Fig. 3From: Hypothalamus-pituitary-adrenal axis involves in anti-viral ability through regulation of immune response in piglets infected by highly pathogenic porcine reproductive and respiratory syndrome virusLevels of proinflammatory cytokines in the peripheral blood of piglets from the four groups. The levels of IL-1β (a) IL-6 (b) and TNF-α (c) were measured using commercial ELISA kits. Each point represents the mean values (±S.D.) generated from all piglets at each DPI. *: Values were significantly different (P < 0.05)Back to article page