Ir aq i J.Pharm.Sc i., Vol.15 (1 )  ,2006 37

Effects of Allopurinol on Ketone Body Metabolism and Tissue Lipid 
Peroxidation in Alloxan Diabetes in Rats.  

Saleh A. Wohaieb 
Receive r  3-8-2003        Acce pted  13-6-2004 

ABSTRACT  
The  a im o f the pres ent stud y is  to  inv es tiga te  whethe r or not xanthine oxid as e (XO)–d eriv ed reac tive  
oxyge n sp ecies  (ROS ) may pla y a role in the  patho ge nes is  of a lloxan (ALX)–induce d diabe te s in ra ts  
us ing the sp ec ific XO inhibito r and hydro xyl radica l sc av enger, a llop urinol 

The  involve ment of oxida tiv e stre ss  in ALX – diabe te s wa s as ses se d by the mea surement of pla sma  and 
va rious  tiss ues  lipid p eroxide s le vels  ( us ing thioba rb ituric  a cid ( TBA ) rea ctive substance s ). 
Furthe rmo re , the ab ility o f allopurino l to influe nc e thes e and  o ther biochemica l pa ra meters, including 
plas ma and urine ke to nes  le vels we re  a ls o inve stigated  in diab etic ra ts . 

Rats  were divide d into  four group s: c ontrol, untrea te d diabe tic , allopurino l – trea te d diabe tic, and  
insulin – tre ated  d ia betics . At the  e nd  o f the one wee k experimenta l pe riod, bloo d and  tiss ue sa mples  
were ob ta ined fro m ane sthe size d anima ls  for the mea sure ment of the ab ove  –  me ntione d pa rameters.  

   Although the s ingle intrap eritonea l (i.p.) injec tion of a llop urinol (25 mg/kg bod y wt.) 1h be fo re  o r 1h 
after ALX injec tion (10 0 mg/kg b ody w t., i.p.) faile d to  p re vent the  ind uction o f diab etes , it did lo wer 
ke to nuria and  the  inc idence of early ketos is–a ss ociated  morta lity in diab etic animals  in co mparison 
with non– allo purinol–treate d d ia be tic rats. S ubs eq uent ad ministra tion o f allopurino l (25 mg/kg b ody 
wt., i.p.) e very 48  hr for 1 wk (i.e., 3  a dditio nal dos es ) als o d ec re ase d plas ma ke to ne  b odies  lev els as  
well a s plasma and  tiss ue (hea rt, liver, kid ney, pa nc re as) lipid pe ro xides  lev els in c omp aris on with 
no n–a llop urinol–tre ated dia betic ra ts . Da ily ins ulin inje ctio n (9–1 2 U/kg bo dy wt., S.C.) for 1wk pe riod  
no rma lize d all o f the ab ove –me ntio ne d abnormalities . 

The  pre se nt res ults sugge st that XO–de rive d ROS play a  minor role (if a ny) in the diabe to ge nic effe ct 
of ALX. On the othe r ha nd, although the  me chanism (s) und erlying the protec tive  e ffe cts of a llop urinol 
on the  d ia betic state is prese ntly unknown, the se  e ffec ts  ma y re fle ct a  p oss ib le  a ss ociation be tween 
impaire d ke to ne  b ody me tabo lism a nd lip id  peroxid atio n: a nd  s ugges t a n effect of allo purinol on ketone  
bod y meta bolis m. 

  :خالصة 
ز٬  كسدي ن انزيم الزانثين او كونة م مت وال علة ٬  ن المتفا جي وكس جود أي دور ألنواع األ كانية و هو تقصي إم ة  ن الدراسة الحالي هدف م إن ال
زيم          ط الخـاص ألـن ب ول ٬ المـث وريـن ار االلوبي خدام عـق ك باسـت ن ٬ وذـل ن في الجـرذا سا طة االلوك ث بواس محد ري ال مراضية داء السك في ا

وك وكسيل الحرة الزانثين ا هيدر ور ال جذ ح  كذلك كاس   .سديز و

وكسيدات الدهن  مستويات بير الل قياس  كسان من خ طة االلو ث بواس محد ري ال هاد التأكسدي في داء السك وتم تقييم الدور الذي يؤديه االج
سجة  الن من ا عديد  وال ما  ك    ( في البالز ورـي وباربتي مـع حمـض الثاي ة  مواد المتفاعل ة  ). بأستخدام ال ك باالضـاف ذل ار     , ـل عـق ة  م دراسـة قابلـي ـت

خـرى  ة اال ة الحياتي ميائي كي ر ال معايي كذلك على ال عايير و ي      , االلوبيورينول في التأثير على هذه الم ات ـف وـن كيت ويات ال ت ـس ومـن ضـمنها م
سكري مصابة بال ي الجرذان ال ول ف زما والب مجاميع. البال ة  ن الى اربع جرذا رة: وتم تقسيم ال ر  , السيط غـي ي  سكر مصابة بال ة ال عالجـ , الم

ة بااللوبيورينول ري والمعالج ة بالسك ولين, المصاب ة باالنس عالج كري والم ة المصابة بالس وع مجم ممتدة . و جربة ال وبعد انتهاء فترة الت
وع واحد سب عايير اعـاله , ال ن اجل قياس الم رة م خد من الحيوانات الم سجة  الن وا من الدم  ن ٬      .تم أخذ عينات  ن الحـق مـن ا رغم  ى اـل عـل و

وا مرة  ول ول ورين وبي الل ون /ملغم 25(حدة ٬ لعقار ا سم في البريـت زن الج غم و كسـان        ) ك ن االلو حـق ن  ـم عـد سـاعة  عة أو ب ل سـا  100(قـب
غم جسم في البريتون/مل زن ال غم و ى   ) ك ذلك إـل ـك وى الكيتون في البول ٬ و ى إلى تقليل مست ري ٬ إال إنه أد ٬ قد فشل في منع حدوث السك

ر كرة الم وث الوفيات المب وزية انخفاض حد كيت جسم(افقة لل ط الكيتون في ال ع تلك غير ) فر كري بالمقارنة م ة بالس ي الحيوانات المصاب ف
ة بااللوبيورينول  ول . المعالج ورين اللوبي مرات ٬ لعقار ا ولثالث  الحق ٬  ى الحقن ال غم 25(وقد أد رة /مل ن ٬ م ريتو جسم في الب وزن ال غم  ك

ة 48كل  و) ساع ك إلى تقليل مست ما والعديد لمدة أسبوع ٬ كذل ي البالز هن ف كسيدات الد ت بيرو مستويا وخفض  ما ٬  ي البالز ون ف كيت يات ال
جة  ن األنس رياس(م ة ٬ البنك كبد ٬ الكلي ب ٬ ال ول ) القل ورين وبي الل جة با معال ر ال غي ري  سك ة بال مصاب وانات ال حي ع تلك ال وقد أدى . بالمقارنة م

مي باالنسولين  1–9(الحقن اليو جسم ٬ /وحدة 2 وزن ال غم  حت الجلدك ي       ) ت ة ـف عـي ر الطبي غـي رات  ع التغـي مـي لمدة أسبوع إلى تصـحيح ج
ري  عاله في حيوانات السك كورة أ مذ ود دور ضـئيل     . المعايير ال ـج ة لو ج الحالـي ائ ة    ) إن وجـد (وتشير النـت متفاعـل كسـجين ال واع األو ألـن

ن سا وك الل ري ل ث للسك محد ي التأثير ال وكسديز ف ن أ زانثي زيم ال من أن ة  من نا. والناتج رىو ة اخ ة     ,حي آللـي ة ا رـف مـن عـدم مع رغم  وعلى ال
آلليات( ي    ) ا ل ـف ين الخـل ما ـب وجود عالقة  ة  مكاني كس إ ها قد تع ر٬ إال إن حاض ول في الوقت ال ورين ن التأثيرات المفيدة لأللوبي ؤولة ع المس

ري العملية رض السك ن في م كسدة الده رو وبين بي ن  كيتو ة لل جود تأثير لعقار,االيضي عملية  وقد تشير أيضاً إلى و ورينول على ال االلوبي
ن  كيتو ة لل   .االيضي

  
  

Dep t. Pharma colog y an d Tox ic ology, Co lle ge of Pha rmacy, Univers ity o f Baghdad, Bagh dad –
Ir aq .  



Ir aq i J.Pharm.Sc i., Vol.15 (1 )  ,2006 38

INTRODUCTION     
     There is co nside ra ble ev id enc e that 
xa nthine  oxid as e (XO) sys tem (o ne so urce  of 
superoxid e rad ic als in the bo dy) ma y b e 
invo lve d in the generatio n of rea ctiv e oxyge n 
sp ecies  (ROS )in s eve ra l co nd itions  a ss oc ia te d 
with o xidative  s tres s, includ ing chro nic 
obs tructiv e p ulmonary d is ea se  (1), isc hemia –
re pe rfus io n injury (2), e ndo thelia l dysfunctio n 
in typ e II diab etes  (3). Furthermore, in v itro 
stud ie s hav e sugge sted that ROS (ge ne ra te d 
during the  oxid ation of hypo xa nthine  by XO) 
may p la y a role in c ausing o xidative d amage to 

ra t pancre atic –c ells (4). 
The  p re se nt s tudy wa s therefore undertaken to 
inve stigate whe ther or not XO–de rive d ROS 
may p la y a ro le  in the pa thoge ne sis of ALX–
induced  diabe tes using the sp ec ific XO 
inhibitor (a nd c ons eq uently of superoxid e 
ge neration) as  well a s hydroxyl ra dical 
sc ave nger, allopurino l (5). If the  mechanis m (s) 
of ROS prod uc tion in ALX–d ia bete s is 
med ia te d, a t lea st in pa rt, through the enzyme 
XO, the n allo purinol sho uld either p re vent or 
at le ast ame liorate the  d ia be tic sta te . 
MATERIALS and METHODS  
    Adult fema le Wista r ra ts  (20 0–2 50 g) were 
ho use d in hanging p la stic  cages  in a room kept 
at 2 2–2 5C with a  1 4hr light and  10 hr d ark 
cycle. Anima ls  we re  a llowe d free  ac ce ss  to 
fo od and water during the entire exp erime ntal 
pe riod exce pt tha t o f the inductio n of d ia bete s 
whe re  a nimals were fas te d fo r 48 hr p rior to  the 
ad minis tration o f alloxa n (6). 
Diabe te s was  induce d in ethe r– ane sthe size d 
anima ls  by the intra pe ritone al (i.p .) inje ction of 
allo xa n (S igma Che mic als Co , USA) at a  d os e 
of 10 0 mg/kg bo dy w eight a s a fres hly 
prepa re d so lution (10 0 mg/ml) in sa line . ALX–
trea ted anima ls  were allo wed to  drink 5% 
gluc ose  s olution ov ernight to o ve rc ome drug–
induced  hypo glyce mia (6). The  diab etic s ta te 
was  mo nitered by the  frequent da ily tes ting for 
gluc osuria (with Lilly Te s–Tape , Eli Lilly & 
Co, US A) a nd  fo r ketonuria  (using strip s 
obta ined fro m Ketostix, Ames  Co , US A). 
  The follow ing group s were studied : 
1- Control rats  (n = 6). 
2- Untre ated  d ia betic ra ts (n = 1 2). Rats  of this 
group re ceive d the alka line  v ehic le  (0.2 –0 .2 5 
ml o f sa line , p H 1 2.0) i.p. 1 hr b efore (n = 6) or 
1hr (n = 6 ) after ALX inje ctio n.  
Diabe tic rats  which survive d this p erio d 
re ce iv ed further a lkaline vehic le  injec tio ns at 
48, 96  a nd 14 4 hrs after ALX inje ctio n. 
3- Allop urinol–tre ated  d ia betic ra ts  (n =12). 
Allo purinol (Sigma  Chemica l Co, USA) wa s 
prepa re d at a  co nce ntra tio n o f 25 mg/ml of 
sa line  pH 12 .0 . Rats re ce iv ed a s ingle i.p. 

inje ctio n of 0 .2 –0.2 5 ml of alkaline ve hicle to 
atta in a fina l do se  o f     25 mg/kg b od y wt. 1hr 
before (n = 6 ) or 1hr (n = 6 ) a fte r ALX 
inje ctio n. Then a llop urinol wa s furthe r give n 
at 4 8 hr, 9 6 hr a nd 14 4 hr o f the  ALX–diab etic 
period. The  d ose  o f allopurino l was  ¼ o f that 
dos e (1 00 mg/kg bod y wt.) re ported to prov id e 
protection aga inst oxid ative– stre ss –induce d 
lipid pe ro xidation in va rious tis sue s of ra ts  (7). 

4- Insulin–treate d diabe tic rats (n = 6) : 
ALX–d ia be tic a nimals were injec te d with 
insulin zinc s us pe nsion (Lente  MC, Nov o 
Indus tri A/S, De nma rk) sub cuta neo us ly a t a 
daily do se o f 9 –12  U/kg bo dy wt. (6) 
imme diately afte r detec tion o f the  diab etic 
state. The  do sa ge of insulin was ad justed  b y 
daily monitering urina ry gluco se and ketone 
le vels. 

   At the end of the  1 wk exp erime ntal perio d, 
a nimals  were a ne sthe size d with e ther, and  
hep arinis ed bloo d samples were ob ta ined  by 
c ardiac  puncture. Animals we re  kille d by 
c ardiac  e xcis ion, a nd tis sue  (he art, pancrea s, 
liver a nd kidney) homogenates  (1 0% w/v) 
w ere  prepa re d in ice –c old 50 mM Tris  – 0.1M 
EDTA buffe r, pH 7 .6 . P la sma  & tis sue  
malond ia ld ehyde  (MDA) lev els (as  a n inde x of 
lipid p eroxida tio n) were determine d b y the  
thio barbituric  ac id  (TBA) re action (8). The  
TBA–rea ctiv e s ubs tanc es  were c alculated  
using a n e xc tinc tion co effic ie nt of MDA of   
1 .56  10 5. 

   Plasma lev els o f gluco se, c hole sterol & 
triglyce ride s as well a s uric ac id  (to  a ss ess  
xanthine o xida se a ctivity) we re  mea sured  
using commercial a ss ay kits (Sigma  Chemica ls  
Co, US A). Pla sma  ketone b odies  lev els (–
hyd ro xyb utyrate) we re  mea sured  us ing the  
metho d o f Williamson and Ma lla nby (9). –
hyd ro xyb utyrate is q uantitatively the  
predo minant ke to ne  bo dy pres ent in the blood  
in unc ontrolle d diabe te s me llitus (10).  

   Statis tic al analys es were performed using 
ANOVA a t significance  leve l of P < 0 .0 5. 
F urther spe cific  gro up d ifferenc es  we re  
d etermined  using Tuke y’s tes t. 

RESULTS 

Ge neral Features of Diabe tes : 

      The  a dministratio n of the  a lkaline vehic le  
(whe ther giv en 1hr be fo re  or 1 hr a fter ALX 
inje ctio n) did not p re vent the incidence  of 
d ia be te s, and  p ro duc ed c ompa ra ble picture in 



Ir aq i J.Pharm.Sc i., Vol.15 (1 )  ,2006 39

re gard to  de gree of ke to sis and  the early 
morta lity amo ng diab etic ra ts . 

   Induc tio n o f diab etes  wa s co nfirmed  b y the 
pres enc e of gluco suria and ke to nuria within 2 4 
after ALX – inje ctio n. During the firs t we ek of 
diab etes, 6 animals died  in ketosis  a nd d ia betic 
co ma, whic h s tarte d a s ea rly as 48  hr a fter 
inductio n of d ia be te s. 
  Anima ls  whic h survive d this  pe riod  (6/12) 
also  s ho wed hype rglycemia  , 
hypertriglyc erid emia , a nd ketone mia (Table 1) 
at the end  o f 1 wk pe riod . How eve r, le vels of 
plas ma      choleste ro l and uric  a cid were not 
changed  during this  p erio d (Ta ble 2). Plas ma 
and tiss ue lipid peroxid e lev els w ere a ls o 
elev ated in ALX– diabe tic  rats (Tab le  3 ). 
Effect of Allopurinol Tre atme nt  
      Al though the  s ingle i.p. injectio n of 
allopurinol (25  mg/kg b ody wt.) giv en 1hr 
prio r to or 1 hr pos t ALX a dministra tion did not 
prevent the induc tio n o f diabetes , it did lower 
the inc id ence of early ketos is–associated 
mortality in these  animals. Unlike the 
high mo rtality in no n– allopurinol–treated 
diabetic  a nimals, only 2 of the 12  a llop urinol–
trea ted diabetic  rats  die d in ke tosis and coma 
(Table 1). The re maining 10  a nimals showed 
gluc osuria  a nd slight ketonuria. Treatme nt with 
allopurinol fo r 1 wk pe riod  did  a ls o lower the 

assoc iated ke to ne mia  (Ta ble 1) as  well as  the 
lipid pe roxide leve ls in plas ma and tiss ues of 
allo purinol–trea te d d iabe tic ra ts c ompared to 
the no n –tre ated  d iabetics  (Table 3). 
Effect of Insulin Tre atment  
   Insulin trea tment (9  –1 2 U/kg bod y wt/da y) 
starte d immediately a fter d etec tion o f diabetes 
preve nted  the ketos is –associa ted c oma  and 
morta lity, and normalize d a ll o f the a bove–
mentioned ab norma litie s (Tab le  1–3). 

  

Table  1: Plasma  a nd ur ine  ke to ne  bo dy leve ls and mortality  rate  in c ontrol, untre ated–ALX 
dia be tic, a llo pur inol–tre a te d–ALX diabe tic, and ins ulin t re ate d–ALX diabe tic  rats after 

1wee k of diabe te s 

 

                   
 
  
 
 
 
 
                         
                                                                                                                                                                                                                                                   
                                                                       
 
 
 
 
 
 
  
 
 
 
           Va lue s  a re  e xpresse d as  me an  SD.     
         - Va lues  with diffe re nt le tters are  significa ntly diffe re nt (P < 0.05).   
         * Ur ine  ketone  body le ve ls  we re qua litativ e ly measure d using ke tostix strips  o btaine d fro m   
           Ame s Co, USA, as  describe d in mate rial and me thods 

 Pla sma  k etones  

(-
hyd ro xybutyrate) 

(mol/L ) 

U rine  
ke tone s*  

(acetoa ce ta te) 

Number o f animals 
d ied with  d iabe tic 

co ma/1wee k 

Con trol 

(n = 6) 
0 .6 8  0.29 a (– ) – 

  Un treated –
dia betic  

(n  = 12) 

9 .2 0  3.60 b (+  +  + ) 
6/12  anima ls 

(50 %) 

A llop urinol
–trea ted 
dia betic  

(n  = 12) 

3 .5 4  2.02 c 
2 (+  + ) 

2 (+) 

8 (–) 

2/12  anima ls 

(17 %) 

In su lin –
trea ted 

dia betic  

(n = 6) 

0 .9 8  0.35 a (– ) – 



Ir aq i J.Pharm.Sc i., Vol.15 (1 )  ,2006 40

 
Ta ble  2: Body  we ig ht a nd bioc he mic al parame te rs in control, untre a te d–ALX d ia be tic, 

allo pur inol–tre a te d–ALX diabe tic, and ins ulin treate d–ALX dia be tic  rats. 

G ro up 
Body wt. 

(g) 

Plas ma  le ve l (mg /dL) 

G luco se Triglyce de Cho les te rl Uric acid 

Contro l 

(n = 6 ) 
2 31   24 146  9 a 104  23 a 65.823.2 1 .80 0.15 

  U ntreated –
diabe tic  

(n = 6 ) 

2 19   26 47875 b 6 35   28 7 b 61.919.3 1 .70 0.19 

A llo purino l–
treated 

diabe tic  

(n = 10 ) 

2 28   18 497  120 b 5 95   21 2 
b 52.511.6 1 .73 0.22 

Insulin–
treated 

diabe tic  

(n = 6 ) 

2 38   32 10930 a 168  53 a 5 8  1 9.3 1 .68 0.20 

        - Values  are  expre sse d as  mean   S D. 
         - With in e ach column, va lue s with diffe re nt le tters are    
          signif ic antly diffe re nt (P < 0 .05). 

 

Ta ble  3: Pla sma and tis sue  TBA–reactive  substances  (a n in de x  o f lipid pe roxida tion) in 
control, untre a te d–ALX d ia be tic, allo pur inol–tre ate d–ALX diabe tic, and ins ulin tre ate d–

ALX diabe tic  rats. 

Gro up 

TBA –Re ac tive  s ubstances  

Plas ma 

n mol/ml 

nmo l/g we t tissue 

He a rt Live r Kidne y Pancre as   

Co ntro l 

(n = 6 ) 
1.44 
0 .32a 

178  
2 5 a 

451    

37  a 
221   
33  a 

184   

 34  a 

Untreated –
d iabe tic  

(n = 6 ) 

5.93 

2.80 b 
600  
7 5 b 

6 12   

 95  b 
386   
6 5 b 

368    

44  b 

Allopurino l
– trea ted 
d iabe tic  

(n = 10 ) 

2.28 
1 .32a 

351  
8 8 c 

273 
101 c 

298 
60  c 

280    

67  c 

Ins ulin–
trea te d 

d iabe tic  

(n = 6 ) 

1 .65 
0.5 4a 

1 56 
13  a 

460    

84  a 
218   
27  a 

172   

 57  a 

             - Value s are  e x pre ss e d as  me an  SD. 
             -  Within e ac h column, v alue s  with diffe re nt le tte rs are  
          sig nifica ntly diffe re nt (P < 0.05). 

 

 

 



Ir aq i J.Pharm.Sc i., Vol.15 (1 )  ,2006 41

DISCUSSION   
The  d ia be tic state  prod uc ed in rats  d uring the 
first wee k follo wing ALX inje ctio n wa s 
co nfirmed  b y gluc osuria ,  ke tonuria, 
hyperglye mia  and ketonemia. The d ia betic 
state wa s also  a cc ompa nied  b y elev ated  plasma 
and tiss ue lip id  pe ro xides  lev els as  well a s 
increa sed  inc idence of early keto sis – re la te d 
mortality. 
 The ab ility of insulin therapy to comp le tely 
re ve rse  the se  c hange s s ugge sts that the y are 
re la ted to  the diabe tic state in this strictly 
insulin– dep endent mo del of exp erime ntal 
diab etes (6). 
In a n a tte mpt to inv es tiga te  whether o r not 
allo purino l c an p re vent the  inductio n of 
diab etes, the single  i.p . ad minis tration of 2 5 
mg/kg b ody wt. fa iled  to prev ent the inductio n 
of d ia bete s, whethe r it was  ad ministra te d 1hr 
be fo re or 1hr afte r ALX injection. This  fac t is 
sugge stive of a  mino r ro le  (if a ny) of XO –
ge nerated  ROS in the diab etoge nic action of 
ALX, and d is agree s with the  conclus io n 
re ac hed  b y Helle r et al.(4) who  s ugges ted that 
ROS ge ne ra te d by XO are re sp ons ib le  for the 
de structio n o f ins ulin –prod ucing –c ells 
during ins ulitis.  
Howe ver, the  single  a llop urinol a dministratio n 
was  a ble not only to lower ketonuria , but a ls o 
the inc id ence o f e arly ke to sis–a ss oc ia te d 
mortality in diabe tic  rats, a fact sugge stive of a 
pos sible effe ct o n ketone b ody me ta bolism. 
Furthe rmo re , preliminary experiments  rev ea le d 
that after a s ingle i.p . a dministratio n of 
allo purino l, urinary ketone b odies  sta rt to 
increa se (afte r the  initia l d ecline in leve l) again 
within 5 0–6 0 hr in a llop urinol–tre ated dia betic 
anima ls  : and b y a pproxima te ly 80  hr of 
diab etes no  significa nt diffe re nc es co uld b e 
obs erve d betwe en a llop urinol–tre ated and non–
allo purinl–tre ated  d ia betic anima ls . This 
find ing, s ugges ts  the  invo lv eme nt of 
allo purino l and /o r its  me ta bolite  a lloxanthine 
in these  p ro te ctive effects , give n that the half–
life o f a llop urinol is 2– 3 hr a nd  that of 
allo xa nthine  is 1 8–3 0hr(11). Acc ordingly, the 
pres ent e xpe riment also a pplied rep ea te d 
ad minis tration o f allo purino l ev ery 48 hr for 6 
da ys. Inte re stingly, thes e rep ea te d 
ad minis tration o f allo purino l did lo wer ketone 
bod y le ve ls  in bo th urine  a nd plas ma and the 
lo wered  mo rtality rate (d ue to the firs t single 
dos e) was  ma intained  till the e nd of 
experimenta l pe riod  (1we ek). 
It is  imp orta nt to po int out that although alka li 
trea tment has  b een reco mmende d to correct 
diab etic  ketoac id os is  (12), the pos sibility that 
the ab ility o f allo purino l to  lowe r ke tonuria is 
in fa ct a ttrib utable to the high alkalinity of the 

disso lv ing vehic le  (pH 12) rathe r than to a  
dire ct effec t of allopurino l per s e has  b een 
rule d out. Dia betic anima ls  re ceiving  the  s ame  
alkaline  ve hicle fa ile d to  de monstra te  s imilar 
protective e ffec ts .  
   In a c ompute r med– line  se arch o f the  
literature from 1 970  –2 002 , no  co mparab le  
re ports  co nce rning the effe ct of a llop urinol 
trea tme nt on keto ne b ody metab olis m in 
diabe te s were found : the re fo re , the  mechanis m 
(s ) re spo ns ib le  for the protective  effects  of 
allo purinol a gains t the increas ed  le ve ls  of 
ketone bo dies rema in (s) to be  inv es tiga te d in 
furthe r stud ie s. It is pos sible that a llop urinol 
exe rts  its  e ffe cts thro ugh a n inhibitio n o f XO; 
howe ve r, the fa ct that a llop urinol trea tme nt did 
not lo wer p la sma  uric acid in ALX –diab etic  
ra ts  make s it an unlikely po ss ib ility. 
  The ability of allo purinol to  lowe r ketonuria  
and  ke tone mia  co uld b e e xp la ined thro ugh 
either inc re as ing ke to ne bo dies  me tabo lism by 
various  tiss ues  and /o r de crea sing the ir 
synthes is  via a ffec ting dea cyla se  o r –
hyd ro xy––methylgluta ryl– CoA fo rma tion (13). 
It is unlikely tha t allo purinol might have  
enhanced  e nd oge nous insulin relea se be ca use  
other ins ulin–d epe nde nt a bno rma litie s we re  
not correcte d by allopurino l tre atment. 
  The a bility o f allo purinol to lo wer ROS–
induc ed lipid pe ro xidation provide s ano ther 
evide nce  for the potential benefic ial effec t of 
allo purinol tre atment o n tiss ue a ntioxida nt 
defense s a ga inst d ia bete s–ind uc ed increa sed  
oxida tive  s tre ss. It further s up ports the findings  
of o ther s tudies  which repo rted  that a llop urinol 
lo wered MDA leve ls  in p la sma  o f p atie nts with 
type II diab etes  with mild hypertens ion (3) and  
in v ario us tis sues  o f ra ts  exp os ed to oxida tive  
stre ss  ind uce d either b y cypermethrin (7) or by 
exp erime ntal acute pancrea titis  
(14).Furthe rmo re , the pos sibilities of a dire ct 
effe ct of allo purinol a nd a lloxanthine on 
ketone bo dy me ta bolism and lip id p eroxida tion 
indep endently of inhibition of XO, o r v ia  
sca ve nging the powe rful hyd ro xyl ra dica ls  (14), 
or ma y invo lv e ge neralized  alte ra tions in tis sue  
antioxida nt s tatus  (2) can not be  ruled  out at 
prese nt. Muc h more  wo rk mus t be  do ne to 
ass es s whethe r the re  is  any re latio nship  
betwee n lip id  p eroxida tion a nd  ketos is  in ALX 
diabe te s and furthe r inve stigate the protec tive  
effe cts of ALP in this  re gard.  
In c onc lusion, the pres ent stud y s ugges ts that 
und er the  c ond itions  tes ted and in the do ses  
and  dura tion of treatme nt us ed , a llop urinol 
thro ugh its  p rob ab le  or ap parent ab ility to  
inhibit ge ne ra tion o f ROS  (es pe cially hydroxyl 
ra dical sca ve nging) ra ther than XO inhibition 



Ir aq i J.Pharm.Sc i., Vol.15 (1 )  ,2006 42

ap pea rs  to hav e a  p ro te ctiv e effe ct on b oth 
lipid pe ro xida tion a nd ketoge ne sis and 
co nse quently early morta lity in ALX–
diab etes . 
REFERENCES 
1. Heunks  LM; Vina J; Van – Herwaa rde n CL, 

et al. Xanthine o xidas e is inv olve d in 
exe rc is e– induc ed  o xidative s tres s in chro nic 
obs truc tive  pulmo nary d is ea se. Am. J. 
Physiol. 19 99 ; 27 7: R1 697  –70 4.  

2. Ala ta s O ; Sa hin A; Colak O , et al a l. 
Benific ial effec ts  of allo purinol o n 
glutathione leve ls  and  glutathione 
peroxid ase  a ctiv ity in rat isc hemic  ac ute 
re nal fa ilure . J. Int. Med. Res . 1 996 ; 2 4: 3 3 –  

3. Butle r R; Morris AD; Be lc h J J, e t a l. 
Allop urinol no rma lizes endothe lial 
dys func tion in type II d ia be tics  with mild 
hyp erte ns io n. Hype rtension 2 000 ; 35 : 74 6 –
51. 

4. Helle r B; Burkart V. Antioxid ant therapy fo r 
the p re vention of typ e I diab etes . Adv. 
Pha rma col. 199 7; 3 8: 6 29 –6 38. 

5. Knight J A. Free Rad ic als, Antioxida nts, 
Aging a nd Dise ase . (ed.). Ame rica n 
Ass ociation for Clinic al Chemistry. 19 99: 
215  – 230 . 

6. Bell RH; Hyd e RJ. Anima l mode ls  of 
diabe te s mellitus  : Phys io lo gy and 
Patho lo gy. J. Surg. Res . 1 983 ; 35 : 43 3 –60 . 

7. Giray B, Gurb ay A; Hinc al F. 
Cype rme thrin–induced  oxida tive  stre ss  in rat 
b ra in and  liver is  p re vented by v itamin E or 
a llop urinol. To xico l. Lett. 20 01; 118 : 13 9 –
4 6. 

8. Ohka wa H; Ohis hi N; Yagi K. As sa y for 
lipid pe ro xides  in animal tis sues b y 
thio barbituric  a cid re action. Ana l. Biochem. 
1 979 ; 9 5: 3 51– 58 

9. Williams on DH; Mellanb y J. D–(–)–3 –
Hydroxybutyra te. In: Be rgmeyer HU (ed ): 
Me thod s of Enzymatic  Analys is . V.4. New 
York. Ac ad emic Press . 1 974 ; 18 36 – 39. 

10. S acks DB. Ca rbo hydrates. In: Tie tz 
te xtboo k of clinical c he mis try. Burtis  CA, 
Ashwo od ER (ed ). 3rd ed ition. WB Saund ers 
Compa ny. Philad elphia . 19 99; 785  – 87. 

11.  Ra ng HP; Dale MM; Ritte r JM. 
P ha rma cology (4th e d.). Churc hill 
Liv ings to ne. Edinb urgh. 19 99; p. 2 40 . 

12. Me rc k Manual o f diagnos is  a nd  the ra py. 
(16 th ed.). Merck a nd Co. Inc. Rahwa y NJ. 
1 992 ; p p. 1 022  

13. Ga no ng WF. Re view of me dical 
p hysiology. 18 th (e d). App le to n and Lange. 
S ta nd fo rd. 19 97; p. 2 82 –2 83. 

14. Czako L; Taka cs  T; Va rga IS, et a l. 
Oxidative stress  in distant orga ns and the 
e ffe cts o f allo purinol d uring exp erime ntal 
a cute  p anc re atitis.Int.J .anc re atol. 20 00; 27: 
2 09 – 16.