Ak. Nanaev et al., IMMUNOHISTOCHEMICAL LOCALIZATION OF EXTRACELLULAR-MATRIX IN PERIVILLOUS FIBRINOID OF NORMAL HUMAN TERM PLACENTA, Histochemistry, 100(5), 1993, pp. 341-346
The extracellular matrix of perivillous fibrinoid in normal human term
placenta was investigated by means of the indirect immunofluorescent
technique. Polyclonal antibodies to collagen types I, III, IV, V, fibr
onectin, fibrinogen, laminin, entactin and heparan sulphate proteoglyc
an and monoclonal antibodies BC-1, IST-9 and IST-4 to human fibronecti
n were used. The antigens can be grouped according to their presence i
n fibrinoid as abundant (fibrinogen, fibronectin, heparan sulphate pro
teoglycan, basement membrane collagen types IV and V), absent (laminin
) and variable between fibrinoids (interstitial collagen types I and I
II, entactin). Our results also demonstrate that fibronectin in fibrin
oid originates from placental cells (presumably cytotrophoblast). Mono
clonal antibodies BC-1 and IST-9 specific to tissue fibronectin do not
stain neighbouring placental extracellular matrix but do bind to fibr
inoids on the same sections. Work by other authors has presented evide
nce that fibrin actually originates from maternal blood and even makes
an attempt to substitute the term ''fibrinoid'' for ''fibrin depositi
on''. Our data on the composition of perivillous fibrinoids and the ab
undance of extracellular matrix components do not support this view an
d suggest that fibrinoid is a more relevant term for this interesting
phenomenon, which deserves further investigation.