The dental pulp consists of loose connective tissue encased in rigid dentinal walls. Because of its topography the tissue has low interstitial compliance and limited capacity to expand during fluid volume changes. Due to limitations regarding access to interstitial fluid, basic knowledge on transcapillary fluid transport parameters is lacking for this organ. The scope of this project was dual: first, we aimed at establishing a method for isolation of pulp interstitial fluid (IF) and second, we applied the method in rats subjected to LPS-induced endotoxaemia. The aim was to measure colloid osmotic pressure (COP) and pro-inflammatory cytokines in the pulp IF during acute inflammation. Fluid volumes and pulpal blood flow (PBF) were measured to obtain more information about microcirculatory changes that take place in this pulpitis model. By centrifugation of incisor pulp at 239 g we were able to extract fluid representative for IF. Pulp IF has a relative high control COP ( 83% of plasma COP) and was similar to plasma COP 3 hrs after LPS challenge. The pulp exhibited a high content of IF (0.60 ± 0.03 ml g^-1 wet weight) and a vascular volume of 0.03 ± 0.01 ml g^-1 w.w. No differences were observed in the distribution of fluid volumes after 1.5 and 3hr LPS exposure. PBF and systemic blood pressure dropped significantly after LPS administration. PBF remained low whereas systemic blood pressure was re-established during the 3 hr period, implying organ dysfunction. There was a differential pattern of cytokine expression in pulp IF and serum with cytokines such as IL-1, IL-1 and TNF- locally produced, whereas others such as IFN- and IL-6 were produced systemically and probably spilled over to the pulp IF after LPS exposure. Our findings show that pulp IF can be isolated by centrifugation and that this method is useful when studying fluid balance and extracellular signalling mechanisms in the dental pulp in normal and pathological conditions.