Growth-related micromorphological characteristics of the porcine common carotid artery.

The purpose of this study was to gain knowledge about the micromorphology of the porcine common carotid artery (CCA) during the period of growth over the bodyweight range of 10-40 kg. CCA samples from German landrace pigs (DL) aged either 2 or 3 months (DL-2 and DL-3) were compared with samples from Göttingen minipigs (GM) aged either 18 or 40 months (GM-18 and GM-40) using transmitted light (phase-contrast mode) and transmission electron microscopy. The GM-18, GM-40 and the DL-3 groups had typical muscular artery histological characteristics. Contrasting to this, the 2-month-old DL pigs had a transitional artery type being characterized by a significantly higher proportion of elastic fibres and a significantly lower number of smooth muscle cells than did the 1 month older DL-3. During the period of maturation, the tunica media of the CCA in GM animals thickened by 1.3× and in DL animals by 2.5× resulting in an overall increased vessel wall thickness. The cumulated thickness of the tunica interna (endothelium, stratum subendotheliale and internal elastic lamina) and the tunica media (including the external elastic lamina) of DL-3 and GM-40 pigs were similar to each other and comparable to that of humans. With an increasing vessel wall thickness, the luminal diameter decreased in GM by 19% and in DL by 11%. Additionally, in the older age groups, GM-40 and DL-3, the internal elastic lamina principally was continuous, but there were also interrupted large segments of elastic lamina separated by gaps. In addition, the principal internal elastic lamina was duplicated in several places.

Human microvascular endothelial cells displaying reduced angiogenesis and increased uptake of lipids during in vitro culture.

Human microvascular ECs from the neonatal foreskin of two donors purchased from one distributor were used in an angiogenesis assay under the same culture conditions. Different angiogenic potency was apparent in these two batches (ECang and ECnon-ang). During the cultivation period of three weeks, ECang ran through all stages of angiogenesis starting from proliferation to migration up to the formation of three-dimensional capillary-like structures. Despite of expression of endothelial markers, ECnon-ang showed excessive intracellular storage of lipids in form of multilamellar bodies and decreased angiogenic potency in contrast to its counterpart, ECang. Results indicate that lipid metabolism differs in ECang versus ECnon-ang. This study points up that these differences are based on the different donors and presents a novel and valuable model for the study of mechanisms of atherosclerosis in endothelial cells in vitro.

In vitro angiogenic potency in human microvascular endothelial cells derived from myocardium, lung and skin.

Human microvascular endothelial cells derived from myocardium (HCMEC), lung (HPMEC) and foreskin (HDMEC) showed different angiogenic potency when cultivated in their original growth media provided by the distributors. In order to standardize microenvironmental conditions in an all-in-one assay of angiogenesis the aim of this study was to find one optimal growth medium for the endothelial cells derived from the different organs. Therefore each endothelial cell type was cultivated under identical conditions in the different original growth media as well as in several media formulations of the original growth media. Results reveal that even if cultivated in the same growth medium under exactly the same cultivation conditions--over a prolonged time period of 60 days--the endothelial cells still showed different angiogenic potency. This is due to a combination of extrinsic factors, i.e. the isolation procedure and in particular the growth medium, as well as to intrinsic differences between cells of diverse origin.