RESUMEN
In work chemical modification of collagen during action visible spectrum sunlight. These changes of collagen were found to indicate a photodegradation and photooxidation processes in collagen.
Asunto(s)
Colágeno/química , Procesos Fotoquímicos , Luz Solar , Animales , Oxidación-Reducción/efectos de la radiaciónRESUMEN
The influence of UV irradiation (270-380 nm) on the biochemical, fluorescence and colorimetric properties of collagen was studied. The long-term UV irradiation (120 h) was accompanied by the increase of structural stability of collagen to specific and nonspecific proteolytic enzymes, by formation of new additional fluorophore-containing molecules, by the increase in quantity of carbonyl groups in the collagen and by strong changing of the distribution pattern of alkaline hydrolysis products during gel-chromatography. The coordinates of colour of the collagen films are also changed. These changes of collagen suggest that UV irradiation induces photomodification and photooxidation processes in collagen.
Asunto(s)
Colágeno/efectos de la radiación , Rayos Ultravioleta , Cromatografía en Gel , Colagenasas/química , Microscopía Electrónica , Oxidación-Reducción , Pepsina A/químicaRESUMEN
The literature data on different factors of collagen aging, the main connective tissue protein, have been analyzed. Mechanisms of reactions that are involved in both old aging and non-enzymatic course of protein aging are discussed. Factory influencing, non-enzymatic protein glycation during-related pathology and some ways for its inactivation by different substances are reviewed.
Asunto(s)
Envejecimiento/fisiología , Colágeno/fisiología , Tejido Conectivo/fisiología , Animales , Técnicas In VitroRESUMEN
We studied changes in collagen resistance to proteases and formation of new fluorescent compounds during in vitro nonenzymatic glycosylation. The inhibitory effects of guanidine chloride and catalase were different: guanidine chloride inhibited cross-linking in collagen molecules, while catalase inhibited the formation of chromophore-containing compounds.
Asunto(s)
Colágeno/química , Catalasa/metabolismo , Colágeno/metabolismo , Colagenasas/farmacología , Glicosilación , Guanidina/farmacología , Reacción de Maillard , Pepsina A/farmacología , Pronasa/farmacología , Solubilidad , Espectrometría de Fluorescencia , Factores de TiempoRESUMEN
Rearrangement of intra- and intermolecular bonds in collagen molecule, disaggregation of proteoglycans and their elimination from cartilage involved in osteoarthrosis are responsible for water accumulation and its increased mobility in cartilage.
Asunto(s)
Cartílago Articular/metabolismo , Cartílago/metabolismo , Osteoartritis/metabolismo , Agua/química , Cromatografía en Gel , Colágeno/metabolismo , Fémur/metabolismo , Guanidina/farmacología , Humanos , Hidrolasas/metabolismo , Proteoglicanos/metabolismo , Espectrometría de Fluorescencia , Ácidos Urónicos/farmacología , Agua/metabolismoRESUMEN
The content and state of collagen in skin, muscle and bone of 2500-year-old Altai mummies were studied. Collagen is the predominant protein in studied tissues of the mummies. High degree of the resistance of collagen to the effect of various proteases (collagenase, pronase, pepsin) and to alkline and acidic hydrolysis suggests on the considerable chemical modification of tissue collagen structures of the mummy. The possibility of increased collagen cross-linkages in tissues of the mummies during long-term storage and of nonenzymatic glycosylation of collagen leading to the formation an Amadori products and other modified structures are discussed.
Asunto(s)
Colágeno/química , Momias , Huesos/química , Endopeptidasas/química , Humanos , Hidrólisis , Músculo Esquelético/química , Piel/química , SolubilidadRESUMEN
The stability of collagen molecules and moisture capacity of human normal and osteoarthrotic (OA) cartilage were studied before and after extraction of glycosaminoglycans (GAG) by 4M guanidinum chloride. The content and nature of water were determined by Fisher titration, DSC and analysis of sorbtion-desorbtion processes of water vapour in cartilage. The stability of collagen molecules was determined by the degree of enzymatic hydrolysis: collagenase, pronase and pepsin. It was found that weakening of bonds between main compounds of the cartilage matrix and decrease of GAG quantities in the OA cartilage were accompanied by structural disorganization of the collagen network, which is manifested by breakdowns of intramolecular bonds in telopeptides and intermolecular bonds in the spiral part of collagen molecules, these changes may contribute to increase of total water in OA cartilage. The correlation of free and bound water fractions in cartilage was increased from 5 to 44 in OA cartilage. These results can be used as a criterion of pathological condition of human articular cartilage.
Asunto(s)
Cartílago Articular/química , Colágeno/química , Osteoartritis/patología , Agua/química , Adulto , Cartílago Articular/patología , Glicosaminoglicanos/análisis , Humanos , Persona de Mediana EdadRESUMEN
In a group of 250 patients suffering from frequent paroxysms of atrial fibrillations (flutters), the application of cordarone for 1 to 5 years prevented the occurrence of arrhythmic paroxysms in 23.6%, contributed to a reduction of their numbers up to 1 a year in 35.6%, up to 2-3 a year in 20.4%. Good and satisfactory results were obtained nearly in 80% of the patients. Cordarone failed to act in 10.4%. In 12.8%, the "escape" phenomenon was observed, i.e. loss of the agents' action following its long-acting effect when the patients were on a maintenance dosage. The results of the preventive usage of cordarone were not clearly related to the degree of atrial dilatation and the pattern of cardiac disease.
Asunto(s)
Amiodarona/administración & dosificación , Fibrilación Atrial/prevención & control , Aleteo Atrial/prevención & control , Adulto , Anciano , Humanos , Persona de Mediana Edad , Factores de TiempoRESUMEN
Biochemical studies of elastin from human large arteries wall were carried out using both native and treated with formaldehyde protein. No differences were observed in sensitivity of native and formaldehyde treated elastin to the effect of various proteases and to alkaline-alcohol hydrolysis. Fractions obtained after enzymatic and alkaline hydrolysis were similar in their composition.
Asunto(s)
Arterias/análisis , Elastina/análisis , Formaldehído , Adulto , Arterias/ultraestructura , Elastina/aislamiento & purificación , Fijadores , Humanos , Hidrólisis , Cinética , Péptido HidrolasasRESUMEN
Acid-soluble and insoluble fractions of collagen were dissimilarly modified by formaldehyde. The insoluble fraction became more stable to proteolysis by pronase, collagenase and pepsin.
Asunto(s)
Colágeno/metabolismo , Formaldehído/farmacología , Fraccionamiento Químico , Electroforesis en Gel de Poliacrilamida , Humanos , Hidrólisis , Técnicas In Vitro , Colagenasa Microbiana/metabolismo , Persona de Mediana Edad , Pepsina A/metabolismo , Pronasa/metabolismoRESUMEN
The results of morphological studies on the structure of mineral deposits in the walls of major arteries in atherosclerosis are presented. Calcium deposits looking like petrificates and microgranular deposits were found. The petrificates consisted of microgranular, microcrystalline and macrocrystalline deposits of calcium salts. In the arterial wall, the crystals consisted of calcium phosphate and calcium carbonate. The relationship between the destruction of elastic fibers and elastic membranes and calcification of the vascular wall was confirmed.
Asunto(s)
Aorta Abdominal/patología , Calcinosis/patología , Arteria Ilíaca/patología , Minerales/metabolismo , Anciano , Humanos , Masculino , Microscopía Electrónica de Rastreo , Persona de Mediana EdadRESUMEN
Resistance of fibrillar proteins from large arteria wall, fixed with formaldehyde to the effect of various proteases was studied. Fixation of these proteins using 4% formaldehyde within 14 days enabled to increase distinctly their resistance to the effect of specific and unspecific proteases. Separation of glycosaminoglycans resulted in a decrease of collagen structure resistance to influence of collagenase.
Asunto(s)
Vasos Sanguíneos/efectos de los fármacos , Colágeno/metabolismo , Elastina/metabolismo , Péptido Hidrolasas/farmacología , Animales , Bovinos , Resistencia a Medicamentos , Formaldehído , Técnicas Histológicas , Hidrólisis , Técnicas In VitroRESUMEN
By the method of raster electron microscopy, the structure of the elastic carcass in the human aortic arc walls and the common carotid arteries were investigated at the age of 30--40 years. Preliminary preparation of vessel samples helped to reveal elastic structures with the preserved interconnections. Peculiar features of the elastic carcass components in the sheaths of the vessel wall were demonstrated. The fenestrated membranes and elastic plexus were found to be interconnected and form a single structural complex of the elastic formations in the middle sheath of the vessels studied.