Matem TUNÇDEMİR, Melek ÖZTÜRK, Fatma Kaya DAĞISTANLI

Yeni doğan streptozotosin diyabetik nefropatide isradipin’in TGF-ß1 ve tip IV kollajen ekspresyonları üzerine etkileri

Bu çalışmada; kalsiyum kanal blokeri olan isradipin’in Tip II diyabetine uygunluk gösteren yeni doğan sıçan streptozotosin (YD-STZ) diyabet modelinde renal fonksiyonlar ve glomerulun yapısal değişimleri üzerine etkilerini incelendi. Yeni doğan wistar türü albino sıçanlardan 4 grup oluşturuldu. 1. ve 2.gruba; doğumu izleyen 2.günde STZ (100 mg/kg, i.p, tek doz) uygulandı. 1.grup;YD-STZ diyabetik kontrol grubu olarak ayrıldı. 2.gruba; 12.haftadan itibaren İsradipin (5 mg/kg/gün, 6 hafta, i.p.) uygulandı. 3.grup; diyabetik olmayan sağlıklı sıçanlara 12. haftadan itibaren isradipin (5 mg/kg/gün, 6 hafta) uygulandı. 4.grup; sağlıklı kontrol grubu olarak ayrıldı. Çalışma süresince tüm gruplardaki hayvanların kan glukoz düzeyi ölçümleri, vucut ağırlık ölçümleri ve mikro-albüminüri düzey ölçümleri yapıdı. Böbrek doku kesitlerine Periodik Asit Schiff boyaması ve TGF-β1, tip IV kollajen antikoru ile immünohistokimyasal boyamalar yapıldı. İsradipin uygulanan diyabetik grubun kan glukoz düzeylerinde belirgin düşme saptandı. Diyabetik gruba kıyasla tedavili diyabetiklerde mikro-albüminüri düzeylerinde anlamlı azalma saptandı. Böbrek ağırlıkları; diyabetik grupta, sağlıklı kontrol gruba kıyasla artış gösterirken, tedavili diyabetik grupta azalma saptandı. Tedavisiz diyabetik grubun diğer gruplardan daha büyük boyutta glomeruller içerdikleri saptandı. Diyabetiklerde glomerul ve tubullerde bazal membran kalınlaşması, belirgin mezangiyal matriks ve hücre artışı gözlendi. YD-STZ diyabetiklerde glomerul membran kalınlaşması, TGF-β1 ve tip IV kollajen immünreaktivitesinde artış gözlendi. İsradipin uygulanan diyabetik gruptaki TGF-β1 ve tip IV kollajen immunreaktivitesi sağlıklı kontrol grubuna benzerdi. İsradipin’in kullanılan doz ve sürede, bu diyabet modelinde renal doku hasarını önlemede yetersiz olduğu, ancak kan glukoz vemikro-albüminüri düzeylerinin azaltarak diyabetik nefropatinin ilerlemesini yavaşlattığı sonucuna varıldı.

The effects of isradipine on TGF-ß1 and type IV collagen expression in neonatal streptozotocin diabetic nephropathy

The effects of isradipine on TGF-ß1 and type IV collagen expression in neonatal STZ diabetic nephropathy In this study, the effects of isradipine as a calcium channel blocker, on glomerulus structural alterations and renal functions were examined in the neonatal streptozotocin diabetes (n-STZ) model. We used 4 groups of newborn Wistar rats. On the 2nd day of birth after STZ (100 mg/kg) injection to the 1st and 2nd group, isradipine (5 mg/kg, i.p) was administered to the 2nd group for 6 weeks from 12 weeks on. The 3rd group was isradipine treated (5 mg/kg, i.p., from 6 weeks to 12 weeks) control group and the 4th group was healty control. During the period of the experiment, blood glucose levels, body weight and microalbuminuria level of the rats were measured. Kidneys were weighted. Tissue sections were immunostained using monoclonal type IV collagen and TGF-ß1 antibodies. The blood glucose levels were markedly decreased in the isradipine treated cortrols. Microalbuminuria levels were decreased in treated diabetics compared to diabetic group. Kidney weights were increased in n-STZ diabetics when compared to non-diabetics. Glomeruli dimensions of n-STZ diabetics were increased in comparison to nondiabetic control group. In the isradipine treated diabetic group the larger glomeruli were observed according to the nondiabetic group. Basal membrane thickening in glomerulus and significant increase in mesangial matrix and mesangial cells and an increased type IV collagen and TGF-ß1 expression in n-STZ diabetics were observed. In the isradipine treated groups type IV collagen and TGF-ß1 immunoreactivity in glomerulus were seen to be similar to nondiabetic controls. Our results show that isradipine could be effective in delaying the progression of nephropathy by decreasing microalbuminuria and blood glucose levels but it didnot completly improved renal morphology.

PDF

___

1. Mogensen CE, Christensen CK. Predicting diabetic nephropathy in insulin depen patients. N Eng J Med 1984; 311:89-93.
2. Cortes P, Dumler F, Goldman J, et al. Relationship between renal function and metabolic alterations in early streptozotocin-induced diabetes in rats. Diabetes 1987; 36: 80-87.
3. Tucker BJ, Collins RC, Ziegler MG, et al. Disassociation between glomeruler hyperfiltration and extracellular volume in diabetic rats. Kidney Int 1991;39:1176-1183.
4. Fujihara CK, Padilha RM, Zatz R. Glomerular abnormalities in Long-term experimental diabetes. Diabetes 1992; 41; 286-293.
5. Bakris GL, Smith A. Effects of sodium intake on albumin excretion in patients with diabetic nephropathy treated with long-acting calcium antagonists. Ann Inter Med 1996;125: 201-204.
6. Gambaro G, Cavazzana AO, Luzi P, et al. Glycosaminoglycans prevent morphological renal alterations and albuminuria in diabetic rats. Kidney Int 1992; 42: 285-291.
7. Gilbert RE, Cox A, Wu LL, et al. Expression of transforming growth factor-beta1 and type IV collagen in the renal tubulointerstitium in experimental diabetes: effects of ACE inhibition. Diabetes 1998;47:414-22.
8. Nakamura T, Miller D, Ruoslahti E, et al. Production of extracellular matrix by glomerular epithelial cells is regulated by transforming growth factor-beta1. Kidney Int 1992;41:1213-1221.
9. Erensoy N, Yılmazer S, Ozturk M, et al. Effects of ACE inhibition on the expression of type IV collagen and laminin in renal glomeruli in experimental diabetes. Acta Histochem 2004;106:279-87.
10. Anderson S, Rennke HG, Brenner BM. Nifedipine versus fosinopril in uninephrectomized diabetic rats. Kidney Int 1989;36:526-536.
11. Bakris GL, Williams B. Angiotensin converting enyzme inhibitors and calcium antagonists alone or combined: does the progression of diabetic renal dissease differ?. J Hypertension 1995;13: 95-101.
12. Brown RA, Lee MM, Sundareson AM, et al. Influence of calcium channel blocers treatment on the mechanical properties of diabetic rat myocardium. Acta Diabetol 1996; 33: 7-14.
13. Kalender B, Ozturk M, Tuncdemir M,et al. Renopro tective effects of valsartan and enalapril in STZ-induced diabetes in rats. Acta Histochem 2002;104:123-130.
14. Shankland SJ, Scholey JW, Ly H, et al. Expression of transforming growth factor-beta 1 during diabetic renal hypertrophy. Kidney Int 1994;46:430-442.
15. Nakamura T, Obata J, Kimura H, et al. Blocking angiotensin II ameliorates proteinuria and glomerular lesions in progressive mesangioproliferative glomerulonephritis. Kidney Int 1999; 55:877-889.
16. Altuğ T, Gürel A, İkitimur E, ve ark. Sıçanlarda neonatal dönemde farklı dozlarda streptozotosin uygulanmasının böbrek kisti ve tümörü oluşturma etkileri. Endokrinolojide Yönelişler 1996; 6: 136-139.
17. Kaya-Dagistanli F, Susleyici-Duman B, Oztürk M. Protective effects of a calcium channel blocker on apoptosis in thymus of neonatal STZ-diabetic rats. Acta Histochem 2005;107:207-214.
18. Portha B, Blondel O, Serades P, et al. The rat models of non insülin dependent diabetes induced by neonatal streptozotocin. Diabete&Metab 1989;15:61-75.
19. Vicent D, Villanueva PML, Volverde I, et al. Impaired in vivo insulin secretion in response to non-glucidic secretogagues in adult rats after neonatal streptozotocin. Acta Diabetol 1994;31: 133-137.
20. Öztürk M. Işık Mikroskopide İmmünoişaretleme Yöntemleri. Uygulamalı Ultrastruktürel İmmunohistokimya Kurs Kitapcığı.Yazarlar:Yılmazer S, Öztürk M. 6-8 Mayıs 1998, İstanbul.
21. Sounders BD, Trappe RG. Basic & Clinical Biostatics. 2. ed. Appleton & Lange, London.1994.
22. Anderson S, Rennke HG, Garcia DL, et al. Short and long term effects of antihypertensive therapy in the diabetic rats. Kıdney Int1992; 41:891-897.
23. Hirose K, Qsterby R, Nozawa M, et al. Development of glomerular lesions in experimental long-term diabetes in the rat. Kidney Int 1982; 21: 689-695.
24. Mogensen CE. Angiotensin converting enzyme inhibitors and diabetic nephropathy. BMJ 1992; 304:327-328.
25. Barthelmebs M, Varlly B, Grima M, et al. Effects of dopamine prodrugs and feroldopam on glomerular hyperfiltration in streptozotocin-induced diabetes in rats. J Cardiovasc Pharmacol 1991; 18: 243-253.
26. Bakris GL. Microalbuminuria: Prognostic implications. Curr Opnion Nephrol Hypertens 1996;5:219-223.
27. Jerums G, Allen TJ, Tsalamandris C, et al. Angiotensin converting enzyme inhibition and calcium channel blokade in incipient diabetic nephropathy. Kidney Int 1992; 41: 904-911.
28. Morelli E, loon N, Meyen T, et al. Effects of convertingenzyme ınhibition on barrier function in diabetic glomerulopathy. Diabetes 1990; 39:76-82.
29. Cavatorta A, Coghi P, Borghetti A. Isradipine in chronic renal failure: Antihypertensive effect and renal production. Curr Ther Res Clin Exp 1994; 55: 1538-1550.
30. Wittenberg C, Rosenfeld J B. Long-term antihypertensive and renal effects of isradipine in hypertensive patients with normal and reduced renal function. J Cardiovasc Pharmacol 1992;19 (Suppl 3) : 393-395.
31. Gaber L, Walton C, Brown S, et al. Effects of different antihypertensive treatments on morphological progression of diabetic nephropathy in uninephrectomized dogs. Kidney Int 1994; 46: 161-169.
32. Tıkkanen I, Johnston CI. Comparison of renal-angiotensin to calcium channel blockade in renal disease. Kidney Int 1997;52(suppl.63):19-22.
33. Reeves WB, Andreoli TE. Transforming growth factor ß contributes to progressive diabetic nephropathy. PNAS 2000; 97: 7667-7669.
34. Branton M.H., Kopp J.B . TGF-B and fibrosis. Microbes Infect 1999; 1:1349-1365.
35. Rocco MV, Chen Y, Goldfarb S,et al. Elevated glucose stimulates TGF-ß gene expression and bioactivity in proximal tubule. Kidney Int 1992; 41:107-114.
36. Hill C, Flyvbjerg A, Gronbeak H, et al. The renal expression of transforming growth factor- ß isoforms and their receptors in acute and chronic experimental diabetes in rats. Endocrinology 2000; 141: 1196-1208.
37. Flyvbjerg A, Hill C, Logan A. Pathophysiological Role of Growth Factors in Diabetic Kidney Disease: Focus on Innovative Therapy. Trends Endocrinol Metab 1999; 10:267-272.
38. Ihm CG, Lee GS, Nast CC, et al. Early increased renal procollagen alpha 1(IV) mRNA levels in streptozotocin induced diabetes. Kidney Int 1992;41:768-777.