Prostacyclin generation by rat aortas obtained by different procedures

Abstract

Endothelium is a monocellular layer very prone to mechanical injury when vessels are handled in vitro. Injury is due to 1) spontaneous vessel shortening and collapse after excision, which produces partial detachment of the endothelium from the matrix (Lewis et al., 1991), and 2) obligated manipulations such as the washing off of blood and periadventitial tissue removal. Apart from this type of mechanical damage, the use of solutions inadequate from a physiological point of view may also produce metabolic injury. Morrison et al. (1976, 1977) reported losses of endothelium in rabbit aorta when solutions without oxygen or nut~ents were utilized. In a previous work (Gabaldon and Capdevila, 1991), we studied the effects of different washing solutions and of several techniques for removal and cleaning of the rat aorta on endothelial integrity determined by silver staining of the interendothelial junctions. As prostacyclin is produced by both the endothelium and the medial layer of the aorta (Ts’Ao et al., 1979; Goldsmith, 1982; Boeynaems et al., 1985), loss of endothelial integrity in preparation may affect diffusion of the reaction product and alter the overall production of prostacyclin by the vessel. The aim of the present paper is to establish the effect of aortic processing on endothelial integrity and prostacyclin synthesis, utilizing I) different solutions for washing of the aorta; 2) different techniques for removal and cleaning of the aorta; and 3) mild in situ