Perioperative normothermia depends on intraoperative warming procedure, extent of the surgical intervention and age of the experimental animal

Distinct effects of NPY13-36, a specific NPY Y2 agonist, in a model of rodent endotoxemia on leukocyte subsets and cytokine levels

Even now, sepsis remains a major problem in modern clinical medicine, leading to systemic inflammatory response including altered leukocyte subset distribution and increased cytokine release. As immune cells are known to express NPY receptors, we investigated the effects of a specific NPY Y(2) receptor agonist (NPY(13-36)) and/or the corresponding Y(2) receptor antagonist BIIE0246 treatment on blood (by FACS analyses) and tissue (by immunohistochemistry) leukocyte subsets as well as on levels of IL-4, IL-6, IL-10, TNF-α, INF-γ (by Cytometric Bead Array) in healthy and acutely endotoxemic rats. Results show a significant decrease in blood monocytes after LPS challenge in endotoxemic control animals (by 93%), in endotoxemic NPY(13-36) treated animals (by 83%) and in endotoxemic BIIE0246 treated animals (by 88%) as compared to the corresponding healthy controls. Endotoxemic control animals showed a significant increase of TNF-α (by 98%) as compared to the healthy control group. A treatment with NPY(13-36) significantly stabilized TNF-α level in endotoxemic animals. This study indicates distinct subset- and cytokine-specific in vivo effects induced by an NPY Y(2) receptor specific treatment after a short-term LPS challenge.

Diet-induced obesity, exogenous leptin-, and MADB106 tumor cell challenge affect tissue leukocyte distribution and serum levels of cytokines in F344 rats

The adipocyte-derived catabolic protein leptin alters cell-mediated immunity and cytokine crosstalk. This may provide new insights into the altered immune response, seen in obese individuals. Therefore, we determined the tissue distribution of immune cells in diet-induced obese (dio) and normal weight F344 rats challenged with MADB106 tumor cells or leptin. Immune cell distribution in blood (by FACS analysis) and tissues (NK cells in spleen and liver, immunohistologically) as well as pro-inflammatory cytokines (IL-6, TNF-α; by flow cytometry) were investigated in 28 normal weight and 28 dio rats (n = 4-6/group). Pro-inflammatory cytokines were increased 3-fold for IL-6 and 7-fold for TNF-α in obese animals. Higher numbers of blood monocytes and NK cells were found in obese as compared to normal weight animals. In dio rats challenged with leptin and MADB106 tumor cells, monocyte numbers were decreased as compared to the obese control animals. Immunohistochemistry revealed an altered NK cell distribution in a compartment-, treatment-, and bodyweight-specific manner. In conclusion, our data reveal a distinct distribution pattern of monocytes and NK cells in dio rats as compared to normal weight littermates and an additional modulatory effect of a leptin- and MADB106 tumor cell challenge.

Fluid heating system (SAF®): effects on clinical and biochemistry parameters in dogs submitted to inhalatory anesthesia

PURPOSE: To evaluate and describe immediate effects of the infusion of saline solution heated by SAF® in bitches submitted to halothane anesthesia. METHODS: Thirteen bitches were employed and submitted to elective ovariohysterectomy in acclimatized operating room at 22ºC, allocated in two groups: GI, which received non-heated fluid and GII, which received fluid heated at 37ºC by SAF®. The following parameters were evaluated in 30-minutes intervals (M0, M30, M60 and M90): rectal and cutaneous temperatures (TR and TC), cardiac and respiratory frequencies (HR and ƒ), mean arterial blood pressure (MAP), serum concentration of urea, creatinin, serum activities of alanin aminotranspherasis (ALT), alkaline phosphatasis (ALP) and also hypnosis parameters. RESULTS: There were no significant alterations on clinical and biochemical, but there was group effect on mean arterial blood pressure, urea, ALT, ALP and hypnosis parameters. CONCLUSION: The isolated use of Fluid Heating System (SAF®) was not enough to avoid hypothermia or lead to significant clinical and biochemical alterations in bitches submitted to halothane anesthesia.

Obesity influences the food consumption and cytokine pattern in ghrelin-treated endotoxemic rats

Obese patients have an increased incidence of systemic infections and higher morbidity and mortality rates than normal weight subjects. Ghrelin is a potent orexigenic signal from the stomach and seems to play a role in the generation and control of immune interactions. To examine a possible benefit of a single ghrelin application on acute endotoxemia, chronic intravenous (i.v.) cannulated lean and diet-induced obese male LEW rats were treated with a bolus injection of either ghrelin (10 nmol/kg) or vehicle, 10 min prior to a challenge with a sublethal bolus of endotoxin (100 microg/kg) or vehicle. Multiple blood samples were taken within a period from 24 h before the experiment up to 24 h after the endotoxin challenge to measure ghrelin and cytokine levels. Additionally, food consumption was recorded and ghrelin expression in fore- and glandular stomach was evaluated immunohistochemically. Despite higher serum ghrelin levels, the food consumption was significantly decreased in obese endotoxemic rats compared to lean littermates after ghrelin treatment. Furthermore we could show an increase of anti-inflammatory IL-10 serum levels after ghrelin treatment of normal weight endotoxemic and an opposite effect in obese animals. As the therapy of disease-associated cachexia and various immunological problems in endotoxemia is still insufficient, peptides such as ghrelin with their modulating abilities for the endocrine and the immune system are of special interest. However, the present study shows that the beneficial effects of ghrelin were attenuated in obese endotoxemic animals. These data further document the necessity to differentiate between normal weight and obese subjects in the attempt to establish ghrelin as a therapeutic target in endotoxemia.