Sheep, cattle, rats and guinea pigs were experimentally infected with F• hepatica. During infection plasma and tissue ascorbic acid and plasma cholesterol levels
decreased whereas the plasma low-density lipoproteins increased. Glucose levels remained unchanged. Disturbance of iron metabolism occurred as evidenced by the decrease in plasma and liver iron concentrations and the increase in the iron-binding capacity and these were related to the changes in ascorbic acid levels.
Supplementation of ascorbic acid to infected rats and guinea pigs was not effective in reducing fluke burdens. However, infected guinea pigs given a low vitamin C dose showed earlier symptoms of illness and mortality.
The phagocytic and bactericidal capacities of polymorphonuclear leukocytes of infected sheep and guinea pigs increased compared to controls. The effect of two dose levels of vitamin C on these activities was investigated in guinea pigs.
The plasma proteins, glycoproteins and lipoproteins were investigated in controls and fluke-infected sheep and cattle. A hyperproteinaemia, due to increased ∝- and ꙋ -globulins was a feature of the prepatent period, and a progressive hypoalbuminaemia developed during the course of infection. Changes
in glycoproteins were expressed as elevated protein-bound hexoses, hexosamine, fucose, seromucoid and sialic acid. The plasma ∝ -lipoproteins decreased while the β -lipoproteins increased after exposure.
Collagenolytic and elastinolytic activities were demonstrated in F• hepatica metacercariae, immature flukes, and adult flukes. Hyaluronidase-like activity was also detected in mature flukes. These findings were discussed in relation to the penetrating mechanisms and migration of these parasites. Plasma of infected sheep inhibited the activities of Cl. histolyticum collagenase and testicular hyaluronidase.