Abstract:

[Abstract] Objective To investigate the expressions of calcium sensitive receptor (CaSR) and tight junction protein (Claudin)-14in renal calcium oxalate stone rat model. Methods Thirty male SD rats were randomly divided into control group (n=15) and model group (n=15). The rat model of renal calcium oxalate stone was established by gavaging 1% glycol (2 mL/d) and2% ammonium chloride. The expression of CaSR protein was detected using immunohistochemical assay. RT PCR was used to detect the Claudin-14mRNA expression. The expression levels of CaSR and Claudin-14protein were de? tected by Western blot assay respectively. The full automatic biochemical analyzer was used to detect rat renal function and changes of blood and urine biochemical indices.Results A large stone crystallization was observed under light microscope in model group. The serum levels of Cr, BUN, 24-h urine calcium and urine volume were significantly higher in model group than those of control group (P＜0.01). There were no significant differences in serum calcium level and urinary pH value be? tween two groups. The expression levels of Claudin-14mRNA and CaSR protein were significantly higher in model group than those of control group (P＜0.01). The Claudin-14protein expression was specifically higher in renal tissues of model group. There was no Claudin-14protein expression in control group. There was a positive correlation between CaSR and Claudin-14protein expression in renal tissues of model group. Also, CaSR and Claudin-14protein expressions were posi? tively correlated with the 24-h urine volume.Conclusion The increased expressions of CaSR and Claudin-14involved in the formation of kidney stone by increasing the urinary calcium excretion.

Key words: kidney calculi, calcium oxalate, receptors, calcium-sensing, rats, Sprague-Dawley, claudin-14