Effects of the endothelial relaxing factor on the orthostatic reaction of systemic hemodynamics in rats

: Experiments with unconscious rats showed that blocking of NO secretion intensifies orthostatic hypotension (mean arterial pressure drops by 72%) and reduces proportionally the calculated total peripheral resistance. A supposition has been made concerning involvement of the endothelial relaxing factor in orthostatic hypotension development, since in orthostasis cardiac output (systemic blood circulation) losses its influence on the endothelial NO secretion.