The Origin and Function of the Mucopolysaccharides of the Connective Tissues

Curran, Robert C (1956) The Origin and Function of the Mucopolysaccharides of the Connective Tissues. MD thesis, University of Glasgow.

Abstract

Collagen formation was studied in the silicotic focus in the peritoneal cavity and subcutaneous tissues of the mouse. The cells which ingested the finely-divided quartz were stimulated to form not only reticulin and collagen fibres but also abundant acid mucopolysaccharide. This substance was liberated from the cytoplasm of the fibroblasts and persisted throughout the evolution of the silicotic focus. Though it was not possible to determine what relationship the mucopolysaccharide had to the argyrophilia of the reticulin, it was clearly not responsible for an intensely metachromatic reaction present in the quartz focus. This was probably caused by a layer of colloidal silicic acid, and a gel of this type might play a role in the development of the silicotic focus similar to that postulated for endogenous mucopolysaccharide in other sites of collagen formation. The presence of a layer of colloidal silica on quartz particles would render the solubility theory of silicosis more feasible, and the metachromatic reaction should be very useful for studying silicosis in man. Administration of cortisone reduced considerably the rate of formation of acid mucopolysaccharide and connective-tissue fibres in the quartz lesion, but inhibition was not complete, and the times of first appearance of mucopolysaccharide and fibres were not delayed under its influence. The hormone effected a quantitative rather than a qualitative reduction in the inflammatory response of the tissues to the dust, and the activities of the individual fibroblast were apparently unaffected. However, cortisone was capable of altering completely the form of the large foci which form on the serosal surface of the abdominal wall; these were replaced by a specific, flat, fibrous plaque. To devise a new technique for studying the acid mucopolysaccharides of the tissues, the distribution of sulphate labelled with S35 was determined by autoradiography in almost all of the tissues of the mouse, and in every case the radioactive material was closely associated with stainable mucopolysaccharide. Even more significant was the high concentration of the S35 within cells which apparently incorporated it in sulphated mucopolysaccharide synthesised by them. This idea was strongly reinforced by the finding that when human cartilage was kept alive by tissue culture, the ion was located only in the cytoplasm of the chondrocyte. The fibroblasts in the quartz focus also took up sulphate, and so it may be inferred that they also form sulphated mucopolysaccharide which they subsequently release into their environment. This conclusion is in accord with that derived previously from use of staining methods. The uptake of sulphate ion by the chondrocyte depended upon the survival of the cell, and a test of viability based on this observation provided much information with regard to the behaviour of human cartilage in grafts and in storage and to the permeability of cartilage matrix. The in vitro method used to show uptake of sulphate by cartilage cells will almost certainly permit investigation of mucopolysaccharide formation in a wide range of human tissue.

• Item Type: Thesis (MD)
• Qualification Level: Doctoral
• Keywords: Medicine, Histology
• Date of Award: 1956
• Depositing User: Enlighten Team
• Unique ID: glathesis:1956-79754
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 31 Mar 2020 09:09
• Last Modified: 31 Mar 2020 09:09
• URI: https://theses.gla.ac.uk/id/eprint/79754