. The molecular weights of SP-A, B, C shown in SDS-polyacrylamide gel were as follows; 28,000-35,000 Da (molecular weight) of SP-A, 15,000-18,000 Da of SP-B, 3,500-5,000 Da of SP-C. The partial N-terminal amino acid sequences of each SPs were; Leu-Glu-His-Asp-Val-Lys- Glu-Val-.... in SP-A, Phe-Pro-Ile-Pro-Ile-Pro-Tyr-.... in SP-B, Leu-Ile-Pro-.... in SP-C, respectively. These results indicated that the amino acid sequences of bovine SPs were different from those of other species, i.e., human, dog and rat, which were reported previously by another investigators and species-specific patterns were shown. The immunogenecity of the purified SP-A was confirmed by the production of polyclonal antibody against mouse. The polyclonal antibody of SP-A could be used for measuring the amount of pulmonary SF in lung lavages. Carbohydrate portion of SP-A was cleaved with N-glycocisidase F. This result suggested that carbohydrate group could be N-glycosylated in some arginine residue of SP-A. CONCLUSIONS: The SP-A, B, C were purified from bovine lung SF, and N-terminal amino acid sequences of each SP-A, B, C were determined. Further studies were needed for the development and use of next generations of exogenous SF preparation, which based on synthetic SP-peptides, for the treatment of neonatal RDS in the future.