J. Physiol. Biochem., 59 (2),145-146,2003 Effect of IGF-I on total serum antioxidant status in cirrhotic rats The role of free radical generation and oxidant injury in the pathogenesis of liver injury and fibrosis is now well established (3,4,9-11, 14). Our previous results showed that the enzymatic antioxidants are reduced in animals with CCI 4- induced liver cirrho- sis (1). Insulin-like growth factor-I (IGF-I) is an anabolic hormone produced mainly by the liver (12, 13). In cirrhosis a progressive fall of serum IGF-I levels is observed (2, 5, 6, 8, 9). The exogenous administration of IGF-I was able to increase the hepatic levels of antioxidant enzymes and to reduce the levels of lipid peroxidation and fibrogenesis (1, 3, 9). The aim of the present study was to ana- lyze serum total antioxidant capacity in rats with compensated or advanced cirrhosis either in untreated or treated with low doses of IGF-I. All experimental procedures were per- formed in accordance with The Guiding Principles for Research Involving Animals. Cirrhosis was induced as previously described (1), following two protocols: Pro- tocol A, included male Wistar rats with early CCl4 -induced cirrhosis (11 weeks of CC1 4 inhalation) divided into two groups: Cl, untreated cirrhotic rats and CI+lGF, cir- rhotic rats treated with IGF-I (2 llg x 100- 1 x day -1) for 2 weeks (n=10, each group). Protocol B, included male Wistar rats with advanced CCl 4 induced-cirrhosis and ascites (30 weeks of CC14 inhalation) divided into two groups: Cl, untreated cirrhotic rats and CI+IGF, cirrhotic rats treated with IGF-I (2 )lg x 100- 1 x day -1) during three weeks (n=10 for each group). In both protocols, age and sex-matched healthy control rats were included (CO, n=10). At the end of the treatment, blood sam- ples were drawn from the retroocular venous plexus from all the rats with cap il- lary tubes (Marienfeld, Germany) and stored at -20°C. After decapitation of ani- mals, the liver was dissected and weighed. A sample from the left major liver lobe was processed for histological examination (fixed in Bouins solution). Sections (4 urn) were stained with haematoxylin and eosin and Masson's trichrome. Serum total antioxidant status was evalu- ated using a colorimetric assay (Randox Laboratories Ltd, Ardmore, Crumlin, UK) using the following principle: Abts (2,2'- Azino-di- [' 3-ethylbenzthiazoline sulphonate]) is incubated with a peroxidase (metmyoglobin) and H202 to produce the radical cation Abts'". This has a relatively stable blue-green colour, which is measured at 600nm. Antioxidants in the added sample cause suppression of this colour production to a degree that is proportional to their con- centration (6). Liver cirrhosis was histologically validat- ed in all animals treated with CCl4 and ascites were observed in all cirrhotic rats included in the Protocol B. In the protocol A, serum total antioxi- dant status (TAS) was diminished in animals with compensated cirrhosis compared to controls (CI= 1.04±0.02; CO= l.35±O.03 mmollL, p<O.Ol) and a significant recovery was found in serum from IGF-l treated-cir- rhotic rats (CI+IGF= 1.15±0.14) as com- pared to untreated cirrhotic group (p<0.05) (Fig. 1,A). In the protocol B, the TAS was signifi- cantly reduced in serum from untreated cir- rhotic rats (CI= 1.03±0.02 mmollL) as com- pared with controls (CO= 1.13±0.02). In the CI+lGF group the TAS was not significant- ly higher (1.09±O.02) than in the untreated cirrhotic animals, and no significant differ- ences were found between both cirrhotic groups (Fig. I,B).