Experimental Urinary Stone Formation by Sex Hormones in Rats and Analysis of Composition of the Stones / 대한비뇨기과학회지

ABSTRACT

PURPOSE: The incidence of renal stones is three times higher in men than women due to sex hormones, and most are calcium oxalate stones. Therefore, the effects of testosterone and estrogen in the formation of urinary stones were investigated. MATERIALS AND METHODS: One hundred female Sprague-Dawley rats were divided into seven groups. The first was the control group; the second was injected with testosterone cypionate into the muscle, every week; the third was fed tamoxifen only, everyday; the fourth was oophorectomized; the fifth was fed tamoxifen after an oophorectomy; the sixth was treated with testosterone after an oophorectomy; and the seventh was injected with testosterone, weekly, and fed tamoxifen everyday after an oophorectomy. The bladder stone formation and degree of renal crystal deposition of the control group was compared with those of the other groups. The composition of the bladder stones was analyzed by SEM (scanning electron microscopy)-EDX (energy dispersive X-ray microanalysis). RESULTS: Bladder stones were found in 9 rats from group 6 only, which also showed the most predominant renal crystal deposition rate (65.5%). There was a statistical significance in the renal crystal deposition rate only between groups 6 and 1. According to SEM-EDX analysis of the bladder stones, they were composed of struvite and apatite. CONCLUSIONS: It is suggested that testosterone and estrogen influenced the formation of struvite and apatite stones.