Nuclear Medicine Technology and Other Health applications Project Title: Metabolism of Carbon Labeled Compounds 13. Publications: Hoshi, M. and Shreeve, W.W. Release and production of insulin by isolated, perfused rat pancreatic islets, (1973). 14. -01-03-(e) Diabetes. 22, No. 1, 16-24 / - fo oS Scope: A) 200 Word Summary: A long range goal in this activity has been a better understanding of the pathogenesis of diabetes and other metabolic diseases. Carbon labeled intermediates of carbohydrates and lipids were used to study the dynamics of interconversion and turnover of carbohydrates and lipids. effect of hormonal and nutritional variations also was investigated. A corollary has been the development of isotopic tracers of diagnostic value which may be useful for guidance of therapy with drugs, special diets, hormones or vitamins. Extensive studies have been carried out using sugars labeled with carbon-14. More recently, carbon-13 and carbon-1ll labeling has offered challenging opportunities, The The amino acid, tryptophan, produces ortho-amino-phenol type compounds believed to induce cancer in animal urinary bladders. In several types of cancer and in other diseases of man, the literature reports significant increases in urinary levels of some tryptophan metabolites. Carbon-14 labeled metabolites are used in animals and man to determine the normal tryptophan metabolic pathway. The labeled metabolites include anthranilic acid, kynurenine, hydroxykynurenine, and hydroxyanthranilic acid. . Diseases studied include anemias, scleroderma, siderosis, malaria, pellagra, and various cancers. B) - Supplement to 200 Word Summary: The relative conversions in vivo of intermediate carbohydrates (e.g., lactate, pyruvate, glycerol, and malate) to blood glucose, liver glycogen and carbon dioxide in diabetic states in man and animals have been previously studied in this laboratory with carbon-14 labeled precursors. So also has the oxidation of glucose-C-14 to 149, been investigated. Similar studies are now done or planned with sugars labeled with carbon-13 (the nonradioactive, stable isotope) with emphasis on diagnostic application. Carbon-l3 will be generally preferred for this purpose because there will be exposure as with C-14, current studies of oxidation of galactose-U-C-14 (and eventually galactose-U-C-13) to CO. are similarly directed toward the diagnosis of hypothyroidism, of liver disease and possibly of diabetes, since in these conditions, intolerance for galactose has either been demonstrated or can be expected on theoretical grounds. A highly valuable, potential aspecce of the use of galactose-U-C-13 is the oppor- (See Continuation Sheet) 1119238 RX - 80