Intracellular localization of samarium in the lactating mammary gland cells: ultrastructural and microanalytical study.

The frequent use of some rare earths in the medical and industrial domains make us worry about their intracellular behavior into the body. Reason for which we have investigated the subcellular localization of one of these elements, the samarium, in the mammary gland of lactating female wistar rats using two very sensitive methods of observation and microanalysis, the transmission electron microscopy and the secondary ion mass spectrometry. The ultrastructural study showed the presence of electron dense deposits in the lactating mammary glandular epithelial cell lysosomes of the samarium-treated rats, but no loaded lysosomes were observed in those of control rats. The microanalytical study allowed both the identification of the chemical species present in those deposits as samarium isotopes ((152) Sm(+)) and the cartography of its distribution. Our results confirm the previous ones showing that lysosomes of the glandular epithelial cells are the site of the intracellular concentration of foreign elements such as gallium. The intralysosomal deposits observed in the mammary glandular cells of the samarium-treated rats are similar in their form and density to those observed with the same element in other varieties of cells, such as liver, bone marrow, and spleen cells. Our ultrastructural and microanalytical results and those obtained in previous studies allow deducing that the intralysosomal deposits are very probably composed of an insoluble samarium phosphate salt.

Histological and ultrastructural study of the intracellular behavior of indium in the testicular tissues.

Indium, a IIIA group element of the periodic chart, has many medical uses for diagnostic and clinical investigations in humans. This element is also used in industry and in nuclear fields where released streams can contaminate environment. Consequently, indium can reach humans mainly by natural ways. In this work, we attempted to study the incidence of this element on the food intake and body and testicle weights of rat, as well as the histological and the ultrastructural consequences of its presence in testicles using conventional transmission electron microscopy. Our study showed that this element induced a significant decrease in the food intake and body and testicles weights and caused necrosis and vacuolization in germinal cells. The ultrastructural observations showed the presence of electron-dense deposits characteristic of indium in the lysosomes of Leydig and Sertoli cells as well as sufferance in mitochondria of indium-treated rats. Despite the role of lysosome in the protection of living cells, by sequestration and concentration of indium in testicle cells under insoluble form, it is probable that this element has noxious effects on food intake and body and testicles weight and induces necrosis on seminal tissues of treated rats.

Ultrastructural study of the intracellular behavior of four mineral elements in the lactating mammary gland cells: study using conventional transmission electron microscopy.

The effects of parenteral injection of aluminum, indium, gadolinium, or terbium in rats have been previously studied in several organs such as the liver, the kidneys, etc., but never in mammary glands. In this work, we have attempted to study the subcellular localization of these elements after their intraperitoneal administration. Their subsequent effects in the lactating mammary gland cells have also been studied. Our results using conventional transmission electron microscopy have shown that the lysosomes of the mammary glandular epithelial cells are the intracellular site of accumulation of the studied elements. Our results have also show intracellular deteriorations such as an expanded ergastoplasm and altered mitochondria after intraperitoneal injection of aluminum and indium.

Lysosomes of the liver and the duodenal enterocytes, a site of handling of two rare earths. Ultrastructural and microanalytical study.

The frequent use of some trace elements such as gadolinium and terbium in medicine and modern industries make us worry about their behavior in the organism. In this work, we study the intracellular localization in the liver and in the intestinal mucosa of two rare earths, gadolinium and terbium, after intraperitoneal and intragastric administration. Three methods of observation and microanalysis were used: conventional transmission electron microscopy, secondary ion mass spectrometry, and electron probe microanalysis. After intraperitoneal administration, gadolinium and terbium were detected with phosphorus in lysosomes of hepatocytes and Küppfer cells and in territories near to biliary canalicule. One hour after intragastric administration, gadolinium and terbium were concentrated in lysosomes of the apical part of duodenal enterocytes. No gadolinium or terbium was detected in duodenum 4 days after administration. After intragastric administration, the microanalytical techniques failed to detect gadolinium or terbium in liver whatever the time of sampling. This mechanism of concentration-precipitation in the lysosomes of enterocytes limits the diffusion through the digestive barrier of foreign elements and then permits their elimination with apoptotic cells in the intestinal lumen. Some of these elements may be toxic, and none of them have a recognized physiological function. The intestinal mucosa plays an important role in the protection of the organism against the invasion of foreign elements.