Computerized 3-D reconstruction of small blood vessels from high voltage electron-micrographs of thick serial cross sections.

Morphological analysis of compartments in terms of volumes and the orientation of the cells and their nuclei within very small mesenteric arteries and arterioles is being carried out. Samples were from simultaneously sham operated and instrumented control and one-clip two kidney Goldblatt sustained (30 days) hypertensive dogs. Collection of specimens was standardized, i.e. sampling location, perfusion fixation, embedding, staining, and sectioning by methods proven to preserve in vivo dimensions. Serial thick cross sections (0.5 mu) were subjected to high voltage electromicrography (1.0 MeV) at 2500x and then linearly enlarged 3x photographically. The glossy micrographs (7500x) were made into montages and the contours of the smooth muscle layer (vascular smooth muscle), the endothelium (E), nuclei (N), and the internal lamina (IL) were digitized on a large GTCO digi-pad with input to a microcomputer (PC-Limited, Turbo) equipped with a 20 MB hard disk and coprocessor. Solid and transparent image reconstructions and computerized dissection of cell compartments were performed. Compartment volumes of vascular smooth muscle, IL, E and N, and individual cell and nuclear volumes, as well as nuclear/cytoplasmic ratios were calculated. Image reconstructions are presented. The emphasis is on methods and these are discussed in terms of useability for determining accurate microvessel morphology in health and disease, with particular emphasis on assessment of hypertrophy and hyperplasia in experimental hypertension, and architectural angiogenesis in general.