The
biological activity and time of appearance of alveolar
hydatid cyst induced splenic
amyloid enhancing factor (AEF) with respect to
amyloid deposition in the spleens were determined in C57BL/6J mice. Mice were infected intraperitoneally with 100 alveolar
hydatid cysts (AHC) and killed bi-weekly between 2 and 14 weeks postinfection (p.i.). AHCs and spleens were excised, weighed and a portion of each spleen was sectioned and stained for quantitation of
amyloid deposits and histological studies. The remaining spleen pieces were sonicated separately in cold
phosphate buffered saline, pH 7.4 (I g/10 ml), centrifuged (27,000 g, 60 min, 4 degrees C) and the supernatant tested for
AEF activity.
Splenomegaly followed the progressive increase in the AHC biomass and
AEF activity coincided with the appearance of
amyloid deposits at 6 weeks p.i. A 2.5 mg intraperitoneal
protein dosage of
AEF in conjunction with a
subcutaneous injection of 0.5 ml of a 0.11 M AgNO3
solution in mice, induced the maximum amount of splenic
amyloid deposition at 48 h; the amount of splenic
amyloid deposits decreased by either increasing or decreasing the
AEF dosage. In vivo, 70% of the
AEF activity was abolished by day 4 post-injection of
AEF and completely by 3 weeks. These findings indicate that AHC-induced
AEF is functionally analogous to
casein-induced
AEF and its appearance in the spleen coincides with neutrophilia,
histiocytosis and
amyloid deposition.