The knowledge of the endocrine glands in aged animals seems necessary in the understanding of the relationship of endocrine glands to the whole organism. Most of our knowledge concerning the senile changes are based on the findings from laboratory animals . Meanwhile, reports concerning the ageing process of the endocrine glands of domestic animals are especially few. The present study is conce...

The fatty acid composition and content of total phospholipids, free fatty acids (FFA), diacylglycerols (DG), phosphatidylcholine (PC), phosphatidylserine (PS), and phosphatidylethanolamine (PE) were studied in lipofuscin granules of human donors in two age groups, young (less than 40 yr old) and old (more than 47 yr old), and compared with lipids of the photoreceptor rod outer segments (ROS). N...

Recent data both from cell-free experiments and from cultured cells have shown that lysosomes can fuse directly with late endosomes to form a hybrid organelle. This has a led to a hypothesis that dense core lysosomes are in essence storage granules for acid hydrolases and that, when the former fuse with late endosomes, a hybrid organelle for digestion of endocytosed macromolecules is created. L...

Intracellular molecular motor-driven transport is essential for such diverse processes as mitosis, neuronal function, and mitochondrial transport. Whereas there have been in vitro studies of how motors function at the single-molecule level, and in vivo studies of the structure of filamentary networks, studies of how the motors effectively use the networks for transportation have been lacking. W...

In the spleen, liver, and kidneys of most mammals may be found varying quantities of yellow-brown granules and to these granules has been given the general name hemosiderin. Since the formation and location of hemosiderin coincides in time and place with the destruction of blood, the idea has become firmly established that hemosiderin represents some step in the disintegration of hemoglobin and...

The structural organization of the retinula cells in the eye of Ligia exotica changes diurnally. At night, the microvilli elongate, losing the regular and parallel alignment characteristic of the day condition. Crystalline cones and distal rhabdom tips are not pushed into each other during the day, but at night the rhabdoms protrude into the crystalline cones by up to 5 microm. Screening pigmen...