Blockade of neurokinin-1 receptor attenuates CC and CXC chemokine production in experimental acute pancreatitis and associated lung injury

Effect of CP-96,345 on the expression of adhesion molecules in acute pancreatitis in mice

We investigated the effect of a specific neurokinin-1 receptor (NK1R) antagonist, CP-96,345, on the regulation of the expression of adhesion molecules ICAM-1, VCAM-1, E-selectin, and P-selectin as well as leukocyte recruitment during acute pancreatitis (AP). AP was induced in male Balb/C mice by 10 consecutive hourly intraperitoneal injections of caerulein. In the treatment groups, CP-96,345 was administered at 2.5 mg/kg ip either 30 min before or 1 h after the first caerulein injection. Animals were killed, and the lungs and pancreas were isolated for RNA extraction and RT-PCR or for immunohistochemical staining. mRNA expression of the four adhesion molecules was upregulated in the pancreas during AP. Treatment with CP-96,345 effectively reduced the mRNA expression of P-selectin and E-selectin but not ICAM-1 and VCAM-1. In the lung, ICAM-1, E-selectin, and P-selectin mRNA expression increased during AP. Antagonist treatment suppressed this elevation. Similar expression patterns were seen in the immunohistochemical stainings. Intravital microscopy of the pancreatic microcirculation revealed the effect of CP-96,345 on leukocyte recruitment. The present study provides important information on the relationship between NK1R activation and the regulation of adhesion molecules. Also, this study points to the differential regulation of inflammation in the pancreas and lung with AP.

Thermoregulation: some concepts have changed. Functional architecture of the thermoregulatory system

While summarizing the current understanding of how body temperature (Tb) is regulated, this review discusses the recent progress in the following areas: central and peripheral thermosensitivity and temperature-activated transient receptor potential (TRP) channels; afferent neuronal pathways from peripheral thermosensors; and efferent thermoeffector pathways. It is proposed that activation of temperature-sensitive TRP channels is a mechanism of peripheral thermosensitivity. Special attention is paid to the functional architecture of the thermoregulatory system. The notion that deep Tb is regulated by a unified system with a single controller is rejected. It is proposed that Tb is regulated by independent thermoeffector loops, each having its own afferent and efferent branches. The activity of each thermoeffector is triggered by a unique combination of shell and core Tbs. Temperature-dependent phase transitions in thermosensory neurons cause sequential activation of all neurons of the corresponding thermoeffector loop and eventually a thermoeffector response. No computation of an integrated Tb or its comparison with an obvious or hidden set point of a unified system is necessary. Coordination between thermoeffectors is achieved through their common controlled variable, Tb. The described model incorporates Kobayashi’s views, but Kobayashi’s proposal to eliminate the term sensor is rejected. A case against the term set point is also made. Because this term is historically associated with a unified control system, it is more misleading than informative. The term balance point is proposed to designate the regulated level of Tb and to attract attention to the multiple feedback, feedforward, and open-loop components that contribute to thermal balance.

Role of cytokine-induced neutrophil chemoattractant in acute lung injury during acute pancreatitis

AIM: To investigate the role of cytokine-induced neutrophil chemoattractant (CINC) in the pathogenesis of acute lung injury (ALI) during acute pancreatitis (AP).

METHODS: AP model was induced by intraperitoneal injection of cerulein or retrograde infusion of 50 g/L sodium taurocholate into the bili-pancreatic duct in Sprague Dawley rats. A total of 84 rats were randomly divided into 4 groups: cerulein group, saline control group, sodium taurocholate group and operational control group. The level of serum amylase, the pulmonary dry/wet weight ratio and histological changes were measured at different time points in each group. The expression of pulmonary CINC protein and mRNA were detected by immunohistochemistry and semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR), respectively.

RESULTS: No significant difference was found between cerulein group and saline control group at different time points (P > 0.05). In comparison with those in operational control group, the level of serum amylase and pulmonary dry/wet weight ratio were significantly higher in sodium taurocholate group 1 h after operation (P < 0.01), and the expression of pulmonary CINC mRNA started to increase at the 1st h after operation (1 h: 0.23 ± 0.07 vs 0.07 ± 0.04, P < 0.05; 3 h: 0.36 ± 0.07 vs 0.06 ± 0.04, P < 0.05; 6 h: 0.56 ± 0.07 vs 0.09 ± 0.05, P < 0.01; 12 h: 0.49 ± 0.09 vs 0.11 ± 0.03, P < 0.01). The expression of pulmonary CINC protein was detected at 3rd h after operation, and then up-regulated gradually. Moreover, the expression of CINC was correlated with pulmonary histological changes.

CONCLUSION: CINC plays an important role in the pathogenesis of ALI during AP.