Intact endothelial and smooth muscle function in small resistance arteries after 48 h in vessel culture.

Long-term culture of resistance vessels allows introduction of molecular biology techniques for use in microvascular research. The aim of the present study was to establish a culture protocol that preserved vascular integrity and function in microvessels for 48 h in culture. Skeletal muscle resistance arteries were excised from the hamster gracilis muscle. Segments were assigned to immediate functional tests or to vessel culture, during which segments were perfused and superfused at a transmural pressure of 45 mmHg with Leibovitz (L15) medium containing 15% fetal calf serum and antibiotics for 48 h. Cultured and freshly isolated vessels showed similar levels of spontaneous tone, myogenic responses, changes in smooth muscle intracellular calcium (Ca(i)(2+)) (fura 2), and vascular diameter (video microscopy) in response to 0.3 M norepinephrine and similar concentration-response curves for acetylcholine (endothelium dependent, +/-N(omega)-nitro-L-arginine) and sodium nitroprusside (endothelium independent). Measurements of endothelial Ca(i)(2+) revealed similar acetylcholine-induced increases in endothelial Ca(i)(2+) in both groups. It is concluded that vascular function can be preserved while maintaining vessels in culture. Thus it is possible to utilize protocols that require long-term treatment.