The relationship between ascorbic acid and lipid peroxidation in hepatocyte cultures using defined medium

THE RELATIONSHIP BETWEEN ASCORBIC ACID AND LIPID PEROXIDATION IN HEPATOCYTE CULTURES USING DEFINED MEDIUM A. Alper, B.J. Fuller, Academic Department of Surgery, Royal Free Hospital Medical School, London NW3 2QG UK. Isolated rat hepatocytes, maintained in serum-free culture, have been shown previously to undergo an iron-related oxidative stress as indicated by increased malonyldialdehyde (MDA) content (I). Since such reaction may effect changes in hepatocyte survival or metabolism, it may be beneficial to attempt to modulate the stress. We have investigated the effect of ascorbic acid on hepatocyte culture. This vitamin is known to have both pro- and antioxidant effects, depending on concentration, presence of transition metals etc. MDA measurements were made as an index of lipid peroxidation; cell function was assessed by dye exclusion, release of lactate dehydrogenase, and synthesis of urea. A range of ascorbate concentrations from 0.001-I0 mM was investigated and the effects of some known anti-radical agents were also examined. The results showed that a basal level of MDA (mean of 0.34 nMoles / ml medium, n=20 ) was produced progressively over 24 hours. Low concentrations of ascorbate ( to 0.01 mM ) reduced MDA formation, whilst 1 mM and especially I0 mM increased MDA up to XIO. At this high concentration dye exclusion was reduced, and also urea synthesis was depressed. Using i0 mM ascorbate, superoxide dismutase, catalase and a combination of the two did not affect MDA or cell function. The iron-chelator desferrioxamine (I mM) partly prevented the rise in MI)A but did not restore urea synthesis fully. The data are discussed in relation to documented effects of ascorbate in other systems. (i) Innes G, Fuller BJ, Hobbs KEF. Lipid peroxidation in hepatocyte culture: by free radical scavengers and iron. In Vitro 1988. In Press.

THE FATE OF I N T E R P O S I T I O N PORTAL HYPERTENSION. G.F.Rondinara, L.De Carlis, D . F o r t i , N i g u a r d a H o s p i t a l , Milan, Italy.

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P.Aseni, F . R o m a n i , M . P u t t i n i , L . T . B e l I i . II C h i r u r g i a ,

In the aim to a n a l y z e the l o n g - t e r m r e s u l t s oF i n t e r p o s i t i o n g r a f t i n g in por tal h y p e r t e n s i o n we have r e t r o s p e c t i v e l y r e v i e w e d the r e c o r d i n g s oF 50 c i r r Z hotlc p a t i e n t s who w e r e s u b m i t t e d to p o r t a - s y s t e m i c s h u n t s by u s i n g small in terposition prostheses,during the p e r i o d 1 9 6 8 - 1 9 8 4 . They were classified a c c o r d i n g to C h i l d ' s c r i t e r i a as follows: c l a s s A: 18 pts, c l a s s B: 29 pts and c l a s s C: 3 pts. The m a t e r i a l used was a 12 mm G o r e t e x in 13 pts, a 10 mm D a c r o n in 17 pts, a 12 m m D a c r o n in 20 pts. In 22 pts a p o r t a - c a v a l i n t e r p o s i t i o n graft was e m p l o y i e d , a m e s e n t e r i c o - c a v a l g r a f t in 17, and a s p l e n o - r e nal g r a f t in 11 pts. O p e r a t i v e m o r t a l i t y was of 2% (I case); the rate o£ ear ly t h r o m b o s i s o£ the g r a f t was 4% (2 cases). A l o n g - t e r m F o l l o w up was avai 3 lable in o n l y 41 pts: 11 had a late t h r o m b o s i s ( 2 7 % ) w i t h 5 c a s e s in p o r t a caval group, 5 in the m e s e n t e r i c o - c a v a l and I c a s e in the s p l e n o - r e n a l g r o u g T w e n t y - n i n e p a t i e n t s w e r e F o l l o w e d - u p For m o r e than 2 y e a r s and they w e r e p r e v e n t e d by F u r t h e r e p i s o d e s of g a s t r o - e s o p h a g e a l b l e e d i n g . In c o n c l u s i o n the use of i n t e r p o s i t i o n g r a f t in p o r t a l h y p e r t e n s i o n seems in our e x p e r i e n ce to be t e c h n i c a l l y e a s i e r then the c o n v e n t i o n a l shunting procedures with good c h a n c e s of p r o t e c t i o n From b l e e d i n g r e c u r r e n c e .

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