İntrauterin Büyüme Gerilikli Ratlarda Böbrekte Yapısal/Fonksiyonel Değişiklikler ve Serum Leptin Seviyesiyle İlişkisi

Abstract

Amaç: Amacımız, intrauterin büyüme geriliğinin İUBG böbrekler üzerine etkilerini ve serum leptin düzeylerinin bu değişikliklerle ilişkili olup olmadığını belirlemektir. Yöntem: Standart diyetle 7 gün besledikten sonra gebe ratlar 8.gün iki gruba ayrılmıştır. Kontrol grubu gebelik sırasında normal diyetle beslenmeye devam ederken, çalışma grubuna normal gereksinmelerinin yarısı kadar besin verilmiştir. Fetüsler 21 günlükken, yavrular ise 3., 6., 16. haftalarda değerlendirilmiştir. Böbrekler yapısal olarak ağırlıkları, ışık mikroskopisi bulguları, nefron sayısı ve glomerül hacmine göre incelenmiş ve işlevsel açıdan renal ekskretuar fonksiyon değerlendirilmiştir. Fetüsler ve 3 haftalık rat böbrekleri yalnızca yapısal açıdan incelenmiştir. Üç, 6 ve 16 haftalık ratların serum leptin düzeyleri 16 haftalıkların ise kan basınçları ve böbrek kan akımları ölçülmüştür. Bulgular: İUBG gruplarının böbrekleri daha hafifti. İUBG grubundaki fetüslerde ve 16 haftalık yavrularda daha az sayıda nefron saptanmıştır. Kontrollerle karşılaştırıldığında idrar akış hızı, renal kan akımı, GFH, Na, K ve Mg klirensleri 16 haftalık yavrularda daha düşük, ancak protein klirensi daha yüksek ve kan basıncı normal düzeylerdeydi. Üç haftalık İUBG olan ratlarda serum leptin düzeyleri anlamlı derecede yükselmişti. Altı haftalık dişilerde leptin düzeyleri kontrollere göre hemen hemen %60 oranında yükselmişti. Tüm yaşlar için leptin düzeyleriyle fraksiyonel böbrek ağırlıkları arasında negatif bir korelasyon mevcuttu. Altı haftalık ratlarda leptin düzeyi ile idrar hacmi koreleydi. On altı haftalık ratlarda leptin ve kan basıncı, kreatinin, Na, K klirensleri arasında pozitif korelasyonlar mevcuttu. Sonuç: İUBG’de sütten kesildikten sonra serum leptin konsantrasyonunda geçici artış en azından erken erişkin döneme kadar böbreklerde yapısal ve işlevsel bozulma ile ilişkili olmayabilir.

Keywords

• İUBG, böbrek, leptin

The Renal Structural and Functional Changes in Rats with Intrauterine Growth Retardation and its Correlation to Serum Leptin Level

Abstract

Objective: Our aim was to determine the effects of intrauterine growth retardation IUGR on the kidney and whether serum leptin level was associated with these changes. Method: After feeding with standard diet for 7 days pregnant rats were divided into 2 groups on the 8th day. While the control group continued to be fed with normal diet during pregnancy, the study group was fed with only half of their normal needs. Structural evaluations were performed in fetuses at 21. gestational days and offsprings at 3, 6, 16 weeks of age The kidneys were investigated according to their weight, light microscopy findings, nephron counts and glomerular volume. Renal excretory function was determined as for functional evaluation. Fetuses and 3 week- old rat kidneys were investigated only structurally. Serum leptin levels were measured at 3, 6, 16 weeks of age, while direct blood pressure and renal blood flows were measured at 16. week of age. Results: Renal weights were lower in the IUGR groups. In IUGR group, decreased number of nephrons were found in fetuses and 16-week-old offsprings. Urine flow rate, renal blood flow, GFR, Na, K and, Mg excretions were lower in the 16-week offspring group compared to the control group, but protein excretion was higher and blood pressure was at normal level. The IUGR rats had significantly elevated serum leptin levels at 3-week-old rats. The leptin levels in 6-week-old females were almost 60% higher than controls. For all ages there was a negative correlation between leptin levels and fractional kidney weights. Leptin level and urine volume were correlated in the 6-week-old rats. There were positive correlations between leptin and blood pressure, excretions of creatinin, Na and K in 16-week-old rats. Conclusion: In conclusion, temporary increase of serum leptin concentration during weaning may not be associated with the deleterious effect of kidney structure and function at least until early adulthood in IUGR.

Keywords

• IUGR, kidney, leptin

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