Archivum histologicum Japonicum = Nihon soshikigaku kiroku最新文献

Recent advances in immunohistochemical studies have revolutionalized our understanding of the adrenal gland with the discovery that many neuropeptides exist in the chromaffin cells and intraadrenal neuronal components. The coexistence of peptides and catecholamines is a constant feature of the chromaffin cells. The coexistene of multiple peptides is also seen in some chromaffin cells. This indicates that there are several subpopulations among the chromaffin cells in terms of bioactive substances contained. Diverging from the traditional view that intraadrenal nerves are predominantly preganglionic cholinergic ones innervating the chromaffin cells, the nerves are revealed to consist of heterogeneous populations containing various different neuropeptides. These are presumed to be of several different origins. The nerves innervate not only the chromaffin cells but partially the cortical cells, too, and are further associated with intraadrenal blood vessels. Several possible courses of action for the neuropeptides in the adrenal gland have been proposed based on immunohistochemical findings. The adrenal gland should be regarded as an endocrine organ, secreting not only catecholamines but also various neuropeptides; it likely plays more important and varied roles than previously believed for the maintainance of the internal environment of the body.

Perineuronal glial nets in the rat spinal cord were studied. According to the density of the nets and the thickness of the processes which form them, different types of nets were demonstrated. In addition to nets originating from microglial cells, nets formed by smooth protoplasmic astrocytes are also described.

Lamellated nerve endings in the cheek mucosa of fifteen adult Sprague-Dawley rats were studied with light and electron microscopes. Serial sections revealed that the terminal axon of the lamellated nerve endings is in the central portion, and that the inner core is made up of two stacks of lamellae. These are characterized by many corpuscles located within a single papilla, which shows structural specializations at several levels. Electron microscopy showed that the corpuscles are circular in shape and that the lamellar sheets possess a rich rough endoplasmic reticulum, mitochondria and numerous glycogen-like granules. Numerous bundles of collagen fibers and an amorphous substance are located in the interlamellar spaces. The axon terminal is characterized by the presence of neurofilaments, neurotubules and mitochondria. The capsule consists of several laminae formed by cytoplasmic extensions of perineural cells presenting many caveolae, mitochondria, rough endoplasmic reticulum profiles and microfilaments.

Morphological changes in the surface mucous cells in the gastric body of the golden hamster occurring during their movement from the lower to the upper portion of the gastric pit have been observed by using scanning as well as transmission electron microscopes. The cells have a wide base and a narrow apex in the lower and middle portions of the pit, while at the opening of the pit to the gastric lumen, they become taller and funnel-like in shape, and are characterized by well developed interdigitations and intermediate filaments sometimes associated with desmosomes. During this transformation of the cell contour, the nucleus moves towards the upper region of the cytoplasm, whereas the Golgi apparatus moves downwards to the infranuclear region. Then, there appear secondary lysosomes showing crinophagy and lipid droplets around or near the Golgi apparatus. Though the basal part of the cells is very small, no images of the detachment of the basal plasma membrane from the basal lamina could be seen even at the site of severe cell degeneration. The tall funnel-shaped cells showing these characteristics are located on the interfoveolar ridges of the underlying fibrous layer and line the free surface of the stomach. Therefore, the interfoveolar cells which have lost the activity of secretory granule production and are going to undergo physiological degeneration are thought to be highly differentiated elements as a covering epithelium to protect the underlying tissue, resembling in this respect the keratinocyte of the epidermis.

The adult cat oviduct was viewed by SEM and TEM as spermatozoa of the same species and inert latex beads were injected into its lumen. The present study demonstrates that nonciliated epithelial cells in extensive areas of the oviduct as well as luminal macrophages are capable of actively taking up both the spermatozoa and the latex beads in the manner of phagocytosis. The epithelial cells are thus able to eliminate foreign bodies including degenerating spermatozoa in order to scavenge the lumen, though the cellular mechanisms involved in their phagocytosic activity remain to be elucidated.

In order to know the mechanism of steroid hormone biosynthesis, the localization of cytochromes P-450 of cholesterol side-chain cleavage enzymes (P-450SCC) and P-450 of 11 beta-hydroxylase (P-450(11)beta) were studied in bovine adrenal glands by light as well as electron microscopic immunohistochemistry, using monoclonal antibodies. With light microscopy the cytoplasm of the glomerulosa cells was faintly immunostained, while that of the fasciculata-reticularis cells was intensely immunostained by both monoclonal antibodies for cytochrome P-450SCC and cytochrome P-450(11)beta, though the capsular connective tissue cells and the adrenal medullary cells were entirely negative for these reactions. Electron microscopic immunohistochemistry revealed that the positive reaction products for cytochromes P-450 were present on the matrix side of the inner mitochondrial membrane including the tubulovesicular cristae of the cortical cells, and especially of the fasciculata and reticularis cells. The present results indicate that both cholesterol side-chain cleaving enzymes and 11 beta-hydroxylase are present in the inner mitochondrial membrane of bovine adrenal cortical cells.

Ito cells (fat-storing cells), containing a few lipid droplets, appeared in the Disse's spaces of the Beagle dog liver. They ranged in diameter from 0.5 to 5 micron. The present study revealed that mast cells were also distributed in the Disse's spaces, while they were encountered only in the interlobular connective tissue in other animals. Although mast cells as well as Ito cells were distributed solitarily in the Disse's spaces, pairing of both types of cells could be frequently observed. Direct contact between both cells was verified using both light and electron microscopy. Also encountered were some peculiar figures of certain Kupffer cells engulfing the cytoplasmic processes and secretory granules of mast cells. These findings indicate a previously unknown intimate relationship between the mast cell and other perisinusoidal cells in the dog liver: the Ito cell, Kupffer cell and endothelial cell.

Ultrastructural localization of alkaline phosphatase activity was studied in astrocytes of the cerebral cortex and corpus callosum, and in the ependymal and subependymal cells of the lateral ventricle of normal rat brain by means of electron microscopic histochemistry employing the lead citrate method. Astrocytes exhibited alkaline phosphatase activity on the plasma membrane of the endfeet facing the vascular basement membrane and at the gap junctions, but not on other parts of the plasma membrane or in the cytoplasm. Immature astrocytes containing small bundles of filaments, a few glycogen granules and other cell organelles, exhibited alkaline phosphatase activity on the inner and outer nuclear membranes, the outer mitochondrial membrane and on portions of the plasma membrane. Thus, it was concluded that the distribution of alkaline phosphatase in astrocytes shifts from the cytoplasm and plasma membrane to the endfeet and gap junctions with cell maturation. Alkaline phosphatase activity was detected on the plasma membrane of the subependymal cells and surrounding processes, but not on the ependymal cells.

The urethral mucosa in the canine penis was immunostained by use of antibodies against substance P and calcitonin gene-related peptide. Numerous nerve fibers immunoreactive for both peptides were found to invade the epithelium from the tunica propria; here they ran various courses with occasional branchings and conspicuous varicosities. Some looped to return into the tunica propria, while others ended on the epithelial surface. These findings confirm and extend our knowledge on the sensory innervation of the urethra which has previously been based on silver impregnation techniques.

Fine structural localization of alkaline phosphatase activity was studied in the neurons of the cerebral cortex and the optics and sciatic nerves of the rat by electron microscopic histochemistry with the lead citrate method. Most neurons in the cerebral cortex demonstrated alkaline phosphatase activity on the plasma membrane of the nerve cell body and dendritic processes, from the thick trunk to the terminal postsynaptic boutons. Alkaline phosphatase was also associated with the axolemma, but only at the terminal presynaptic boutons and at the nodal and paranodal region of the nodes of Ranvier. The axolemma covered by myelin sheaths did not show any activity. The alkaline phosphatase reaction of the Ranvier node could also be demonstrated in the optic and sciatic nerves.