Nuclear Medicine Technology and Other Health Applications Project Title: Metabolism of Carbon Labeled Compounds 15. Relationship to Other Projects: (Cont'd) RX-01-03- (e) tryptophan metabolite inhibition of glycolysis; Miller, University of Rochester, on induction of the tryptophan pyrrolase enzyme; Wagner, Vanderbilt University, on tryptophan metabolite inhibition; and Hayaishi, Kyoto University, Japan, on pyridine nucleotide synthesis in animals. Some of these investigators suggest that the stimulation or depression of the pyrrolase enzyme is the factor that controls the abnormalities seen in urinary tryptophan metabolite excretion. Studies at BNL gave evidence that other factors such as vitamins and diet are also involved. 16. (Hankes ) Technical Progress in FY 1973: Clinical studies with C-13 labeled sugars were commenced during past year with the use of glucose-U-C-13 in a test of oxidation to (in the breath) after oral administration in a glucose load. the C05 Studies were begun with glucose-U-C-13 instead of glucose-1l-C-13, as intended a year ago, because of more rapidly successful biosynthesis of glucose-U-C-13 in adequate quantities. Seven non-diabetic and six diabetic subjects (distributed between the University of New Mexico and Brookhaven National Laboratory in a joine study) were tested to date. One diabetic with excessive glucose intolerance oxidized glucose-U-C-13 at less than half the mean normal rate, but all other diabetics, who had mild glucose intolerance (according to blood glucose concentration), were within the normal range of oxidation. This suggests that this test will not be generally useful for diagnosis of early or sub-clinical diabetes. However, the findings imply that continued high rates of hepatic gluconeogenesis after a giucose load account largely for glucose intolerance in mild diabetics. Therefore, studies were initiated to measure plasma glucose-C-14 after oral administration of L-lactate-U-C-14 in load quantity; the formation of 4c05 is also observed, since earlier studies indicated that formation of M405 is diminished as well as formation of glucose-C-14 increased from lactate-C-14 (intravenously) in diabetics. The study of interacting effects of high sucrose diet and of anovulatory steroids on formation and turnover of plasma triglycerides was continued by the inclusion of eight more obese women. Effects of these parameters on conversion of ingested sucrose-C-14 to triglycerides, turnoyer of triglycerides after labeling with glycerol-2-H-3, insulin respo@@® to sucrose load, and plasma posct-heparin lipolytic activity (PHLAdame re studied. Results confirm previous findings that more sucrose is ¢ irted to triglycerides after high-sucrose than after high-starch diet and during regimens of estrogen-containing contraceptives, but not those with only progestagens. PHLA of plasma (after glucose) is diminished on high-sucrose diets, but turnover of plasma triglycerides in the post-absorptive state is not significantly changed. principally supported by non-AEC funds. (See Continuation Sheet) bir d9z4l This study was RX-83