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1.
Acta bioquím. clín. latinoam ; 41(2): 237-245, abr.-jun. 2007. ilus, graf, tab
Article in Spanish | LILACS | ID: lil-633009

ABSTRACT

El agente tensioactivo pulmonar es un material compuesto de fosfolípidos, lípidos neutros y proteínas que se encuentra en la superficie alveolar de los pulmones y facilita la ventilación alveolar. La organización molecular de los componentes del agente tensioactivo aislado de pulmones de ternera fue analizada por calorimetría diferencial de barrido y por dispersión dinámica de luz y posteriormente comparada con los componentes organizados en liposomas uni y multilamelares; además, se probó la actividad de superficie al desarrollar en cobayos el síndrome de dificultad respiratoria. Los estudios de calorimetría mostraron que las interacciones lípido-proteína fueron considerablemente abatidas en el agente tensioactivo nativo, en comparación con las del agente tensioactivo en forma de liposomas uni o multilamelares. Los experimentos de dispersión dinámica de luz indicaron que el agente tensioactivo nativo tiene forma fibrilar con interacciones limitadas entre lípidos y proteínas, lo que sugiere que se encuentra organizado en una estructura en forma de reja formando una película de estructura estable. Los resultados obtenidos resaltan la importancia de la organización molecular del agente tensioactivo. Cuando éste fue usado para tratar a los animales con síndrome de dificultad respiratoria, los valores del pH arterial y de PaCO2 mejoraron casi hasta alcanzar los valores normales; cuando se utilizó el agente tensioactivo reconstituído como liposomas uni o multilamelares, los animales no se recuperaron. Es importante enfatizar que el método seguido en el protocolo de aislamiento del agente tensioactivo pulmonar de ternera permitió obtenerlo en una forma fisiológicamente activa.


Surfactant, a highly surface-active material composed of phospholipids, neutral lipids and proteins, lines the lungs' alveolar surface facilitating alveolar ventilation. The molecular organization of surfactant components isolated from calf-lungs was analyzed by differential-scanning calorimetry and dynamic light-scattering, and subsequently compared to surfactant components organized in uni and multilamellar liposomes. The respiratory distress syndrome developed in adult guinea pigs was used for assessing surfactant activity. Calorimetry studies showed that lipid-protein interactions were considerably abated in native surfactant as compared to those of surfactant in uni or multi-lamellar liposomes. Light-scattering experiments indicated that native surfactant has a fibrillar shape with limited lipid-protein interactions, suggesting that it is organized in a lattice-like structure forming a stable film. These findings underscore the importance of the native molecular organization of surfactant. When surfactant reconstituted as uni- or multilamellar liposomes was administred to animals under respiratory distress, they did not recover. In contrast, when native surfactant was used to treat sick animals, arterial pH and PaCO2 values improved, almost reaching normal values. It is important to emphasize that fewer steps in the protocol for isolation of calf lung surfactant made it possible to obtain it in a physiologically active molecular form.


Subject(s)
Animals , Cattle , Guinea Pigs , Respiratory Distress Syndrome, Newborn/veterinary , Respiratory Distress Syndrome/veterinary , Pulmonary Surfactants/chemistry , Pulmonary Alveoli/physiology , Pulmonary Surfactants/therapeutic use , Calorimetry/veterinary , Dynamic Light Scattering/veterinary
2.
Clinics ; 61(2): 153-160, Apr. 2006. graf
Article in English | LILACS, SES-SP | ID: lil-426297

ABSTRACT

OBJETIVO: Estudar a imunogenicidade e a estabilidade do surfactante de origem porcina produzido pelo Instituto Butantan. MÉTODO: Experimento imunogenicidade: 16 coelhos da raça New-Zealand-White (Peso de 1000g) foram divididos em grupos de 4 animais. Cada grupo foi designado para receber: a) Surfactante do Butantan, b) Survanta® (Abbott Laboratories), c) Curosurf (Farmalab Chiesi) e d) nenhum tratamento com surfactante. Os surfactantes foram administrados via intratraqueal e o sangue dos animais foi coletado antes, 60 e 180 dias após a administração do surfactante. O soro obtido foi analisado quanto a presença de anticorpos anti-surfactante pelo método ELISA (enzyme-linked immunosorbent assay). Experimento estabilidade: O surfactante do Butantan usado neste experimento tinha sido armazenado por um ano em refrigerador (4 a 8°C) e sua estabilidade foi analisada em condições distintas de experimentação, usando o modelo de coelho prematuro. RESULTADOS: Experimento imunogenicidade: Nenhum dos surfactantes analisados determinou a produção de anticorpos contra seus constituintes. Experimento estabilidade: Os resultados deste estudo demonstraram que o surfactante do Instituto Butantan mostrou eficácia semelhante a do Curosurf após ter sido submetido à condições adversas ao longo do tempo. A eficácia foi demonstrada através da complacência pulmonar dinâmica, pressão ventilatória e da curva pressão-volume. CONCLUSÃO: Os resultados deste estudo demonstraram que o surfactante do Instituto Butantan pode representar um tratamento alternativo de reposição de surfactante.


Subject(s)
Animals , Female , Pregnancy , Rabbits , Pulmonary Surfactants/chemistry , Pulmonary Surfactants/immunology , Models, Animal , Animals, Newborn , Respiratory Tract Diseases/drug therapy , Time Factors , Pulmonary Surfactant-Associated Proteins/immunology , Pulmonary Surfactants/therapeutic use , Swine
3.
Braz. j. med. biol. res ; 33(3): 279-85, Mar. 2000. ilus, tab
Article in English | LILACS | ID: lil-255046

ABSTRACT

The morphology of the rat lung was studied by light microscopy in different situations: after surgical and pharmacological castration and after administration of testosterone to the castrated rat to determine if the androgen is required to maintain the normal morphology of the lung. We also determined the effect of flutamide on the phospholipid composition of both the surfactant and microsomes of the lung. Rats were separated into five groups: I - control non-castrated rats, II - castrated rats sacrificed 21 days after castration, III - castrated rats that received testosterone daily from day 2 to day 21 after castration, IV - castrated rats that received testosterone from day 15 to day 21 after castration, and V - control rats injected with flutamide for 7 days. The amount of different phospholipids in the surfactant and microsomes of the lung was measured in group I and V rats. At the light microscopy level, the surgical and pharmacological castration provoked alterations in the morphology of the lung, similar to that observed in human lung emphysema. The compositions of surfactant and microsomes of the lung were similar to those previously reported by us for the surgically castrated rats. These results indicate that androgens are necessary for the normal morphology as well as for some metabolic aspects of the lung.


Subject(s)
Animals , Male , Rats , Androgen Antagonists/pharmacology , Flutamide/pharmacology , Gonadal Steroid Hormones/pharmacology , Lung/cytology , Microsomes/drug effects , Orchiectomy , Pulmonary Surfactants/drug effects , Testosterone/pharmacology , Lung/metabolism , Microsomes/chemistry , Orchiectomy/adverse effects , Phospholipids/analysis , Pulmonary Surfactants/chemistry , Rats, Wistar
4.
Rev. méd. Panamá ; 24(1): 26-33, Jan.-May 1999.
Article in Spanish | LILACS | ID: lil-409807

ABSTRACT

The pulmonary surfactant is a lipoproteic complex that serves to lower surface tension at the air-liquid interface in the pulmonary alveoli. Approximately 2 to 4% of the pulmonary surfactant is constituted by the protein A (SP-A). The objective of the study was to determine the effects that maternal protein calorie malnutrition has on the fetal pulmonary growth and the production of SP-A messenger RNA in fetal rats. MATERIALS AND METHODS: Pregnant Sprague Dawley rats were divided into two groups, which received a diet with either 8% or 21% of proteins from gestational day 1 until the day 20. In this last day 11 fetuses were extracted by caesarean section and their lungs were removed to quantify the mRNA of the SP-A. First the mRNA was boosted using the technique of reverse transcriptase and polimerase chain reaction (RT-PCR) and then its concentration was determined by means of fluorodensitometry. RESULTS: There was a reduction in body weight and in wet lung weights of malnourished fetuses in comparison with the normal fetuses (5.03 +/- 0.20 g vs. 4.32 +/- 0.32 g, p < 0.05 and 79.0 +/- 3.8 mg vs. 146.0 +/- 3.4 mg, p < 0.05, respectively). The densitometric analysis of the SP-A mRNA concentration demonstrated a reduction of 32% in the malnourished fetuses (0.52 +/- 0.11 vs. 0.77 +/- 0.07, p < 0.05) compared with the normal fetuses. CONCLUSIONS: The maternal protein calorie malnutrition affected the pulmonary development and the synthesis of the SP-A mRNA. These data suggest that a defect occurrs at pre-transcriptional level that results in a diminution of the concentration of mRNA of SP-A in the neumocytes type II


Subject(s)
Animals , Female , Pregnancy , Rats , Protein-Energy Malnutrition , Pregnancy Complications , Pulmonary Surfactant-Associated Protein A/genetics , Lung/embryology , RNA, Messenger/analysis , Pulmonary Surfactants/chemistry , Rats, Sprague-Dawley
5.
Acta physiol. pharmacol. ther. latinoam ; 48(4): 175-90, 1998. ilus, tab
Article in Spanish | LILACS | ID: lil-226085

ABSTRACT

El surfactante pulmonar es una mezcla lipoproteica sintetizada y secretada por las células alveolares pulmonares tipo II. Su principal función es la disminución de la tensión superficial formando una monocapa en la superficie alveolar. Su deficiencia es el principal factor asociado al síndrome de dificultad respiratoria del recién nacido (RDS) y al síndrome de dificultad respiratoria del adulto (ARDS). Desde 1980 se está estudiando la administración exógena del surfactante pulmonar para el tratamiento de estos dos síndromes. En este trabajo se describen los surfactantes exógenos disponibles para uso clínico, las técnicas de administración y el esquema de dosificación. La utilización del surfactante natural exógeno (ENS) marcado con (99m)Tc((99m)Tc-ENS) para su utilización como radiofármaco en centellografía aérea pulmonar también es descripta en este trabajo.


Subject(s)
Humans , Infant, Newborn , Adult , Pulmonary Surfactants , Respiratory Distress Syndrome, Newborn/drug therapy , Respiratory Distress Syndrome/drug therapy , Pulmonary Surfactants , Pulmonary Surfactants/chemistry , Pulmonary Surfactants/deficiency , Pulmonary Surfactants/physiology , Pulmonary Surfactants/therapeutic use
6.
Anon.
Rev. méd. Panamá ; 22(2): 22-30, May-Sept. 1997.
Article in Spanish | LILACS | ID: lil-409860

ABSTRACT

This is an admission thesis to the Panamenian Academy of Medicine and Surgery. We reviewed the use of the pulmonary surfactant in neonatology, the history, biochemical and biophysical properties; the metabolism and commercially available preparations were also analyzed. We presented the international clinical experience and our own in Panama


Subject(s)
Humans , Infant, Newborn , Pulmonary Surfactants , Panama , Pulmonary Surfactants/chemistry , Pulmonary Surfactants/metabolism , Pulmonary Surfactants/therapeutic use
8.
Rev. Inst. Nac. Enfermedades Respir ; 8(2): 150-8, abr.-jun. 1995. ilus, tab
Article in Spanish | LILACS | ID: lil-158954

ABSTRACT

La ausencia de surfactantes pulmonares trae como consecuencia el incremento de la tensión superficial a lo largo del epitelio alveolar, provocando un colapso alveolar y la lisis de las células epiteliales. Este proceso culmina con la aparición de un síndrome de insuficiencia respiratoria, que es la causa principal de morbimortalidad en niños prematuros. Recientemente, la aplicación de mezclas de agentes surfactantes con fines terapéuticos ha constituido un gran apoyo para la terapia respiratoria, ya que permite una evolución más rápida de los niños que padecen este síndrome. Por todo esto, resulta de gran importancia el conocimiento más detallado de la función, el metabolismo y la regulación de la expresión genética de las proteíinas surfactantes, para el diseño de nuevas y mejores estrategias terapéuticas para combatir este síndrome


Subject(s)
1,2-Dipalmitoylphosphatidylcholine/biosynthesis , 1,2-Dipalmitoylphosphatidylcholine/chemistry , Phospholipids/biosynthesis , Phospholipids/chemistry , Lectins/chemistry , Pulmonary Alveoli/drug effects , Pulmonary Alveoli/physiology , Pulmonary Surfactants/chemistry , Pulmonary Surfactants/genetics , Pulmonary Surfactants/ultrastructure
9.
Indian J Biochem Biophys ; 1992 Oct; 29(5): 433-7
Article in English | IMSEAR | ID: sea-27696

ABSTRACT

A pulmonary surfactant-associated protein complex with components of 36, 32 and 28 kDa was isolated from human lung homogenates and reassembled with surfactant lipids prepared as small unilamellar liposomes. The role of divalent cations in the assembly of this recombinant lipoprotein complex was studied by monitoring the changes in turbidity, intrinsic tryptophanyl fluorescence and surface activity. The protein-facilitated lipid aggregation was promoted on addition of 5 to 20 mM Ca2+. Intrinsic fluorescence measurements on SP-A (28-36 kDa) indicated that the tryptophan side chains were in a relatively hydrophobic environment, that the wavelength of maximum fluorescence emission and also the relative fluorescence, were changed upon the binding of lipid. Tryptophanyl fluorescence of the lipoprotein assembly was quenched as indicated by a reduction in the effective Stern-Volmer constant. These results suggest that Ca2+ lipid-protein interactions are involved in the structure and function of extracellular lung surfactant assembly.


Subject(s)
Adult , Glycoproteins/chemistry , Humans , Kinetics , Liposomes/chemistry , Lung/physiology , Male , Nephelometry and Turbidimetry , Proteolipids/chemistry , Pulmonary Surfactant-Associated Protein A , Pulmonary Surfactant-Associated Proteins , Pulmonary Surfactants/chemistry , Spectrometry, Fluorescence
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