Ethanol consumption and serum lipid profiles in Sinclair (S-1) miniature swine

Life Sciences, Vol. 34, pp. 819-826 Printed in the U.S.A.

ETHANOL

Laurie

Pergamon Press

C O N S U M P T I O N AND S E R U M L I P I D P R O F I L E S S I N C L A I R ( S - I ) M I N I A T U R E SWINE

Foudin, Richard

M y r o n E. T u m b l e s o n , A l b e r t Y. W. G e l s l e r and G r a c e Y. Sun

IN

Sun

S i n c l a i r C o m p a r a t i v e M e d i c i n e R e s e a r c h Farm, U n i v e r s i t y of M i s s o u r i , C o l u m b i a , MO 65201 (Received in final form December 13, 1983) Summary

E t h a n o l c o n s u m p t i o n w a s c o r r e l a t e d w i t h c h a n g e s in a c y l g r o u p p r o f i l e s of p h o s p h a t i d y l e h o l i n e and t r i a c y l g l y c e r o l s in s e r u m of S i n c l a i r ( S - l ) m i n i a t u r e boars. Serum t r i a c y l g l y c e r o l s in the c o n t r o l p i g s w e r e h i g h in l i n o leate (18:2) (48%) a n d l o w in s t e a r a t e ( 1 8 : 0 (3%). Upon feeding with 10% ( w / v ) e t h a n o l ad l i b f o r t w o w e e k s , the p r o p o r t i o n of 18:2 in s e r u m t r i a c y l g l y e e r o l s decreased to 1 2 - 1 5 % with a concomitant increase in 16:0, 18:0 and 18:1. S i m i l a r , but l e s s e x t e n s i v e , aeyl g r o u p c h a n g e s w e r e o b s e r v e d in the s e r u m p h o s p h a t i d y l choline. In a d d i t i o n , there was a decrease in the proportion of 2 0 : 3 ( n - 6 ) , but a biphasic change was s h o w n in 20:4(n-6) w i t h r e s p e c t to e t h a n o l c o n s u m p t i o n . In g e n e r a l , the high ethanol consumers (7.0 g / k g / d a y ) indicated a m o r e r a p i d r a t e of a e y l g r o u p c h a n g e t h a n the l o w c o n s u m e r s (3.8 g / k g / d a y ) . Upon withdrawal of ethanol, acyl groups of triacylglycerols rapidly r e t u r n e d t o w a r d s the c o n t r o l values, w h e r e a s o n l y s m a l l changes were observed for the recovery in p h o s p h o lipids. In t h i s s i t u a t i o n , the low-consumer group i n d i c a t e d a m o r e r a p i d r e c o v e r y t h a n the h i g h - c o n s u m e r group. Results indicate t h a t w i t h the s w i n e m o d e l , serum lipid changes c a n be a u s e f u l parameter for correlating biological changes upon ethanol consumption. Sinclair(S-l) miniature s w i n e a r e o n e of t h e f e w a n i m a l species which consume alcohol voluntarily. Due to t h i s and o t h e r behavioral and physiological parameters, they have been consid e r e d a g o o d a n i m a l m o d e l for the s t u d y of a l c o h o l i s m (I,2). In s p i t e of this, m a n y of the b i o c h e m i c a l p a r a m e t e r s of the s w i n e in r e s p o n s e to e t h a n o l c o n s u m p t i o n h a v e not yet b e e n i n v e s t i g a t e d in detail. It is w e l l - r e c o g n l z e d t h a t t h e l i v e r is o n e of t h e p r i m a r y t a r g e t o r g a n s for m e t a b o l i s m of i n g e s t e d e t h a n o l , and the c o n s e quences of the m e t a b o l i c response are often reflected in t h e serum components. Therefore, c h a n g e s in acyl g r o u p c o m p o s i t i o n of s e r u m p h o s p h o l l p l d and t r l g l y c e r i d e s obtained from alcoholic 0024-3205/84 $3.00 + .00 Copyright (c) 1984 Pergamon Press Ltd.

820

Ethanol and Serum Lipids in Swine

Vol. 34, No. 9, 1984

patients were reported (3-6). However, the lipid changes in humans are quite different from those found in rodents (7). S i n c e the d r i n k i n g c h a r a c t e r i s t i c s , as w e l l as m a n y p h y s i o l o g i c a l parameters of the s w i n e , closely resemble the h u m a n , we decided to e x a m i n e the serum lipid changes in swine with respect to chronic alcohol consumption and withdrawal. Furthermore, the extent of l i p i d c h a n g e s was compared among animals consuming e i t h e r l o w or h i g h l e v e l s of e t h a n o l . A preliminary report of the s t u d y has b e e n m a d e (8). Methods Animals.

ethanol

administration

and

blood

samDlinz

Ten adult Sinclair(S-l) miniature boars with mean body w e i g h t of 60.3 ± 10.3 kg ( S i n c l a i r C o m p a r a t i v e Medicine Research Farm, Unlversity of M i s s o u r i , Columbia, MO) w e r e u s e d f o r t h e experiment. The animals were housed in individual stalls and w e r e fed o n c e d a i l y for f o u r w e e k s p r i o r to e t h a n o l a d m i n i s t r a tion with a ration formulated to p r o v i d e 4000 total c a l o r i e s w i t h 339 g protein, vitamins, minerals and lipids (9). The lipids w e r e in the f o r m of s o y b e a n m e a l w h i c h a c c o u n t e d for 2.5% of the total caloric intake. This ration also contained 500 g c o r n starch (1800 calories), which was intended to be a s o u r c e of carbohydrate isocaloric w i t h the p r o j e c t e d a m o u n t of e t h a n o l to be c o n s u m e d . After the ethanol was presented, cornstarch was r e m o v e a f r o m the ration. D i e t a r y e t h a n o l w a s s u p p l l e d ad lib v i a l i x i t s as c o m m e r c i a l 4% (w/v) b e e r f o r t i f i e d w i t h 95% e t h a n o l to effect a final concentration of 10% (w/v). Fresh drinking water was provlded ad lib. The swine were on the ethanol program for six weeks during which time the mean caloric intake was 5143 ± 983 calories/day, and the mean protein intake w a s 68.4 ± 14.6 g/Kcal. The m e a n e t h a n o l c o n s u m p t i o n for the a n i m a l s w a s 5.72 ± 2.45 g / k g body w t / d a y (n=10) w i t h a w i d e r a n g e v a r y i n g f r o m 2.29 to 10.25 g / k g / d a y . T h i s a m o u n t of e t h a n o l r e p r e s e n t s 44.0 ± 7.7% of the t o t a l c a l o r i c i n t a k e . Blood was drawn from each animal before ethanol administration, e v e r y t w o w e e k s during the ethanol program, a n d at 48 hr after withdrawal from ethanol. Venous blood samples were allowed to clot at r o o m t e m p e r a t u r e a f t e r w h i c h they w e r e c e n t r i f u g e d at 1 0 0 0 ~ f o r 10 rain to s e d l m e n t the blood cells. The serum was transferred to c a p p e d v i a l s a n d s t o r e d at - 2 0 ° C u n t i l t i m e f o r analysis. Lipid

analysis

Aliquots of s e r u m were extracted i n 5 v o l of c h l o r o f o r m methanol, 2:1 (v/v) and v o r t e x e d v i g o r o u s l y . The t u b e s w e r e t h e n c e n t r i f u g e d to f a c i l i t a t e p h a s e s e p a r a t i o n , and the l o w e r o r g a n i c l a y e r w a s t a k e n to d r y n e s s by a r o t a r y e v a p o r a t o r . Samples were redlssolved in chloroform and stored at 4 ° C until further analysis.

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Ethanol and Serum Lipids in Swine

821

For isolation of t r i a c y l g l y c e r o l s (TG), an a l i q u o t of t h e l i p i d e x t r a c t w a s a p p l i e d to TLC p l a t e s c o a t e d w i t h s i l i c a gel G and developed in a solvent system containing hexane-ether-15M NH4OH (80:20:0.1, by vol). After solvent development, plates w e r e s p r a y e d w i t h 0.1% 2 ' , 7 ' - d i c h l o r o f l u o r e s c e i n , and l i p i d s p o t s were visualized u n d e r a UV lamp. The l i p i d b a n d c o r r e s p o n d i n g to TG w a s s c r a p e a i n t o t e s t t u b e s a n d a k n o w n q u a n t i t y of h e p t a d e c a n o i c a c i d m e t h y l e s t e r w a s a d d e d as s t a n d a r d . The acyl g r o u p s of TG w e r e c o n v e r t e d to m e t h y l e s t e r s by b a s e - m e t h a n o l y s i s with 0.5 M N a O H in m e t h a n o l . After base-methanolysis, chloroform and water were added to m a k e a phase partition. The lower phase containing mainly the fatty acid methyl esters was filtered through anhydrous N a 2 S O 4 a n d t a k e n to d r y n e s s under nitrogen. Methyl esters were redissolved in h e x a n e and a n a l y z e d by GLC. For a n a l y s i s of the acyl g r o u p c o m p o s i t i o n of p h o s p h a t i d y l choline (PC), a n a l i q u o t of t h e t o t a l l i p i d e x t r a c t was applied to T L C p l a t e s w h i c h w e r e d e v e l o p e d in chloroform-methanol-15M NH4OH (140:55:10, by vol). After solvent development, the TLC plates were sprayed with 2',7'-dichlorofluorescein, a n d t h e PC b a n d s w e r e t a k e n for b a s e - m e t h a n o l y s i s as d e s c r i b e d above. The f a t t y acid m e t h y l e s t e r s w e r e a n a l y z e d on a H e w l e t t P a c k a r d 5840 research gas c h r o m a t o g r a p h equipped with dual f l a m e ionization detectors a n d an a u t o m a t i c digital integrator. Conditions for s e p a r a t i o n of the m e t h y l e s t e r s w i t h t e m p e r a t u r e programming have been described (10). Serum cholesterol content was determined a c c o r d i n g to the p r o c e d u r e of B o w m a n and W o l f (11). ~sults Alcohol

consumption

in m i n i a t u r e

boars

The boay w e i g h t s of the m i n i a t u r e b o a r s u s e d for t h i s s t u d y ranged f r o m 42.0 to 72.7 k g w i t h a m e a n a n d S.D. of 60.3 ± 10.7 (n=10). All were given free access to e t h a n o l and water for a p e r i o d of six w e e k s . B a s e d on t h e i r m e a n w e e k l y e t h a n o l c o n s u m p tion rates, the animals were arbitrarily divided into a low c o n s u m e r g r o u p (n=4) w h i c h h a d a m e a n a l c o h o l c o n s u m p t i o n r a t e of 3.8 ± 1.0 g / k g / d a y and a high consumer g r o u p (n=6) w h i c h h a d a mean consumption r a t e of 7.0 ± 2.3 g / k g / d a y . Previous studies (2) of l o n g - t e r m ethanol consumption with the swine indicated that t h e s e l e v e l s are r e p r e s e n t a t i v e of h i g h and l o w c o n s u m p t i o n . Serum lipid f e e d i n ~ and

c h a n ~ e s in withdrawal

low

and

high

consumers

durin~

ethanol

The acyl group composition of t h e s e r u m TG w a s c o m p r i s e d mainly of 18:2, 18:1 a n d 16:0 w i t h a rather low level of 18:0 ( T a b l e I). W h e n a n i m a l s w e r e a l l o w e d to c o n s u m e e t h a n o l for t w o weeks, marked changes in the acyl group composition were observed. There was a decrease in t h e p r o p o r t i o n of 18:2 ( f r o m 4 8 % to 1 0 - 1 5 % ) and an increase i n 16:0, 18:0, a n d 18:1. The decrease i n 18:2 s e e m e d to r e a c h a m a x i m u m after two weeks on ethanol, whereas the increase i n 18:0 a n d 16:0 w a s m o r e g r a d u a l and was observed over the entire 6 week period. Although there

822

Ethanol and Serum Lipids in Swine

Vol. 34, No. 9, 1984

was a marked increase in the proportion of 18:1 d u r i n g the i n i t i a l t w o w e e k s of e t h a n o l c o n s u m p t i o n , a steady decrease was observed after this time. The acyl group profile started to r e v e r s e t o w a r d s the c o n t r o l a f t e r the a n i m a l s w e r e w i t h d r a w n from e t h a n o l for 48 hr. A similar change with respect to t h e d e c r e a s e i n 18:2 w a s shown upon analysis of t h e a c y l g r o u p s of s e r u m PC ( T a b l e II), al~hougn t h e r a t e of d e c l i n e w a s n o t as d r a m a t i c as i n TG. The decrease i n 18:2 w a s m a x i m a l at 2 w e e k s on ethanol, and after this time, the proportion started to i n c r e a s e . The decrease in 18:2 w a s m a r k e d by a n i n c r e a s e i n 16:0 a n d 18:1, b u t n o t 18:0. In a d d i t i o n , the proportion of 2 0 : 3 ( n - 6 ) d e c r e a s e d w i t h t i m e of ethanol consumption, but the p r o p o r t i o n of 20:4(n-6) i n d i c a t e d an i n c r e a s e p r i o r to the d e c r e a s e . U n l i k e the TG, w h i c h i n d i c a t e d a d r a m a t i c i n c r e a s e in 18:0, the p r o p o r t i o n of 18:0 in PC a c t u a l l y decreased upon ethanol consumption. Only a s m a l l r e v e r s a l of the PC a c y l g r o u p p r o f i l e was observed 48 h r a f t e r w i t h d r a w a l from ethanol. TABLE Acyl Group f r o m Low

Acyl Groups

I

Composition of T r i a e y l g l y c e r o l s in Pig S e r u m and H i g h D r i n k e r s a d u r i n g C h r o n i c E t h a n o l C o n s u m p t i o n and W i t h d r a w a l Weeks

Control

2 Low

16:0

16.9

18:0

3.3

18:1 18:2

on

test

4

+_ 5.5 b 21.7

+_ 6.0

±

48 hr Withdrawal

6

Drinkers

25.6

+_ 5.4

36.3

+__ 1.7

22.1

+ 2.2 ± 2.0

0.6

11.5

±

1.4

9.2

± 2.4

11.4

± 2.2

6.1

31.8

+_ 2.5

46.5

+_ 9.3

32.9

+_ 3.1

36.3

+_ 2.1

40.6

±

3.3

47.9

±

15.4

±

19.3

±

15.9

+

3.1

31.4

±

3.1

High

Drinkers

5.9

3.2

3.7

16:0

13.2

±

4.0

18.8

+_ 5.0

30.4

+_ 8.0

35.5

±

0.9

29.2

+_ 4.2

18:0

3.2

~

0.b

15.6

±

3.1

12.5

±

2.9

13.1

±

1.9

5.8

+_ 1.1

18:1

34.2

±

2.4

52.3

+_ 4.2

34.1

+_ 3.1

37.3

+_ 1.4

44.6

~

1.6

18:2

47.8

~ 6.9

9.8

~

13.3

±

14.0

±

20.4

±

3.9

4.3

3.7

aAverage ethanol consumption of l o w ~/kg/day (n=4) and 7.0 g / k g / d a y (n=6), V a l u e s are the m e a n ± S.D., e x p r e s s e d

I .5

and high drinkers was respectively. as p e r c e n t a g e w e i g h t .

Some differences w e r e o b s e r v e d in the rate of b e t w e e n the l o w and h i g h c o n s u m e r groups. In fact,

lipid these

3.8

changes differ-

Vol. 34, No. 9, 1984

Ethanol and Serum Lipids in Swine

823

ences were already obvious a f t e r t w o w e e k s of a l c o h o l consumption, a t i m e w h e n the a n i m a l s w e r e s t i l l a d a p t i n g to the e t h a n o l intake (I). In g e n e r a l , the decrease in 18:2 was larger in the high consumer group than in the low consumer group, and this difference was observed i n b o t h TG a n d PC. In c o n t r a s t , the i n c r e a s e in 20:4 w a s m o r e d r a m a t i c in the l o w c o n s u m e r g r o u p as compared to the h i g h c o n s u m e r group. Nevertheless, the g r a d u a l increase i n 16:0 a n d c o n c o m i t a n t decrease of 18:1 w a s t h e s a m e i n b o t h groups. During withdrawal, the l o w c o n s u m e r s s e e m e d to s h o w a m o r e r a p i d r a t e of r e v e r s a l t h a n the h i g h c o n s u m e r group.

TABLE Aoyl

Acyl Groups

II

Group Composition of P h o s p h a t i d y l c h o l i n e s f r o m L o w and H i g h D r i n k e r s a d u r i n g C h r o n i c Consumption and Withdrawal Weeks Control

2 Low

on 4

in Fig S e r u m Ethanol

test

48 hr Withdrawal

6

Drinkers

16:0

17.0

+

1.4 b

17.2

~

1,5

21,0

±

1,8

19,9

±

1.3

19,2

.+_ 1 , 5

18:0

24,9

±

1 .6

25,5

±

2.0

19,8

+ 2.7

22.0

~: 1,t~

25.8

:lh 2 , 5

18:1

15.6

+

1,6

21 ,1

+

3,7

19,9

+

2,0

10,7

±

3.2

18,2

±

1,5

18:2

34.5

_+_ 3 - 5

22.2

+

3,9

24,7

+

1.1

26.8

±

3.4

29,2

+

2,7

20:3

2.2

±

1.6

2.1

±

0.3

1.6

±

0.3

20:4

5.1

±

3.0

10.4

±

1.3

9.6

±

1.7

High

Tr 6.7

±

Tr 1.7

7.3

+

1 .~,

1,1

Drinkers

16:0

14.9

±

4.2

18.6

+

4,1

21,6

+_ 3 , 3

21,9

.+_ 2 , 8

19,2

+

18:0

26,5

±

4,8

23.4

+

3.2

19.8

+

2,5

22.8

+

2,5

27,5

~_ 2 . 3

18:1

16.0

±

2,2

28.5

±

3,5

24,8

±

1.6

24,0

+

1.9

22.5

+ 2,1

18:2

33,7

.+_ 4 , q

17.8

.+_ 2 , 1

21.2

±

1,7

24,5

±

2,4

22,2

~_ 2 . 6

20:3

2.4

+_ 1 , 2

1 ,6

±

0,3

1 .5

+ 0,3

20:4

5,b

+

7,6

+

1,7

7,3

+

2,8

aAverage ethanol consumption of l o w ~/kg/day (n=4) and 7.0 g / k g / d a y (n=6), V a l u e s a r e the m e a n ± S.D., e x p r e s s e d <1.0~.

1,2

Tr 5,5

~. 0 , 6

Tr 7,7

+

1.6

and high drinkers w a s 3.8 respectively. as p e r c e n t a g e w e i g h t ; Tr =

824

Ethanol and Serum Lipids in Swine

Vol. 34, No. 9, 1984

Analysis of the s e r u m c h o l e s t e r o l i n d i c a t e d no s i g n i f i c a n t c h a n g e in l e v e l s t h r o u g h o u t the 6 w e e k s on test, but an i n c r e a s e of 25% w a s o O s e r v e d u p o n w i t h d r a w a l of the e t h a n o l (FIG. I).

c

A Low Ethanol Consumers o High Ethanol Consumers

120

lee

8O "O O

•

6O

o u

2tl

•

l

I

Control

e

!

I 2

I 3

I 4

Weeks on ethanol

FIG.

i S

• 0

I 1

Withdrawal

I

T o t a l s e r u m c h o l e s t e r o l l e v e l s of l o w and h i g h e t h a n o l - c o n s u m i n g Sinclair(S-I) miniature boars during chronic ethanol administration and withdrawal. * Denotes data that are significantly d i f f e r e n t (p<0.001) f r o m t h o s e at t i m e of w i t h d r a w a l . Discussion M i n i a t u r e s w i n e are one of f e w a n i m a l s p e c i e s w h i c h c o n s u m e a l c o n o ± on a v o l u n t a r y b a s i s (1,2). S i n c e m a n y of the b e h a v i o r a l and physiological parameters d u e to a l c o h o l consumption also s a t i s f y the c r i t e r i a for d i a g n o s i s of a l c o h o l i s m (I), it w o u l d be i m p o r t a n t to o b t a i n b i o c h e m i c a l c o r r e l a t e s for the i n v e s t i g a t i o n . A d e f i n i t e a d v a n t a g e of the s w i n e m o d e l is t h a t m a n y p a r a m e t e r s s u c h a s t h e l e v e l of d i e t a r y i n t a k e a n d t h e d u r a t i o n of e t h a n o l consumption c a n be c o n t r o l l e d . On t h e o t h e r h a n d , s t u d i e s o n alcoholic patients admitted to the h o s p i t a l are f r e q u e n t l y complicated by n u t r i t i o n a l and biochemical factors, and in most cases, these patients have already developed secondary health complications.

of

M a r K e d c h a n g e s in s e r u m l i p i d s w e r e o b s e r v e d a f t e r t w o w e e k s ethanol consumption. One of the m o s t s t r i k i n g c h a n g e s is the

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dec~ ease in the p r o p o r t i o n or l i n o l e i c a c i d s h o w n in both TG and PC. These changes were so r a p i d that a maximum level was attained within two weeks after ethanol administration. In general, the d e c r e a s e in s e r u m 18:2 in s w i n e c o n s u m i n g a l c o h o l is greater in TG t h a n i n PC. Our results on acyl group changes are in g o o d a g r e e m e n t with the human data reported by A l l i n g et al. (3-5), but d i f f e r s o m e w h a t f r o m t ho s e of H o l m a n and J o h n s o n (6). D i f f e r e n c e s in r e s u l t s on h u m a n a l c o h o l i c s u b j e c t s m a y be a t t r i b u t e d to the type of d i e t a r y i n t a k e a m o n g a l c o h o l i c p a t i e n t s f r o m different geographical locations as w e l l as o t h e r e n v i r o n m e n t a l fac~brs. In t h e s w i n e e x p e r i m e n t , however, animals were given t h e s a m e a m o u n t of p r o t e i n a n d f a t ( s o y b e a n m e a l ) 4 w e e k s p r i o r to e t h a n o l consumption and throughout the test period. Consequently, the level of linoleic acid intake should remain constant. Based on this information, a decrease in t h e p r o p o r t i o n of 18:2 m a y be t h e r e s u l t of a n i n c r e a s e in other fatty aclds. Experiments are in p r o g r e s s to test this h y p o t h e s i s . Since the majority of t h e s e r u m l i p i d s o r i g i n a t e from the liver, the s e r u m l i p i d c h a n g e s are r e f l e c t i v e of the r e s p o n s e of the hepatic lipid synthesizing system towards ethanol intake. The delta-6 desaturase, a key hepatic enzyme for oxidative desaturation of 18:2(n-6), is k n o w n to be a f f e c t e d by n u t r i t i o n a l and hormonal factors (12-14). T h e r e is e v i d e n c e that ethanol administration to r a t s can s u p p r e s s the a c t i v i t y of t h i s e n z y m e , thus l e a d i n g to e ± e v a t e d 18:2(n-6) (15,16). Possibly, the s w i n e may exhibit an opposite response to t h e e t h a n o l regime. The phenomenon m a y p r o v i d e an e x p l a n a t i o n for the e x i s t i n g s p e c i e s related differences in r e s p o n s e to e t h a n o l (7). It is i n t e r e s t i n g to n o t e that in spite of t h e i n i t i a l increase in 20:4(n-6), there is a steady decrease in 20:3(n-6) (dihomogammalinolenic acid) in the s w i n e s e r u m PC w i t h r e s p e c t to ethanol consumption. S i n c e this f a t t y a c i d is the p r e c u r s o r for prostaglandin E I (PGEI) , a decrease in t h e p r e c u r s o r fatty acid m a y be a s s o c i a t e d with a decrease in the supply of p r e c u r s o r fatty acld for synthesis of P G E I. On t h e other hand, the increase in 20:4(n-6) m a y l e a d to a n i n c r e a s e in the precursor fatty aclds for the biosynthesis of prostaglandins E 2 a n d F2-. a Although Horrobin (17) h a s p r o p o s e d that a disturbance of t ~ e prostaglandin l e v e l s m a y o c c u r d u r i n g c h r o n i c e t h a n o l intake, and t h i s c h a n g e m a y be a s s o c i a t e d with the b e h a v i o r a l and physiological abnormalities observed, m o r e s t u d i e s are n e e d e d to substantiate the h y p o t h e s i s . In s p i t e of t h e l a r g e c h a n g e i n a c y l g r o u p c o m p o s i t i o n of the g l y c e r o l i p i d s , the serum cholesterol level remained rather constant during the period on test. An i n c r e a s e in the cholesterol level is s h o w n only upon withdrawal of e t h a n o l . The physiological significance underlying the i n c r e a s e with respect to w i t h d r a w a l r e m a i n s to be f u r t h e r i n v e s t i g a t e d . Many factors are known to a f f e c t the pattern in humans. Apparently, endocrine important r o l e in the r e g u l a t i o n . In f e m a l e

individual drinking factors may play an s w i n e , the v a r i a t i o n

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in a m o u n t of a l c o h o l c o n s u m p t i o n as a f u n c t i o n of e s t r u s has been described (9). The f a c t o r s a s s o c i a t e d w i t h the v a r i a n c e in a l c o h o l c o n s u m p t i o n a m o n g the boars m a y be a c o m p l e x p h e n o m e n o n r a t h e r than a single one. R e s u l t s here i n d i c a t e that s e r u m lipid c h a n g e s a r e u s e f u l i n d i c a t o r s f o r a c o r r e l a t i o n of the e t h a n o l consumption. B a s e d on these criteria, the high c o n s u m e r s may be more rapiuly aoapted to t h e a l c o h o l intake than the low consumers. On the other hand, the low c o n s u m e r s m a y e x h i b i t less withdrawal s y n d r o m e a n d r e t u r n to n o r m a l at a f a s t e r r a t e t h a n the high consumers. Acknowledgements W e t h a n k J. T i n s l e y f o r t e c h n i c a l for help w i t h the m a n u s c r i p t .

assistance

a n d D. T o r r e s

References I. 2.

3. 4. 5. 6.

J.D. D E X T E R , M.E. T U M B L E S O N , D.P. H U T C H E S O N and C.C. MIDDLETON, Ann. N.Y. AeaO. Sei. 27R, 188-193 (1976). M.E. TUMBLESON, D.P. H U T C H E S O N , J.D. D E X T E R and C.C. MIDDLETON, Fermented F o o d B e v e r a g e s in N u t r i t i o n (ed, C.F. GASTINEAU, W.J. D A R B Y and T.B. TURNER) pp. 457-477, A c a d e m i c Press, New York (1979). C. A L L I N G , J. B A L L D I N , K. K A H L S O N AND R. O L S S O N , S u b s t a n . Alcohol A c t i o n s / M i s u s e I, 5 5 7 - 5 6 3 (1980). C. A L L I N G , S.J. D E N C K E R , L. S V E N N E R H O L M and J. T I C H Y , A e t a Med. Stand. 185, 99-105 (1969). C. A L L I N G , G. A S P E N S T R O M , S.J. D E N C K E R and L. S V E N N E R H O L M , Acta Med. Scand. Suppl. 6RI, 1-38 (1979). R.T. H O L M A N and S. J U H N S O N , Prog. L i p i d Res. 20, 6 7 - 7 3

(1981). 7. 8.

16.

R.C. REITZ, Prog. Lipid Res. 18, 87-115 (1979). L. F O U D I N , G.Y. SUN, M.E. T U M B L E S O N a n d R.W. G E I S L E R , Fed. Prec. 40, 800 (1981). (Abstr.) M.E. T U M B L E S O N , J.D. D E X T E R a n d P. VAN C L E V E , Prog. B i o c h e m . Pbarmacol. 18, 190-195 (1981). G.Y. S U N a n d L.A. H O R R O C K S , J. L i p i d R e s . 12, 153-157 (1969). R.E. B U w M A N and R.C. WOLF, Clin. Chem. ~, 3 0 2 - 3 0 9 (1962). I.N.T. DE G O M E Z D U M M , M.J.T. DE A L A N I Z AND R.R. B R E N N E R , L 1 p l O s /.I, 6 4 9 - b 5 2 (1970). I.N.T. DE G O M E Z D U M M , M.J.T. DE A L A N I Z and R.R. B R E N N E R , J. Lipid Res. 20, 8 3 4 - 8 3 9 (1979). R.R. BRENNER, Prog. Lipid Res. 20, 41-48 (1981). A.M. N E R V I , R.O. P E L U F F O , R.R. B R E N N E R and A.I. L E I K I N , L l p z c s 15, 2 6 3 - 2 6 ~ (1980). D.L. W A N G and R.C. R E I T Z , A l c o h o l i s m Clin. Exp. Res. ~, 2 2 0 -

17.

226 (1983). D . F . HORROBIN, Med. Hypoth. E, 929-942 (1980).

9. 10. 11. 12. 13. 14. 15.