Infection-induced coronary dysfunction and systemic inflammation in piglets are dampened in hypercholesterolemic milieu.

ABSTRACT

The synergism of infection with conventional cardiovascular risk factors in atherosclerosis is much debated. We hypothesized that coronary arterial injury correlates with infection recurrence and pathogen burden and is further aggravated by hypercholesterolemia. Forty-two Göttingen minipigs were assigned to repeated intratracheal inoculation of PBS, Chlamydia pneumoniae (Cpn), or both Cpn and influenza virus at 8, 11, and 14 wk of age. Animals were fed either standard or 2% cholesterol diet (chol-diet). At 19 wk of age coronary vasomotor responses to acetylcholine (ACh) and adenosine were assessed in vivo and blood and tissue samples were collected. Nonparametric tests were used to compare the groups. In cholesterol-fed animals, total cholesterol/HDL was significantly increased in infected animals compared with noninfected animals [3.13 (2.17-3.38) vs. 2.03 (1.53-2.41), respectively; P = 0.01]. C-reactive protein (CRP) rose in infected animals [10.60 (4.96-18.00) vs. 2.47 (1.44-3.01) µg/ml in noninfected; P < 0.01] without significant difference between the mono- and coinfected groups. Among coinfected animals, both CRP and haptoglobin were lower in those fed chol-diet than in those fed standard diet (P < 0.05). The vasoconstricting response to ACh was most prominent in coinfected animals {769.3 (594-1,129) cm; P = 0.03 vs. noninfected [342 (309-455) cm] and P = 0.07 vs. monoinfected [415 (252.5-971.8) cm]}. Among monoinfected animals, similar to CRP, a trend for less vasoconstriction was observed in those fed chol-diet (P = 0.08). Coinfection of piglets appears to be associated with more pronounced coronary muscarinic vasomotor dysfunction. In monoinfected animals, use of chol-diet seems to dampen both coronary dysfunction and systemic inflammation induced by infection.