Como enterder los estandares internacionales

1056

Specialia

120

1st. INJ EGTION

Normal

o

100 Tolerant

"5, 80

3h following ~norpNne

60

40

0

1

JECTi

g

P ho spho~i0Fds

Free cholesterol

Ct~oPeslerol

Tr iglycerides

esters

Fig. 2. Changes in morphine effects in -various lipid fractions of rabbits plasma during chronic intoxication. IVfean values ~2 SE, p is given by Student's t-test. * p < 0.01. ** p < 0.05.

7 B. DESBALS, P. DESBALS and R. AGID, Adipose tissue (Academic Press, New York and London 1970).

EXPERIENTIA 3019

t i o n s are clearly h i g h e r t h a n in controls. F i n a l l y , in a n i m a l s w i t h d r a w n f r o m m o r p h i n e for several d a y s or e v e n weeks, t h e F F A c o n c e n t r a t i o n r e m a i n s elevated, as does t h e i m m e d i a t e h y p o l i p e m i c effect of t h e drug. I t is difficult t o e x p l a i n t h e effects on p l a s m a lipids b y c h a n g e s in e n d o c r i n e a c t i v i t y e v e n t h o u g h t h e s e effects occur s i m u l t a n e o u s l y w i t h c h a n g e s in h o r m o n a l secretion. T h e initial i n j e c t i o n of m o r p h i n e elicits A C T H secretion as well as t h a t of g l u c a g o n a. I t is k n o w n t h a t t h e s e 2 h o r m o n e s m o b i l i z e f a t t y acids ; h o w e v e r , we h a v e o b s e r v e d t h e o p p o s i t e effect o n F F A . A single dose of m o r p h i n e also causes a s e c r e t i o n of corticosteroids~ w h o s e i m m e d i a t e effects in r a b b i t s are to lower p l a s m a lipids 7. I t is possible that under these conditions the postmorphinic hypolipem i a r e s u l t s f r o m a h y p e r s e c r e t i o n of corticosterone. N e v e r t h e l e s s t h i s e x p l a n a t i o n is n o t v e r y s a t i s f y i n g w h e n one considers t h e case of c h r o n i c a l l y t r e a t e d a n i m a l s in w h i c h m o r p h i n e r e t a i n s its d e p r e s s i v e effect on p l a s m a F F A a n d in w h i c h t h e d r u g a c t u a l l y depresses r a t h e r t h a n increases t h e s e c r e t i o n of c o r t i c o s t e r o n e 2. I n c h r o n i c a l l y m o r p h i n i z e d r a b b i t s , t h e F F A level in b l o o d w i t h d r a w n 24 h a f t e r a g i v e n i n j e c t i o n is a b n o r m a l l y high. A t t h e p r e s e n t t i m e we h a v e n o e x p l a n a t i o n s for this. T o conclude, i t is v e r y difficult t o s u p p l y a p u r e l y e n d o c r i n o l o g i c a l e x p l a n a t i o n for t h e effects of m o r p h i n e o n b l o o d lipids. O t h e r e x p e r i m e n t s are n e c e s s a r y to e l u c i d a t e t h e a c t i o n s of m o r p h i n e as well as t h e c h a n g e s in a c t i o n d u r i n g chronic i n t o x i c a t i o n a n d w i t h d r a w a l .

Rdsumd. Chez le L a p i n , 1 h aprgs u n e i n j e c t i o n de m o r p h i n e on n o t e u n e baisse du t a u x des p h o s p h o l i p i d e s , des triglyc6rides et des acides gras libres (AGL) d u sang. A n cours du t r a i t e m e n t c h r o n i q u e cet effet d6pressif n e s ' o b s e r v e plus q u ' a u n i v e a u des A G L d o n t le t a u x est a n o r m a l e m e n t 61ev6 24 h apr6s la derni6re injection. R. SABLE-AMPLIS, R. AGID a n d D. ABADIE

Institut de Physiologic, E R A - C N R S No d12, 2, rue Franfois Magendie, F - 3 1 0 7 8 Toulouse-Cedex (France), 11 March 7974.

Effect of Long T e r m L i t h i u m T r e a t m e n t on Brain F u m a r a s e Activity T h e specificity of l i t h i u m t h e r a p y for m a n i c - d e p r e s s i v e p s y c h o s i s is b y n o w u n d i s p u t e d 1, ~; h o w e v e r t h e m e c h a n i s m of t h i s r e m a r k a b l e effect is still far f r o m a s a t i s f a c t o r y e x p l a n a t i o n 3, ~. I n s p i r e of t h e r e b e i n g l i t t l e or no effect o n m o s t e n z y m e s s t u d i e d 4, o u r p r e v i o u s comm u n i c a t i o n s r e p o r t e d t h e a c t i v a t i o n of s u c c i n a t e deh y d r o g e n a s e 5 a n d t h e i n h i b i t i o n of a c o n i t a s e 6 in t h e b r a i n s of mice t r e a t e d w i t h Li 2 CO~. T h e s e r e s u l t s led us t o s t u d y t h e effect of Li+ o n b r a i n f u m a r a s e ( f u m a r a t e h y d r a t a s e , E.C. 4.2.1.2 ) a c t i v i t y . 31aterial and methods. T h e e x p e r i m e n t s were carried o u t w i t h m a l e Swiss mice ( m e a n i n i t i a l b o d y w e i g h t 20 g) m a i n t a i n e d in a s t a n d a r d b a l a n c e d d i e t a d l i b i t u m . To t h e c o n t r o l g r o u p of mice, distilled w a t e r was given. T h e o t h e r g r o u p of a n i m a l s received as d r i n k i n g w a t e r a s o l u t i o n c o n t a i n i n g 100 m g Li 2 CO8/1. A f t e r a p e r i o d of 132 d a y s of e x p e r i m e n t a t i o n , t h e mice were killed b y cervical d i s l o c a t i o n a n d t h e b r a i n s r e m o v e d q u i c k l y a n d s t o r e d a t - - 2 0 ~ u n t i l used. B r a i n h o m o g e n a t e s (10%) were p r e p a r e d in ice-cold 0.1 M p h o s p h a t e buffer, p H 7.4, a n d t h e f u m a r a s e a c t i v i t y was d e t e r m i n e d b y a m o d i f i c a t i o n of t h e s p e c t r o p h o t o m e t r i c m e t h o d of RACKER 7. T h e final v o l u m e was 2.0 m l i n c l u d i n g 1.0 m l of 0.1 M

s o d i u m L-malate, p H 7.4, 0.95 m l of 0.1 M p h o s p h a t e buffer, p H 7.4, a n d 0. 05 m l of b r a i n h o m o g e n a t e to s t a r t t h e r e a c t i o n . I n c u b a t i o n was carried o u t a t 37 ~ for 10 m i n a n d t h e r e a c t i o n was s t o p p e d b y t h e a d d i t i o n of 2.0 m l of 0.5 M HC104. A c o n t r o l was p r e p a r e d for e a c h s a m p l e b y t h e a d d i t i o n of HC104 a n d h o m o g e n a t e to t h e b u f f e r e d s u b s t r a t e a t t i m e zero. S p e c t r o p h o t o m e t r i c d e t e r m i n a t i o n s in t h e s u p e r n a t a n t s were m a d e a t 240 n m in a Shim a d z u QV-50 s p e c t r o p h o t o m e t e r e q u i p p e d w i t h cells of 10 m m l i g h t p a t h . T h e e n z y m a t i c a c t i v i t y follows a zero o r d e r k i n e t i c s a n d it is p r o p o r t i o n a l t o c o n c e n t r a t i o n s of t h e h o m o g e n a t e u p t o 0.25 ml. O n e u n i t of e n z y m a t i c a c t i v i t y is e q u i v a l e n t to a c h a n g e i n o p t i c a l d e n s i t y of 0,001 in 10 m i n a t 37 ~ T o t a l p r o t e i n s is t h e h o m o g e n a t e s 1 C. P. BAASTRUP and M. Scitou, Archs gen. Psychiat. /6, 162 (1967). M. Scnou, Acta psychiat, seand., Suppl. 207, 49 (1969). 8 S. GERSHON, A. Rev. lVfed. 23, 439 (1972). D. SAMUELand Z. GOTTESFELD, Endeavour 32, 122 (1973). 5 L. A. ABREU and R. R. ABREU, Nature New Biol. 236, 254 (1972). s L. A. ABREU and R. R. ABREU, Experientia 29, 446 (1973). 7 E. RACKER, Bioehim. biophys. Acta d, 211 (1950).

15.9. 1974

1057

Specialia

Effect of Li+ on mouse brain fumarase activity Treatment

No. of mice

Body weight (g)

Fumarase (units]rag of protein)

Li,aCOa

20

29.7 ~c 0.8

1547 -b 29

Controls

20

28.8 =k 1.0

1414 • 53

Each vaIue represents the mean ~= standard error of the mean.

were d e t e r m i n e d b y t h e b i u r e t mefliod of GORNAL, ]~3ARDAILWL a n d DAVID s, using c r y s t a l l i n e b o v i n e p l a s m a a l b u m i n as s t a n d a r d a n d t h e specific a c t i v i t y of f u m a r a s e was e x p r e s s e d as u n i t s / m g of p r o t e i n . Results and discussion. T h e m e a n i n t a k e s of w a t e r or LieCO~ s o l u t i o n t h r o u g h o u t t h e p e r i o d of e x p e r i m e n t a t i o n were 6.3 a n d 6.4 m l / m o u s e / d a y , r e s p e c t i v e l y . This v o l u m e is e q u i v a l e n t t o 21.5 m g Li~COJkg b o d y w e i g h t / d a y , w h i c h is in t h e r a n g e of t h e dose used in m a n i c - d e p r e s s i v e p s y c h o s i s ~. T h e final w e i g h t s of mice a n d t h e b r a i n I u m a r a s e specific a c t i v i t y are s h o w n in t h e Table. T r e a t m e n t w i t h Li2CO , does n o t influence t h e w e i g h t s of t h e a n i m a l s (t = 0.703, P < 0.5). A s i g n i f i c a n t (t ~ 2.201, P < 0.05) increase of t h e specific f u m a r a s e a c t i v i t y was o b s e r v e d in Li+ t r e a t e d mice. Our e x p e r i m e n t s to d e m o n s t r a t e an in v i t r o effect of Li+ were negative. A d d i t i o n of Li2CO~ up t o 0.5 rag/0.05 ml of t h e h o m o g e n a t e a n d i n c u b a t i o n (37~ p H 7.4) for 15 m i n before f u m a r a s e d e t e r m i n a t i o n did n o t c h a n g e t h e e n z y m e a c t i v i t y . FORN a n d VALD~CASAS9 r e p o r t e d t h e in v i t r o i n h i b i t i o n of r a t a n d r a b b i t c e r e b r a l c o r t e x a d e n y l cyclase b y a wide r a n g e of Li+ c o n c e n t r a t i o n s . On t h e o t h e r h a n d , t h e a c t i v a t i o n of f u m a r a s e b y Li+, as well as our p r e v i o u s l y r e p o r t e d effects of t h i s ion on s u c c i n a t e d e h y d r o g e n a s e s

(activation) a n d a c o n i t a s e ~ (inhibition), w e r e o b t a i n e d a f t e r long t e r m a d m i n i s t r a t i o n . These d a t a suggest t h a t t h e effects of l i t h i u m on t h o s e 3 e n z y m e s of t h e K r e b s cycle are indirect. T h e lack of k n o w l e d g e of Li+ m e c h a n i s m of action p r e c l u d e s t h e e x a c t e v a l u a t i o n of t h e role of t h e s e e n z y m e s in m a n i c - d e p r e s s i v e psychosis.

Rdsumd. L ' a c t i v i t 6 sp6cifique de la f u m a r a s e c6r6brale des souris trait6es p e n d a n t 132 j o u r s au l i t h i u m (Li2CO3) a 6% d6termin~e. On a observ6 u n e a c t i v a t i o n significative de l ' e n z y m e . C e p e n d a n t , cet effet n ' a pas 6t6 c o n s t a t * iD vitro. L u i z A. ABREU a n d R. RAPOSO ABREU 1~ Laboratory o[ Biochemistry. Department o[ Chemistry and Experimental Therapeutics, Instituto Oswaldo Cruz, P.O. Box 926-ZC-00, Rio de Janeiro (Brasil), 22 March 7974. s A. G. GORNAL,C. J. BARDAWILLand M. M. DAVID, J. biol. Cheul. 177, 751 (1949). 9 j. FORN and F. G- VALDECASAS,Biochem. Pharmac. 20, 2773 (1971). lo R. R. A. is working with a research grant from the Conselho Nacional de Pesquisas (National Research Council of BrasiI).

Effect of C a r b o x y - or M e t h e m o g l o b i n e m i a on M o t o r C o n d u c t i o n Velocity T h e r e are several references t o i m p a i r m e n t s of peripheral motoric nerve function after carbon monoxide (CO) i n t o x i c a t i o n : CO p o i s o n i n g m a y p r o d u c e p e r i p h e r a l n e u r o p a t h y l - l ~ in d e p e n d e n c e on CO p a r t i a l pressure, t h e a m p l i t u d e of a c t i o n p o t e n t i a l of isolated u,12 or d i s s e c t e d ~ n e r v e s d e c r e a s e d ; a n d CO p r o d u c e s a r e t a r d a t i o n of t h e n e r v e c o n d u c t i o n ~, ~3,14. To d e t e r m i n e w h e t h e r t h e affection on t h e p e r i p h e r a l n e r v e is a h y p o x i c result only, we e x a m i n e d t h e m o t o r c o n d u c t i o n v e l o c i t y of t h e N. ischiadicus a f t e r a c u t e c a r b o x y - or m e t h e m o g l o b i n e mia. Methods. Male albino r a t s ( o u t b r e d stock, a b o u t 200 g) in g r o u p s of 8-15 a n i m a l s received s.c. i n j e c t i o n s of 0.5, 0.8, 2.4, a n d 12 m m o l CO/kg or i.p. i n j e c t i o n s of 0.4, 0.8 a n d 1.2 m m o I s o d i u m n i t r i t e (NaNO~)/kg. Blood s a m p l e s were t a k e n a f t e r 30 rain f r o m t h e r e t r o - o r b i t a l plexus. T h e r a t s were a n a e s t h e t i z e d b y h e x o b a r b i t a l (100 m g / k g i.p.) a n d t h e m o t o r c o n d u c t i o n v e l o c i t y of N. ischiadicus d e t e r m i n e d a c c o r d i n g to t h e m e t h o d of GLATZEL et al. xS. R o o m t e m p e r a t u r e was 22~ The c a r b o x y h e m o g l o b i n (CO-Hb) level w a s calculated f r o m h e m o g l o b i n a n d CO level in blood. H e m o g l o b i n was d e t e r m i n e d as c y a n m e t h e m o g l o b i n . CO in blood was a n a l y s e d a c c o r d i n g t o t h e m e t h o d of WIENNSESLAND16 as m o d i f i e d b y us 1Lls. The m e t h e m o g l o b i n (Met-Hb) level in blood was a s s a y e d b y t h e m e t h o d of PFORDTE xgS t u d e n t ' s t-test was used for s t a t i s t i c a l c o m p a r i s o n s .

1 ~'. CONTAMIN, M. GOULON and A. 1VfARGAIRAZ, Revue neurol. 703,

341 (1960). 2 G. J. GILBERTand G. H, GLASER,New Engl. J. Med. 261,1217 (1959). 3 I. GoTo, T. Mlvosm and Y. OOYA,Folia psychiat, neuroL jap. 26, 35 (1972). 4 B. PAULEIKHOFF, H. MOLLER-FAHLBUSCH, H. MESTER a n d U. MEISSNER, Fortschr. Neurol. Psychiat. 39, 349 (1971). 5 H. R~NFERT and A. DREW, Ann. intern. Med. 42, 942 (1955). 6 R.]Y[. SGHMIDT, Der Liquor cerebrospinalis. Untersuchungsmethoden und Diagnostik (VEB Verlag Volk und Gesundheit, BeNin 1968), p. 826. 7 B. 8CHOTT, M. TOMMASI, C. BOURRAT and D. MICHEL, Revue neu-

rol. 116, 429 (1967). s R.D. SNYDER, Neurology 20, 177 (1970). 9 A.M. VEGER, Soy. Psikhonevrol. 1t, 208 (1935). lo G. W~LSON and N.W. WINKELlVlAN, J. Am. reed. Ass. 82, 1407 (1924). 11 A. ARVAmTAmand N. CHALAZONITIS,Arch. intern. Physiol. 5d, 406 (1947). 1~ F.O. SCHmTT, Am. J. Physiol. 95, 650 (1930). la p. BARRIOS,W. KOLL and G. MALOR~Y,Naunyn-Schmiedeberg's Arch. exp. Path. Pharmak. 26d, 1 (1969). 14 W. GLAVZEL, J.U. GRO~ES, D. PA~KOW, W. PONSOLD and K. TIETZE, Int. Arch. Arbeitsmed. 37, 329 (1973). la W. GLATZEL,W. PONSOLD,J. U. GR~NES and K. TIETZE, Wiss. Z. Univ. Halle 26 (M), 99 (1972). 16 R. W~NNES~AND, Acta physiol, scan& 7, 49 (1940). 17 D. PANKOWand W. PO~SOLD, Z. reed. Labortechn. 73, 232 (1972). is D. PANKOWand W. PONSOLD,Z. reed. Laborteehn. 14, 360 (1973). 19 K. PFORDTE, Z. ges. Hyg. 79, 35 (1973).