Rat Granulation Research Articles

79) - Effect of histamine on cyclic AMP content in rat granulation tissue

79) - Effect of histamine on cyclic AMP content in rat granulation tissue

Effects of sialoadenectomy and parotin hormone on the development of rat sponge-induced granulation tissue

A study was made concerning the effects of sialoadenectomy and parotin hormone administration upon sponge-induced granulation tissue of young adult rats. The effects of sialoadenectomy alone and sialoadenectomy plus a single subcutaneous injection of parotin hormone, in two different doses (0.15 and 0.30 mg), on the development of 15-day-old granulation tissue were observed. The action of parotin hormone administration without sialoadenectomy was also investigated. The results have shown that sialoadenectomy produces a retardation effect upon the development of the tissue. This effect was partially inhibited by 0.15 mg and totally eliminated by the administration of 0.30 mg of the hormone. When administered in rats which were not sialoadenectomized, the dose of 0.30 mg caused increased fibroplasia and vascularization of granulation tissue, while a dose of 0.15 mg did not cause any significant difference when compared to the control tissue.

Collagen profile in rat granulation tissue after cyclophosphamide treatment.

Abstract: The collagen profile was studied in 2–3 week old granulation tissue, induced in rats by subcutaneous implantation of viscose cellulose sponges. Cyclophosphamide was given daily intraperitoneally, in a dose of 10 mg per kg during the entire experiment, beginning either 7 days before or on the day of the sponge implantation. Cyclophosphamide caused an increase in the water percentage, and decreased the dry weight and the total amount of collagen in the granulomas, reflecting a suppression of collagen synthesis. The catabolism of collagen was also inhibited in the cyclophosphamide treated rats, as indicated by a fall in the content of free OH‐proline and a lowering of the alpha/beta ratio in acid extracted collagen. Cyclophosphamide treatment increased the collagen solubility in acetic acid and increased the aldehyde content in relation to OH‐proline in purified collagen. This indicates that cyclophosphamide may inhibit the cross‐linking of collagen by blocking the aldehydes or decrease the stability of the collagen molecule by decreasing the hydroxylation of proline. Pretreatment with cyclophosphamide did not influence the effect of cyclophosphamide given during the development of granulation tissue.

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

Influence of estrogen and progesterone on vascularization of granulation tissue in preformed cavities. A microangiographic study.

The influence of estrogen and progesterone on the vascularity of granulation tissue in oophorectomized rats has been studied with microangiography. Estrogen alone, progesterone alone, and both combined were given daily for three weeks. Two weeks after the beginning of the hormone treatment, perforated wound chambers were implanted subcutaneously in the back of each rat. One week later the vascular system was filled with colloidal carbon. Cross sections of the chambers with surrounding granulation tissue capsule were examined regarding the thickness of the capsule and the degree of proliferation of granulation tissue into the chamber. The vascular system of the newly formed tissue within the perforations of the chamber wall was examined morphometrically. Estrogen suppressed the vascularization around the chamber wall as well as the proliferation of the granulation tissue while progesterone enhanced the vascularization around the chamber wall and produced a granulation tissue the vascular volume of which wa...

Transfer RNA changes in rat granulation tissue possibly related to collagen synthesis

Transfer RNAs for glycine, proline, lysine, serine and leucine were compared in developing rat granulation tissue 6 and 15 days after sterile subcutaneous implantation of pieces of cellulose sponge. The acceptance of glycine, proline and lysine by unfractionated tRNAs were ca. 30 per cent greater in tRNA derived from 15-day granulation tissue, whereas those of serine and leucine were unaltered. Cochromatography on benzoylated DEAE-cellulose of the 3H- and 14C-labeled aminoacyl-tRNAs from the two sources revealed a significant increase in the relative amount of one of the three glycyl-tRNA fractions in the 15-day granulation tissue, whereas the elution profiles for prolyl-, lysyl-, seryl-, and leucyl-tRNAs were unaltered. The changes observed suggest a causal relation to the enhanced synthesis of collagen in the late-stage granulation tissue.

Quantitative differences in proline tRNA content of rat liver and granulation tissue

The relative amount of proline tRNA in tRNA extracted from rat granulation tissue is shown to be significantly greater than in tRNA similarly prepared from rat liver. Chromatography on methylated albumin-Kieselguhr revealed no qualitative differences between proline tRNAs from the two sources. These findings are considered in terms of a possible coupling between the synthesis of specific tRNAs and the relative rates of incorporation of the related amino acids into proteins.

Effect of thyroid hormones, somatotrophin, insulin and corticosteroids on synthesis of collagen in granulation tissue both in vivo and in vitro.

ABSTRACT The effect of hormonal factors on the collagen synthesis in experimental granulation tissue of rats was studied (1) in vivo by assessing the development of the tensile strength and (2) in vitro by measuring the capacity of collagen synthesis from 14C-proline by incubated granuloma slices. The hormonal agents were either administered in vivo or added to the incubation media. When hormones were given in vivo, only cortisol affected the tensile strength of the granuloma markedly, but when the capacity of collagen synthesis was assessed, it was found that somatotrophin slightly increased and thyroxine decreased the synthesis. The effect of glucocorticoids, if any, was to increase the conversion of labelled proline into hydroxyproline. In those experiments in which the hormonal factors were added to the incubation media, thyroxine and particularly insulin, increased the incorporation of 14C-proline into collagen. Somatotrophin decreased the incorporation of proline in these experiments, presumably by artifact reactions.

Time-course Concentration of N-Acetyl-neuraminate Lyase from Rat Granulation Tissue

THE time sequence of enzymatic and metabolic alterations during inflammatory response and repair by connective tissue has been inadequately studied. Enzymatic changes related to connective tissue and the inflammatory process are virtually unknown. However, observations during the development of the chick embryo1 and of biological development of tissue-specific proteins and metabolic adaptations in response to environmental effects or with ageing2 suggest that similar events are operative when injury occurs and inflammation and repair are initiated by connective tissue.

Response of the level of acid mucopolysaccharides in rat granulation tissue to cortisol.

Wet weight, dry weight, total nitrogen and the content of acid mucopolysaccharides of granulomas induced by cotton ball implantation in adrenalectomized untreated and cortisol-treated rats were determined. It was found that greater decreases occurred in the level of acid mucopolysaccharides (73 %) than in total nitrogen (56%), dry weight (61%) or wet weight (34%) in the treated animals. Although little or no change occurred in the actual quantities of total nitrogen per unit weight, the level of acid mucopolysaccharides was reduced by approximately 29 %. It would appear that cortisol can specifically affect the content of acid mucopolysaccharides in granulation tissue induced by cotton pledgets.

Isolation of a glycoprotein from granulation tissue in rats

A homogeneous glycoprotein was isolated from 7-day-old rat granulation tissue by a method which included water extraction, dialysis, and concentration at 80 °C. to eliminate heat-coagulable protein. Purification was achieved by zone electrophoresis on starch with a borate-sulfate buffer, pH 8.6, μ = 0.1. Physical properties of this material include a sedimentation constant of 2.2 S, an electrophoretic mobility of −6.0 × 10 −5 sq. cm./sec./v. at pH 8.6 in Veronal buffer, and an interpolated isoelectric point at pH 3.8. Fourteen to 16 amino acids and galactosamine and glucosamine were demonstrated in the glycoprotein.

Studies on granulation tissue production in alloxan-diabetic rats.

SUMMARY Alloxan-diabetic rats produce significantly less granulation tissue than normal ones. Locally applied growth hormone (STH), which stimulates granulation tissue in normal rats, lost this ability in diabetic animals. Adrenalectomized alloxan-diabetic rats also fail to respond by increased granulation tissue growth to STH. The stimulation of granulation tissue by STH seems to depend on an adequate supply of insulin.