Scanning Electron Microscopic Observation of Endothelial Surface of Heart and Blood Vessels

Abstract

The introduction of the scanning electron microscope into biological research has revolutionized the possibilities of studying the surface structures of biological specimens. The method was used originally for the surface of hard tissue ; however, the improved fixation method, which preserves quite well the ultrastructure of soft tissues as shown by Barber and Boyde (1968) ,1) has now made it possible to observe the fine structure of the surface of soft tissues.The present investigation is a study of the surface of vascular endothelium in the rabbit and man. These endothelia have already been studied by transmission electron microscopy, so their structure is partially known. This is the preliminary report of the study. Materials and methods.The endothelial surface of aortas, coronary and renal arteries, inferior vena cavas, right and left ventricles and atria from 13 male rabbits and aortas, inferior vena cavas, right and left ventricles and atria of two men, 21 and 74 years old, who died of Crohn's disease and myeloma, respectively, were examined in the present study.The method of Barber and Boyde (1968)1) was modified and used. Namely, the isolated specimens were carefully washed by LockeRinger's solution, then 1 % osmium tetroxide (with veronal acetate to pH 7.4) was poured into the vessel lumen. The specimen was cut into small blocks 3 mm x 10 mm in size. The blocks were fixed for one hour under cold temperature in an ice-box and were dehydrated in graded Analar acetone solutions of 50%, 70%, 80%, 90%, 95%, and two changes of absolute acetone.After air drying, the specimens were mounted at an angle of 45° to an evaporation source and rotated during the deposition of a conducting coat of about 100300 A of gold in a vacuum.The specimens were studied with a scanning electron microscope (JSM-II) of Japan Electron Optics Laboratory Co. Ltd., using a beam accelerating voltage of 610 0 Ky. The micrograph recorded with a scanning electron beam on the film with an exposure time of 3060 seconds.

Lyophilized Veins Studied by Scanning Electron Microscopy

“…2a). These observations are consistent with already published scanning electron-microscopical find ings [6] about the inner surface of freshly prepared venous material. Ac cording to these observations, the smaller extensions of the longitudinal prominences may represent endothelial processes ( fig.…”

“…A folded and wrin kled profile of the luminal surface has already been observed in larger vessels by scanning electron-microscopical studies. It is particularly prominent in arteries [4] but also clearly visible in veins [6] and is evi dently formed by the internal elastic membrane. The integrity of the en dothelial layer is certainly a most important indication, whether the prep aration of the lyophilized material was of optimal quality or not.…”

Scanning Electron Microscopic Observations on the Luminal Surface of the Rabbit Common Carotid Artery Sublected to lschemia by Arterial Occlusion

“…2), as described by Garbarsch and Christensen 9 with silver nitrate staining. "Bridge-like structures" such as those described by Shimamoto et al 10 and Sunaga et al 11 were sometimes observed in tissues from control animals. They were also present in the area which had been compressed by the clip (fig.…”

A Scanning Electron Microscope Study on the Endothelium of Vessels

“…The endothelial surface structure of the heart has been studied by scanning electron microscopy (SEM) by a few research groups (SHIMAMOTO, YAMASHITA and SUNAGA, 1969;MAGUIRE, 1972;WHEELER, GAVIN and HERDSON, 1973;BUSS, DAHM and LINDENFELSER, 1973;TOKUNAGA, OSAKA and FUJITA, 1973). Apparently because of the strong contraction and shrinkage easily occurring during the procedures of specimen preparation, the results obtained by these authors are conspicuously divergent.…”

“…However, relatively few papers have been published in this field of study. SHIMAMOTO, YAMASHITA and SUNAGA (1969) reported the existence of "intercellular bridges"…”