Circulatory Reaction of Tolerant and Nontolerant Dogs to Polyvinylpyrrolidone and of Rats to Dextran

¹ From the National Institute of Arthritis and Metabolic Diseases, National Institutes of Health, Bethesda, Maryland

In dogs the decrease in mean arterial blood pressure and appearance of gross signs after rapid intravenous injection of 350 mg PVP/kg became less severe after pretreatment with the colloid. When the same dosage was injected 1 hour previously, the reaction was completely absent in 9 dogs out of 12, and the remainder were relatively refractory. Refractoriness in rats to a second injection of dextran (600 mg/kg) was demonstrated in the same manner. The blood pressure pattern, erythema and edema with extravasation of dye indicate that both colloids produce in the sensitive species an initial vasodepressor action followed by capillary permeability changes. No vasodepressor reaction occurred in relatively tolerant dogs given dialyzed PVP.