Document Type
Thesis
Date of Award
1-31-1988
Degree Name
Master of Science in Biomedical Engineering - (M.S.)
Department
Biomedical Engineering Committee
First Advisor
David S. Kristol
Second Advisor
L. Horn
Third Advisor
Richard Clyde Parker
Abstract
The mesenteric arterioles (outer diameter < 100 µ) from a normotensive and a hypertensive dog were perfused in situ, excised, post-fixed and embedded in Spurr medium block. Thick serial cross sections (0.5 µ) of the vessels were obtained from hand formed mesas and placed on Formvar coated slot grids.
The cross sections were subjected to High Voltage Electron Microscopy (HVEM) and five or more electronmicrographs were taken to cover the individual cross sections. The prints of electronmicrographs were linearly enlarged (3X) and made into photomontages of sections. The membrane contours in the montages were traced on transparent overlays, producing polygons which in turn were traced on GTCO digitizing pad. All polygons were labeled, color coded and stored in IBM PC's filing system. The vessels were reconstructed from up to 100 whole cross sections and subjected to cell compartmentalvolume analysis. The reconstructed images can be rotated in X, Y, and Z planes, made solid or transparent and analyzed for orientation and arrangement of individual cellular components.
The fine structure of microvessel wall, including vascular smooth muscle (VSM), internal lamina (IL) and endothelium (EN) were reconstructed, visually inspected and analyzed; also their individual components were subjected to a similar regime.
The display of reconstructed vessels offers substantial assistance in evaluating physiological and pathological aspects of blood vessel morphology. This method allows detailed architectural analysis of the wall components of small blood vessels.
In general, cells and nuclei of the EN were oriented longitudinally. The luminal side of EN was smoother than the basal side. The vessel lumen contour was irregular, especially in the vicinity of EN cell nuclei. EN cells formed extensive protrusions or pseudopods on the basal side. IL presented a smooth cylindrical appearance at VSM junction, and were fenestrated. The VSM cells typically possessed multiple processes which were oriented circumferentially. Within VSM the nuclei were at a small angle or parallel to the vessel's circumference.
The normotensive dog vascular smooth muscle cells had an average volume of 561 µ3 and endothelial cells of 323 µ3; for hypertensive dogs the values were 548 µ3 and 376 µ3 respectively. The IL of a hypertensive dog was somewhat thicker (0.37 µ and 0.32 µ) than in the case of a normotensive dog; also, the thickness of the entire hypertensive vessel wall was greater than for the normotensive specimen (3.25 µ and 2.26 µ respectively).
Vessels from the hypertensive specimen showed substantial changes in conformation of the wall structures, which may reflect considerable cellular changes and mobility of wall elements. Because the sample vessels were obtained from only two animals, further research is needed to validate these results.
The 3-D reconstruction method proved to be more reliable, accurate and faster for reconstruction and cellular volume calculations than any other technique previously employed.
Recommended Citation
Krajewski, Wieslaw Slawomir, "Morphological analysis of microvessels using high voltage electron microscopy (HVEM), IBM personal computer and 3-D reconstruction software" (1988). Theses. 3256.
https://digitalcommons.njit.edu/theses/3256
