Abstract
The value of short term screening techniques for examining chemicals for their ability to cause cancer and the development of methods which facilitate the early detection of tumour growth is now widely accepted. The use of the quantitation of oncofoetal proteins has recently been proposed as a useful technique in both these fields of carcinogenesis. This thesis describes the development of a very sensitive radioimmunoassay for one such oncofoetal antigen, alphafoetoprotein, and examines the production of this protein during transplantation of tumour tissue and during treatment of cell cultures with carcinogens and non-carcinogens. A number of other parameters proposed as short-term screening procedures including DNA repair, increase in cell division, induction of biphenyl-2-hydroxylase activity and morphological changes are assessed and compared with the production of alphafoetoprotein. The role of alphafoetoprotein in stimulating cell growth and division is assessed along with its relationship to tumour immunology. The cell culture system is examined as an experimental model with which to study the effect of xenobiotics on animals and is compared to the commonly used technique of long-term parenteral administration of chemicals. The results obtained from these experiments are discussed in relation to the current literature in an attempt to rationalize a mechanism of tumour production.