Pichinde virus infection in strain 13 guniea pigs reduces intestinal protein reflection coefficient with compensation

Pichinde virus inoculation into strain 13 guinea pigs is a model with features reputed to be similar to hemorrhagic fever in humans. Although the infection is lethal by day 13-19, guinea pigs of approximately 600 g do not show edema or effusions. This raises the questions of whether capillary damage is present in such infected animals and, if it is, why edema is absent. The effects of Pichinide virus on protein transport across jejunal capillaries were examined in 38 normal and 7 infected strain 13 guinea pigs 12 days after inoculation. The latter lost 20.3% body weight but maintained normal blood pressure, serum protein concentration, and jejunal lymph flow. However, their protein solvent drag reflection coefficient (sigma) was reduced to .52 +/- .03 (mean +/- SE) from .73 +/- .02 (2P less than .001), while permeability-surface area product was not changed. In the absence of gross edema or effusions, Pichinde virus-infected guinea pigs demonstrated a leaky gut capillary wall to protein compatible with an increase in pore size or large pore number less than sufficient to change permeability-surface area product. Compensatory mechanisms that prevent edema at this stage are efficient and may include reduced capillary pressure or some degree of capillary flow stasis.