DISTRIBUTION OF CALCIFIED CONCRETIONS AND CALCIUM-IONS IN THE PIG PINEAL-GLAND

Serial sections of pig pineal glands were stained with von Kossa's and Alizarin red S methods to determine the occurrence and localization o f calcified concretions. In the pineal glands of pigs aged eight month s, concretions were not found. A small number of concretions was obser ved in all investigated pineal glands of three years old pigs. The con cretions were distributed in the connective tissue of the pineal capsu le and septa. The potassium pyroantimonate method:was used for ultracy tochemical localization of calcium ions. In pinealocytes,precipitates were observed in nuclei, mitochondria, Golgi apparatus, endoplasmic re ticulum and cytoplasmic matrix. Single precipitates were found on the outer membranes of dense bodies, multivesicular bodies and lysosomes. There were no differences in the amount or the localization of precipi tates between dark and light pinealocytes and between pinealocytes of animals aged both eight months and three years. The results suggest th at: (1) the calcified concretions in the pig pineal gland are formed b y the leptomeningeal tissue without participation of the pinealocytes, (2) cytoplasmic dense bodies, specific components of the pig pineal g land, are only slightly involved in calcium turnover in the pinealocyt es.