Amount Of Soluble Collagen Research Articles

Liveweight and Sex Effects on Instrumental Meat Quality of Rubia de El Molar Autochthonous Ovine Breed.

Simple SummaryA total of 84% of the autochthonous livestock breeds in Spain are in danger of extinction. This decline is mainly produced because they are not very productive and the farmers have been oriented to the most productive breeds, neglecting the rest. There are many factors that push us to conserve autochthonous breeds with little census. These animals are very adapted to their environment, so they are the ones that best exploit the geographical characteristics of their area; besides, their products have a high quality and these breeds have very beneficial genetic components: they are a source of very useful and not sufficiently known gene variants that make them a genetic heritage of undoubted value. If they become extinct, we would be losing an irreplaceable genetic quality. Rubia de El Molar sheep, an autochthonous breed of Madrid, Spain, is currently in serious danger of disappearing. In this work, the meat quality of lambs from Rubia de El Molar breed was studied to test both weight and sex effects on meat quality, assessed by means of instrumental methods. This is the first work that studies the instrumental quality of Rubia de El Molar suckling lamb meat.The effects of sex and weight on instrumental meat quality characteristics of Rubia de El Molar autochthonous ovine breed were studied. Four weight groups (10, 15, 20 and 25 kg, each of the groups with seven males and seven females) were assessed. A decrease of longissimus thoracis muscle (LT) lightness from 43.39 for 10 kg lambs to 38.84 for 25 kg group was observed. LT redness and yellowness indices and chromaticity values increased as weight increased. The percentage of juice expelled increased from 11.52 (10 kg) to 17.15 (15 kg). The percentage of intramuscular fat in biceps femoris (BF) and supraespinatus (SE) muscles increased as weight increased. Warner–Bratzler shear force (WBSF) in raw meat and hardness in cooked meat increased as liveweight increased. However, a decrease in the amount of soluble collagen in quadriceps femoris (QF), biceps femoris (BF) and infraespinatus (IE) muscles was observed as weight increased. Sex effect was only observed for intramuscular fat content in QF and BF muscles (2.4% in males and 2.9 in females) and WBSF in raw meat (26.12 N for males and 21.25 N for females). Weight had a greater effect than sex on Rubia de El Molar meat quality characteristics.

Apoptosis through Bcl-2/Bax and Cleaved Caspase Up-Regulation in Melanoma Treated by Boron Neutron Capture Therapy

Boron neutron capture therapy (BNCT) is a binary treatment involving selective accumulation of boron carriers in a tumor followed by irradiation with a thermal or epithermal neutron beam. The neutron capture reaction with a boron-10 nucleus yields high linear energy transfer (LET) particles, alpha and 7Li, with a range of 5 to 9 µm. These particles can only travel very short distances and release their damaging energy directly into the cells containing the boron compound. We aimed to evaluate proliferation, apoptosis and extracellular matrix (ECM) modifications of B16F10 melanoma and normal human melanocytes after BNCT. The amounts of soluble collagen and Hsp47, indicating collagen synthesis in the ECM, as well as the cellular markers of apoptosis, were investigated. BNCT decreased proliferation, altered the ECM by decreasing collagen synthesis and induced apoptosis by regulating Bcl-2/Bax in melanoma. Additionally, BNCT also increased the levels of TNF receptor and the cleaved caspases 3, 7, 8 and 9 in melanoma. These results suggest that multiple pathways related to cell death and cell cycle arrest are involved in the treatment of melanoma by BNCT.

Analysis of advanced glycation end product modifications in collagen of cardiac tissue and graft material from patients suffering from coronary heart disease

Background: Advanced glycation end products (AGEs) seem to be involved in ageing as well as in the development of cardiovascular diseases. During ageing, the AGEs accumulate in matrix proteins like collagen and fibronectin inducing tissue stiffness. The Bypass operation is the most common intervention in patients suffering from coronary heart disease. However as the majority of the patients are older than 60, the graft material (vein or artery) of these patients is probably enriched on AGE-modifications. To which extent these modifications may affect the quality and functionality of bypass graft material and the heart function after operation is unknown. We analyzed the AGE-modifications in the collagen from the right atrium and residual bypass graft material (saphenous vein and internal thoracic artery) to elucidate in which extension the collagen of graft material is AGE-modified. Methods: Collagen type I and III (soluble fraction) were isolated from veins, arteries and the right atrium by proteolysis with pepsin. The residual insoluble fraction was extracted by digestion with collagenase type I and proteinase K. Collagen was quantified by 4-hydroxyproline assay and AGEs by the AGE intrinsic fluorescence (360nm excitation and 440nm emission). Results: The AGE fluorescence in patient material (vein, atrium) increased with patients age (p=0.0025). Decreasing amounts of extracted insoluble collagen correlate with increased AGE fluorescence (p=0.0001). Comparing vein, artery and atrium of the same patients we isolated equal levels of soluble and insoluble collagen in arteries and atriums, whereas only in veins increased amounts of soluble collagen were extracted in comparison to the insoluble fraction (p<0.05). The soluble fraction in every tissue was significantly less modified in comparison to the insoluble collagen (p<0.05). Conclusion: Ageing is reflected by an increase in AGE related tissue collagen fluorescence. Increase crosslinking of collagen, reflected by high AGE fluorescence, may be the cause of reduced amounts of insoluble extracted collagen. High levels of AGE-modifications are known to block the proteolytic degradation by matrix metalloproteinase. Arteries and cardiac tissue (right atrium) showed significantly more modifications compared to vein graft material of the same patients. Our results may indicate why veins and arteries behave differently as bypass graft material. This will be further evaluated from our group.

Morphological and Biochemical Changes During Aging and Photoaging of the Skin of C57BL/6J Mice

The differences between the dorsal skin of 11- and 16-week-old C57BL/6J mice were examined morphologically and biochemically. The dermis of the 16-week-old mice was thinner than that of the 11-week-old mice due to decreases in the amounts of soluble collagen and elastin. Next, the changes in dorsal skin exposed to UVA irradiation for 8 weeks (576 J/cm2) were examined in 3 (younger)- and 8 (older)-week-old C57BL/6J mice. The thickness of the dermis was not significantly different between the UVA-irradiated and control mice in either the younger or older group. The increase in the amount of collagen was related to the increase in the level of soluble collagen in the younger mice. In contrast, it was related to the increase in the level of insoluble collagen in the older mice. In the UVA-irradiated older mice, the activity of the latent form of MMP-13 was significantly higher than that in the control mice. These results suggest that aging and UVA-induced photoaging in the skin are histologically and biochemically different phenomena.

Macrophage Induced Effect of Particulate Silica on Rat Mesenchymal Stem Cells In Vitro

The role of silica and macrophages in fibrosis is well documented, but in bone formation it is relatively unknown despite decades of research with bioactive glasses. In this study macrophages were isolated from rat peritoneal and then cultured for five days in the presence of two types of silica microparticles with different solubilities. After the fifth day the culture medium was collected, purified and used as an additive in bone marrow derived rat stem cell cultures. The stem cells were cultured for five days in α-mem containing only 0,5% of FCS, enabling cell survival but disrupting their proliferation. As controls, stem cells were also cultured in α-mem containing silica microparticles. At days one and five the amount of soluble collagen was assayed from the culture medium and the cells were counted. All stem cell cultures with macrophage medium additives were found to be proliferative, with statistically significant difference to controls. However, collagen was only produced in cultures containing medium from macrophages cultured with fast-dissolving silica microparticles. This suggests that silica can induce cell proliferation and extra cellular matrix protein secretion which is mediated by macrophages, and that the solubility of silica is also a major factor in this reaction.

Amounts and Variation of Soluble Collagen in Mink Skin During Growth from Kits to Adult Animals

The soluble collagen from mink skin was extracted from 2-week to 6-month-old animals. A total of 14 different age groups, each containing three animals, was studied by using two different buffers for collagen extraction. The amount of soluble collagen was measured. The various collagen species were characterized using capillary zone electrophoresis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis and protein blotting followed by antibody analysis for type I collagen. The data showed that the amount of soluble collagen declines with age. Using capillary electrophoresis it was also found that the distribution of soluble collagen differs in very young kits' skin compared with older animals' skin, whereas the skin from animals more than 2 weeks old was found to contain the same proportions of various collagen species. Antibody analysis of type I collagen found no difference in the relative amount between different age groups, and only the acetic acid-containing buffer extracted type I collagen from the mink skin.

Influence of multiple injections of vitamin E on intramuscular collagen and bone characteristics in suckling lambs.

We studied the influence of vitamin E on intramuscular collagen characteristics and on metacarpal growth plate evolution in suckling lambs. Twenty-four 5-d-old Ile de France suckling male lambs were divided into four equal weight groups, and weekly i.m. injections of DL-alpha-tocopheryl acetate (Control group, 0 IU; Group 1, 625 IU; Group 2, 1,000 IU; and Group 3, 1,500 IU) were given until the lambs were 33 d old. Blood samples were withdrawn for plasma alpha-tocopherol, cholesterol, and triglyceride analyses when the lambs were slaughtered at 40 d of age. Hot carcass weight, metacarpal and metatarsal bone characteristics, and metacarpal growth plate width were measured. After 24 h at 2 to 4 degrees C, semitendinosus muscles were removed for intramuscular collagen analyses. Weight was not influenced by treatment, but lambs in Group 1 had a higher (P < .01) intramuscular collagen content than the other groups. A positive quadratic correlation was found between total collagen and vitamin E doses (r = .511; P < .05). Amount and percentage of soluble collagen increased in muscles of all three vitamin E-treated groups compared with the control group. However, hydroxylysyl pyridinoline concentration decreased with vitamin E injection, but the difference compared to control lambs was only significant for the group injected with 1,000 IU. Amount of soluble collagen was strongly correlated to total collagen concentration (r = .879; P < .0001). It was also related to the alpha-tocopherol/(cholesterol + triglycerides) ratio in plasma (r = .431; P < .04). However, the correlation between soluble collagen percentage and alpha-tocopherol concentration in plasma was not significant (r = .369; P < .08). Bone length, weight, and diameter did not change, but the thickness of metacarpal growth plate increased as the DL-alpha-tocopheryl acetate dose increased; in Groups 2 and 3, the growth plate was significantly wider than in Group 1 and the controls. Growth plate width correlated with alpha-tocopherol/(cholesterol + triglycerides) ratio in plasma (r = .481; P < .02).

The effects of vitamin E deficiency on rat skin.

The effect of vitamin E deficiency on the levels of lipid peroxide and solubility of collagen was investigated in Wistar rats that were fed a vitamin E deficient diet for 3 and 6 months. The lipid peroxide content in the skin and subcutaneous tissue was markedly increased as compared with that of control rats on a normal diet. The lipid peroxide content in the tissues of rats deficient in vitamin E for 3 months, was greater than that found in those on the diet for 6 months. The effect of UV irradiation on the lipid peroxide content in the skin of control rats was not significant, but there was a marked difference in lipid peroxide content in those animals on a deficient diet. The amount of insoluble collagen in the skin of rats on a vitamin E deficient diet for 6 months was increased and by more than in those animals on the diet for 3 months. The amount of soluble collagen in the rats deficient in vitamin E for 6 months was markedly reduced when compared with those on the diet for 3 months. These results suggest that vitamin E deficiency promotes the peroxidation of lipids and accelerates the cross-linking of collagen in the skin.

The influence of indomethacin on tendon healing. A biomechanical and biochemical study.

The influence of indomethacin on the biomechanical and biochemical properties of tendons during their healing was investigated. In 68 New Zealand White rabbits a transverse tenotomy followed by repair with a criss-cross suture was performed in the plantaris longus tendon of the left hind limb. The leg was immobilized for 4 weeks postoperatively in a long-leg plastic splint. Half of the animals were treated with indomethacin, 10 mg/kg/day orally, and the other half with placebo. After 4, 8, and 16 weeks of treatment the animals were killed and biomechanical and biochemical parameters were measured. After 16 weeks there was a significant increase in tensile strength in the indomethacin group. There were only small biochemical differences between the groups. However, there was a slight but significant decrease in the amount of soluble collagen in the indomethacin group. This may indicate a higher degree of cross-linkage following indomethacin treatment, which might explain the increased tensile strength.

Changes in the mechanical strength of the bone and in the collagen solubility of the bone and the skin of carp caused by .BETA.-aminopropionitrile and D-penicillamine.

β-Aminopropionitrile (β-APN) and D-penicillamine, when administered orally to carp, caused a marked decrease in the mechanical strength of the vertebral column and an increase in the amount of soluble collagen in the bone and skin. Intraperitoneal administration of these drugs to carp also caused a reduction in the mechanical strength of the bone. When β-APN and D-penicillamine were added to acid-soluble collagen derived from normal carp skin, D-penicillamine, in contrast to β-APN, prevented the formation of stable collagen fibrils in vitro. These results indicate that the skeletal deformity induced in carp by β-APN and D-penicillamine is due to the reduced mechanical strength of the bone resulting from a collagen maturation defect.

Lack of effect of chronic lithium chloride on bone composition and metabolism.

Lithium chloride (LiCl, 1.43 ±changes in the total amount of soluble collagen, 0.13 mEq/k/day) was administered in distilled the rate of collagen resorption under standardized water to 13 adult female rats for 40 days; 6 rats conditions in vitro, or the rate of collagen forma-served as controls. LiCl had no effect on theserumtion. Serum lithium rose to 0.42 ± 0.10 mEq/1 total calcium and inorganic phosphorus or on and bone lithium content to 29/μg/g wet weight. metaphyseal bone composition or collagen metabo-The data fail to demonstrate any effect of lithium lism. There were no significant changes in the on female rat bone composition or metabolism percentage bone wet weight of mineral salts,ni doses which are many times the usual human organic matrix, or fat and water; there were no prophylactic dose of 0.2–0.4 meq/k/day and ad-changes in the content per unit wet weight of ministered under the experimental conditions calcium, hydroxyproline, or DNA. There were nodescribed.(Endocrinology 94: 915, 1974)

Increased Amount of Soluble Collagen by New Extraction Methods and its Relation to the Nature of Assocating Forces Among Collagen Molecules

About 50% of collagen in calf skin was solubilized by repeatedly changing the pH of an extraction medium from acid to neutral and neutral to acid and keeping temperature at 23°-25°C during acid extraction. This method is called 'pH relaxation extraction'.Addition of glucose (10%) to neutral buffer solubilized a large amount of collagen from calf skin.It was found that the collagen solubilized by these methods contained more β component than α and showed normal capability for fibril formation. The rate of fibril formation was higher than that of so-called acid soluble collagen. Amino and composition of the pH relaxation soluble collagen was little different from that of the acid soluble collagen.The mechanism of collagen solubilizatron by pH relaxation extraction is discussed in relation to the associating forces of insoluble collagen.

Protocollagen proline hydroxylase and collagen synthesis in developing eggs of Ascaris lumbricoides

1.1. Protocollagen proline hydroxylase (PPH) activity in developing eggs of Ascaris lumbricoides first appeared in the late blastula-early gastrula stages, was most active at or near the molting stage and disappeared in infective eggs. PPH activity was closely correlated with the amount of soluble collagen.2.2. Little hydroxyproline was present in gelatin extracted from the insoluble proteins of one-celled eggs. It increased forty-hold during development, whereas the gelatin increased only three-fold.3.3. The apparent Michaelis constant (Kma) of egg PPH was strongly affected by temperature, being minimal at 30°C. That of PPH from adult A. lumbricoides muscle was less strongly affected, with a minimum at 38°C.4.4. Oxygen concentrations exceeding 5 vol. per cent inhibited muscle but not egg PPH. Catalase did not relieve the inhibition.5.5. Egg and muscle PPH gave electrophoretically distinct peaks on acrylamide gel columns.6.6. The protocollagen proline hydroxylases of eggs and muscle seem to be isoenzymes which are adapted to the developmental physiology of A. lumbricoides.

Regulation of collagen and hyaluronate formation in human synovial fibroblast cultures.

Abstract Development of a method permitting quantitative analysis of tissue culture medium for protein-bound hydroxyproline led to the detection of large amounts of soluble collagen formed by human synovial fibroblasts. The soluble collagen was found in greatest concentration in media from mature cultures where deposition of fibrous collagen was in process. Viscometric studies revealed intrinsic viscosity values in excess of 11.0 dl. per gram, suggesting a molecular weight similar to undegraded collagen. Ascorbic acid, 200 μg per milliliter of culture medium, markedly enhanced formation of hyaluronic acid without evidence of a depolymerizing effect. Both soluble and fibrous collagen formation in cultures of synovial fibroblasts were greatly enhanced by ascorbate. Cortisol, on the other hand, markedly depressed formation of hyaluronate, fibrous, and soluble collagen, even in the presence of the stimulatory vitamin. This cell culture system may be a valuable model for studying factors regulating the transition between the soluble and fibrous forms of collagen in living systems.

The effect of antirheumatic drugs on the extractable collagen in lathyric chick embryos.

Abstract The lathyrogenic effect of 2·5 mg of β-aminopropionitrile in the chick embryo has been measured by the increase in the extractability of collagen from bones using M saline. Sodium salicylate (3 mg/embryo) and hydrocortisone (1·5 mg/embryo) applied 24 hr after the injection of β-aminopropionitrile decreased the elevated amount of soluble collagen. Phenylbutazone, chloroquine diphosphate and sodium aurothiosulphate were ineffective in this experimental system.

Action of ultra-violet light on soluble collagens.

IT has been shown1 that rat tail tendon becomes less soluble after exposure to short wave ultra-violet light and that the amount of soluble collagen in mouse skin was decreased after irradiation2. Fujimori3, working with acetic acid solutions of calf skin collagen, recently showed that irradiation resulted in the acquirement of ability to fluoresce in long wave ultra-violet light. These changes in properties have been ascribed to the formation of cross-links from the aromatic side-chains of phenyl-alanine and tyrosine3,4. Working with suspensions of acid-soluble and neutral salt-soluble collagens from rat skin we have also found that short wave ultra-violet light does produce fluorescence, and we have sought to measure the fluorescence quantitatively and correlate this with changes of solubility and shrinkage temperature after different periods of irradiation.

Collagen development in heart and skin of the chick embryo

1. 1.|The development of the collagenous framework was studied in the chick-embryo heart and skin. Collagen was detected in the heart on the 3rd day of development. The heart growth and collagen growth from the 5th to the 21st day of development can be described by continuous exponental functions. However, collagen increases more rapidly than heart weight as described by the relationship: Collagen = K (heart wet wt.) 1.61 2. 2.|A mechanical interpretation of the data suggests that the increasing proportion of collagen in the enlarging heart may be related to the increasing mechanical strength requirements of the enlarging heart. 3. 3.|The amount of soluble collagen in the heart was found to be almost directly proportional to the net rate of collagen synthesis in the heart. 4. 4.|Collagen growth in the skin does not follow a continuous exponential time curve. Rather, there is an abrupt increase in skin collagen concentration between the 12th and 17th days of development. 5. 5.|This discontinuity in the synthesis of skin collagen points up the difficulty in attempting to relate soluble collagen content to the rate of growth of the organism or tissue.

Collagen defect induced by penicillamine.

Collagen synthesis, as judged by the accumulation of collagen in a subcutaneous, induced granuloma, was significantly decreased by penicillamine. Penicillamine also caused a marked increase in the amount of soluble collagen in skin and a sharp drop in insoluble material. These findings, which reflect an abnormal pattern of collagen metdbolism, are accompanied by an inhibition of wound-healing and by skin fragility.

Connective tissue. I. Age and sex influence on protein composition of rat tissues.

SummaryTissues from tail tendon, aorta, skin, uterus, lung, muscle, heart, liver, kidney and spleen of male and female rats at 3–5 wk, 8 mo and 2 yr of age were fractionated into soluble protein, insoluble collagen and elastin. Amount of soluble collagen in the soluble protein fraction was calculated according to amount of hydroxyproline. Significant changes in these fractions with age occurred only in skin, tendon, uterus and aorta, with scleroprotein increased and non-scleroprotein decreased.