In this thesis, report is made of studies of the enzyme lactate dehydrogenase (E.G. 184.108.40.206) . The main emphasis has been directed towards a definition of the influence of significant physiological perturbations on the turnover of this enzyme in major tissues.
A technique has been developed for the comparison of the turnover characteristics of total soluble proteins and lactate dehydrogenase, and in the initial study this was applied to comparing turnover between male and female mice. Subsequently, the turnover characteristics of foetal mice in the last week of pregnancy were investigated, along with a series of dietary perturbations; namely, fasting, protein deprivation, and thiamine deficiency (chronic and acute). The growth of ascites tumour was also selected for study as a significant potential effector of turnover.
The results of an exercise regimen on the turnover of lactate dehydrogenase were also investigated and were compared for a number of muscles in the mouse of different fibre type.
The lactate dehydrogenase distribution and isoenzyme composition in the rat and mouse ovary have been studied histochemically using a gelled substrate technique, as an extension of the previously mentioned ontogenetic studies; and finally, the affinity chromatography system which was used to purify the lactate dehydrogenase in the turnover studies, was again utilized to study the equilibrium constants between the enzyme and reduced coenzyme.
A fuller description of the results of these studies is presented in the form of General Summary (Chapter 11) and, of course, in the main test.
Publications arising from this thesis are as follows:
Brinkworth, R.I., Masters, C.J., and Winzor, D.J. (1975) "Evaluation of Equilibrium Constants for the Interaction of Lactate Dehydrogenase Isoenzymes with Reduced Nicotinamide-Adenine Dinucleotide by Affinity Chromatography". Biochem. J. 151; 631-636.
Brinkworth, R.I., Don, M., and Masters, C.J. (1976) "The Physiological Variation of Isozyme Turnover in Mammalian Tissues" Proc. Aust. Biochem. Soc. 9; 30.
Brinkworth, R.I., and Masters, C.J. (1977) "Sex Differences and the Comparative Turnover Rates of Lactate Dehydrogenase Isozymes in Mouse Tissues" Int. J. Biochem. 8; 311-315. doi:10.1016/0020-711X(77)90138-0
Brinkworth, R.I., and Masters, C.J. (1977) "Ontogenic Characteristics of LDH Turnover in the Mouse" Biochim. Biophys. Acta. 482; 241-250. doi:10.1016/0005-2744(77)90238-8
Papers related to the work described in chapters 5-9 have been submitted for publication.