Pınar DURAK, Orhan CANPOLAT, Sevda MÜFTÜOĞLU, Özcan ERDEMLİ, Sema KULTUFAN, Gülhan ÖZGEN, Sevim EBİL, Esin AŞAN

Hiperoksik sıçan akciğer dokusunda N-asetilsisteinin antioksidan özelliğinin histopatolojik ve biyokimyasal incelenmesi

Bu çalışmanın amacı; hiperoksiye maruz kalan sıçan akciğer dokusunda oral N-Asetilsistein (NAS) kullanımı ile oluşan histopatolojik ve biyokimyasal değişikliklerin incelenmesidir. Etik kurul onayından sonra 28 adet yetişkin beyaz Wistar rat çalışma grubuna alındı ve dört gruba ayrıldı (n=7). 1 Grup: kontrol, II Grup: 24 saat %100 O2 inhalasyonu, III. Grup:1 gr.kg-1 oral NAS, IV Grup: 1 gr.kg-1 oral NAS+%100 O2. Ratlar 90 mg.kg-1 intraperitoneal ketaminle anestezi uygulandıktan sonra median sternotomi ile akciğer dokularından örnekler alındı. Süperoksit dismutaz (SOD), katalaz (CAT), malondialdehit (MDA) ve glutatyon peroksidaz (GsHPx) değerleri ve mikroskobik analiz için doku örnekleri hazırlandı. Yüzde yüz oksijen kullanılan II. Grupta belirgin konjesyon, ödem, Tip II septal hücrelerde lameller pattern izlenirken. III. Grupta minimal morfolojik değişikliklerin yanında Tip II septal hücrelerde tipik lameller görünümün köpüksü hücrelere dönüştüğü izlendi. Elektron mikroskopta alveolar duvar normal görülürken, Tip II hücrelerin lameller özelliklerini kaybedip dağılmış oldukları izlendi. IV. Grupta ise akciğer dokusunda kopiller konjesyonunun kaybolduğu %100 oksijene göre daha az hemoraji ve perivasküler ödem olduğu görüldü. Alveol ve bronşiollerin geniş, Tip II hücrelerin ise tekrar lameller yapılarına döndükleri izlendi. Biyokimyasal açıdan gruplar arasında GsHPx ortalama değerlerinde fark yoktu. SOD değerleri oksijen grubunda diğer gruplara göre daha düşüktü (p

Anahtar Kelimeler:

Biyolojik yararlanım, Katalaz, Süperoksit dismutaz, Yükseltgenme-indirgenme, Glutatyon peroksidaz, Serbest radikaller, Akciğer, Asetilsistein, Malondialdehit, Hiperoksi, Sıçanlar

Histopathologial and biochemial evaluation of potential antioxidant property of N-acetylcysteine in hypoxic rat lung tissue

The aim of this study was to investigate the relationship between hyperoxic condition and lung free radical metabolism and to establish a possible protective role for N-acetlcysteine (NAC) agonist to this condition. All of the experimental procedures were reviewed and approved by our animal care and use committee of the institution. Twenty-eight male adult Wistar rats were used in the study and divided into four groups. I Group: Control group, II. Group: Oxygen (100%) was administered to animals for 24 hours. HI Group: Animals were treated with 1 mg.kg-1 p.o NAC for three days. IV Group: NAC + O2%. All of the rats were anesthetized with 90 mg.kg-1 ketamine intrapenitoneally. The lung tissues were taken for biochemical and histopathological examinations. Catalase (CAT), gluthione peroxidase (GsH-Px) and superoxide dismutase (SOD) activities were measured. As a peroxidation index, the malondialdehyde (MDA) concentration was determined. Light and electron microscopy studies were performed. As for statistical analysis Mann Whitney-U test was used. p<0.05 was considered as statistically significant. CAT activity was higher in the oxygen group than NAC and oxygen + NAC groups and controls (p<0.05). There were not any significant difference in mean activity values of the GSH-Px enzymes among the groups. SOD activity was lower in the oxygen group with respect to the control group (p<0.05). MDA concentrations of NAC and NAC+O2 groups were higher than the control group (p<0.05). There were no significant difference in GsH-Px concentration of oxygen and control groups. In group II, lung tissue appeared with prominent congestion and edema. All capillary lumens were filled with erythrocytes. Type II septal cells showed their typical lameller pattern of secretuar granules. In group III, there were minor morphologic changes including congestion of vessels. Abundant foamy cells probably alveolar macrophages or septal cells were scattered throughout the tissue. In group IV, capillary congestion and edema were lost and type II septal cells returned to their lameller pattern. It is possible that NAC could scavenge the active oxygen species directly by nonenzymatic reduction. The interaction of NAC with O2 or OH would lead to the formation of N-acetylcysteine disulfide, with the intermediate formation of the thinyl radical. The significance and reactivity of such a radical is unknown. Our results showed that MDA levels of NAC +O2 groups were higher than the control group in the lung tissues. The increase in catalase activity may occur as a compensatory mechanism against increased free radical metabolism. Further studies are needed to investigate the antioxidant effects of NAC and the relationship between type II septal cells and glutathione.

Keywords:

Biological Availability, Catalase, Superoxide Dismutase, Oxidation-Reduction, Glutathione Peroxidase, Free Radicals, Lung, Acetylcysteine, Malondialdehyde, Hyperoxia, Rats,

___

1. Yu BP. Cellular deferences against damage from oxygen species. Physiol Rev 1994; 74: 139-62.
2. Lunec J. Free Radicals: Their invalümentin disease process. Ann Clin Biochem 1990; 27: 173-82.
3. Martinez - Cayuela M. Oxygen free radicals and human disease. Biochimie 1995; 77: 147-61.
4. Heffner JE, Repine J. Pulmonary strategies of antioxydant defense. Ann Rev Respir Dis 1989; 140: 531-54.
5. Del Maestro RF. An approach to free radicals in medicine biology. Acta Physiol Scan 1980; 492 (Suppl): 153-68.
6. Southora PA. Free radicals in medicine. 1. Chemical nature and biological reactions. Mayo Clin Proc 1988; 63: 381-9.
7. Kehrer JP. Smith CV. Free radicals in biology: Sources, reactivities, and roles in the etiology of human diseases. In: Prei B. (ed.) Natural Antioxidants Human Health And Disease. San Diego: Academic Press 1994; 25-62.
8. Halliwell B. Oxidative stress nutristion and health. Experimental strategies for optimiation of nutritional antioxidant intake in humans. Free Radical Res. 1996; 25: 57-74.
9. Nakazawa H, Genka C, Fujishima M. Pathological of active oxygens free radicals. Japan J Physiol 1996; 46: 15-32.
10. Freeman BA, Crapo JD. Free radicals and tissue injury. Lab Invest I982; 47: 412-26.
11. Hallivel B, Gutteridge JMC. The antioxidants of human extracellular fluids. Arch Biochem Biophys 1990; 280: 1-8.
12. De Flora S, Izzotti A, De Agostini F, et al. Antioxidant activity and other mechanisms of thiols involved in chemprevention of thiols involved in chemoprevention of mutation and cancer. Am J Med 1991; 91: 122-30.
13. Forman MB, Puert DW, Cates Cu, et al. Glutathione redox pathway and reperfusion injury: Effect of N-acetlcysteine on infact size and ventricular function. Circulation 1988; 78: 202-13.
14. Henderson A, Hayes P. Acetylcysteine as a cytoprotective anitoxidant in patients with severe sepsis: Potential new use for an old drug. Ann Pharmacother 1994; 28: 1086-8.
15. De Flora S. Dennicelli C, Camoriono A, et al. In vivo effects of N-acetylcsteine on glutathione metabolism and on the biotransformation of carcinogenic and or mutagenic compounds. Carcinogenesis 1985; 6: 1375-45.
16. Aruoma 0I, Halliwell B, Hoey BM, et al. The antioxidant action N-acetylcysteine: Its reaction with hydrogen peroxide, hydroxyl radical, superoxide, and hypochlorous acid. Free radic Biol med 1989; 6: 593-7.
17. Aebi H. Catalase. In:Bergemeyer HU, (ed) Methods Of Enzymatic Analysis. New York London, Academic Press 1974; 673-677.
18. Johnson KJ, Fortene JC, Kaplan J. Word PA. Invivo damage of rat lungs by oxygen metabolits. J Clin Invest 1981; 67: 983-93.
19. Van Ye TM, Roza AM, Pieper GM, Henderson JR J, Johnson CP, Adams MB. Inhibition of intestinal lipid peroxidation does not minimize morphological damage. J Surg Res 1993; 55: 553-8.
20. Holdiness MR. Clinical pharmacokinetics of N-acetylcystein. Clin Pharmacokinet 1991; 20: 123-34.
21. Lowry O, Rosenbraugh N, Farr L, Dandall R. Protein measur-ment with folin phenol reagent. J Biol Chem 1951; 182: 265-75.
22. Cotgrevae I, Eklund A, Larsson K, Maldeus P. N-penetrarion of analy administered N-acetylcystein into bronchoalveolar lavage fluid eurid. Respir Dis 1987; 70: 73-7.
23. Cotgreave IA, Moldess P. Lung protection by thiol containing antioxidants. Bull Eur Pysiopathal Respir 1987; 23: 275-7.
24. Moldess P, Berggren M, Grofstom M. N-acetylcysteine protection agonist the toxicity of cigarette smoke condemsates in various tissues and cell in vitro. E J Respir Dis supp 1985; 139: 123-9.
25. Moldess P, Contgreave IA, Bergajmen M. Lung protection by a thiol-containing antioxidant N-acetylcysteine. Respiration 1986:50:31-42.
26. Webb W. Clinical evaluation of a new mucolytic agent, acetylcysteine. J Thor Cardiovas Surg 1962; 44: 330-9.
27. Suter MP, Domenighetti G, Schaller M. N-acetylcysteine enhances recovery from acute lung injury in man a randomized, double blind, placebo-controlled clinical study. Chest 1994; 105: 190-4.