Three-Dimensional Architecture of Glomerular Endothelial Cells Revealed by FIB-SEM Tomography.

Focused-ion beam-scanning electron microscopic (FIB-SEM) tomography enables easier acquisition of a series of ultrastructural, sectional images directly from resin-embedded biological samples. In this study, to clarify the three-dimensional (3D) architecture of glomerular endothelial cells (GEnCs) in adult rats, we manually extracted GEnCs from serial FIB-SEM images and reconstructed them on an Amira reconstruction software. The luminal and basal surface structures were clearly visualized in the reconstructed GEnCs, although only the luminal surface structures could be observed by conventional SEM.

Three-dimensional imaging of podocyte ultrastructure using FE-SEM and FIB-SEM tomography.

Podocytes are specialized epithelial cells used for glomerular filtration in the kidney. They can be divided into the cell body, primary process and foot process. Here, we describe two useful methods for the three-dimensional(3D) visualization of these subcellular compartments in rodent podocytes.

Effects of Dietary Fish Oil and Apple Polyphenol on the Concentration Serum Lipids and Excretion of Fecal Bile Acids in Rats.

We studied the effects of fish oil and apple polyphenol combined with a high cholesterol diet in rats, and assessed serum and liver lipids concentrations, serum oxidative stress and fecal bile acid excretion. Young male rats were fed a diet containing the control (Control), apple polyphenol (AP), fish oil (FO) or fish oil+apple polyphenol (FO+AP) for 4 wk. The control diet contained a lard component.

Organ Specificity and Functional Relevance of the Arterial Structure: A Comparative Study in the Kidney and the Skeletal Muscle with Electron Microscopy.

The differences in circulation among various organs are well known, but the structural differences have only been poorly investigated. In the present study the wall structure of arteries was observed with electron microscopy in rat kidney and skeletal muscle. The wall thickness was almost equal in both organs at about 40 μm in luminal diameter, while it was relatively thin in the larger arteries and thick in the smaller arteries in the kidney compared with that in the skeletal muscle.

Are the precapillary sphincters and metarterioles universal components of the microcirculation? An historical review.

The microcirculation is a major topic in current physiology textbooks and is frequently explained with schematics including the precapillary sphincters and metarterioles. We re-evaluated the validity and applicability of the concepts precapillary sphincters and metarterioles by reviewing the historical context in which they were developed in physiology textbooks. The studies by Zweifach up until the 1950s revealed the unique features of the mesenteric microcirculation, illustrated with impressive schematics of the microcirculation with metarterioles and precapillary sphincters.

Structural arrangement of collagen fibrils in the periarterial connective tissue of the kidney: their functional relevance as a structural stabilizer against arterial pressure.

Periarterial connective tissue with a moderate amount of collagen fibrils is known to be a specialized domain in the renal interstitium. This study aimed to clarify the microscopic architecture of the periarterial connective tissue as a mechanical supportive structure of the intrarenal arteries. Transmission and scanning electron microscopy revealed two populations of collagen fibrils in the periarterial connective tissue.

Structural organization of pulmonary veins in the rat lung, with special emphasis on the musculature consisting of cardiac and smooth muscles.

Recent physiological studies have indicated the significant role of pulmonary veins in the total resistance of pulmonary vasculature. The structure of pulmonary veins in the rat was reinvestigated to clarify the different venous segments and their ultrastructure with regard to the musculature including cardiac muscles and smooth muscles with light and electron microscopy. The cardiac muscles were located in the axial and the primary branches of the pulmonary veins within a certain distance limit from the hilum (CM segment) and not in the peripheral region (non-CM segment).

Mechanical components of rat intestinal villi as revealed by ultrastructural analysis with special reference to the axial smooth muscle cells in the villi.

The ultrastructure of the rat intestinal interstitium with regard to the mechanical components was analyzed from a functional viewpoint utilizing serial horizontal as well as longitudinal sections through the lamina propria mucosae, including both villi and crypts. The axial smooth muscle cells in the villi (villus-axial SMs) exhibited different configurations at various levels of the wall. They were separated from the voluminous fluid-filled spaces by sheet-like processes of fibroblasts in the upper part of the intravillous interstitium, formed a sheet around the central lymphatics, and were covered by the sheet-like processes of fibroblasts in the lower part of the intravillous interstitium.

Structural and mechanical architecture of the intestinal villi and crypts in the rat intestine: integrative reevaluation from ultrastructural analysis.

The ultrastructure of the rat intestinal interstitium was analyzed from the viewpoint of mechanical dynamics to stabilize the intestinal villi, crypts and mucosal folds. In the rat, the small intestine lacks circular folds, but the large intestine possesses spiral folds. The intestinal villi, the largest in the duodenum, decreased in size in the jejunum and ileum successively, and were absent in the large intestine.

The ultrastructure of periductal connective tissue and distinctive populations of collagen fibrils associated with ductal epithelia of exocrine glands.

The ultrastructure of the connective tissue around the intraglandular ducts was observed in rat exocrine glands. Connective tissue with a dense population of collagen fibrils was found either around the ducts and blood vessels (perivasculoductal connective tissue; PVDCT) as in the lacrimal and salivary glands and liver, or solely surrounding the ducts (periductal connective tissue; PDCT) as in the exocrine pancreas, whereas the interlobular and intralobular interstitium of the glands-except for the liver-contained substantially fluid-filled spaces without collagen fibrils. The PVDCT and PDCT of these glands contained two populations of collagen fibrils-fibroblast-associated and epithelium-associated-although the development and density of these fibrils varied considerably in individual glands.

Fibroblasts and antigen-presenting cells in the renal interstitium of streptozotocin-induced diabetic rats on a high cholesterol diet.

The cortical peritubular interstitium of the normal kidney contains both fibroblasts and antigen-presenting dendritic cells. Characteristics of these interstitial cells were analyzed in an overnutrition model by electron microscopy after the cold-dehydration technique and immunohistochemistry for antigen-presenting cells. In control rats, fibroblasts and dendritic cells were clearly identified by electron microscopy on the basis of their distinct ultrastructures.