Skin microvascular membrane permeability was assessed in anesthetized dogs after resuscitation from endotoxin shock. Infusion of Ringer's lactate solution, in a volume equal to 7 per cent of the body weight, reversed hypotension produced by an intravenous injection of Escherichia coli endotoxin (0.5 milligrams per kilogram). The shock group was compared with a group of dogs not given endotoxin and infused with a similar dose of Ringer's lactate solution and a with control group of dogs. Prenodal lymph was collected from both hindpaws and three to four hours before ending an increase of 20 to 28 millimeters of mercury in venous pressure of the hindpaw was produced in one limb by tightening a tourniquet. This maneuver produced an increase in lymph flow associated with an increase in lymph protein flux that was similar in all three groups. The wet to dry tissue weight ratio of skin samples did not increase in the endotoxin group. Skin microvascular membrane permeability did not increase. The safety factors that helped to prevent edema after infusion of Ringer's lactate solution included an increase in lymph flow and sieving by the intact microvascular membrane which diluted the interstitial protein concentration.