Nucleotide profiles in normal minipig arterial tissue.

Abstract

The purpose of this study was to characterize the nucleotide profiles of a normal porcine elastic and muscular artery. Tissue samples (50 to 150 mg) were excised from the descending thoracic aorta and from the femoral artery of 14 normocholesterolemlc, anesthetized mlnlplgs. In three animals, transmural myocardlal samples were also obtained. Nucleotide and nucleoslde concentrations were analyzed by using a recently developed ion-palrlng, reverse-phase, high-performance liquid chromatographlc method. The arterial samples contained relatively low concentrations of adenoslne triphosphate, approximately one-eighth that of the myocardlal counterpart. Relative to the femoral artery, the aortic samples had significantly lower adenylate energy charges and higher levels of adenoslne dlphosphate, adenosine monophosphate, adenoslne, and inoslne. These baseline aortic levels did not change after In vitro exposure to 95% oxygen. The different energy states observed In the two arteries may reflect functional or metabolic differences in their medial smooth muscle cell populations. Alternatively, the lower energy state observed in the thicker walled aorta may be a manifestation of Inadequate medial oxygen delivery that persists despite oxygen enrichment In vitro. We conclude that arterial energy states exhibit regional variation. This Information will serve as a point of departure for the Investigation of the role energy states may play In the atherosclerotic process. (Arteriosclerosis 10:745-750, September/October 1990) E nergy-requiring processes in the arterial wall, as in all tissues, require adequate levels of high-energy compounds, generally adenosine triphosphate (ATP). A significant proportion of the required high energy compounds is generated by the oxidative catabolism of various substrates.1 •^ Since oxygen is required for such reactions, the ability to maintain adequate levels of high-energy compounds would appear to depend on oxygen delivery to the metabolizing arterial cells, of which the medial smooth muscle cells are quantitatively most important. Studies done in rabbits have suggested that oxygen delivery in many arteries is insufficient to maintain an aerobic environment in the mid-media] regions. 45 It is plausible that such tissue hypoxia may be associated with alterations of highenergy phosphates and their metabolites. The purpose of this study was to characterize the nucleotide and nuclecside profiles of a normal porcine muscular artery (femoral artery) and elastic artery (descending thoracic aorta) to assess whether such profiles suggest the presence of medial hypoxia and to assess whether such profiles vary in these two types of arteries. Methods Experimental AnimalsFourteen 2-to 3-year-old normocholesterolemic minipigs (Sinclair Research Farm, Columbia, MO) with an average weight of 75 kg were used in this study. All procedures were approved by the Institutional Laboratory Animal Care and Use Committee at the Ohio State University. The animals were anesthetized with ketamine (40 mg/kg) plus acepromazi...

Effect of various blood-derived and semisynthetic nutrient media on in vitro uptake of 125I-albumin across the intact porcine aortic endothelial surface in an organ-support system.

“…23 The concentrations of the serum proteins and most of the electrolytes listed below the thin line in Table 1 appeared to remain stable over the incubation period. However, glucose, trigh/ceride, and HCO 3 " decreased significantly.…”

“…In either case, the degree of agreement between their in vivo data and the present M/c 0 data supports the validity of the OSS approach for t<4-hour in vitro studies of vascular mass transport. In view of this as well as the evidence in Table 1 for glucose (and perhaps lipid) metabolism, oxygen consumption (see footnote on page 360), and the previously demonstrated maintenance of tissue high-energy phosphate levels, 23 it appears that the OSS provides a suitable environment in which certain characteristics of arterial function can be studied uniquely under controlled experimental conditions. a FIGURE …”