A humoral factor in the plasma of dogs with hemorrhagic hypotension causing histopathologic changes when infused into normals.

The presence of circulating factors in the plasma of shocked dogs which would be capable of causing lung lesions when infused into normotensive dogs was demonstrated by light and electron microscopy. Light microscopy only identified significant differences in atelectasis, vascular congestion, and interstitial edema in the shock and shock-plasma recipient animals. On electron microscopy, interstitial edema and disruption of collagen bundles were consistently found in shocked dogs and in dogs that had received shocked plasma. There was a consistent increase in pulmonary interstitial sodium in both shock and shock-plasma recipient groups. It is concluded that a plasma factor present in the serum of shocked dogs may be transferred to other dogs and cause histopathologic changes seen in the lungs of shocked animals.