Origin and Structure of a Fibrin-Type in Normal Blood

Abstract

If normal blood from the rabbit and guinea pig is washed and centrifuged 4 to 6 times in 20 times the blood volume of Ringer or Ringer-saline solution, the same type of fibrin-filaments attached to red corpuscles may be observed as were previously described. 1 These filaments appear within 25 minutes to 2 hours after the hanging-drop preparation has been made, and exhibit the same functional manifestations that were observed in ordinary blood hanging-drops. These filaments therefore have their origin in the red corpuscles themselves, and probably arise from the fibrinogen-like substance which Horino 2 isolated from washed red corpuscles.

The ordinary fibrin threads of plasmatic origin forming about platelets do not exhibit the phenomena described for the fibrin filaments attached to red corpuscles. Moreover the addition of sodium oxalate, hirudin or heparin in sufficient amounts to largely abolish the formation of plasmatic fibrin, had only little effect on the formation and activity of the fibrin-filaments from red corpuscles.

Observation of the fibrin-filaments issuing from red corpuscles shows in favorable instances that it is composed of fibrils which are twisted about each other like the strands of a rope. Rupture of such a fibril brings about the formation of small pellet which may rotate around the main stem with gradually increasing radius until it swings free on its own pedicle from the base of the main filament. Such pellets may again twist themselves around the parent stem in a spiral manner and disappear. The largest number of such pellets observed on one ruptured filament was 5. These fibrils are in turn composed of invisible (bright-light field) sub-fibrils. The presence of such invisible sub-fibrils is demonstrated by their distorting effects on red corpuscles, by the alternate disappearance and reappearance of sections of the filament, and by the sudden movement of apparently free corpuscles or microcytes.