Fibrinogen or its derivatives in the Kurloff cells

We have investigated the occurrence of fibrinogen or its derivatives in the Kurloff bodies of female guinea pigs by means of immunofluorescence, histochemistry and ultrastructural analysis. The Kurloff bodies are fluorescent after incubation with anti-guinea pig fibrinogen immuno-globulins coupled with fluorescein isothiocyanate. PTAH, Martius scarlet blue, Masson 44--41, Picro-Mallory V stain the Kurloff bodies just as they stain fibrin and fibrinoid. However, the ultrastructure of the central mass of the Kurloff body is finely granular without fibrils. Thus the Kurloff body contains no fibrin but incompletely polymerized fibrinogen derivatives or breakdown products of fibrin.