Age-related changes of the concentrations of select elements in the prostates of Japanese.

To elucidate compositional changes of the prostate with aging, the authors investigated age-related changes of elements in the prostates and the relationships among their elements using Japanese and Thai. After ordinary dissections by students at Nara Medical University and Chiang Mai University were finished, the prostates were resected from the subjects. Fifty-seven Japanese subjects ranged in age from 65 to 101 years (average age = 82.5 +/- 7.8 years), whereas 13 Thai subjects ranged in age from 43 to 86 years (average age = 67.9 +/- 11.9 years). After ashing with nitric acid and perchloric acid, element contents were determined by inductively coupled plasma-atomic emission spectrometry. It was found that although there were no significant correlations between age and seven element contents, such as Ca, P, S, Mg, Zn, Fe, and Na, in the prostates of Japanese, high contents of Ca (>5 mg/g) and P (>4 mg/g) were contained in one fourth of the prostates of Japanese over 70 years of age. In the prostates of Thai, a significant direct correlation was found between age and Ca content, but it was not found between age and the other element contents, such as P, S, Mg, Zn, Fe, and Na. Regarding the relationships among their elements, extremely significant direct correlations were found among the contents of Ca, P, Mg, Zn, and Na in the prostates of Japanese. In the prostates of Thai, significant direct correlations were found among the contents of Ca, Mg, and Zn, but no significant correlations were found between Ca and P contents and between P and Mg contents. Regarding the relationships among their elements, there were differences between the prostates of Japanese and Thai. To examine whether element contents changed in prostatic hypertrophy, the transverse width of the Japanese prostates was measured. No significant correlations were found between the transverse width and element contents, such as Ca, P, S, Mg, Zn, Fe, and Na, in the Japanese prostates. Therefore, it is unlikely that the increase of elements results in prostatic hypertrophy.