title: The effect of starvation on leucine, alanine and glucose metabolism in obese subjects.
abstract: The relationship between changes in ketone concentrations and leucine metabolism (seven obese subjects), glucose and alanine metabolism (seven obese subjects) was investigated using radioisotopic techniques after 12 h, 60 h and 2 weeks starvation. Leucine metabolism was also measured in five lean subjects after 12 h and 60 h starvation. In the obese subjects leucine concentration increased after 60 h starvation and leucine metabolic clearance rate, glucose and alanine concentration decreased (P < 0.05). Glucose and alanine production rate (Ra) decreased after 2 weeks (P < 0.05) but there was no change in leucine Ra after 60 h or 2 weeks. In the lean subjects leucine concentration, production rate and oxidation rate were increased after 60 h (P < 0.005, P < 0.05, P < 0.05). Ketone concentration was inversely related to alanine Ra (r = -0.51, P < 0.02) but was not related to measurements of protein metabolism in the obese subjects. This study demonstrates that the effect of short-term starvation on protein metabolism differs in lean and obese subjects. The decrease in glucose Ra during long-term starvation may be in part due to a decreased supply of alanine for gluconeogenesis.
authors.affiliation: Department of Endocrinology, UMDS, London, UK.
authors.forename: A M
authors.initials: AM
authors.lastname: Umpleby
authors.forename: I N
authors.initials: IN
authors.lastname: Scobie
authors.forename: M A
authors.initials: MA
authors.lastname: Boroujerdi
authors.forename: P H
authors.initials: PH
authors.lastname: Sönksen
mesh_terms: D000328:Adult; D000409:Alanine / Q000378:metabolism*; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007328:Insulin / Q000097:blood; D007930:Leucine / Q000378:metabolism*; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D009765:Obesity / Q000378:metabolism*; D013217:Starvation / Q000378:metabolism*
chemical_list: D005230:Fatty Acids, Nonesterified; D007328:Insulin; D007930:Leucine; D005947:Glucose; D000409:Alanine