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Biomedical subjects

E Bańkowski

Publications and source records attributed to E Bańkowski.

At least 55 records · Page 3Linked to original sources

Liver collagen of rats submitted to chronic intoxication with acetaldehyde.

It was found that chronic intoxication of rats with acetaldehyde results in a distinct, progressive increase of 5-3H-proline incorporation into collagen synthesized by liver. At the same time biosynthesis of other proline-containing (noncollagenous) proteins does not change significantly. On the other hand the collagen content in the rat liver did not increase in the early stage of acetaldehyde administration, but increased when acetaldehyde feeding was continued for 6 months. About 40% increase of total collagen content was found in livers of the intoxicated animals. All the investigated collagen types (I, III, IV and V) grew in the same degree. No changes in proportional relationships between collagens of different types were found.

Acetaldehyde↗

Collagen of umbilical cord arteries and its alterations in EPH-gestosis.

We decided to investigate the EPH-gestosis--connected alterations in collagen of the umbilical cord arteries. The samples of arterial walls were submitted to histological and biochemical studies. It was found that umbilical cord arteries taken from newborns of mothers with EPH-gestosis contain more than twice the amount of collagen in comparison to corresponding arteries of newborns from normal pregnancies. An increase of collagen content in these vessels in accompanied by a slight decrease of its solubility. Types I, III, IV, V and VI collagens were found both in normal umbilical cord arteries and in those of newborns delivered by mothers with EPH-gestosis but their proportional relationships were different. EPH-gestosis is accompanied by an increase of a proportional amount of type III-collagen and a decrease of type I collagen in umbilical cord arteries. It seems that these changes in the umbilical cord arteries may be responsible for the decrease of blood flow in fetus of woman with EPH-gestosis.

Collagen↗

Stimulation of alveolar macrophages by BCG vaccine enhances the process of lung fibrosis induced by bleomycin.

It was found that the BCG vaccine injected subcutaneously to the rats enhances the process of lung fibrosis induced by bleomycin. Pretreatment of rats with this vaccine results in accumulation of activated macrophages in lung interstitium and in the bronchoalveolar spaces. It may be suggested that the activated macrophages release various cytokines which may stimulate the proliferation of fibroblasts and biosynthesis of extracellular matrix components.

Animals↗

Changes in IGF-binding proteins in rats with experimental diabetes.

The effects of streptozotocin-induced diabetes on proteolytic activity and collagen biosynthesis in skin lesions in rats and on IGF-I binding proteins in their serum were evaluated. It was found that both collagen in intact skin and collagen biosynthesis in skin lesions were lower compared to control animals. Concurrently, there was an increase in proteolytic activity both in intact and lesioned skin. The livers and sera of diabetic animals also showed higher proteolytic activity. Inhibitors of cathepsin D (pepstatin and potato-derived inhibitor) prevent the decrease of collagen biosynthesis in the skin of diabetic rats. These observations indicate the co-existence of two phenomena in the investigated animals: an increase in proteolytic activity in tissues and a decrease in collagen biosynthesis. Furthermore, the diabetic rats showed significant changes in the composition of IGF-I serum binding proteins. The amount of high molecular weight binding proteins (HMW-BPs) was distinctly decreased, whereas the content of low molecular weight binding proteins (LMW-BPs) was significantly increased. Large amounts of LMW-BPs have been previously found in the sera of fasted and scorbutic animals. They are inhibitors of IGF-I activity. It is suggested that the increase in LMW-BP concentration in diabetic serum may be responsible for the inactivation of IGF-I resulting in decreased collagen biosynthesis. The role of proteolysis in the production of LMW-BPs in diabetic serum is discussed.

Animals↗

Pharmacological and physicochemical properties of collagen breakdown-products.

It has been found that the pharmacologically active, low molecular products obtained by digestion of telopeptides-deprived type I collagen with bacterial collagenase is a heterogenous mixture of at least 21 peptides of different molecular weight. They contain 3 to 15 amino acid residues. About 80% of them are tripeptides of the sequence Gly-Pro-X. The most abundant are two peptides: Gly-Pro-Hyp and Gly-Pro-Ala. The peptides injected into the lateral cerebral ventricle of the rat evoked some behavioral effects. They decreased the psychomotoric activity (evaluated with Lat's test) and increased the cataleptic action of haloperidol. On the other hand, they did not exert any effect on amphetamine-induced stereotypy and did not counteract the apomorphine-induced stereotypy.

Amino Acid Sequence↗

[Content and distribution of collagen in aorta double velour DALLON grafts].

The aim of the study was to determine the collagen content, distribution and quantitative ratios between main types of collagen (found in normal vascular walls) in various layers of double velour DALLON grafts at different periods after implantation. Double velour DALLON prostheses were implanted into the abdominal aorta of 24 dogs. These grafts were excised 7 days, 1, 4 and 12 months after implantation and together with normal arteries, after dissection into intimal, medial, and adventitial layers, tested for their hydroxyproline content. Type I, III, V collagen was also determined (fractionation of pepsin digestion products). Already 7 days after implantation collagen appeared in all the newly-formed layers of the grafts. With the passage of time after the operation collagen content was gradually increasing. After 12 months collagen content in the intimal and adventitial layers was significantly higher than in normal arterial wall. Approximate quantitative ratio between collagen types I, III and V in all graft layers was 7:2:1 and did not change during the 1-year-observation. Rise in collagen content results in graft wall stiffening, and the presence of III type collagen increased platelet-aggregating activity. Both these factors created a tendency to the formation of thrombosis in the graft.

Animals↗

Chronic intoxication with acetaldehyde stimulates collagen biosynthesis in rat liver.

It was found that chronic intoxication of rats with acetaldehyde results in a distinct, progressive increase of 5(3)H-proline incorporation into collagen synthesized by liver. At the same time, biosynthesis of other proline-containing (noncollagenous) proteins does not change significantly. The effects are similar to those induced by chronic intoxication of rats with ethanol. Since acetaldehyde is an intermediary metabolite formed during ethanol oxidation in liver, it may be concluded that acetaldehyde is a factor responsible for alcohol-induced liver fibrosis.

Acetaldehyde↗

Proteolytic activity of vitreous-humour.

It has been found that the bovine vitreous--humour did not digest in vitro collagen at physiological and acidic pH. A proteolytic activity against haemoglobin in acid pH was found both in bovine and human vitreous-humours. The activity of human vitreous-humour increased significantly in endophtalmitis and glaucoma. In all pathological conditions studied the pH optima were at more acidic values than in control.

Animals↗

Collagenolytic activity of methylcholanthrene-induced rat fibrosarcoma.

It has been found that the methylcholanthrene-induced rat fibrosarcoma contains an enzyme (probably a cathepsin) which digests type I and type III collagens in acid pH. At physiological pH no proteolytic activity against collagen was found. It may be concluded that the tumour collagen is degraded mainly by the action of cathepsin(s).

Animals↗

Collagen of breast with benign dysplasia.

Benign dysplasia is a pathological process in the female breast associated with hypertrophy of interlobular and periductal connective tissue. It leads to disappearance of the lobular structure of this organ. It was found that the mammary tumours contain more collagen in comparison to the normal breast. In the normal breast collagen type I and type III constitute 70% and 25% of the total collagen content, respectively. The investigated tumors contain mainly a complex of collagen type I and type III which cannot be dissociated by the methods used for collagen preparation.

Adult↗

Effect of lathyrogen on collagen of methylcholanthrene-induced sarcoma of rat.

Since the lathyrogen beta-aminopropionitrile is known to affect the fibrogenic and physical properties of collagen polymers, we have examined its effects on collagenous components of methylcholanthrene-induced fibrosarcoma in rat. Lathyrogen treatment reduced total collagen content of tumours from approximately 17 to 12 mg collagen/g tissue. It also proportionately increased the solubility of specific collagen fractions, the summation of all extractable solubilized collagens reflecting 37 and 67% of total collagen content for control and lathyric tumours, respectively. Although lathyrogen had no significant effect on the growth and overall size of fibrosarcoma, histological studies confirmed that changes had occurred to appearance and distribution of collagenous components of extracellular matrix.

Aminopropionitrile↗

Soluble non-collagen proteins of bovine vitreous humour.

Bovine vitreous humour contains 0.6 +/- 0.04 mg of proteins per cm3. Three main protein fractions were obtained by CM-cellulose chromatography and their homogeneity was confirmed by isoelectric focusing and SDS-gel electrophoresis. The Mr and pl values of the separated fractions were: fraction I, 67,000 and 4.02; fraction II, 59,000 and 5.22; fraction III, 43,000 and 7.48, respectively.

Amino Acids↗

An increase of collagen biosynthesis precedes other symptoms of ethanol-induced liver damage in rats.

Treatment of rats with 10% ethanol for 6 months induced a 3-4-fold increase of [3H]proline incorporation into liver collagen and enhanced the level of prolyl hydroxylase activity in liver and serum of intoxicated rats. Several diagnostic tests used to assess liver disease failed to demonstrate any symptom of liver damage. Therefore, increased collagen biosynthesis appears to precede other symptoms of liver damage induced by ethanol.

Animals↗