Abstract
Summary: In this study, we investigated the histological examination of the pineal gland, the degree of brain sand accumulation, and the state of pineal cells by immunohistochemistry using melatonin antibodies in 20 corpses aged between 59 and 98 years. We also investigated changes in the bone mineral density of the calcaneus and the degree of arteriosclerotic lesions of the ascending aorta and evaluated the relationship between them. In the cadavers examined in the present study, the size of the pineal gland did not differ from that described in previous studies. However, there was no statistically significant association between the degree of brain sand formation and age or sex, and a negative correlation was found between the degree of brain sand accumulation and the number of melatonin antibody-positive cells. The higher the degree of accumulation of brain sand in the pineal gland, the lower the bone density of the calcaneus. Furthermore, the higher the accumulations of cerebral sand in the pineal gland, the higher the aortic arteriosclerotic lesions. These results suggest that the pineal cell depletion that occurs with brain sand accumulation probably reduces bone density, which in turn affects calcium metabolism, possibly leading to arteriosclerotic lesions.
