Ethanol Clearance and Oxidation of Ethanol to Carbon Dioxide in Persons with and Without Liver Disease

Vol. 55, No.6 Printed in U.S.A.

GASTROENTEIWLOGY

Copyright© 1968 by The Williams & Wilkins Co.

ETHANOL CLEARANCE AND OXIDATION OF ETHANOL TO CARBON DIOXIDE IN PERSONS WITH AND WITHOUT LIVER DISEASE CH.\RLES G. CLARK, M .D., ,\N D JOH N R . SENIOR, M .D. Gastrointestinal Research Laboratories, Th e Ph1:ladelphia General Ho spital, and Departmen t of Medic1:ne, University of Pennsylvani a School of Medicine, Philadelphia, P ennsylvania

It is not clear why only a small frac t ion of chronic alcoholics develop cirrhosis. Nutritional factors, while known t o be important in contributin g to some forms of liver disease, do not seem to explain entirely the differences in liver damage observed among heavy drinkers who apparently have equally poor dietary intakes. Therefore, individual variation in alcohol metabolism or in t issue response to metabolic products might be of some importance in this problem. Cherrick et aJ.l foun d t hat chronic alcoholi cs with cirrhosis showed excess1ve hepatic accumulation of reduced nicotinamide adenine dinucleotide (NADH) and greater eleva tions of blood ethanol a fter a standard intravenous dose of ethanol, when compared with chronic a lcoholics wi thou t cirrhosis. The implication of t hese findin gs was t hat certain persons may have a limi tation in capacity to oxidize etha nol or NAD H , whi ch may be correlated with liver damage. Such liver dam agl' mi ght be either the cause or the effect of reduced oxidative capacity for ethanol or various products of its meta bolism. The present study was carried out in an attempt to determine whether a limitation Heerivrd Augu5t 2. 1!167 . ..\ ct·r pted Ma~· 15. 1968. Add rrss reCJIH'SI fo r reprin ts to: Dr. John R. SPnior, Gastroin tcst innl Hesearch Lnborato ri rs. Th e Philndelphi a Genernl Hospital, P hilade lphin, Pennsylvani a 19104. This study was support r d in part by Training Gmnt T1 AM-05415 and Clinical Research Centf'r Grant FR-0107 from the ;\Tationn l Institutes of H ealth , Bethesda, M aryland. The au thors ap preciate t he contributions of Dr. Gordon Powers in th e development of techniqu es for carbon dioxide determination.

in ethanol metabolism was correlated with liver damage or whether those who had already begun to show hepatic changes could be distinguished from normal subjects on the basis of ethanol metabolism, using a radioisotopic method of assessment in para llel with older established methods. Methods and Materials Ethanol clearance after oral or intravenous ethanol. Five p a tients wi th vary ing degrees of hep a ti c fatty fibrotic changes by liver biopsy, who for 2 weeks or longe r had had no a lcohol and had received good nutrition in the hospita l, 2 similarly a lcoholic patients with ulcer disease a nd lung a bscess, a nd 5 apparently normal occasional use rs of alcohol without demonstra ble liver disease were g iven alcohol (ethanol 0.5 to 0.75 g per kg of body weight ) by mouth or in t ravenously over a 30-min p eri od. All pat ients a nd su bjects had fasted overni ght prior to t he experiment and for at lea st 4 to G hr after t.he a lcohol administration. The alco hol for oral usc W:ls mixed with ice and dilut ed with up to 200 ml of :ntifi cia lly S\Y ec tcned, carbo nated beve ra ge containing less t han 1 ca lori e. Alco hol for in t ra venous use was diluted to 300 ml with isotonic saline a nd the mixture was infused :1t 10 ml p er min. Whole n·nous blood ethanol a nd lactate concent ration s we re m easured every 30 to GO min fo llowing a lco hol close . Et ha nol lewis we re determin ed on 1.00 ml of venous blood by a n en zym atic dete rmina t ion (Sigma, T echni cn l Bulletin no. 330- UV), whil e la ctate was determined \Yit h la ctic de hydrogen:1se a nd diphosphopy ridine nu cleotide (Sigm:l , T ec hnic a l Bull etin no. 825-UV). The ct h;l nol co nc0n t rat ion at zero tim e (C.), a th eo retical value without actual physical reali ty use ful fo r comparison, wn s obt ained by hac k ext ra polation of t he linea r portion of t he et ha nol di sapp ea rance curve, atta ined usually

G70

D ecem ber 1968

ETHANOL M.ETABOL!Sl\II Illi LIVER DISEASE

b,· 1 hr after all of the ethanol was consumed o~ infused (fig. 1) . Clearance of ethanol, in milligrams per kilogram of body weight per hour, \ras computed from tthe product of the hourly decrease in ethanol concentration (milligrams per 100 ml per hr) and dose (milligrams of ethanol per kilogram of body \\·eight) di,·ided b~· Cu (milligrams per 100 ml). The bromsulphalein (BSP ) excretion was expressed as per cent dye left in serum 45 min after intravenous inj ection of 5 mg per kg of body weight . The amount of fibrosis and fatty infiltration seen on liver needle biopsy was eYaluated independently by two different examiners. The following gra ding scale was used: 0, none; 1+ , minimal ; 2+ , mild ; 3+ , moderate ; -f+, exte nsive; 5+, ve ry severe. Expired C''O, after an ethanol load. Five pa tients with liver disease, 1 in mild congestive heart fa ilure, and 4 normal control subj ects "·ere given ethanol, 0.75 g per kg of bod~· weight, afte r an overnight fast. Ethanol, diluted :1 s befo re with ice and low calorie carbonated beverage, was given orally over a 30-min period. At the end of t he 30-min period 30 fJ. C (1.2 g) of ethanol-1-C'' (New England Nuclear Corporation , Boston, M ass ., lot no. Hi:3-2S:3) was given in trave nously. No food was gi,·en un t il 4 hr later. At least three blood ethanol levels were obtained 1 to 3y2 hr after alcohol ingestion to determine ethanol clearance :11HI C,. from the ext rapolated curves. During the experiment, patients rema ined at rest and expired air was collected in a Douglas h:q:!; fo r 3-min periods at 45- to 60-min intervals for at lea st 10 hr. The volume of air \ras mea sured by a ga ~ meter to give the expiratio n rate (res pir:1 tor~· minu te volume) . Some of t lu• air wa s lr d into a " ha g in bott.le" system , :IJHI a. 1.5-li tc r s ~· ringr (Chemical Rubber Compan~ ·, Cle,·rland , Ohio ) was used to aspira tc from tlw b:1g and to deliver 1.33 liters of the air (measured at 1 atmosphere pressure, room temperature) in to a train in which the :1i r w:ls s l ow !~ · bubbled through 5 ml of 1 K H,SO , . The sulfuri c acid solution was found to rr move 95'/n of rt hanol vapor, but no r:1 rbon dioxide, from the expired air . This de
671

bubbled through 4 ml of ethanolamine-ethylene glycol monomethyl ether ( 1: 5 by volume) and then through another 3 ml of t he same solution, in special glass tubes (designed by Dr. Pete r White, Hospital of the University of Pennsylvania ). One milliliter of the solution of the 4 ml in the second tube was removed for titration of total C02 with 0.25 N HC!. The two tube system was found to remove 99.9% of the C" 0 2 from the air passed t hrough it. The 3-ml portions of solution remaining in t he second and third tubes were separately mixed with 15 ml of the ethylene glycol monomethyl ether-toluene (1 :2 volume) solut ion containing 5.5 g per liter of 2, 5 diphenyloxazole (PPO, scintillation grade, Packard Instrument Company, LaGrange, Ill. ), and coun ted by means of a Packard TriCarb Liquid Scintillation Spectrometer, model 314-A. This method of counting C" O,, as descri bed b~· J effay and Alvarez,' gaYe an effic iency of 513%, determined using a toluene-C' ' internal stancbrd. Expired C"O, wa s expressed as nanocuries per minute. Liver bi o ps ~· ,,·as not felt to be justified routinely in normal volunteers without clinical or labo ratory evidence of liver disease, so t hat un equivocnl proof of liver normality was not ava ilable.

Results Two of t he subj ects wi thout di agnosable liwr disease gave histories of heavy a lcohol consump t ion (J. B. a nd A. A .), but showed no greater clearance rates of etha nol than other norma l subj ects who did not consume a lcohol excessiY ely (table 1). Pati en t V. L. , a dmitted with delirium t rem ens 1 mon t h prior to the experimen ts, refused liver biopsy but becau::-e of 38 % B SP r etention a nd hep atomega ly was considered to have significa nt lin'r disease. Subj ect P. P. , whose liver biopsy ha d been don e in diag nostic sear ch of gra nuloma tous disease, had a normal Ji,·e r histologically but did no t have B SP or bilirubin d etermination s. No significant difference in Co or clearance of ethanol was observed betvveen the groups with or without lin• r disease (table 1). Also, simila r ethano l cleara nce a nd blood etha nol C 0 were found when the sam e ethanol close as had been given ora lly w as administ ered intra venously sever a l d ays later (patients V . L ., J . B ., C. H ., a nd W. S.). A modest rise in

672

CL A RK A N D SEN IOR T AB L E

Patient

Age, sex

Diagnosis

tion°

;;::

Fibros is

- - -

-- -

-

Bilirubin Dose

Fat

--

kg

Blood lactate

E thanol BSP

consump-

·;;; ""

yr

1. Res ponse to ethanol load AI- Liver biopsyb cobol

;:

Vol . 55, No . 6

Co

- -

- - - %

mg/100 ml

g

m g/ 100 ml

Cleara nee

Ini- 1 Incre. tial ment

- m g/kg

m g/ 100 ml

/ ltr

With liver disease

O.B .

w.w.

45, M 64 59, M 69

V. L.

48, M 80

M.G.

53, F 52 24, M 60

R . B.

Lung infilt rate Wernicke 's syndrome D elirium t remens Ascites D elirium tremens

3 4

2+ 1+

3+ 2+

6 20

1.0 0.9

26 (i.v.) 30 (p .o. )

4

ND c ND

38

0.8

(4) 4

5+ 2+

0 5+

ND ND

5.3 1.6

40 40 23 27

(p.o. ) (i.v.) (i.v .) (i .v.)

35 35 ND ND 3 0.5 32 ND ND ND ND 40 ND ND 5 1.2 66 ND ND 5 0.6 22 22 N D ND 3 0.4 30 30 0 0 ND ND 38

(p .o .) (i.v .) (p.o .) (p .o.) (p .o .) (p .o.) (i.v.) (p .o. ) (i.v.) (p .o .)

90 97

102 13.1 3.0 94 11 .7 11 .0

104 104 110 ND

88 14 .4 7.2 53 16.0 10 .1 132 15 .2 8.7 ND 12.2 0.4

67 74 104 105 130 132 106 76 74 91

67 78 100 60 75 114 85 153 132 86

Without liver disease

J. B.

38, M 69

Lung abscess

4

A.A . G . P.

w. s.

35, M 60

Duodenal ulcer Volunteer Volunteer Chronic bra in sy ndrome Sarcoidosis

4 1 1

C. H.

18, 30, 38, 74,

1

P.P .

65, M 75

Pneumonia

2

J . s.

M 64 M 80 M 88 F 43

?

ND

ND

2

0.4

7.7 4.3 7.2 15 .3 18.0 10 .8 12. 6 12 .6 13.9 121. 6

6.7 4.7 7.2 0.0 0.0 4.5 7. 0 8. 1 5.2 0.0

i

Alcohol consump t ion : 0, none; 1, occasional ; 2, light-social ; 3, heavy at t imes; 4, heavy , sustained ; ) former consumption. b See text for histological severi ty grading, p. 671. c ND, not done. a

venous blood lactate usually occurred with or immediately after the peak ethanol level, but in 4 patients (R. B., G. P ., J . S., and P . 0 .) no increase in lactate was seen after the ethanol load. The increment in venous lact ate among the patients with liver disease ranged from 0.4 to 11.0 mg per 100 ml, not appreciably different from the range of 0 to 8.1 mg per 100 ml in the patients without liver disease. In figure 1 is seen a representative curve from a patient with mild cirrhosis (W. W.) who was admit ted 1 month prior to the experiment with delirium tremens. His highest blood ethanol level occurred 75 min after the ethanol dose had been ingested, then decreased approximately linearly until the concentration was less than 10 mg per 100 mi. Subject J . B.,

who drank wine and beer daily but had normal liver function, was given the same dose of ethano l intravenously that he had received orally 3 days before; similar blood lactate increments, peak blood ethanol levels, and rates of blood ethanol clearance were observed (table 1). The results of studies on the production of C14 0 2 from ethanol-1-C14 are summarized in table 2. Again, no difference was demonstrated in Co or ethanol clearance in the two groups of subjects with and without liver disease. P atient E. H. was placed in the group with liver disease because he had mild congestive heart failure, secondary to valvular heart disease, and a BSP retention of 16%. His delay in C 14 0 2 release (peak at 8.0 hr) was probably a result of decreased hepatic blood

December 1968

ETHANOL METABOLISM I N LIVER DISEASE

flow and hepatic cellular hypoxia. The peak C 14 0 2 ranged from 3.0 to 8.5 hr with no significant difference between the two groups. A general correlation was noted, however, between BSP retention and time to reach peak C14 0 2 expiration (corre-

lation coefficient, r = 0.76, for whole group, although the coefficient for those with liver disease was even better, r = 0.87). Approximately 85% of the radioactivity from intravenous ethanol was released as expired C14 0 2 in the first 10 hr in most subjects, and 93% or more within 24 hr. Urinary excretion of ethanol-C 14 appeared to be less than 4% in 24 hr, and expiration of ethanol-C 14 as vapor was estimated as less than 2%. The results from the study of G. W., who had no liver disease, are shown in figure 2A . The expired C14 0 2 reached a peak of 80 nc per min at 3 hr after the ethanol-1C14 dose; at 11 hr the amount of C14 0 2 was only 6% of peak level. It is apparent that C 14 0 2 continued to be expired in large amounts well after ethanol disappeared from the blood within about 6 hr following ethanol ingestion. Patient P. F., who had mild to moderate fibrosis on liver biopsy, had results similar to G. W.

Hours

Fra. 1. Curves of blood ethanol ( • - • ) and mctate ( 0--0), following oral administration of 0.5 g per kg of ethanql to patient W. W . in the first Y2 hr ( ~>:::>·:.·.:J) of the time period shown. TABLE

2. C140 2 production from ethanol-1-C 14 Alcohol

Pa tient

Age, sex

~

..c:

Addi tiona! diagnosis

~

yr

With liver disease P. F . R. S. R.D . G. G . E. H.

59, M

57

C. E .

Fi· brosis

Peak C"O' of expired air

Fat

Dose

-- -- --

-

-

Co

Clear· ance

- ncj

%

g

mg/100

mg/k g

ml

/hr

3+ 3+ 2+ 5+ 0

11 13 12 17 1

.54 53 36 72 36

114 106 114 101 94

125 162 96 45 138

8.5 4.3

86 79 88 57 91

16

44

99

68

8 .0

66

67

57 80 84 82

hr

mtn

I 70 69 46 94 46

Without liver disease J. s. G.W. G . S.

- -

Ethanol BSP

sump~

kg

50,M 42, M 37, M 24, M 39, M

v. s.

Liver biopsyb

COD•

tio a

·;; ""

---

673

Pneumonia Eczema P a ncreatitis Diabetes Pancreatic insufficiency Rheumatic heart disease, failure

4 4 4 3 (3) 1

ND c ND

Volunteer D iabetes Aortic insufficiency Asbestosis

1 2 1

ND ND ND

ND ND ND

5 0 1

51 42

98 80 119

70 119 76

5 .5 3.0 6 .0

1

ND

ND

4

44

101

102

6.3

2+ 2+

I+ I+ 2+

5.5 5 .5

G.O

I I I 39 , M 55, M 43, F

88 67

54, M

57

54

Alcohol consumption: 0, none; 1, occasional; 2, light-social; 3, heavy at times; 4, heavy, sus ta ined; ) former consumption . b See text for histological severity grading, p . 671. c ND, not done. a

CLARK MW SE!v"JOR

67-:l:

-~c:

_;

120

E

.E

(i;

u

80

ci>

c:'

60

C..c:

E .Q

A

0

80

a· e 40 ~ 20

c:

"

~0

c: ...

s-u

go

c0 \

c

8

60

60

·.;:; ·a. _g

\

100 \ \

0 ~100 0~c.. "'

Vol. 55, N o. 6

2

4

6

8

Hours

10

12

40

40

20

20

\

·~·-'~•~ >------>---.--+- o.q<....-.---.~_,__---+-->----~~....:::..

2

4

6 8 Hours

10

12

0

2

4

6 8 Hours

10

12

14

0 "' -£0 UJO:O

FrG. 2. CurYes of C''O, in expired air ( .6.--.A. ) and blood ethanol ( e - - e ) following oral administration of: (A) 0.77 g per kg of ethanol to subj ect G. W. in the Y2 hr (1'·:·.·.-:,·.:1) before ethanol-1-C" dose at zero hour ; (B) 0.77 g per kg of ethanol to patient P. F.; and (C) 0.76 g per kg of ethanol to patient R . D.

except for some delay to 5.5 hr in reaching peak C 14 0~ (fig. 2B). P a tient R. D ., an obese diabetic who drank excessively a nd h ad liver biopsy evidence of severe fa tty infiltration with mild fibrosis, showed a low etha nol clearance of 45 mg per k g p er hr (fi g. 2C ) , a nd slow release of C HO~ in rxpired air, with a peak no t reached until 8.5 hr a ft er eth a nol in gestion was completed. Discussion

Ethanol metabo lism has recently been revi r wed.a-G The liv er is res ponsible for 90% or more of ethanol oxid ation ,6 thought prin cipally to be due to cytoplasmic' alcohol dehydrogenase and oxidized nicotinamid e ad enine dinucleotide. Whil e human li Ycr has been estimated t o contain only abou t 3 mmolcs of tota l nicotinamide adenine dinucleotide s,~ in our experiment::; up to 1500 mmoles of ethano l were admini::;t.erccl in 30 min, so that under con dition::; ::;uch as these nicotinamide adenine dinuclcoticle reoxidation is obviously necessary . C lwrrick ct a[.l found in creased a mounts of NADH in liYer tissue of chroni c a lcoholic:; 4 hr a fter an etha nol infusion of 1.5 g per k g. Those without liver disease had no increase in NADH , ·while those with th e most advanced liver da m age had the largct
proportion to live r disease. These findings indicated th at delayed eth a nol oxidation was not clue to reduced alcohol dehydrogenase activity but to lack of sufficient ni cot in a mide a denin e dinucleotide, presumably because of inadequa t e oxid ative regeneration , refl ected by a ccumula tion of NADH. Rubin and Liebern have shown by electron microscopy th a t after 8 days of etha nol inges tion human li ver mitochondri a became enl a rged with irregular form s and distorted cristae, >'imilar to changes in rat liver mito chondria after a large ethanol dose reported ea rlier by H a rtroft a nd Porta.10 The ques tion arises as to wh eth e r t he::;e chan ges may be either ca use or effect of a n in t race llular excess of NADH or oth er reduced intermediate compounds, or wheth er the endoplasmic reticular chan ges in nonalcoholic volunteers after 2 days of a lcohol 11 m ay be associa ted with a quantitatively significant m em bran e oxida tion system for ethanol.1 2 If after ethanol in gestion th e liver mit ochondria were unabl e to oxidize the excess reducing equi\' alents, utilization of a ltemate pathways for NADH oxida tion , such as in c reased lact a te production, might occur. Se ligson et a l. 13 showed that 60 min a fter 9 normal subjects were given 50 ml of etha nol intra venously, the hepa tic Yein lacta te concentrations more tha n doubl ed. However, Mende loff 14 in 1954 demonstrated a significant elevation in peripheral venous blood lactate in all of .5 norm a l p a tients "·ith wnous blood etha nol

D ecem ber 1968

ETH Alv'OL ME TABOLISM I N LIVER DISEASE

peripheral venous blood lactate in all of 5 normal patients with venous blood ethanol levels of 25 to 82 mg per 100 ml but only 3 of the 5 showed increased hepatic venous lactate concentrations. For this reason we measured peripheral venous lactat e levels, but patients with liver disease did not show significant difference in syst emic venous lactate increments in response to the ethanol load when compared with subjects without liver disease. It may be that sampling hepatic venous blood might have been more sensit ive. Lieber et aP 5 demonstrated in 13 normal patients a mean rise in arterial blood lactate of 200% after intravenous ethanol gave a mean arterial ethanol level slightly over 80 mg per 100 ml. A larger ethanol dose, a more prolonged exposure to ethanol , or a recent inadequate diet might have been necessary to produce a larger lactate difference. We did not observe higher ethanol blood levels nor any decrease in rate of ethanol disappearance in patients with liver disease. Lieberman 1 u found ethanol clearance the same in normal and nonicteric cirrhotic patients at serum levels similar to ours, but cirrhotic patients with jaundice t> howed a decreased ethanol clearance. Asada and Galambos17 agreed, although t hey used 30- to 120-min postinfusion specimens to dete rmin e t he slope of t he ethano l disappearance lin e, which can re~ml t in falsely elevated clearance rates, t>in ce it may require considerably longer t han 30 min for infused ethanol to equilibrate with body wate r. ~ In seeking a more sensit ive index of ethanol oxidative capacity than lactate production or ethanol clearance rates, the C 1 4 0~ produ ction from ethanol-l-C 14 was cl etennin ed. Re lease of C 14 0 2 from cthanol-1- C 14 requires six oxidative steps whereas ethanol disappearance requires only on e. Bartlett and Barn etl 0 in 1949 found 90% of C 14 -ethanol given to rats was oxidized to C 14 0 ~ in 10 hr. Campos et a l. ~n in 1964 demon strated that cirrhotic rats given ethanol-1- C 14 produced C 14 0 ~ at t he same rate as norma l rats until 4 hr, after which t he C 14 02 production diminished. They a lso concluded t hat ethanol clearance in rats appeared to in1

crease with chronic administration of a lcohol. This was recent ly confirmed in alcoholic human subj ects without liver di:3ease by Mendelson and co-worken} 1 " ·ho showed that most increased their rates of ethanol-1-C 14 metabolism to C 14 0 2 after 3 to 14 days of heavy consumption of eth anol, but after abstinence from alcohol for 3 weeks t his adaptation disappeared. 22 In our experiments a single loadin g dose of 0.75 g of unlabeled ethanol per kg of body weight was given prior to the ethanol-1-CH dose. Larger doses WE're not given because t he patient had to be cooperative enough t o permit co ll ection of expired a ir. No difference was fo un d between the norma l and cirrhotic pat ients in maximal C 14 0 2 production rate; but there was a suggestion t hat the t im e to attain this peak after intravenous inj ection of radioactive alcohol seemed to be related to the severity of liver disease (fig. 2). Th e degree of liver disease should perlmp,.; he considered more strongly when comparin g data in various patients OJ' experimenta l an imals. The importance of pro tein malnu tri tion , a lcohol close, and duration of administration of ethanol are other y;ui a bles which need fur ther in ve~t i gation with respect to the indiYidua l':; rat C' of ethanol metabolism and correlation \Yith hepatic ce ll damage. Summary

An attemp t was made to dC't('nllin e whether a lcoholi c individuals who den lop liver fibro sis have a limi tation in ethanol meta bolism. Ethanol oxidation in pat i('nh with liver disease has been ob,;eJTed in other studies 1 to result in the accumu lat ion of hepatic NADH , wh ich might he CXJ H'C'ted to produce excessive form ation of laetntc from pyruv ate. Howe\·er, a ft er a loading dose of 0.50 to 0.75 g per kg of eth anol no difference in the in crement of periph era l venous lactate leve ls or in the ethano l clearance rate was found in 5 patients ·with liver damage when comparee! \\·ith 7 subj ects without liver disease. In seeking a more sensitive index of ethanol metabolism, we determined the rate of formation of C 14 0 2 from ethanol- 1C 14 given intravenously after an ora l

676

CLARK AND SENIOR

ethanol load of 0.75 g per kg. Again, on the basis of rate of C 14 0 2 production from labeled ethanol, it was not possible to discriminate 6 patients with liver disease from 4 subjects without liver disease. It is concluded that no over-all decrease in the rate of ethanol oxidation can be demonstrated in heavy users of alcohol who have evidence of liver disease, using moderate doses of ethanol in hospitalized, adequately fed patients.

11.

12.

13.

14.

REFERENCES 1. Cherrick, G. R., M. M. Howard, W. tenHove,

and C. M. Leevy. 1964. The varying susceptibility of man to alcohol hepatotoxicity. J. Clin. Invest. 43: 1253. 2. Jeffay, H ., and J. Alvarez. 1961. Liquid scintillation counting of carbon-14. Use of ethanolamine-ethylene glycol monomethyl ether-toluene. Anal. Chern. 33: 612-615. 3. Lieber, C. S. 1967. Metabolic derangement induced by alcohol. Ann . Rev. Med. 18: 35-54. 4. Isselbacher, K. J ., and N . J. Greenberger. 1964. Metabolic effects of alcohol on the liver. New Eng. J . Med. 270: 351-356, 402-

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5. Senior, M. R. 1967. Ethanol and liver disease . Postgrad. Med. 41: 65-71. 6. Lundsgaard, E. 1938. Alcohol oxidation as a function of the liver. Compt. Rend. Lab. Carlsburg, Ser. Chim. 22 : 333-337. 7. Nyberg, A., J. Schuberth, and L. Angg!lrd. 1953. On the intracellular distribution of catalase and alcohol dehydrogenase in horse, guinea pig and rat liver tis,ues. Acta Chern. Scand. 7: 1170-1172. 8. Seligson, D . 1963. Biochemical considerations of the linr. In Leon Schiff [ed.], Diseases of th e liver, p. 74. J . B. Lippincott Company, Philadelphia. 9. Rubin, E., and C. S. Lieber. 1967. Early fine structural changes in the human liver induced by alcohol. Gastroenterology 52 : 1-13. 10. Hartroft, W. S., and E. A. Porta. 1964. Ultra-

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20 .

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Vol . 55, No . 6

structural hepatic changes in acute ethanoltreated rats. Gastroenterology 46: 304-305. Rubin, E ., and C. S. Lieber. 1968. Alcoholinduced hepatic injury in non-alcoholic volunteers. New Eng. J. Med. 278: 869-876. Lieber, C. S., and L. M . DeCarli . 1968. Hepatic microsomes: a new site for ethanol oxidation (abstr.). J. Clin. Invest. 47: 62a63a. Seligson, D ., H. H. Stone, and P. N emir . 1958. The metabolism of ethanol in man. Surg. Forum 9: 85-88. Mendeloff, A. I. 1954. Effect of intravenous infusions of ethanol upon estimated hepatic blood flow in man. J. Clin. Invest. 33: 1298-1302. Lieber, C. S., C. M. Leevy, S. W. Stein, W. S. George, G. R. Cherrick, W. H . Abelman, and C. S. Davidson. 1962. Effect of ethanol on plasma free fatty acids in man. J. Lab . Clin. Med. 59: 826-832. Lieberman, F. L. 1963. The effect of liver disease on the rate of ethanol metabolism in man. Gastroenterology 44 : 261-266. Asada, M ., and J. T. Galambos. 1963. Liver disease, hepatic alcohol dehydrogenase activity, and alcohol metabolism in the human. Gastroenterology 45: 67-72. Eggleton, M. G. 1940. Determination of the metabolic rate of alcohol. J. Physiol. (London) 98: 228-238 . Bartlett, G. R., and H . N. Barnet. 1949. Some observations on alcohol metabolism with radioactive ethyl alcohol. Quart. J. Stud. A1coho110: 381-397. Campos, I., W. Solodkowska, E. Muii.oz, N. Segovia-Riquelme, J. Cembrano, and J. Mardones. 1964. Ethanol metabolism in rats with experimental liver cirrhosis. Quart. J . Stud. Alcohol 25: 417-422. M endelson, J. H., S. Stein, and N. K. Mello. 1965. Effects of experimentally induced intoxication on metabolism of ethanol-1-C" in alcoholic subjects. Metabolism 14 : 12551266. Mendelson, J. H. 1968. Ethanol-1-C" metabolism in alcoholics and non-alcoholics. Science 159: 319-320.