UC Irvine

Gastric mucosal microvessels were isolated after arterial perfusion of the rat stomach with magnetized iron oxide suspension. After homogenization of scrapped gastric mucosa, microvessels were initially separated with a high power magnet and further separated and purified by using a nylon sieve. Aliquots of purified microvessels were assessed for viability, histologic appearance, ultrastructure and generation of prostacyclin. Microvessels were plated on Matrigel and cultured in DMEM with high glucose and 10% FBS for 1, 3 or 5 days. After 1, 3 and 5 days of culturing, endothelial viability was assessed with Fast green exclusion, and the basal and stimulated (with calcium ionophore) generation of prostacyclin was determined by assaying aliquots of the incubating medium for 6-keto PGF(1alpha). At 1 and 3 hrs after isolation, microvessels demonstrated intact morphologic structures as reflected by transmission EM and 92+/-4% of viable endothelial cells. The microvessels plated on Matrigel maintained good viability for at least 5 days and generated prostacyclin at the baseline and following ionophore stimulation. These data demonstrate that isolated microvessels cultured under optimal conditions are fully viable and functional.