Effects of calcitriol on structural changes of kidney in C57BL/6J mouse model

This aim of the study is to investigate the effects of calcitriol (vitamin D) on mouse kidneys under obese conditions. Male C57BL/6J mice were maintained on either low fat diet (LFD) or high fat diet (HFD) with/without calcitriol treatment (150 IU/kg/day) for 16 consecutive weeks. Results of HFD fed mice demonstrated more weight gain and showed numerous structural abnormalities in the corticomedullary region compared to those under control and LFD conditions. Near nephropathy condition in HFD mice were characterized by damage in renal tubules, including dilatation of interstitial cells and blood vessels. Furthermore, exfoliation and shedding of proximal tubular cells takes place. The conditions further worsen by thickening the basement membrane and interstitial inflammation, as evidenced by abundant interstitial debris. Additionally, a large number of degenerated mitochondria, fat droplets, lysosomal bodies' mesangial expansion, and cellular debris were found throughout the kidney. Sustained cell hypertrophy was also evident by transmission electron microscope confirming a marked increase in degeneration of cells within renal areas. No significant variances were detected in the glomerulus' area and diameter in both low and high fat diets with/without calcitriol treatment as well as inner and outer diameters of both distal and proximal tubule in all groups. Evidently, calcitriolcould act as a protective agent to normalize kidney structure in obese condition. This study suggests that calcitriol could normalize the function of kidney and protect its structural integrity in obesity.