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Updated: Mar 16, 2026
Unilateral Ureteral Obstruction Model for Investigating Kidney Interstitial Fibrosis
Published on: April 25, 2025
Melatonin protects kidney against apoptosis induced by acute unilateral ureteral obstruction in rats
Mehmet Erol Yildirim1, Hüseyin Badem2, Muzaffer Cakmak3
1Turgut Özal University School of Medicine, Department of Urology, Ankara, Turkey.
Introduction:
To investigate whether there was a protective effect of melatonin on apoptotic mechanisms after an acute unilateral obstruction of the kidney.
Material And Methods:
A total of 25 rats consisting of five groups were used in the study, designated as follows: Group 1: control, Group 2: sham, Group 3: unilateral ureteral obstruction treated with only saline, Group 4: unilateral ureteral obstruction treated with melatonin immediately, and Group 5: unilateral obstruction treated with melatonin one day after obstruction. Melatonin was administered as a 10 mg/kg dose intraperitoneally. The kidneys were evaluated according to the apoptotic index and Ki-67 scores.
Results:
Comparison of all obstruction groups (Group 3, 4, and 5), revealed that the apoptotic index was significantly higher in Groups 1 and 2. Despite melatonin reduced apoptotic mechanisms in Groups 4 and 5, there was no significant difference between Groups 4 and 5 in terms of the reduction of apoptosis. However, the reduction of apoptosis in the melatonin treated group did not decrease to the level of Groups 1 and 2.
Conclusions:
Despite melatonin administration, which significantly reduces the apoptotic index occurring after acute unilateral ureteral obstruction, the present study did not observe a return to normal renal histology in the obstruction groups.
Insights
Melatonin treatment reduced kidney apoptosis after unilateral ureteral obstruction. However, renal histology did not return to normal levels, indicating incomplete protection against kidney injury.
Area of Science:
- Nephrology
- Endocrinology
- Cell Biology
Background:
- Acute unilateral ureteral obstruction (UUO) can lead to significant kidney damage.
- Apoptosis plays a critical role in the pathogenesis of UUO-induced renal injury.
- Melatonin, a hormone with antioxidant and anti-inflammatory properties, is investigated for its potential renoprotective effects.
Purpose of the Study:
- To determine if melatonin administration can mitigate apoptotic mechanisms in the kidney following acute UUO.
- To evaluate the timing of melatonin administration (immediate vs. delayed) on its protective efficacy.
Main Methods:
- A rat model of acute UUO was established.
- Five experimental groups were included: control, sham, UUO with saline, UUO with immediate melatonin, and UUO with delayed melatonin.
- Kidney tissues were analyzed for apoptotic index and Ki-67 scores.
Main Results:
- UUO significantly increased the apoptotic index compared to control and sham groups.
- Melatonin treatment (both immediate and delayed) reduced the apoptotic index in UUO kidneys.
- However, melatonin did not fully restore the apoptotic index to control levels, and there was no significant difference between immediate and delayed melatonin administration.
Conclusions:
- Melatonin demonstrates a protective effect by reducing apoptosis in kidneys subjected to acute UUO.
- Despite apoptosis reduction, melatonin administration did not normalize renal histology, suggesting limited efficacy in complete renoprotection.
- The timing of melatonin administration did not significantly impact its apoptotic-reducing effect in this model.
