Plasma ascorbic acid level and erythrocyte fragility in preeclampsia and eclampsia

GYNECOL-9

European Journal of Obstetrics & Gynecology and Reproductive Biology 71 (1997) 35 40

ELSEVIER

Plasma ascorbic acid level and erythrocyte fragility in preeclampsia and eclampsia Hakan

O z a n a'*, A h m e t

E s m e r b, N e d r e t

K o l s a l b, O m e r

Utku

C o p u r c, B f i l e n t E d i z J

~LDepartment of Obstetrics and Gynaecology, ]zmit Milita O' Ho~?ital, ]zmit, Turkey bDepartment qf Obstetrics and Gynaecologg', Medical Faculty, Uluda~: UniversiO', Bursa, Turkey CFaculo, ()[' Agriculture, Uluda,,#, University, Bursa, Turkey dDepartment o1' Statistics, Medical Faculo,, UludaR University, Bursa, Turkey

Received 17 January 1996; revised 24 September 1996: accepted 3 October 1996

Abstract

An imbalance between oxidants and antioxidants in the circulation is blamed to cause preeclampsia and eclampsia. In this study plasma ascorbic acid level was analysed in 13 eclamptic, 14 mild preeclamptic, 12 severe preeclamptic and 20 uncomplicated pregnancies to see whether there is any correlation with blood pressure, proteinuria, serum triglyceride level, erythrocyte fragility and leukocyte count. Plasma ascorbic acid level was normal and had no significant difference among the groups. Fasting serum triglyceride level was significantly higher in the study group than in the control group but it did not differ among the three study groups. Erythrocyte fragility was found to be increased in all three study groups. Blood leukocyte count was increased in the study groups, especially in the eclampsia group. However, plasma ascorbic acid level and erythrocyte fragility were found to have no significant correlation with blood pressure and proteinuria. It was concluded that though the ascorbic acid levels were normal in both the study and the control groups, erythrocyte fragility increased probably due to an elevation in peroxide and free radical levels in preeclampsia and eclampsia groups, but without any correlation with the severity of the clinical picture. Copyright © 1997 Elsevier Science Ltd. Keywords: Ascorbic acid; Eclampsia; Erythrocyte fragility; Preeclampsia; Pregnancy

1. Introduction

Preeclampsia and eclampsia cause high maternal and foetal morbidity and mortality with still obscure pathogenesis. Oxygen (O:) has been the origin o f life on earth but also has been a threat for life by leading to oxidation reactions to get energy for physiological processes. Pero x i d e s - - e n d p r o d u c t s o f the lipid o x i d a t i o n - - a p p e a r in the circulation as a result o f cell metabolism and exert intracellular toxicity [16]. The i m m u n e system o f the organism contributes to this process, while fighting * Corresponding author. Present address: ibrahimpa~a Mah., inane; SoL Ozpirin~ Apt., A Blok, No: 20/5, 16010 Bursa, Turkey. Tel.: + 90 224 2241110; fax: + 90 224 4428888.

with the microorganisms by producing superoxides, H202 and HOC1 [22]. D u r i n g evolution, organisms have developed antioxidant systems to neutralize those toxins. While enzymes such as superoxide dismutase, catalase and glutathione peroxidase are responsible for intracellular protection, n o n e n z y m a t i c mechanisms, especially ascorbic acid, are involved in extracellular defence [5,19]. However, any imbalance between oxidants and antioxidants leads to some dysfunctions in the organism. D u r i n g chronic inflammation, increased numbers o f activated m a c r o p h a g e s and neutrophiles migrate to host tissues and release oxidants into the extracellular space which dominate over an antioxidant system [22,1,11]. Those oxidants then exert cytotoxicity on tissues such as endothelial cells, erythrocytes and

0301-2115/97/$17.00 Copyright ~ 1997 Elsevier Science Ltd. All rights reserved Pll S0301 -2115(96)02613-9

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tf. Ozan et al. / EuropeaH Journal q/Obstetrics & Qvnecoloxu" and Reproductive Biology 71 (1997) 35 40

t h r o m b o c y t e s . Recently, it was p r o p o s e d t h a t this imb a l a n c e has an ethiological role in p r e e c l a m p s i a a n d eclampsia. A n arrest in the d e v e l o p m e n t o f the uterop l a c e n t a l vascular bed w o u l d lead to h y p o x i a , which w o u l d cause increased p r o d u c t i o n o f free radicals and lipid peroxides f r o m dec±dual l y m p h o i d tissues [17]. T h o s e o x i d a n t s act directly on v a s c u l a r s m o o t h muscle directly beneath the d a m a g e d e n d o t h e l i u m to cause v a s o c o n s t r i c t i o n . T h e y also increase the relative concent r a t i o n o f p r o s t a c y c l i n e to t h r o m b o x a n e A 2 by activating c y c l o o x y g e n a s e while inhibiting p r o s t a c y c l i n e synthetase a n d lead to elevated b l o o d pressure indirectly [17]. Studies up to now have s h o w n an inverse c o r r e l a t i o n between b l o o d pressure a n d p l a s m a ascorbic acid conc e n t r a t i o n [25,18,13]. A s c o r b i c acid was f o u n d to cause v a s o d i l a t i o n by increasing e n d o t h e l i u m derived relaxing factor [3]. It also neutralizes o x i d a n t s and enhances p r o s t a c y c l i n e p r o d u c t i o n indirectly [19]. A s c o r b i c acid is also an i m p o r t a n t c o e n z y m e in the biosynthesis o f carnitine, which is i m p o r t a n t in the t r a n s p o r t a t i o n o f long chain fatty acids into the m i t o c h o n d r i a for fl-oxid a t i o n [15,26]. Hence, in its absence, transfer o f long chain fatty acids into the m i t o c h o n d r i a b e c o m e s impossible a n d their m e t a b o l i s m shifts to triglyceride synthesis [15]. In this study, p l a s m a a s c o r b i c acid a n d serum triglyceride levels were m e a s u r e d and a n a l y s e d if any correlation with b l o o d pressure, p r o t e i n u r i a , leukocyte c o u n t a n d e r y t h r o c y t e fragility exists in p r e e c l a m p s i a a n d eclampsia.

2. M a t e r i a l s

and methods

Thirteen eclampsia, 14 mild p r e e c l a m p s i a , 12 severe p r e e c l a m p s i a patients a n d 20 u n c o m p l i c a t e d p r e g n a n cies w h o gave birth in U l u d a g University M e d i c a l F a c u l t y , D e p a r t m e n t o f Obstetrics a n d G y n a e c o l o g y between O c t o b e r 1993 a n d A u g u s t 1994 were included in the study. W r i t t e n i n f o r m e d consent was o b t a i n e d f r o m all p a r t i c i p a n t s . Patients were classified as mild p r e e c l a m p s i a as they fulfilled the s t a n d a r d criteria: absence o f a history o f h y p e r t e n s i o n before p r e g n a n c y a n d c o n f i r m a t i o n o f the

Table 1 Characteristics of the patients (mean -+ S.D.) Groups

Age

Gestation

Parity

Abortion

Study group (n = 39) Eclampsia 07 = 13) Severe preeclampsia (n = 12) Mild preeclampsia ( n - 14) Control group (n - 20)

27.1 +6.0

2.2_+ 1.4

0.8+ 1.2

(I.4-+(I.8

23.3 _+3.6

1.8 + 1.0

0.5 ± 0.8

0.5 _+0.9

29.2 ± 6.4

1.9 +_ 1.5

0.8 i 1.5

0.1 + 0.3

28.8+6.2

2.8 ± 1.6

1.1 ±1.1

0.7±0.8

27.2 _+4.3

2.0 + 1.2

0.5 ± 0.5

0.5 _+ 1.0

a n a m n e s i s with o p h t h a l m o l o g i c a l e x a m i n a t i o n ; presence o f o e d e m a ; a b l o o d pressure higher t h a n 140/90 m m H g o r an increase in diastolic pressure o f 15 m m H g o r systolic pressure o f 30 m m H g c o m p a r e d with b l o o d pressures o b t a i n e d before 20 g e s t a t i o n a l weeks; p r o t e i n uria > 0 . 5 gm/24 h or > 30 m g / d l on at least two occasions m o r e than 6 h apart. As the b l o o d pressure was shown to be higher t h a n 160/110 m m H g ; 24 h p r o t e i n u r i a exceeded 5 g m / d a y ; urine o u t p u t decreased below 400 m l / d a y ; p u l m o n a r y o e d e m a , cyanosis, cerebral s y m p t o m s , visual i m p a i r m e n t s , o r epigastric p a i n developed, they were classified as severe preeclampsia. T h o s e cases c o m p l i c a t e d with loss o f conscious a n d tonic-clonic c o n v u l s i o n s c o n s t i t u t e d the e c l a m p s i a group. B l o o d pressures were m e a s u r e d three times 2 h a p a r t in sitting p o s i t i o n after a 30 min rest. Blood pressure was assessed by a u s c u l t a t i o n o f b r a c h i a l artery using a s p h y g m o m a n o m e t e r . T h e a p p e a r a n c e o f the first K o r o t k o f f s o u n d was r e c o r d e d as the systolic a n d the d i s a p p e a r a n c e o f fifth s o u n d was r e c o r d e d as the diastolic b l o o d pressure. P e r i p h e r a l b l o o d s a m p l e s for c o m p l e t e b l o o d c o u n t and fasting serum triglyceride ( T G ) level m e a s u r e m e n t s were o b t a i n e d at a d m i s s i o n to hospital. All patients were on oral f e r r u m m e d i c a t i o n . Patients with a history o f ant±hypertensive m e d i c a t i o n , c a r d i a c disorder, d i a b e t e s mellitus, h y p e r l i p i d a e m i a , hepatic or renal disorder, the s m o k e r s a n d the d r i n k e r s were excluded t¥om the study.

Table 2 Gestational age, birth weight. Apgar score and the time of peripheral blood sampling in the groups (mean +_S.D.) Groups

Gestational age (days)

Birth weight (g)

5th minute apgar score

Date of blood sampling (days)

Study group (17= 39) Eclampsia (n - 13) Severe preeclampsia 07 121 Mild prceclampsia 01 - 141 Control group (17= 20)

235.1 i 32.8 228.6 ± 35.8 224.(I-+ 31.2 25(/.1-+ 27.3 269.2 i I 1.9

1759.9 + 847.8 1573.(/i 723. l 1511.7 _+849.5 2161.5 +862.6 3210.0 + 409.3

4.8 + 3.9 4.8 _+4. I 4.6 ± 3.9 5.1 +_4.(I 8.7 i 0.8

233.3 + 33.2 228.4 + 36.0 222.2 ± 32.0 247.1 +28.8 222.4 + 36.6

H. Ozan et al. / European Journal of Obstetrics & Gynecology and Reproductive Biology 71 (1997) 35-40

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Table 3 Complete blood counts of the groups (mean + S.D.) Groups

Leukocyte (count x 109/I)

Haemoglobin (g/dl)

Haematocrit (%/dl)

Thrombocyte (count x 109/1)

Ascorbic acid a (mg/100 ml)

Triglyceride (mg/100 ml)

Study group (n = 39) Eclampsia (n = 13) Severe preeclampsia (n = 12) Mild preeclampsia (n = 14) Control group

12.5_+4.8

12.9_+2.3

37.6_+6.1

194+92

0.6_+0.5 (0.1-2.0; 0.42)

315.8_+161.5

16.4+4.4 9.9 _+ 3.7

12.8+_1.9 14.1 _+ 2.6

37.2+5.4 40.7 _+ 6.4

17.5_+90 189 _+ 101

0.6_+0.5(0.1-1.7;0.55) 0.5 _+0.5 (0.1-1.6; 0.33)

295.5_+126.8 336.8 _+215.1

11.2_+3.9

12.1 +2.2

35.4-+5.9

215-+88

0.7-+0.6 (0.1 2.0; 0.42)

317.1 + 146.5

10.3-+ 1.9

11.8_+ 1.2

35.5+2.6

227_+47

0.7_+0.4 (0.3 1.8; 0.55)

213.2_+88.3

(n = 20) a Ranges and median values are in parantheses.

Serum triglyceride levels were determined by enzymatic-spectrophotometric methods (BioSystems). Erythrocyte fragility of the patients was determined in our haematology laboratory by using NaC1 solutions at 17 different concentrations. Heparinized blood sample (0.05 ml) was added to each 10 ml NaC1 solution. Final solutions were incubated at room temperature for 30 min and then centrifuged. Measurements were done spectrophotometrically at 546 nm wave length. The first tube (100% NaC1) was used as the blank solution and its absorbance value was accepted as 0% haemolysis. The last tube (0% NaC1) was accepted as 100% haemolysis. Haemolysis percent of the other solutions were calculated as: % haemolysis

-

optic density of the upper part of the tube optic density of the upper part of the 17th tube x 100

Plasma ascorbic acid was measured by the 2,6dichloroindophenol method [6]. Heparinized blood sample, taken before delivery, was centrifuged at 3000 rpm for 10 min and stored at - 2 5 ° C at dark. One millilitre plasma was homogenised with 7 ml 0.4% oxalic acid and then filtrated. Measurements were done spectrophotometrically at 520 nm wave length by using a 1 ml filtrate and 9 ml distilled water solution as blank. The L, reading was done with a 1 ml 0.4% oxalic acid and 9 ml 2,6-dichloroindophenol solution and the L 2 reading was performed with a 1 ml filtrate and 9 ml 2,6-dichloroindophenol solution, maximally within 15 s. Ascorbic acid level was calculated as: Ascorbic acid (mg/l)--

(Ll -- L2) × 17.71 x 1000 Amount of sample (mg)

Results were statistically analysed by using Student's t-test, Anova test, Tukey-Kramer multiple com-

parisons test, Bartlett homogeneity of variances test and regression-correlation analysis. MicroStat and InStat softwares were used and a P value less than 0.05 was accepted as significant.

3. Results

Patients were on a normal diet and were not using any medication or vitamin-mineral supplementation, but oral ferrum preparations. There was no history of alcohol or cigarette consumption or any exercise program other than normal physical activity and no family history of hypertension. There was not any significant difference between the groups in means of number of pregnancies, parities and abortions ( P > 0 . 0 5 ) but ages (Table 1). Eclamptic patients were significantly younger than those of the mild and the severe preeclampsia groups (P < 0.05). The mean gestational age at delivery ( P < 0 . 0 0 1 ) , the mean birth weight of the newborn (P < 0.001) and the 5th min. Apgar score ( P < 0 . 0 0 1 ) were significantly higher in the control group than in the study group (Table 2). However, there was no significant difference between the groups according to the time of peripheral blood sampling (P > 0.05). Plasma ascorbic acid levels did not differ significantly between the study and control groups ( P > 0.05, Table 3). Though the study group had a significantly higher serum T G (P < 0.005) level than the control group, the mean serum T G level did not differ significantly among the study groups (P > 0.05). Serum ascorbic acid and T G levels showed no correlation with the mean ages (P > 0.05). The mean leukocyte count is higher in the study group than in the control group ( P < 0.01, Table 3). Among the study groups, eclamptic patients have significantly higher leukocyte counts than the mild

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H. Ozan et al. ' European Journal o/ Obstetrics d Gvnecolojzy attd Reproductive Biology 71 (1997) 35 40

p r e e c l a m p t i c ( P < 0.01) and the severe p r e e c l a m p t i c (P < 0 . 0 0 1 ) patients, t h o u g h there was no significant difference between the mild p r e e c l a m p s i a and the severe p r e e c l a m p s i a g r o u p s ( P > 0.05). H o w e v e r , none o f theg r o u p s differed significantly from each o t h e r in terms o f the m e a n h a e m o g l o b i n , h a e m a t o c r i t and t h r o m b o c y t e c o u n t s ( P > 0.05). C o m p l e t e b l o o d c o u n t s o f the study g r o u p s h a d no c o r r e l a t i o n with the b l o o d pressure, p r o t e i n u r i a , e r y t h r o c y t e fragility and p l a s m a a s c o r b i c acid level ( P > 0.05). H a e m o l y s i s was detected at 70'¼, N a C I solution for the first time a n d till 40% NaC1 c o n c e n t r a t i o n there was a statistically significant difference between the e c l a m p sia g r o u p a n d the mild a n d the severe p r e e c l a m p s i a g r o u p s (P < 0.001, T a b l e 4). T h e r e was no significant difference between the g r o u p s at m o r e dilute N a C I c o n c e n t r a t i o n s ( P > 0.05). T h e m e a n systolic b l o o d pressure was significantly higher in the severe p r e e c l a m p s i a g r o u p t h a n in the mild p r e e c l a m p s i a ( P < 0.001) a n d the e c l a m p s i a ( P < 0.01) groups, b u t there was no significant difference between the mild p r e e c l a m p s i a a n d the e c l a m p s i a g r o u p s (P > 0.05, T a b l e 5). W h e n the m e a n diastolic b l o o d pressures were considered, the severe p r e e c l a m p sia g r o u p h a d significantly higher values t h a n the mild p r e e c l a m p s i a ( P < 0.001) a n d the e c l a m p s i a ( P < 0.05) groups. T h e m e a n diastolic b l o o d pressure o f the e c l a m p s i a g r o u p was significantly higher t h a n t h a t o f the mild p r e e c l a m p s i a g r o u p ( P < 0.01). A s a whole, the study g r o u p had significantly higher values t h a n the c o n t r o l g r o u p ( P < 0.001). H o w e v e r b l o o d pressure a n d p r o t e i n u r i a s h o w e d no significant c o r r e l a t i o n with p l a s m a a s c o r b i c acid a n d e r y t h r o c y t e fragility in the study g r o u p ( P > 0.05).

4. Discussion A s c o r b i c acid (vitamin C) is the only e n d o g e n o u s a n t i o x i d a n t in p l a s m a which can prevent the p e r o x i d a tion o f l i p o p r o t e i n s by a q u e o u s p e r o x y l radicals c o m pletely [7]. T h a t is only when the a s c o r b a t e is c o n s u m e d , o t h e r w a t e r - s o l u b l e a n t i o x i d a n t s , such as uric acid a n d bilirubin, can bind some o f the a q u e o u s peroxyl radicals. On the o t h e r h a n d , fat-soluble peroxyl radicals, are m a i n l y c a p t u r e d by a s c o r b i c acid a n d m i n i m a l l y by bilirubin, b u t no o x i d a t i o n can be seen in uric acid [8]. T h o u g h the n o r m a l p l a s m a level o f a s c o r b i c acid is 1.0 mg/100 ml, some a u t h o r s accept the lower limit to be 28 m m o l / l or 0.5 mg/100 ml in h u m a n [15,2]. M a r ginal p l a s m a a s c o r b i c acid level is 1 1 - 2 3 m m o l / l or 0.2 0.4 mg/100 ml. W h e n the level is below 11 mmol/1 or 0.2 mg/100 ml, the situation is called a mild v i t a m i n C deficiency [4]. U n d e r n o r m a l c o n d i t i o n s a l m o s t all a s c o r b i c acid in p l a s m a exists in the r e d u c e d form [12]. Free radicals cause o x i d a t i o n in v a r i o u s tissues a n d m e m b r a n e s . A q u e o u s peroxyl radicals oxidize p h o s p h o lipid l i p o z o m a l m e m b r a n e s , e r y t h r o c y t e m e m b r a n e s and the L D L molecule. F o r example, o x i d a t i o n o f e r y t h r o c y t e m e m b r a n e results in h a e m o l y s i s o f various degrees, which is related to the level o f free radicals [24,14]. A d d i t i o n o f a s c o r b i c acid into the m e d i u m leads to a d o s e - d e p e n d e n t decrease in haemolysis. Increase in e r y t h r o c y t e fragility in o u r eclampsia, mild p r e e c l a m p sia and severe p r e e c l a m p s i a g r o u p s s u p p o r t s the hypothesis o f increased levels o f free radicals in the circulation. W h e n the significantly higher leukocyte c o u n t s either in the study g r o u p in c o m p a r i s o n with the c o n t r o l g r o u p or in the e c l a m p s i a g r o u p in c o m p a r i s o n with the mild and the severe p r e e c l a m p s i a g r o u p s are

Table 4 Erythrocyte fragility values of the groups (mean _+S.D.) NaCI Concentration (%) Normal value C/, haemolysis) Eclampsia ( n - 13)

Severe preeclampsia ( n - 12)

Mild preeclampsia ( n - 14)

I00 90 85 80 75 70 65 60 55 50 45 40 35 30 20 10 0

0.0 + 0.0 0.0 + 0.0 0.0 + 0.0 0.0 + 0.0 0.0 + o.o 1.4 + 0.2 22.6 _+2.3 31.9 + 2.4 54.3 _+3.4 68.9 + 2.6 90.7 _+6.5 97.7± 1.1 98.1 + 1.5 99.0+0.8 98.7 _+ 1.4 100.0 ± 0.0 100.0 + 0.0

0.0 + 0.0 0.0 + 0.0 0.0 + 0.0 0.0 + 0.0 o.o _+o.o 1.4 + 0.2 20.2 _+ 1.9 29.8 + 3.1 52.7 _+3.3 72.8 _+4.3 90.2 +_2.6 97.2+1.6 98.5+0.5 98.6_+0.9 99.1 _+0.8 100.0 _+().(t 100.0 + 0.0

0 0 0 0 0 0 (I (I 0 0 0 50 90 97 100 100 100

5 45 90 99 100

0.0 ± 0.0 0.0 + 0.0 0.0 + 0.0 0.0 + 0.0 0.0 + o.o 1.3 + 0.1 7.6 + 1.3 21.9 + 2.3 27.5 _+3.9 69.6 + 3.2 85.3 _+2.8 94.8+ 1.4 97.7+2.5 9.1_+1.3 98.1 +2.4 100.0 + 0.0 100.0 + 0.0

H. Ozan et al. / European Journal o f Obstetrics & @necology and Reproductive Biology 71 (1997) 35 40

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Table 5 Blood pressure and proteinuria values of the groups (mean _+S.D.) Groups

Systolic blood pressure (mmHg)

Diastolic blood pressure (mmHg)

24 h urine protein value (g)

Study group (n = 39) Eclampsia (n = 13) Severe preeclampsia (n-12) Mild preeclampsia (n = 14) Control group (n = 20)

159 ± 24 157 _+20 181 +21 142 i 14 110 -- 12

104 ± 1 105 ± 10 117 _11 92 + 8 78 ± 9

2.5 + 1.7 2.6 _+ 1.6 3.0_+2.0 1.9 _+ 1.4 0

t a k e n into a c c o u n t , the c o n t r i b u t i o n o f l y m p h o i d tissue p r o d u c i n g circulating lipid p e r o x i d e s a n d free radicals to the w a s t a g e o f a s c o r b i c acid can be c o n s i d e r e d (Tables 3 a n d 4). L i p i d p e r o x i d a t i o n activity is directly related to the g e s t a t i o n a l age a n d decreases after delivery. U o t i l a et al. have p r o p o s e d an increase in the p e r o x i d a t i o n reactions, which in t u r n s t i m u l a t e a n t i o x i d a t i v e system d u r ing p r e g n a n c y [21]. Since there was no significant difference a m o n g o u r g r o u p s in m e a n s o f the d a t e o f b l o o d sampling, g e s t a t i o n a l age was n o t expected to have a n y influence on o u r results ( T a b l e 2). T h e r e f o r e the sole f a c t o r c o n t r i b u t i n g to the increased e r y t h r o c y t e fragility was t h o u g h t to be the h y p o t h e t i c a l l y increased levels o f free radicals a n d p e r o x i d e s d u r i n g the developm e n t o f p r e e c l a m p s i a a n d eclampsia. E p i d e m i o l o g i c a l studies from U S A , F i n l a n d and J a p a n have shown an inverse c o r r e l a t i o n between a s c o r b i c acid i n t a k e a n d systolic and diastolic b l o o d pressures [25,13,20]. V i t a m i n C level was f o u n d to be low in hypertensive rats a n d its s u p p l e m e n t a t i o n was s h o w n to lower the b l o o d pressure in a n i m a l studies [23,10]. H o w e v e r , there was neither a significant difference in a s c o r b i c acid levels a m o n g the g r o u p s n o r a c o r r e l a t i o n between the p l a s m a a s c o r b i c acid value a n d b l o o d pressure in o u r s t u d y (Table 3). T h e m e a n p l a s m a a s c o r b i c acid level was n o r m a l in all g r o u p s in o u r study. T h e m e t h o d we used to m e a s u r e the p l a s m a a s c o r b i c acid level was d e p e n d e n t on the p r i n c i p a l o f r e d u c i n g the c o l o r e d 2 , 6 - d i c h l o r o i n d o p h e n o l dye to the colourless l e u c o - f o r m by a s c o r b i c acid, hence it was specific for the r e d u c e d f o r m o f the molecule [6]. T h e oxidised form o f a s c o r b i c acid is negligible a n d is a l m o s t t o t a l l y in its r e d u c e d form in p l a s m a , which is i m p o r t a n t for the p r e v e n t i o n o f p e r o x i d e s a n d free radicals. H o w e v e r , in recent times high p e r f o r m a n c e liquid c h r o m a t o g r a p h y ( H P L C ) is used to m e a s u r e a s c o r b i c acid levels with higher accuracies [4]. To confirm o u r result, we m e a s u r e d serum T G levels o f the p a t i e n t s a n d f o u n d no significant difference a m o n g the s t u d y g r o u p s in m e a n s o f the serum T G levels in this study (Table 3). The role o f a s c o r b i c acid in T G synthesis s u p p o r t s the finding o f indifferent levels o f a s c o r b i c acid in these groups.

A s c o r b i c acid acts as a p r o o x i d a n t r a t h e r t h a n as an a n t i o x i d a n t u n d e r s o m e c o n d i t i o n s , especially when the metal ions are present in the m e d i u m . Niki, has f o u n d t h a t the c a t a l y t i c a c t i o n o f ferric ion in fatty acid o x i d a t i o n , was s t i m u l a t e d by a s c o r b i c acid [16]. Recently G i r o t t i et al. have o b s e r v e d b o t h p r o o x i d a n t a n d a n t i o x i d a n t roles o f a s c o r b i c acid in lipid p e r o x i d a t i o n o f e r y t h r o c y t e m e m b r a n e s [9]. H a e m e p r o t e i n s , released f r o m the h a e m o l y s e d e r y t h r o c y t e s , might be p r o v o k i n g the p r o o x i d a n t effect o f a s c o r b i c acid, which in turn w o u l d c o m p l e t e the vicious circle. W e c o n c l u d e d that, t h o u g h the a s c o r b i c acid levels were n o r m a l in b o t h the s t u d y a n d c o n t r o l groups, e r y t h r o c y t e fragility increased p r o b a b l y due to an elev a t i o n in p e r o x i d e a n d free radical levels in p r e e c l a m p s i a a n d e c l a m p s i a groups, b u t w i t h o u t a n y c o r r e l a t i o n with the severity o f the clinical picture. This in turn, w o u l d lead to release o f h a e m e p r o t e i n s into the circulation. The p r o o x i d a n t effect o f the a s c o r b i c acid w o u l d p r e d o m i n a t e in ferric ion-rich m e d i u m a n d this might worsen the clinical picture o f p r e e c l a m p s i a a n d eclampsia.

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