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Biomedical subjects

I Syrový

Publications and source records attributed to I Syrový.

At least 19 recordsLinked to original sources
PubMed1994

Glycation of albumin: reaction with glucose, fructose, galactose, ribose or glyceraldehyde measured using four methods.

Albumin was glycated (nonenzymatically glycosylated) with glucose, fructose, galactose, ribose or glyceraldehyde for 5, 9, 15 and 19 days. The extent of glycation was determined (a) by the thiobarbituric acid method, (b) by fructosamine assay, (c) by method based on the reaction with hydrazine, and (d) by measurement of fluorescence. Results show that the three colorimetric methods used differ in the sensitivity and in addition with the use of each method not the same extent of glycation with various sugars was found.

Albumins↗
PubMed1994

Glycation of myofibrillar proteins and ATPase activity after incubation with eleven sugars.

Rat skeletal muscle myofibrils were incubated in the presence of D-glucose, D-fructose, D-galactose, D-ribose, D-tagatose, D-arabinose, D-xylose, D-mannose, L-sorbose, L-rhamnose or DL-glyceraldehyde and myofibrillar ATPase activity as well as the extent of glycation was measured. The attachment of sugars to proteins during glycation was generally dependent on the percentage of a given sugar present in the open-chain form. Glycation resulted in the decrease of myofibrillar ATPase activity. This decrease was low after incubation of myofibrillar proteins with slowly glycating sugars (e.g. glucose) and high with fast glycating sugars (e.g. ribose or glyceraldehyde). ATPase activity was less reduced in the presence of beta-mercaptoethanol.

Animals↗
PubMed1992

Non-enzymatic glycosylation of myosin: effects of diabetes and ageing.

The influence of diabetes mellitus, streptozotocin-induced diabetes and ageing on the non-enzymatic glycosylation of myosin from cardiac and skeletal muscles was investigated. In cardiac muscle, and to a lesser extent also in skeletal muscles of the rat, non-enzymatic glycosylation of myosin increases with the age, as measured in 6-, 12- and 29-month-old animals. Skeletal muscle myosin from diabetic humans and also that from diabetic rat cardiac muscle are more glycosylated when compared with control myosin preparations. Ca(2+)-ATPase activity of myosin is lower in muscles of diabetic individuals as compared with control muscles.

Aged↗
PubMed1991

Staining and quantification of proteins separated by polyacrylamide gel electrophoresis.

The present review concentrates on techniques for the staining and quantification of proteins separated by polyacrylamide gel electrophoresis. Staining with organic dyes has been used for approximately thirty years; the silver staining technique was introduced in 1979. The problems of silver staining are presented separately because the mechanism of this staining is in principle different from staining with organic dyes. Less attention has been devoted to quantification of two-dimensional gels, because this autoradiography is preferred because of its high sensitivity and fewer problems with accurate quantification in contrast to silver staining.

Electrophoresis, Polyacrylamide Gel↗
PubMed1989

Expression of myosin in atrial areas of the bovine myocardium.

1. A comparison of myosins from defined areas of the bovine atrial myocardium was performed by measuring Ca2+-ATPase activity and electrophoretic separation of myosin light chains. 2. Some areas of atrial myocardium contained myosin with slightly higher ATPase activity than others. 3. There were also clear differences in the amount of one ventricular light chain of myosin in defined regions of atrial myocardium. 4. No close relationship existed between the expression of ventricular and atrial myosin light chains and myosin ATPase activity.

Animals↗
PubMed1989

The effect of time, 2-mercaptoethanol and inhibitors of proteases on isolation of cardiac myosin and its properties.

Myosin was isolated from the ventricular myocardium of adult rats and the effect of time, 2-mercaptoethanol and inhibitors of proteases was investigated on its properties. It was found that the storage of cardiac muscle up to 4 hours does not influence the myosin ATPase, the electrophoretic pattern of light chains of myosin or the pattern of peptides produced by digestion of myosin with chymotrypsin. Neither does the presence of pepstatin and phenylmethyl sulfonylfluoride during myosin preparation influence the activity of myosin ATPase. It was found that the presence of 2-mercaptoethanol during myosin preparation enhances myosin ATPase of the product. This myosin was more stable when kept at 4 degrees C for four days.

Animals↗
PubMed1989

Ontogenic differentiation of pig atrial and ventricular myosin.

Myosin was isolated from pig atrial and ventricular myocardium during postnatal development and Ca2+-ATPase was determined and myosin light chains were analysed by electrophoresis in sodium dodecylsulfate polyacrylamide gel. During ontogenesis ATPase activity of ventricular myosin remains virtually unchanged, whereas that of atrial myosin increases. The patterns of myosin light chains of atrial and ventricular myosin differ from each other, but the individual pattern remains unchanged during the development.

Aging↗
PubMed1988

Contractile function and Ca2+ transport system of myocardium in ageing.

Experiments with animals with various species-specific life span (rats, rabbits, cats, dogs) and different models (in situ heart, isolated perfused heart, isolated papillary muscle) have proved the reduction of functional capacity of the ageing heart. Diversely directional age-dependent shifts have been established involving myocardial Ca2+ transport system, i.e. an increase in the rate of Na+-Ca2+ exchange and passive Ca2+ transport across sarcolemma and a decrease in its Ca2+-binding capacity and a decrease in Ca2+ accumulation by sarcoplasmic reticulum and mitochondria (Ca2+ uptake). The experiments revealed a decrease in the Ca2+ ATPase myosin activity in the myocardium of aged animals and absence of age changes in the K+ ATPase activity. The findings obtained suggest that the development in the cardiac contractile function disorders in ageing largely depends on the age-related changes in the Ca2+ transport system.

Aging↗
PubMed1988

Ventricular myosin from young and adult animals with respect to the thyroid state.

Studies were conducted to analyze the effect of the thyroid hormone on ventricular myosin during ontogenesis of mice, rats and rabbits. Hypothyroidism was induced in mice and rats by administering propylthiouracyl in drinking water. Rabbits were made hyperthyroid by chronic administration of thyroxine. The change in the thyroid state of rats and rabbits influenced young and adult animals differently depending on whether V1 or V3 was the major ventricular isomyosin form present. Measurements of Ca2+-ATPase activity of myosins from young and old control animals and from animals with changed thyroid state showed that hypothyroidism in rats is associated with a greater decrease of myosin ATPase in young rats which contain V1 isomyosin only, when compared with old rats which contain a preponderance of V3 isomyosin and less of the V1 form. In rabbits, ATPase activity of ventricular myosin was more elevated after thyroxine administration in adult rabbits, which contain V3 isomyosin only, than in young rabbits in which myosin consists of V1 and V3 isomyosins. Ventricular myosins of young and adult mice did not differ in their ATPase activity and the treatment of mice with propylthiouracyl had only slight effect on myosin ATPase. It can be concluded based on these results that the hypothesis concerning hypothyroidism inducing transformation of V1 into V3 isomyosin does not hold generally.

Adenosine Triphosphatases↗
PubMed1987

Properties of atrial and ventricular myosin in mammals of various size.

Myosin was isolated from atria and ventricles of adult rats, rabbits and pigs, and characterized by ATPase activities, the effects of temperature on the latter, the influence of alkaline preincubation on enzymatic activity and by electrophoretic fractionation of myosin peptides. It was shown that ventricular myosins are clearly distinguished by their ATPase activities and their response to pH and temperature, whereas atrial myosins were more similar to each other in this respect. However, the electrophoretic patterns of rat, rabbit and pig atrial myosin peptides produced by digestion with S. aureus V8 protease were different.

Adenosine Triphosphatases↗
PubMed1986

Relation of fast and slow skeletal, and atrial and ventricular myosin in various mammals.

Myosin was isolated from adult mouse, rat, rabbit and cat atrial and ventricular myocardium and fast and slow skeletal muscles and examined by measuring Ca2+-ATPase activity and by electrophoretic fractionation of chymotryptic peptides and MLCs. The myosin from mouse atrial and ventricular myocardium were very similar. The properties of cat soleus muscle myosin and ventricular myocardium were also very similar (ATPase activity and electrophoretic pattern of chymotryptic peptides of myosin). The electrophoretic pattern of MLCs, however, was distinct when comparing mouse and feline muscles. These observations are consistent with the idea that atrial and ventricular alpha MHCs are closely related and that beta MHCs from ventricular myocardium and slow skeletal muscle fibres are also closely related.

Animals↗
PubMed1986

Thyroxine influences on contractile proteins from atrial and ventricular myocardium.

When thyroxine is administered to rats or rabbits, both heart ventricles eventually undergo hypertrophy. Both atria and ventricles show a relative weight increase and this mainly involves sarcoplasmic proteins. Ventricular myosin from thyrotoxic rabbits has higher Ca2+-ATPase activity when compared with euthyroid rabbits, the hyperthropied atria however, show no change in myosin ATPase after thyroxine administration.

Animals↗
PubMed1985

Atrial and ventricular myosin ATPase--divergence with increasing animal species size.

Myosin was isolated from mouse, rat, rabbit, pig and bovine atrial and ventricular myocardium and Ca2+-ATPase activity was examined. In the mouse the ATPase activity of myosin was the same in atrial and ventricular myocardium. In larger animal species, the activity of atrial myosin ATPase was higher than that of ventricular myocardium and the larger the animal species the greater the divergence between the activities of atrial and ventricular myosin ATPase. The relevance of these observations to regulation of heart contractility is discussed.

Adenosine Triphosphatases↗
PubMed1984

Separation of muscle proteins.

This review covers various methods used in the separation and isolation of individual muscle contractile proteins. It is shown which methods have been most useful for the separation of contractile proteins and their fragments and in extending our knowledge of muscle biochemistry and physiology.

Actins↗
PubMed1984

Changes in rat ventricular myosin in old age.

Myosin was isolated from rat ventricular myocardium, and its properties were compared in adult and very old animals. Ca2+ -ATPase activity of ventricular myosin was found to be lower in very old animals as compared with adult ones; K+ -ATPase activity, however, does not change with the aging process. Neither were there any differences between the two age groups in the pattern of ventricular light chains of myosin.

Adenosine Triphosphatases↗