Studies on the Histochemical Identification of Mucopolysaccharides

Hale, Arthur J (1954) Studies on the Histochemical Identification of Mucopolysaccharides. PhD thesis, University of Glasgow.

Abstract

The initial intention was to investigate the effect of yaluronidase on growing connective tissue and to elucidate its relationship to inhibition of connective tissue formation by-adrenal corticosteroids. It has been shown that persistent application of the enzyme to granulating tissue causes rapid invasion of the surface exudate by fibroblasts and that the normal formation of bundles of reticular tissue is impaired. Investigation of the effects of a single application of hyaluronidase and the relationship of these effects to simultaneous corticosteroid application was not carried out as the histological techniques being used in the investigation were unsatisfactory. Investigation of these techniques, the background of which is described, led to the adoption of newer ones. One of the techniques adopted was that of using water soluble polyethylene glycol wax as an embedding medium. It permits identification of lipids in serial sections and reduces losses and distortion of tissue constituents during embedding. While using this wax difficulties in sectioning were encountered and investigation showed that these were caused by high atmospheric relative humidities causing absorption of water by the very hygroscopic wax. In order to eliminate chemical loss or alteration, or physical change in the tissue, freeze-drying was adopted as a method of preparation. Due to inadequate knowledge at that time of the problems involved the theory of tissue freeze-drying was entered into in some detail and a new apparatus, based on the theoretical findings, was designed and built. Because of the lack of specificity of the histochemical chniques available for the identification of hyaluronic acid attempts were made to develope a new one. These attempts are described. The fact that exposure of conventionally prepared sections to sodium hydroxide, before periodic acid oxidation, greatly enhances the colour reaction obtained in certain tissues with the periodic acid-Schiff technique, was noted. The investigation of this effect is described and it is shown that formalin appears to affect certain substances, possibly by polymerizing them, so that they only react weakly with this technique. The alkali reverses this formalin effect so that they react strongly to the periodic acid-Schiff technique again. The relationship between this formalin effect and the chemical structure of the usbstances involved is discussed. The conclusion reached is that hyaluronidase has a definite effect on fibroblastic infiltration and fibre formation in growing connective tissue but the relatioship of this function to the action of adrenocorticosteroids is not clear. In a histochemical study of this type it is essential to ensure that the substances involved in the study, hyaluronic acid in this case, are not being lost during preparation for microscopic examination, and that there is available a reliable technique for identifying them. As these two criteria were not satisfied in this case freeze-drying and the use of polyethylene glycol waxes were adopted in order that the first would be. Investigation of the second has shown that although there is no histochemical method for identification of hyaluronic acid available it might be possible to develope one based on the alkaline decomposition of its hexosamine content. Then it might be possible to return to a accurate study of the inter-relationship of hyaluronidase and luronic acid function in fibroblastic activity.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Histology
• Date of Award: 1954
• Depositing User: Enlighten Team
• Unique ID: glathesis:1954-79112
• 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/79112