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At least 19 recordsLinked to original sources
PubMed1979

Formation of granulation tissue in subcutaneously implanted sponges in rats. A comparison between granulation tissue developed in viscose cellulose sponges (Visella) and in polyvinyl alcohol sponges (Ivalon).

A comparison was made between the granulation tissue formation in two different synthetic sponge types. Visella and Ivalon, of different sizes. The granulation tissue formed in the two sponge types did not differ qualitatively, and had the character of wound tissue and inflammatory tissue in man. The rate of tissue formation in the Visella sponges was faster and the tissue was more homogenous than in the Ivalon sponges. Fourteen-day-old Visella implants of either size contained more granulation tissue than Ivalon sponges, probably owing to the smaller pore size of the former material. This may also account for the more frequent occurrence of giant cells in the Visella implants. In contrast to the Visella sponges, the trabeculae of the Ivalon polymer showed calcification and positive staining properties with histological staining procedures, and deformation was frequent among the Ivalon implants. Thin sponges of either type closed in about 21 days, thick ones after about 42 days of implantation. Calculated per 2 cm3 of implant, thin sponges produced more tissue after 14 days of implantation than thick noes. It is concluded that the Visella sponge type is best suitable for this experimental model of inflammation.

Animals↗
PubMed1979

Elastin and granulation tissue.

The contraction of granulation tissue is an important factor in wound healing. The tract of an abdominal drainage tube closes at the rate of 1 mm/h once the tube is removed. Specialized myofibroblasts are generally believed to be responsible for this process and the presence of elastin in granulation tissue has been debated for many years. A 3-mm polyethylene tube was inserted through the left lobe of the liver in 41 rats. A tube of granulation tissue formed around the plastic. This granulation tissue was isolated, after periods ranging from 8 to 20 days, by removing the left lobe of the liver and scraping away the surrounding liver tissue. Biochemical assay for elastin revealed that normal hepatic tissue does not contain any detectable amount of elastin. All 41 samples of granulation tissue contained elastin with a mean value of 8.5 X 10(-6) g of elastin per milligram of tissue. Normal rat aorta contains 31.4 X 10(-6) g of elastin per milligram of tissue. These tubes of granulation tissue were histologically normal and the presence of elastin was recognized using elastin stains. The exact role of elastin in granulation tissue is uncertain but this experiment clearly demonstrates its generation and presence there.

Animals↗
PubMed1978

The effect of chlorhexidine gluconate on the formation of experimental granulation tissue.

The aim of the study was to investigate the effect of chlorhexidine gluconate on the connective tissue formation. Granulation tissue was produced with a method in which sponges were inserted beneath the back skin of rats. Dry sterilized sponges were impregnated either with 0.45% NaCl solution (control) or or 0.2% chlorhexidine solution [test]. The sponges were removed after 3, 5, 7, 10, 14, 19 and 23 days. The content of hydroxyproline, hexosamines, DNA and RNA was estimated from the sponges. The acid glycosaminoglycans were further purified and analyzed. The results of the study indicate that chlorhexidine had a clear delaying effect on the formation of granulation tissue.

Animals↗
PubMed1977

Cyclophosphamide effect on collagen metabolism in granulation tissue, skin, and aorta of rats.

Granulation tissue was produced in rats by subcutaneous implantation of viscose cellulose sponges. Cyclophosphamide 10 mg/kg was given daily intraperitoneally to 15 rats from the day of sponge implantation. Fifteen rats served as pair-fed controls, and 15 rats served as non-starved controls. After 14 days of treatment the animals were decapitated. Groups of 3 rats were given 50 muci 14C-proline intraperitoneally 1, 3, 6, 12, or 24 hours before death. The aorta, skin, and granulation tissue were examined. Cyclophosphamide caused no effect on collagen of the aorta, while in skin, the only detectable effect was a decrease in 14C-OH-proline biosynthesis. In granulation tissue, cyclophosphamide caused a fall in the dry weight, a decrease in 14C-proline uptake and 14C-OH-proline synthesis, as well as an increase in the alpha-amino nitrogen to OH-proline ratio in purified collagen. These results indicate that cyclophosphamide inhibits the synthesis of proteins, including collagen, and inhibits the hydroxylation of proline in collagen. No effect of cyclophosphamide could be detected on the amount of salt soluble OH-proline or on collagen cross-linking. The registered effects of cyclophosphamide on granulation tissue is probably of importance with regard to the anti-inflammatory action of cyclophosphamide. This action as well as the tissue differences in the sensitivity of cyclophosphamide may be of relevance to the clinical application of cytostatics in rheumatological diseases.

Animals↗
PubMed1992

Analysis of the leukotriene D4 receptor in the granulation tissue of allergic inflammation in rats.

Leukotriene (LT) D4 receptor in the granulation tissue formed in the air pouch-type allergic inflammation model in rats was analyzed. Membrane preparation of the granulation tissue obtained 3-9 days after the antigen challenge has specific binding sites of [3H]LTD4. Scatchard analysis showed that the affinity (Kd) and the density (Bmax) were not changed among the granulation tissue obtained 3-9 days after the antigen challenge. The Kd value in the granulation tissue (0.90 +/- 0.12 nM) was close to that in the rat lung (1.00 +/- 0.24 nM) and the guinea pig lung (0.86 nM). On the other hand, Bmax (62 +/- 8 fmol/mg protein) in the granulation tissue was higher than that in the rat lung (21 +/- 4 fmol/mg protein) but was far less than that in the guinea pig lung (405 fmol/mg protein). LTC4 and LTE4 inhibited the binding of [3H]LTD4 to the membrane preparation of the granulation tissue in a concentration-dependent manner. IC50 of LTC4 and LTE4 were 1 x 10(-7) and 2 x 10(-7) M, respectively. A guanine nucleotide, guanyl-5'-yl-imido-diphosphate (GppNHp), reduced [3H]LTD4 binding to the membrane preparation of the granulation tissue suggesting that LTD4 receptors in the granulation tissue are associated with G proteins. These results indicate that LTD4 binding sites in the granulation tissue are high affinity receptors for LTD4. A possible role of LTD4 in the recurrence of allergic inflammation in the chronic phase is discussed.

Animals↗
PubMed1976

Collagen in granulation tissues.

Collagen is abundantly synthesized in granulation tissues and reaches a concentration higher than in normal neighbouring tissues. Such newly formed collagen is characterized by an abnormally low solubility and an easy degradation by collagenases and collagenolytic cathepsins. The activities of these two types of enzymes are high (especially collagenases) in tissues of acute inflammations when the granuloma is resorbing. These activities are lower in sub-acute inflammation and the collagen content of the persistent granuloma remains high. The collagen synthesized in granulation tissues is cross linked by hydroxylysino-5-keto-norleucine, the stable cross-link of collagen in embryonic skin. It is progressively replaced by the two aldimine cross links of normal adult skin when the granuloma is resorbed (acute inflammations induced in rats; human normal scars). The cross link of embryonic skin, on the contrary, is permanently present in collagen of tissues of subacute, chronic inflammations (sponge implants in rats, human hypertrophic scars and keloids. Studies of the structure of alpha-chains revealed that type III collagen (embryonic collagen) is present in granulation tissues.

Animals↗
PubMed1975

Deamination of biogenic amines and other nitrogenous compounds in granulation tissue from experimental wounds.

In the granulation tissue of skin wounds an increase in the content of hydroxyproline was accompanied by changes in lipid peroxidation products. At the same time deamination of 5-hydroxytryptamine, tyramine or adenosine-5'-monophosphate decreased, but the ability to deaminate histamine, putrescine and lysine appeared. Pargyline prevented the appearance of these new deaminating properties. Adenosine-3'-monophosphate slowed down to the weight increase and lowered the content of hydroxyproline in the growing granulation tissue; it also changed the dynamics of deamination of tyramine or 5-hydroxytryptamine and significantly inhibited the deamination of histamine, lysine and adenosine-5'-monophosphate. The patterns of changes in deamination of nitrogenous compounds and the effects caused by pargyline and adenosine-3'-monophosphate suggest that qualitative alteration (transformation) in catalytic properties of monoamine oxidases may occur in the growing granulation tissue from wounds.

Adenosine Monophosphate↗
PubMed1976

Collagen and myofibroblasts of granulation tissue. A chemical, ultrastructural and immunologic study.

In granulation tissue produced in the rat by subcutaneous injection of turpentine oil or polyvynile sponge implantation, the great majority of fibroblasts (myofibroblasts) possess a contractile apparatus which makes them similar to smooth-muscle cells. Chemical analysis shows that these granulation tissues contain a high proportion of Type III collagen, a genetically distinct collagen normally associated with embryonic dermal tissue. Type III collagen may persist up to 9 months after sponge implantation and myofibroblasts are seen in granulation tissue by means of electron microscopy and immunofluorescence. When granulation tissue is resorbed 50 days after turpentine oil injection, myofibroblasts disappear and the dermis contains Type I collagen. The concurrent presence of myofibroblasts and Type III collagen suggests that myofibroblasts, in addition to their contractile activity, synthetize, at least in part, type III collagen.

Animals↗
PubMed1975

Oxygen consumption by granulation tissue in bipedicle tube flaps.

The oxygen consumption rate (QO2) of granulation tissue from cylinders implanted in bipedicle tube flaps of rabbits was measured weeks 2 to 7 in vitro in a Biological Oxygen Monitor. Granulation tissue from cylinders implanted in skin folds was used as control. The QO2 of granulation tissue decreased slowly as the oxygen tension in the medium fell. All measurements were made at an oxygen tension of 75 mmHg. At week 2 the QO2 of granulation tissue in flaps was high and a decrease occurred between week 2 and week 4. A further decrease took place between weeks 6 and 7 and a very low QO2 was found at week 7. Control granulation tissue showed a higher QO2 than skin flap granulation tissue at weeks 3, 4, 5 and 7.

Animals↗
PubMed1979

Ribonuclease activities in developing experimental granulation tissue with reference to polysomes.

The Mg2+-precipitable polysomes in experimental granulation tissue increase up to three weeks and decrease slowly thereafter. Polysomes from young granulation tissue are, on a weight basis, more active in cell-free protein synthesis than polysomes from old granulation tissue. RNase activity is highest in polysomes from 1-week tissue. The polysomes contain both acid and alkaline RNase, but the alkaline RNase is the latent form, manifested by the addition of p-chloromercuribenzoate (pCMB). The high RNase activity of granulation tissue renders the analysis of polysomal patterns and functions of the polysomes difficult. In the post-polysomal supernatant of granulation tissue the RNase activity is highest in 2-4 week old tissue; it is maximal at pH 7-8 and only slightly influenced by pCMB.

Animals↗
PubMed1975

The effects of cyclophosphamide and azathioprine on collagen in skin and granulation tissue in rats, and the effects of cyclophosphamide on collagen in human skin.

Granulation tissue was produced in rats by subcutaneous implantation of cellulose sponges. The effect of daily intraperitoneal injections of cyclophosphamide or azathioprine on rat skin and granulation tissue was examined after 14 and 42 days. Skin biopsies from patients with glomerulonephritis were analyzed before and after 42 days of treatment with cyclophosphamide or placebo. In the rats, cytostatic treatment caused an increase in the dry weight of the skin, and azathioprine increased the dry weight and the protein content of the granulomas. The increase in the dry weight was accompanied by a decrease in water percentage. The alpha-amino nitrogen/OH-proline ratio in purified acid soluble collagen from skin and granulation tissue increased with the dose and duration of cytostatic treatment. No effect on the aldehyde content was observed. Cyclophosphamide caused a decrease in the alpha/beta ratio in acid soluble collagen from granulation tissue, but not in the collagen from the skin. Salt soluble collagen was increased in the skin after 14 days of cytostatic treatment, but remained unchanged in the granulation tissue. In human skin cyclophosphamide caused no statistically significant changes in the amount of salt soluble or total collagen. It is concluded, that daily treatment of rats with cyclophosphamide or azathioprine from 14 to 42 days seems to inhibit the catabolic processes in the skin and granulation tissue, to decrease the hydroxylation of proline in collagen, and to inhibit the intermolecular cross-linking in collagen.?222

Animals↗
PubMed1978

Reversibility of the effects of cyclophosphamide on collagen: biochemical studies on skin and granulation tissue and determination of thermal stability of tail tendons of rats.

Granulation tissue was produced in rats by subcutaneous implantation of viscose cellulose sponges. Treatment with cyclophosphamide in a dose of 10 mg/kg/day for 14 days caused an increase in acid soluble OH-proline and a decrease in alpha/beta ratio of acid soluble collagen of granulation tissue. Forty-two days of continuous cyclophosphamide treatment caused a decrease in dry weight, in free OH-proline, and in salt soluble OH-proline in granulation tissue. These findings are in accordance with previous observations of a decreased collagen synthesis and an inhibited collagen degradation in granulation tissue after cyclophosphamide treatment. In skin, the only change after cyclophosphamide was a decrease in total content of OH-proline and an increase in alpha/beta ratio of acid soluble collagen after 42 days of treatment. No effect of the subcutaneous sponge implantation was observed on the collagen variables in the skin. In comparison with unstarved controls, a reduction in dry weight and in free OH-proline in granulation tissue, as well as an increase in salt soluble OH-proline in the skin were observed 28 days after a 14-day treatment with cyclophosphamide. These observations indicate a sustained effect of cyclophosphamide on collagen 28 days after cessation of treatment. In addition the thermal stability of rat tail tendons was decreased 28 days after withdrawal of cyclophosphamide to the same extent as after starvation for 42 days and after 42 days of continuous cyclophosphamide treatment. It is concluded that the cyclophosphamide-induced collagen alterations, which may be of importance in the anti-inflammatory action of cyclophosphamide, are only in part reversible, 28 days after cessation of 14 days of cyclophosphamide treatment.

Animals↗
PubMed1975

[The ultrastructure of the cellular elements of granulation tissue].

Electron-microscopy studies of the granulation tissue cells in an experimental wound in mice during one week after its infliction were carried out. Twenty four hours following the trauma neutrophilic leucocytes were found to be predominant in the wound. Disintegrating, they were utilized by macrophages, the latter being numerous in the granulation tissue on the 2nd-3rd day. Their protoplasm was found to contain multitude of various vacuoles and inclusions, which testified to a high phagocytic activity of these cells, whose main function in the wound process is purification of the wound. Evolution of the ultrastructural changes in fibroblasts of the granulation tissue was followed up. On the 5th-7th day they showed a pronounced hyperplasia of the granulation endoplasmic reticulum and an increased number of ribosomes. These changes in fibroblasts reflect their high synthetic activity and represent a structural base of the intensive collagenformation.

Animals↗
PubMed1979

Effect of a deproteinized blood extract on experimental granulation tissue.

The present work was undertaken to study the effects of a deproteinized extract of calves' blood (Solcoseryl) on developing granulation tissue in rats. Cylindrical hollow viscose cellulose sponge implants were used as an inductive matrix for the growth of granulation tissue. In the first, sham group the implants were treated daily by withdrawing 1 ml of wound fluid from the central dead space of the implant and then re-injecting the fluid. In the second, experimental group the aspirated wound fluid was replaced by a corresponding volume or Solcoseryl. Analyses of wound fluid and granulation tissue were carried out 4, 10 and 21 days after implantation. A statistically significant increase of granulation tissue hemoglobin (+21%) was observed at 10 days in the Solcoseryl group as compared with the sham-treated rats, indicating an enhanced capillary ingrowth. Concurrently, the mean amount of DNA in the Solcoseryl-treated tissues was elevated by 48% over the level of the sham-treated group, demonstrating an augmented cellularity of granulation tissue. At 21 days the mean amount of collagen hydroxyproline of the Solcoseryl group was 31% above the level measured in the sham-treated animals. PO2, PCO2 and pH in the wound fluid and the amounts of RNA and uronic acids showed no essential differences between the two groups. These data demonstrate a stimulatory effect of Solcoseryl on several aspects of granulation tissue formation: augmented vascularization, elevated cellularity and subsequent enhancement in the accumulation of collagen.

Animals↗
PubMed1975

Granulation tissue formation in viscose cellulose sponges of different design.

Granulation tissue formation was studied in subcutaneously implanted viscose cellulose sponges of different design using histological and chemical methods. Two different models of sponges were used, one of cubical shape and another rectangular and thin. The sponges had the same weight. After one week of implantation, histological examination of the cubical sponges showed granulation tissue only in the periphery and a central cavity filled with inflammatory cells. The histological texture of the thin sponges showed that they were almost completely filled with granulation tissue with a minimal central cavity and very few inflammatory cells. DNA values of the cubical sponges were about 20% higher than those of the thin sponges. After aspiration of the exudate in the cubical sponges, the DNA values were about the same as those in the thin sponges. The amount of hydroxyproline and RNA were about the same regardless of whether the sponges were cubic or thin or the exudate of the cubic sponges had been aspirated or not. At two weeks there was still a central cavity in the cubic sponges but very few inflammatory cells. DNA values at this time of observation were also the same in both models of sponges. Thus the thin-shaped model of sponge seems to be preferable to the cubic one when the time of observation is shorter than two weeks.

Animals↗
PubMed1978

Alkaline ribonuclease associated with polyribosomes in fibroblasts of experimental granulation tissue.

Alkaline ribonuclease (RNase) from polyribosomes derived from experimental granulation tissue has been purified 1900-fold through affinity chromatography. The preparation was homogeneous in sodium dodecyl sulfate (SDS) polyacrylamide-gel electrophoresis with an estimated molecular weight of 15 000. Purified RNase was completely inhibited in the presence of divalent ions Mg2+(100 mM) and Ca2+(100 mM) but activated slightly with Na+(50 mM). The enzyme is an endonuclease and the best substrates were poly(U), mixed RNA from yeast, rRNA from granulation tissue and poly(C). The estimated apparent Km-values were 0.037, 0.064, 0.13 and 0.27 g1-1, respectively. In polyribosomes RNase occurred in both free and p-chloromercuribenzoate (pCMB)-liberated forms. The total activity was at the highest but the proportion of the free activity minimal in the granulation tissue during the maximal synthesis of collagen.

Animals↗
PubMed1975

Collagen development in granulation tissue as compared with collagen of skin and aorta from injured and non-injured rats.

Granulation tissue in rats was produced by subcutaneous implantation of viscose cellulose sponges. Granulomas, aortae, and skin samples were taken 4, 8, 14, 22, 33, and 42 days after the sponge implantation and compared with age-matched non-operated rats. 14C-proline was given 4 hours before death to animals killed on day 0, 14, and 42. The 14C-OH-proline activity in salt insoluble collagen was higher in granulation tissue and aorta than in skin. This indicates a faster formation, or an increased stability of the intermolecular cross-links in granulation tissue and aorta, than in skin. The percentage of free OH-proline was than in skin, reflecting a relatively increased collagen degradation in granulation tissue. An increased collagen degradation may also, in part, explain a registered higher alpha/beta ratio in collagen from granulation tissue than from skin, as well as the increase in alpha/beta ratio in the older granulomas. The sponge implantation did not affect the collagen of aorta and skin, but caused a decrease in the dry weight of aorta and skin, and an increase in the number of granulocytes in the blood.

Animals↗