ASPECTS OF THE STRUCTURE AND FUNCTION OF THE HUMAN SALIVARY GLANDS

Mohamad M. ADI

The aims are to study the morphological, morphometric and histochemical aspects of the human fetal labial, lingual and submandibular salivary glands. This will allow, by employing stereomorphometric analysis a statement to be made of the volumes occupied by the various salivary gland components. By using conventional histochemical methods, the study will differentiate neutral from acidic mucins and distinguish sialyated from sulphated acidic carbohydrates. Information regarding the structure of complex carbohydrates in each of these classes will be provided by lectin histochemistry. The specific affinity of lectins for individual terminal or internal sugar residues will permit the localization in tissue sections of oligosaccharide constituents available for binding to them in glycoproteins of salivary mucins. The present study will use a battery of biotinylated lectins in order to demonstrate complex

carbohydrates applied in the investigation into the nature of glycoconjugate composition in these glands. The histochemical observations should provide the first evidence for the diversity of complex carbohydrates in human fetal salivary glands. The current study will for the first time investigate parenchymal cell differentiation in the human fetal salivary glands using polyclonal antibody to S-100 protein.

The outline of the study is as follows:

This work is presented in nine chapters. The first chapter is concerned with the morphogenesis of the salivary glands. Special attention is paid to aspects of developmental biology, embryology and cell structure. The usefulness of morphometric analysis of individual cell types is discussed in the context of the ageing salivary gland. The final sections of the chapter consider the role of histochemistry in our understanding of salivary gland function. An account of routine histochemistry is followed by an outline of our knowledge of lectin histochemistry and S-100 protein reactivity.

The second chapter is devoted to an account of the materials and methods used in the present study. Attention is paid to source of fetal tissue, stereological methodology and cytochemical techniques.

The results of the study are presented in the chapters three to seven and are supported by illustrations and Tables throughout the text where appropriate.

A discussion of the significance of the results obtained is the subject of the eighth chapter.

The final chapter highlights the conclusions of the whole investigation for which references and appendices are attached.