Plasma amino-acid patterns in liver disease

Transcription

1 Gut, 1982, 23, Plasma amino-aid patterns in liver disease MARSHA Y MORGAN*, A W MARSHALL, JDITH P MILSOM, and SHILA SHRLOCK From the Department of Mediine, Royal Free Hospital, London SMMARY Plasma amino-aid onentrations were measured in 167 patients with liver disease of varying aetiology and severity, all free of enephalopathy, and the results ompared with those in 57 ontrol subjets mathed for age and sex. In the four groups of patients with hroni liver disease (26 patients with hroni ative hepatitis, 23 with primary biliary irrhosis, 11 with ryptogeni irrhosis, and 48 with aloholi hepatitis±irrhosis) plasma onentrations of methionine were signifiantly inreased, while onentrations of the three branhed hain amino-aids were signifiantly redued. In the first three groups of patients plasma onentrations of aspartate, serine, and one or both of the aromati amino-aids tyrosine and phenylalanine were also signifiantly inreased, while in the patients with aloholi hepatitis±irrhosis plasma onentrations of glyine, alanine, and phenylalanine were signifiantly redued. In the three groups of patients with minimal, potentially reversible liver disease (31 patients with aloholi fatty liver, 1 with viral hepatitis, and 18 with biliary disease) plasma onentrations of proline and the three branhed hain amino-aids were signifiantly redued. Patients with aloholi fatty liver also showed signifiantly redued plasma phenylalanine values. Most hanges in plasma amino-aid onentrations in patients with hroni liver disease may be explained on the basis of impaired hepati funtion, portal-systemi shunting of blood, and hyperinsulinaemia and hypergluagonaemia. The hanges in patients with minimal liver disease are less easily explained. The effets of liver disease on amino-aid metabolism have reeived muh attention. Several early workers found abnormally high onentrations of methionine, ysteine, and the aromati amino-aids in patients with irrhosis,'8 and a generalised or seletive amino-aiduria has been reported Conversely, in other early studies no onsistent hanges in plasma or urinary aminoaids ould be found in patients with irrhosis.'517 In reent years, with improving tehniques for measurement, speifi and reproduible plasma amino-aid patterns have been shown in patients and experimental animals with hroni liver failure, 125 and in patients with fulminant hepati failure Almost without exeption these studies have onentrated on patients with appreiable hepatoellular dysfuntion evidened by the presene of either aute or hroni hepati enephalopathy. Little information is available on the plasma amino-aid patterns in patients with hroni though well-ompensated liver disease, or in patients with minimal liver damage Addition- * Address for orrespondene: Dr M Y Morgan, Medial nit, Royal Free Hospital, Hampstead, London NW3 2QG. Reeived for publiation 14 September 1981 ally, although ertain animal work suggests that hanges in plasma amino-aids after liver damage may be speifially linked to the nature of the damaging agent, few attempts have been made to relate this work to liver disease in man We have therefore siudied the plasma amino-aid onentrations in a large number of patients with liver disease of varying aetiology and severity, but without hepati enephalopathy, to look for patterns of hange related to the nature of the damage present. As age and sex both influene plasma amino-aid onentrations33 34 areful mathing of the ontrol group was neessary. Sex differenes are more pronouned in the fasting state than postprandially;34 thus in all ases blood samples were taken two hours after a standard meal. Methods PATINTS The study group omprised 167 patients in hospital. The aetiology and severity of their liver disease was assessed linially, with biohemial and serologial tests, liver histology and, where neessary, by oral, 362 Gut: first published as /gut on 1 May Downloaded from on 12 September 218 by guest. Proteted by opyright.

2 Plasma amino-aids in liver disease intravenous, or retrograde holangiography. None of the patients had linial or eletroenephalographi evidene of portal systemi enephalopathy. None of the aloholi patients had taken alohol for at least three days.29 The ontrol group of 57 individuals, of whom 21 were laboratory personnel and the remainder hospital inpatients without hepati or renal disease, was arefully mathed by age and sex to the patient groups. Subjets in both ontrol and patient groups were weighed, their mean daily protein intake was estimated, and note made of any mediations taken. All plasma samples were olleted at 1., two hours after a standard breakfast.34 The plasma was separated and deproteinised in a final onentration of 3% sulphosaliyli aid. Norleuine was added to the supernatant after deproteinisation to a final onentration of 25mM to at as an internal standard. All samples were stored at -2 C until analysed using a Tehnion TSM amino-aid analyser.34 In most patients two or more samples taken under the same standardised onditions were examined. Although the values for individual amino-aids in the ontrol group were normally distributed, those obtained in the various patient groups were not; thus non-parametri statistial analyses were used. Amino-aid values in ontrol and patient groups were ompared using Kruskal-Wallis analysis of variane. Values of amino-aids showing signifiant intergroup differenes were then ompared in eah disease group with ontrol values using the Mann- Whitney test. Beause of the diffiulty in obtaining reliable results from analysis for tryptophan, glutami aid, Table 1 Details of ontrol subjets and patient groups and glutamine,34 these amino-aids have been omitted from this study. Results DTAILS OF PATINTS (Table 1) The patient group of 167 omprised 26 patients with hroni ative hepatitis with progression to irrhosis, 23 with primary biliary irrhosis with stage 3 or 4 hange on liver biopsy, 11 with ryptogeni irrhosis, 48 with alohol-related hepatitis with or without irrhosis, 31 with alohol-related fatty hange, 1 with viral hepatitis (non-b), and 18 with holelithiasis and holangitis with only minimal nerosis and inflammatory infiltration in the portal and periportal areas of the liver. The mean age and age range of all the patient groups were similar to those of the ontrol group, with the exeption of the patients with viral hepatitis who tended to be younger. The mean weight for most of the patient groups was similar to the ontrol mean. The patients with primary biliary irrhosis had a lower mean weight and the patients with alohol-related fatty hange a higher mean weight than the ontrols. This probably reflets the predominane of women in the primary biliary irrhosis group and of men in this aloholi group. The mean daily protein intake per kg body weight in the disease groups did not differ signifiantly from the ontrol mean. Most patients reeived vitamin supplements, and the patients with hroni ative hepatitis reeived prednisolone in doses of from 2.5 to 2 mg daily. No women in the patient or ontrol groups were taking an oral ontraeptive.34 Age Weight Daily protein (mean (mean intake Sex ratio range) range) (mean) Group No. M:F (yr) (kg) (glkg) Mediations Control subjets 57 31: (17-94) (35-112) Chroni ative hepatitis 26 6: Prednisolone (17-81) (4-89) 25-2 mg/day Primary biliary irrhosis 23 3: Vitamins A, D, K (37-73) (45-78) Cryptogeni irrhosis 11 9: (22-65) (49-9) Aloholi hepatitis±irrhosis 48 27: Vitamins B, C (27-73) (4-18) Aloholi fatty liver 31 29: Vitamins B, C (29-61) (4-11) Viral hepatitis 1 6: Vitamins B, C (19-61) (55-76) Biliary disease 18 9: Vitamin K (22-75) (5-86) 363 Gut: first published as /gut on 1 May Downloaded from on 12 September 218 by guest. Proteted by opyright.

3 364 PLASMA AMINO-ACID CONCNTRATIONS (Table 2) No signifiant differenes in plasma amino-aid onentrations were observed in repeat samples obtained from any given patient. The overall reproduibility of results was onsistent within ±5%. Values of seven amino-aids - asparagine, alpha-aminobutyri aid, ysteine, ornithine, lysine, histidine, and itrulline - showed no signifiant intergroup differenes. Comparisons of the values of the remaining 13 amino-aids in eah disease group with ontrol values showed several signifiant inreases and dereases (p<5) as indiated in Table 2. CHRONIC ACTIV HPATITIS (Fig. 1) Plasma onentrations of aspartate, threonine, serine, methionine, and the aromati amino-aid tyrosine were signifiantly raised, while onentrations of proline and of the three branhed hain amino-aids valine, isoleuine, and leuine were signifiantly redued. PRIMARY BILIARY CIRRHOSIS Plasma onentrations of aspartate, threonine, serine, arginine, methionine, and tyrosine were signifiantly raised, while onentrations of the 1.._ m Morgan, Marshall, Milsom, and Sherlok three branhed amino-aids were signifiantly redued. CRYPTOGNIC CIRRHOSIS Plasma onentrations of aspartate, serine, methionine, and the aromati amino-aids tyrosine and phenylalanine were signifiantly raised, while the onentrations of the three branhed hain amino-aids were signifiantly redued. ALCOHOLIC HPATITIS±CIRRHOSIS (Fig. 2) The plasma onentration of methionine was signifiantly raised while onentrations of glyine, alanine, phenylalanine, and the three branhed hain amino-aids were signifiantly redued. Thus in the four groups of patients with hroni liver disease a ommon pattern of hange in plasma amino-aid was seen in whih the onentration of methionine was inreased and the onentrations of the three branhed hain amino-aids were redued. Conentrations of aspartate, serine, and one or both of the aromati amino-aids tyrosine and phenylalanine were raised in the groups with hroni ative hepatitis, primary biliary irrhosis, and ryptogeni irrhosis, but not in the patients with aloholi hepatitis±irrhosis. Changes in the ['.I Control n=57 M CAH n-26 ASP THR' SR ASN PRO GLY'ALA GAB VAL CYSMTH I L TYR PA ORN LYS HIST ARG Fig. 1 Plasma amino-aid onentration in patients with hroni ative hepatitis (CAH) that show signifiant differenes from ontrol values (p<o.os). Bloks represent median values. Gut: first published as /gut on 1 May Downloaded from on 12 September 218 by guest. Proteted by opyright.

4 Plasma amino-aids in liver disease. tii Cq s: z esl Cq. :t L. '..r O _l 2~ II rn 11 : N _ N _ N I ~4 O >N N N- N Nt N- N -) N N Nr I\ - NN - N N N N <,I, II I 1N N - m N N r _ N o, v, _- N ~..-r o>enn rn a, I.... -NN t - N O al4 fn_ N N N N I t N 7, u 'I o D.\. 46irobro. J m. N, _ ~ ~ ~ ~ ~~~- u- - _ x -- N x s NON:-XN _- r v --rr _ - ovo--, v-,.mr p- m o _ N N N N x6rx - r <. o kn Qm77o-7.s oe X,Co Nrao I_.N7N_. N NX N N N NN _ * _ **N_ N _ NNxF NNs-NtO-rN N NN -_ -No_ tnn o N N NN - Nt ono i N oa,,v7z vd Neo '. oo-xo m xn- N N or- N N r- N 6 8q N N NN N- N NN 4 *d.>ntn't *e. vn N N N IV).tt* drnx N NNd *1t e<nn 1 tni'4 2 o ~~~~~~~~~~7 ' ' ex!1 :t 3 t' ^ V _ g S o = s 5v, g. * _> = Y S o %;:. fl % s W v) t u C = O Q Y r W._ CO, u r Y Q - ex o r._._ 365 Gut: first published as /gut on 1 May Downloaded from on 12 September 218 by guest. Proteted by opyright.

5 366 CD *._ ( Morgan, Marshall, Milsom, and Sherlok r-] Control n-57 M Aloholi hepatitis ± irrhosis n=48 Fig 2 Plasma amino-aid onentrations in patients with aloholi hepatitis±irrhosis that show signifiant differenes from ontrol values (p<oo5). Bloks represent median values. onentrations of ertain other amino-aids ourred in eah group in addition to the ommon hanges observed. ALCOHOLIC FATTY LIVR Plasma onentrations of proline, phenylalanine, arginine, and the three branhed hain amino-aids were signifiantly redued. ACT VIRAL HPATITIS Plasma onentrations of aspartate and methionine were signifiantly raised, while onentrations of proline and of the three branhed hain amino-aids were signifiantly redued. BILIARY DISAS (Fig. 3) Plasma onentrations of proline and of the three branhed hain amino-aids were signifiantly redued. Thus even in patients with minimal, potentially reversible liver disease signifiant hanges were seen in plasma amino-aid profile - notably, redued onentrations of proline and of the three branhed hain amino-aids. Disussion This study has shown that signifiant hanges our in plasma amino-aid onentrations in patients with hroni well-ompensated liver disease and also in patients with minimal liver damage. Certain hanges were ommon to all groups of patients while others appeared to relate to the severity of the liver disease, its ativity, or even to its aetiology. Speifi and reproduible plasma amino-aid patterns have been shown in patients and experimental animals with hroni liver failure.1825 The typial hanges are inreased onentrations of one or both of the aromati amino-aids tyrosine and phenylalanine together with methionine and dereased onentrations of the three branhed hain amino-aids - valine, isoleuine, and leuine. This pattern was onfirmed in the patients with hroni liver disease in the present study with Gut: first published as /gut on 1 May Downloaded from on 12 September 218 by guest. Proteted by opyright.

6 Plasma amino-aids in liver disease C H1 Control n=57 I Biliary disease n=18 Fig. 3 Plasma amino-aid onentrations in patients with biliary disease that show signifiant differenes from ontrol values (p<o.os). Bloks represent median values. the exeption that patients with aloholi hepatitis±irrhosis showed redued plasma phenylalanine onentrations. The patients with hroni ative hepatitis, primary biliary irrhosis, and ryptogeni irrhosis also showed inreased onentrations of aspartate and serine, while, in ontrast, the patients with aloholi hepatitis±irrhosis showed redued onentrations of glyine and alanine. Plasma proline onentrations were signifiantly redued in the group with hroni ative hepatitis. Previous studies have not differentiated patients on the aetiology of their liver disease so that omparisons annot be made. In the three groups of patients with minimal potentially reversible liver disease the onsistent abnormality was of a redution in the onentrations of the three branhed hain amino-aids and of proline. The patients with aloholi fatty liver, in ommon with the patients with aloholi hepatitis±irrhosis, showed signifiantly redued plasma phenylalanine values. No previous studies are available for omparison. xplanations are available for several of these findings. In all patient groups the plasma onentrations of the three branhed hain amino-aids were signifiantly redued. In normal man the liver is of major importane in amino-aid transamination. Its ability to use the three branhed hain amino-aids, however, is limited,35 and these 367 amino-aids are primarily atabolised via the skeletal musle.18 i6 37 The apaity of the extrahepati tissues to metabolise these amino-aids may assume ompensatory proportions if liver gluoneogenesis dereases, with the result that plasma onentrations will fall. Insulin ats diretly on the liver inhibiting gluogenesis and peripherally it suppresses musle output of branhed hain aminoaids.38 Hyperinsulinaemia 39 may our in hroni liver disease4 as a result of portal-systemi shunting and dereased hepati atabolism The low levels of branhed hain amino-aids may be related to the raised irulating insulin levels. Fasting insulin and amino-aids values do not orrelate,4 however, and branhed hain amino-aid onentrations have been shown to fall in rats after hepatetomy when peripheral and portal insulin levels are low Thus the low onentrations of irulating branhed hain amino-aids in these patients annot be attributed solely to hyperinsulinism. It has reently been suggested that spontaneous portal-systemi shunting itself is losely related to the redution in plasma branhed hain amino-aids independently of the presene of liver disease ;46 the mehanism is not lear. Plasma gluagon values tend to be raised in irrhoti patients and ould influene plasma branh hain amino-aid onentrations. Similarly, plasma noradrenaline onentrations may be raised in Gut: first published as /gut on 1 May Downloaded from on 12 September 218 by guest. Proteted by opyright.

7 368 Morgan, Marshall, Milsom, and Sherlok irrhoti patients51 and infusion of noradrenaline in healthy subjets results in dereased plasma aminoaid onentrations.52 None of these explanations serve, however, to explain the redued irulating branh hain amino-aid onentrations in the patients with minimal liver disease. Hyperinsulinaemia has been reported in patients with viral hepatitis28 but would at best provide only a partial explanation for these findings. The aromati amino-aids and methionine are atabolised mainly in the liver;36 their raised values in patients with hroni liver disease probably result from impaired hepati metabolism and portal systemi shunting of blood.3 The presene of a ataboli state with hypergluagonaemia and inreased gluoneogenesis ould also ontribute to the abnormal amino-aid pattern. 5 High plasma aspartate onentrations were found in patients with hroni ative hepatitis, primary biliary irrhosis, and ryptogeni irrhosis but not in patients with aloholi hepatitis±irrhosis. Inreased plasma aspartate onentrations have previously been reported in irrhoti patients.23 Reently, a signifiant redution in whole blood aspartate onentration was reported in a group of well-ompensated irrhoti patients, suggestin partial intraellular depletion of this amino-aid. Aspartate serves as a nitrogen donor in the urea yle; if intraellular values were low, impaired ammonia detoxifiation ould result. Aspartate may also serve as an exitatory neurotransmitter in the brain,54 so that low intraellular levels ould result in impaired erebral funtion. The majority of patients in this reent study52 were aloholis with irrhosis; in this group of patients in the present study we found normal plasma aspartate levels. Information is not available on the whole blood aspartate values in irrhoti patients in whom plasma aspartate onentrations are high. Plasma proline onentrations were signifiantly redued in patients with hroni ative hepatitis and in all three groups of patients with minimal liver damage. Proline is used in ollagen synthesis, and low levels might indiate inreased ollagen prodution. The normal proline levels in the other groups of patients are unexplained. A perentage of patients with liver disease are malnourished, and protein-alorie malnutrition is assoiated with redued plasma onentrations of all amino-aids exept glyine and alanine.55 The patients in the present study, however, were of normal body weight and took a normal diet, suggesting that malnutrition is an unlikely explanation for the hanges observed. In animal studies aute administration of ethanol in vivo or in vitro inhibits the ative intestinal transport of L-phenyl-alanine, L-leuine, L-glyine, L-alanine, L-methionine, and L-valine Although none of the aloholi patients in the present study had taken alohol within three days of the study, it is still possible that the low phenylalanine onentrations seen in these patients, in ontrast with the findings in the other groups of patients, might be explained as an effet of alohol. The patients with hroni ative hepatitis were reeiving prednisolone, whih is known to influene protein and purine metabolism.59 Peripherally, prednisolone mobilises protein and amino-aids from skeletal musle, thus inreasing their irulating onentrations. Steroids will probably have ontributed to some of the plasma amino-aid hanges seen in this group. Signifiant hanges our in plasma amino-aid onentrations in patients with well-ompensated hroni liver disease and also in patients with minimal liver damage. Most of the hanges ourring in patients with hroni liver disease an be explained on the basis of impaired hepati funtion, portal-systemi shunting of blood, and hyperinsulinaemia and hypergluagonaemia. The hanges ourring with patients with minimal liver damage, however, are less readily explained; nevertheless their presene indiates that amino-aid metabolism an be signifiantly disturbed by liver injury that is judged by all other riteria to be minor. Referenes 1 arle DP, Vitor J. The effets of various diets on the liver damage aused by exess ysteine. J xp Med 1942; 75: Dunn MS, Akawaie S, Yeh HL, Martin H. rinary exretion of amino aids in liver disease. J Clin Invest 195; 29: Gabuzda GJ, khardt RD, Davidson CS. rinary exretion of amino aids in patients with irrhosis of the liver and in normal adults. J Clin Invest 1952; 31: Walshe JM. Disturbane of amino aid metabolism following liver injury. Q J Med 1953; 22: Wu C, Bollman JL, Butt HR. Changes in free amino aids in the plasma during hepati oma. J Clin Invest 1955; 34: Iber FL, Rosen H, Levenson SM, Chalmers TC. The plasma amino aids in patients with liver failure. J Lab Clin Med 1957; 5: Payet M, Cesaire OG, Camain-Giabiani R. Renseignements donnes pas l'exploration hromatographique des aides amines libres du serum dans les irrhoses et la aner primitif du foie. Strasbourg Med 1958; 9: Guai L, Ronhi F, De Pasquale C, Massimo- Simonetti SD. 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8 Plasma amino-aids in liver disease 369 irrosi epatia. Med Clin Speriment 1963; 13: Kinsell LW, Harper HA, Barton HC, Huthin M, Hess JR. Studies in methionine and sulfur metabolism. I. The fate of intravenously administered methionine in normal individuals and in patients with liver damage. J Clin Invest 1948; 27: Martin, Milhaud G. Studies in amino aid metabolism with paper hromatography. Chemial Abstr 1953; 47: Pain SK, Banerjee S. Studies on the nitrogenous onstituents of urine in normal subjets and in patients suffering from irrhosis of the liver, subaute nephritis and hypertension. Indian J Med Res 1957; 45: Knauff HG, Selmair H, Reitlinger A. ntersuhunger uber die freien aminosauren in harn und blut plasma von gesunden und von leberkranken. Klin Wohenshr 196; 38: Mehta S, Wahia BNS, Ghai OP, Taneja PN. A qualitative study of plasma and urinary amino aids in Indian hildhood irrhosis. Indian J Pediatr 1964; 31: Ambert JP, Pehary C, Lemonnier A, Housset, Hartmann L. Dosage et differeniation des aid amines urinaires hez le irrhotique avant et apres anastomose porto-ave. Ann Biol Clin (Paris) 1966; 24: Wheeler J, Gyorgy P. Studies of urinary exretion of methionine by normals and by patients having liver diseases. Am J Med Si 1948; 215: Dent C, Walshe JM. Amino aid metabolism in liver disease. In: Wolstenholme CW, Sherlok S, eds. Ciba foundation symposium on liver disease. Philadelphia: Blakiston, 1951: Knauff HG, Seybold D, Miller B. Dei freien plasmaaminosauren bei leberirrhose und hepatitis. Klin Wohenshr 1964; 42: MMenamy RH, Vang JH, Drapanas T. Amino aid and alpha-keto aid onentrations in plasma and blood of the liverless dog. Am J Physiol 1965; 29: lob V, Coon WW, Sloan M. Altered learane of free amino aids from plasma of patients with irrhosis of the liver. J Surg Res 1966; 6: Zinneman HH, Seal S, Doe RP. Plasma and urinary amino aids in Laenne's irrhosis. Am J Digest Dis 1967; 14: Iob V, Mattson WJ, Jr, Sloan M, Coon WW, Turotte JG, Child CG III. Alteration in plasma free amino aids in dogs with hepati insuffiieny. Surg Gyneol Obstet 197; 13: Aguirre A, Yoshimura N, Westman T, Fisher J. Plasma amino aids in two experimental forms of liver damage. J Surg Res 1974; 16: Fisher J, Yoshimura N, Aguirre A, James JH, Cummings MG, Abel RM, Deindoerfer F. Plasma amino aids in patients with hepati enephalopathy: ffets of amino aid infusions. Am J Surg 1974; 127: Fisher J, Funovis JM, Aguirre A, James JH, Keane JM, Wesdorp RIC, Yoshimura N, Westman T. The role of plasma amino aids in hepati enephalopathy. Surgery 1975; 78: Rosen HM, Yoshimura N, Hodgman JM, Fisher J. Plasma amino aid patterns in hepati enephalopathy of differing etiology. Gastroenterology 1977; 72: Reord CO, Buxton B, Chase RA, Curzon G, Murray- Lyon IM, Williams R. Plasma and brain amino aids in fulminant hepati failure and their relationship to hepati enephalopathy. urop J Clin Invest 1976; 6: Hsia DY. Gellis SS. Amino aid metabolism in infetious hepatitis. J Clin Invest 1954; 33: Mellinkoff SM. Boyle D, Frankland M. The effet of amino aid-gluose infusions upon the serum amino aid and blood sugar onentrations in viral hepatitis. J Lab Clin Med 1955; 46: Siegel FL, Roah MK, Pomeroy LR. Plasma amino aid patterns in alohol: the effets of ethanol loading. Pro Nat Aad Si 1964; 51: Levine RJ, Conn HO. Tyrosine metabolism in patients with liver disease. J Clin Invest 1967; 42: Ning M, Lowenstein LM, Davidson CS. Serum amino aid onentrations in aloholi hepatitis. J Lab Clin Med 1967; 7: Mata JM, Kershenobih D, Villarreal. Rojkind M. Serum free proline and free hydroxyproline in patients with hroni liver disease. Gastroenterology 1975; 68: Armstrong MD, Stave. A study of plasma free amino aid levels. III. Variation during growth and ageing. Metabolism 1973; 22: Milsom JP, Morgan MY, Sherlok S. Fators affeting plasma amino aid onentrations in ontrol subjets. Metabolism 1979; 28: Noda C, Ihihara A. Control of ketogenesis from amino aids. II. Ketone bodies formation from alpha-ketoisoaproate, the ketoanalogue of leuine by rat liver mitohondria. J Biohem (Tokyo) 1974; 76: Miller LL. The role of the liver and the non-hepati tissues in the regulation of free amino aid levels in the blood. In: Holden JT, ed. Amino aid pools. Amsterdam: lsevier, 197: Odessey R, Goldberg AL. Oxidation of leuine by rat skeletal musle. Am J Physiol 1972; 223: Luk JM, Morrison G, Wilbur LF. ffet of insulin on amino aid ontent of blood. J Biol Chem 1928; 77: Felig P, Wahren J. Protein turnover and amino aid metabolism in regulation of gluoneogenesis. Fed Pro 1974; 33: Collins JR, Crofford OB. Gluose intolerane and insulin resistane in patients with liver disease. Arh Intern Med 1969; 124: Crentzfeldt.W, Frerihs H, Sikinger K. Liver disease and diabetes mellitus. In: Popper H, Shaffner F, eds. Progress in liver disease, volume 3. London: Heinemann, 197: Munro HN, Feinstrom JD, Wurtman RJ. Insulin, plasma amino aid imbalane and hepati oma. Lanet 1975; 1: Johnston DG, Alberti KGMM. Hyperinsulinism of hepati irrhosis: diminished degradation or hyperseretion? Lanet 1977; 1: 1W Greo AV, Cruitti F, Ghirlanda G, Manna R, Altomonte L, Rebuzzi AG, Bertoli A. Insulin and Gut: first published as /gut on 1 May Downloaded from on 12 September 218 by guest. Proteted by opyright.

9 37 Morgan, Marshall, Milsom, and Sherlok gluagon onentrations in portal and peripheral veins in patients with hepati irrhosis. Diabetologia 1979; 17: Smith-Laing G, Sherlok S, Faber. ffet of spontaneous portal-systemi shunting on insulin metabolism. Gastroenterology 1979; 76: Iwasaki Y, Sato H, Ohkubo A, Sanjo T, Futagawa S, Sugiura M, Tsuji S. ffet of spontaneous portalsystemi shunting on plasma insulin and amino aid onentrations. Gastroenterology 198; 78: Leffert H, Alexander NM, Faloona G, Rubalava B, nger R. Speifi endorine and hormonal reeptor hanges assoiated with liver regeneration in adult rats. Pro Nat Aad Si SA 1975; 72: Burher NLR, Weir GC. Insulin, gluagon, liver regeneration and DNA synthesis. Metabolism 1977; 25: Sherwin R, Joshi P, Hendler R, Felig P, Conn HO. Hypergluagonemia in Laenne's irrhosis. The role of portal systemi shunting. N ngl J Med 1974; 29: Marhesini G, Forlani G, Zoli M, Angiolini A, Solari MP, Bianhi FB, Pisi. Insulin and gluagon levels in liver irrhosis. Relationship with plasma amino aid imbalane of hroni hepati enephalopathy. Dig Dis Si 1979; 24: riksson S, Hagenfeldt L, Wahren J. Intravenous infusion of alpha-ketoisoaproate - influene on amino aid and nitrogen metabolism in patients with liver irrhosis. Clin Si 1982; in press. 52 Shamoon H, Jaob R, Sherwin RS. pinephrineindued hypoaminoaidemia in normal and diabeti human subjets. ffet of beta blokade. Diabetes 198; 29: Sato Y, riksson S, Hagenfeldt L, Wahren J. Influene of branhed-hain amino-aid infusion on arterial onentrations and brain exhange of amino aids in patients with hepati irrhosis. Clin Physiol 1981; 1: Snyder SH, Young AB, Bennett JP, Mulder AA. Synapti biohemistry of amino aids. Fed Pro 1973; 32: Saunders SJ, Truswell AS, Barbezat GO, Wittman W, Hansen JDL. Plasma free amino aid pattern in protein-alorie malnutrition. Lanet 1967; 2: Chang T, Lewis J, Glazko AJ. ffet of ethanol and other alohols on the transport of amino aids and gluose by evented sas of rat small intestine. Biohim Biophys Ata 1967; 135: Israel Y, Salazar I, Rosenmann. Inhibitory effets of alohol on intestinal amino aid transport in vivo and in vitro. J Nutr 1968; 96: Israel Y, Valenzuela J, Salazar I, garte G. Alohol and amino aid transport in the human small intestine. J Nutr 1969; 98: Ashmore J, Weber G. Hormonal ontrol of arbohydrate metabolism in the liver. In: Dikens F, Randle PJ, Whelan WJ, eds. Carbohydrate metabolism and its disorders, volume 1. New York: Aademi Press, 1968: Gut: first published as /gut on 1 May Downloaded from on 12 September 218 by guest. Proteted by opyright.