Effect of arterial pressure on arterial and venous resistance of intestine

Abstract

The effect of local alteration of arterial pressure on arterial and venous resistance of the intestine was investigated by means of the Pappenheimer isogravimetric technique. Reduction of arterial pressure caused a decrease in total vascular resistance in 70% of the experiments (autoregulation). This response was localized to the arterial portion of the circuit, specifically to vessels less than 0.5 mm o.d. Also associated with the reduction in arterial pressure was an increase in venous resistance. Venous resistance increased threefold as arterial pressure was reduced from 100 to 30 mm Hg. This venous response was seen in all preparations tested. It is suggested that both the venous response and autoregulation of arterial vessels aid in maintenance of a normal capillary pressure. Submitted on November 6, 1961