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O.83 Forearm leucine metabolism studied by stable isotope technology
E METABOLISM STUDIED BY STABLE ISOTOPE TECHNOLOGY. M.J. Rennie, R.C. Grlgg~ .M. Matthews, R.H.T. Edwards, W.W. Read, C. Forde & D. Halliday. Department alversity College London School of Medicine, London WCIE 6JJ and Division ~.R.C., Northwick Park Hospital, Harrow, England. the exchange of unlabelled leucine and its transaminated metabolite ~-ke~ IC), as well as the exchange of labelled amino and keto acids and C02 in s of post-absorptive man under normoxic and hypoxic conditions during the [13C]leucine. At rest, despite a net efflux of leucine from forearm tissues rked arteriovenous difference of labelled leucine amounting to 30% of the hment. Of the leucine entering the free pool of the forearm only 5% could ~r by release of labelled ~-ketoisocaproate and a further 13% by t h e ~ l e a s e 2. This suggests that most of leuclne taken into forearm tissues was ineorrotein. There was no evidence to support the hypothesis that the major fate n of leucine transamlnated within skeletal muscle was export as the keto ete oxidation elsewhere. Isometric forearm exercise caused a large stimuirectional leuclne uptake and a somewhat greater stimulation of leucine o x ~ ~duction of labelled ~-KIC by forearm tissues was completely inhibited by tivity. The onset of hypoxia(PB 425 mm Hg) caused marked changes in foretabolism. The net efflux of leucine from the tissues was increased, partly bition of unidirectional leucine uptake. Leucine oxidation was also signlfl~d but was nevertheless sufficient to account for the fate of two thirds of ap by muscle. Under these circumstances protein synthesis in forearm tissues depressed. The results suggest that leucine metabolism in human forearm ely monitored by use of stable isotope techniques and that it is markedly eular activity and hypoxia. Re Welleome Trust, Medical Research Council and the Stanley Thomas Johnson
ITICS OF ABSORPTION AND THE UTILISATION OF ORALLY APPLICATED ZIDS IN T H E I M M E D I A T E P O S T O P E R A T I V E P E R I O D - S T U D I E D WITH 1~ N
E. H.-D. C z a r n e t z k i , R. Reding, W. Hartig, F. Faust (Surgical D e p a r t m e n t Wilhelm-Pieck-Universit~it Rostock,GDR) t h e r e is a r e n a s c e n c e of the oral or enteral t r e a t m e n t of pre- and postoperative :ein with amino acids or oligopeptids. The aims of our investigations were : 1. le optimal t i m e to s t a r t an oral application of amino acids immediatly a f t e r • to examine the protein synthesis) the urea- and a m m o n i a - f o r m a t i o n and the )rally administered amino acids a f t e r an operation. Method : The kinetics of lnd the utilization of amino acids were investigated in the i m m e d i a t e postoperah patients 12 and 24 hours a f t e r c h o l e c y s t e c t o m y by using oral application of t r a c e r , tn fixed intervals we investigated the rest-N in serum and the total-N, monia-N in urine and their abundances of 15 N. The results were calculated latical model of the protein metabolism. Results : 1. The intestinal absorption :id administered 12 hours a f t e r the operation was very unimportant. The absorpno acid administered 24 hours a f t e r c h o l e c y s t e c t o m y was not altered compared s o n s . 2. The elimination of total 15 N andurea 15 N increases under stress-condip e r c e n t a g e of orally applicated amino acid is eliminated in urine in the i m m e i r e period. ~. The utilization of the orally administered amino acid is diminished t i o n c o m p a r e d to healthy persons. 5. 66,4 % and 56)95 % of the 15 N intake for the N-synthesis in the both c h o l e c y s t e c t o m i z e d groups a f t e r the operation. oral administration of amino acids is very i m p o r t a n t in keeping the patient sible balance a f t e r an operation. 6. The 15 N - t r a c e r technique is very suitable s of the nitrogen metabolism.
ITICS OF ABSORPTION AND THE UTILISATION OF ORALLY APPLICATED ZIDS IN T H E I M M E D I A T E P O S T O P E R A T I V E P E R I O D - S T U D I E D WITH 1~ N
E. H.-D. C z a r n e t z k i , R. Reding, W. Hartig, F. Faust (Surgical D e p a r t m e n t Wilhelm-Pieck-Universit~it Rostock,GDR) t h e r e is a r e n a s c e n c e of the oral or enteral t r e a t m e n t of pre- and postoperative :ein with amino acids or oligopeptids. The aims of our investigations were : 1. le optimal t i m e to s t a r t an oral application of amino acids immediatly a f t e r • to examine the protein synthesis) the urea- and a m m o n i a - f o r m a t i o n and the )rally administered amino acids a f t e r an operation. Method : The kinetics of lnd the utilization of amino acids were investigated in the i m m e d i a t e postoperah patients 12 and 24 hours a f t e r c h o l e c y s t e c t o m y by using oral application of t r a c e r , tn fixed intervals we investigated the rest-N in serum and the total-N, monia-N in urine and their abundances of 15 N. The results were calculated latical model of the protein metabolism. Results : 1. The intestinal absorption :id administered 12 hours a f t e r the operation was very unimportant. The absorpno acid administered 24 hours a f t e r c h o l e c y s t e c t o m y was not altered compared s o n s . 2. The elimination of total 15 N andurea 15 N increases under stress-condip e r c e n t a g e of orally applicated amino acid is eliminated in urine in the i m m e i r e period. ~. The utilization of the orally administered amino acid is diminished t i o n c o m p a r e d to healthy persons. 5. 66,4 % and 56)95 % of the 15 N intake for the N-synthesis in the both c h o l e c y s t e c t o m i z e d groups a f t e r the operation. oral administration of amino acids is very i m p o r t a n t in keeping the patient sible balance a f t e r an operation. 6. The 15 N - t r a c e r technique is very suitable s of the nitrogen metabolism.