Effect of flosequinan on human small subcutaneous arteries.

We have investigated the effect of the novel hypotensive agent, flosequinan, on human small artery constrictor function. Concentration-dependent tension development to both noradrenaline and K+ was reduced in the presence of flosequinan. Arteries pre-contracted with noradrenaline demonstrated a greater concentration-dependent relaxation to flosequinan than did those pre-contracted with K+. Flosequinan depressed the sensitivity to extracellular Ca2+ of arteries pre-contracted with noradrenaline, but this effect was less marked in arteries pre-contracted with K+. These data support previous studies which suggest that flosequinan may affect receptor-mediated contraction by reducing Ca2+ sensitivity.