Effects of vasodilators and peritoneal dialysis solution on the microcirculation of the rat cecum.

SummaryPeritoneal dialysis solutions produce vasodilation of small arteries and veins on the mesothelial surface of the rat cecum. Dilation in the artery is not altered by the addition of nitroprusside to the dialysis solution. However, there is a dramatic increase in dilation of the small vein upon addition of nitroprusside. This small vein phenomena is not unique to nitroprusside since papaverine can produce dilation of equal magnitude. However, of the three vasodilators tested (nitroprusside, papaverine, and isoproterenol), at comparable vein dilation, nitroprusside produced the greatest small artery dilation. Thus, a unique combination of small vein and small artery mechanisms may in part explain the increases in clinical clearances observed with the addition of nitroprusside to dialysis solution.