Endotoxin increases plasma leptin and ghrelin levels in dogs

Thromboelastographic evaluation of the effectiveness of choline or CDP-choline treatment on endotoxin-induced hemostatic alterations in dogs

Sepsis/endotoxemia associates with coagulation abnormalities. We showed previously that exogenous choline treatment reversed the changes in platelet count and function as well as prevented disseminated intravascular coagulation (DIC) in endotoxemic dogs. The aim of this follow-up study was to evaluate the effect of treatment with choline or cytidine-5'-diphosphocholine (CDP-choline), a choline donor, on endotoxin-induced hemostatic alterations using thromboelastography (TEG). Dogs were randomized to six groups and received intravenously (iv) saline, choline (20 mg/kg) or CDP-choline (70 mg/kg) in the control groups, whereas endotoxin (0.1 mg/kg, iv) was used alone or in combination with choline or CDP-choline at the same doses in the treatment groups. TEG variables including R- and K-time (clot formation), maximum amplitude (MA) and α-angle (clot stability), G value (clot elasticity), and EPL, A, and LY30 (fibrinolysis), as well as overall assessment of coagulation (coagulation index - CI), were measured before and at 0.5-48 h after the treatments. TEG parameters did not change significantly in the control groups, except for CI parameter after choline administration. Endotoxemia resulted in increased R-time and A value (P < 0.05), decreased K-time (P < 0.05), α-angle (P < 0.001) and CI values (P < 0.01) at different time points. Treatment with either choline or CDP-choline attenuated or prevented completely the alterations in TEG parameters in endotoxemic dogs with CDP-choline being more effective. These results confirm and extend the effectiveness of choline or CDP-choline in endotoxemia by further demonstrating their efficacy in attenuating or preventing the altered viscoelastic properties of blood clot measured by TEG.

Can Procalcitonin Be Dosed in Bovine Milk Using a Commercial ELISA Kit?

Simple Summary

Mastitis is one of the major economic and animal welfare problems on dairy farms. The gold standard test for mastitis diagnosis is milk culture, but bacteria are not always isolated (only in 11–44% of milk samples from clinical cases of mastitis) and sometimes a positive culture can result from a contamination of the milk. Procalcitonin is a new biomarker which may lead to an early detection of inflammation due to bacterial infection. In humans, procalcitonin concentration has also been evaluated in milk in addition to plasma. The authors aimed to evaluate the possible application of a commercially available ELISA kit for bovine procalcitonin for the assessing of procalcitonin in bovine milk samples. Plasma and milk samples from cows with mastitis were collected to measure procalcitonin concentrations by using a bovine procalcitonin ELISA kit. Our results showed that the ELISA kit tested can be employed to assess bovine procalcitonin in plasma but not for analyzing milk samples.

Abstract

The aim was to evaluate the use of a bovine procalcitonin (PCT) ELISA kit (Cusabio, China) for assessing PCT in bovine milk samples. Validation was performed by using 10 plasma and corresponding milk samples from mastitic cows. The limit of detection (LOD) was calculated. The coefficient of variation (CV%) of the readings of five plasma samples measured five times in the same plate (intra-assay) and the CV% of the same five samples read five times in three separate plates was evaluated. Parallelism was determined by serial twofold dilutions of five plasma and corresponding milk samples. Milk samples were analyzed with and without centrifugation. Regarding plasma PCT, the method presented an inter- and intra-CV < 23.7% and parallelism had very good recovery values. The ELISA kit studied can measure bovine plasma PCT concentrations. The kit antibodies fail in binding PCT in milk samples because all centrifuged milk samples showed a lower LOD than blank samples. Only three uncentrifuged milk samples showed measurable PCT concentrations. Due to these results, the commercial ELISA kit investigated could not be employed for the detection of PCT in milk samples.

Choline or CDP-choline restores hypotension and improves myocardial and respiratory functions in dogs with experimentally - Induced endotoxic shock

Endotoxin shock is associated with severe impairments in cardiovascular and respiratory functions. We showed previously that choline or cytidine-5'-diphosphocholine (CDP-choline) provides beneficial effects in experimental endotoxin shock in dogs. The objective of the present study was to determine the effects of choline or CDP-choline on endotoxin-induced cardiovascular and respiratory dysfunctions. Dogs were treated intravenously (i.v.) with saline or endotoxin (LPS, 0.1 mg/kg) 5 min before i.v. infusion of saline, choline (20 mg/kg) or CDP-choline (70 mg/kg). Blood pressure, cardiac rate, myocardial and left ventricular functions, respiratory rate, blood gases, serum electrolytes and cardiac injury markers were determined before and at 0.5-48 h after endotoxin. Plasma tumor necrosis factor alpha (TNF-α), high mobility group box-1 (HMGB1), catecholamine and nitric oxide (NO) levels were measured 2 h and 24 h after the treatments. Endotoxin caused immediate and sustained reductions in blood pressure, cardiac output, pO₂ and pH; changes in left ventricular functions, structure and volume parameters; and elevations in heart rate, respiratory rate, pCO2 and serum electrolytes (Na, K, Cl, Ca and P). Endotoxin also resulted in elevations in blood levels of cardiac injury markers, TNF-α, HMGB1, catecholamine and NO. In choline- or CDP-choline-treated dogs, all endotoxin effects were much smaller in magnitude and shorter in duration than observed values in controls. These data show that treatment with choline or CDP-choline improves functions of cardiovascular and respiratory systems in experimental endotoxemia and suggest that they may be useful in treatment of endotoxin shock in clinical setting.

Neopterin, procalcitonin, clinical biochemistry, and hematology in calves with neonatal sepsis

This study aims to determine how neopterin, procalcitonin, biochemical and hematological parameters change during treatment of calves with neonatal sepsis. A total of 25 calves divided into two groups. Sepsis group was composed of 15 newborn calves aged 0–10 days which met neonatal sepsis criteria, but did not receive any treatment. Control group included 10 healthy calves aged 0–10 days. Clinical examinations (respiratory rate, rectal temperature, heart rate, capillary refill time, sucking reflex) were performed at certain times before (0th h) and during (12th, 24th, 48th, and 72th h) the treatment. The blood was taken from the jugular vein from the sepsis group before (0th h) and during the treatment (12th, 24th, 48th, and 72nd h) and once from the control group. Procalcitonin pretreatment (0th h) and control group concentrations were found as 178.08 ± 2.4 (pg/mL) and 42.78 ± 1.25 (pg/mL), respectively (p < 0.001). Neopterin pretreatment (0th h) and control group concentrations were determined as 14.44 ± 0.30 (ng/mL) and 3.63 ± 0.29 (ng/mL), respectively (p < 0.001). As a result, neopterin and procalcitonin concentration decreased along with the treatment, confirming the presence of sepsis in calves and suggesting that sepsis could be a prognostic indicator. Therefore, both procalcitonin and neopterin can be prognostic and diagnostic in calves with sepsis.

Procalcitonin Detection in Veterinary Species: Investigation of Commercial ELISA Kits

Simple Summary

Among sepsis biomarkers, procalcitonin resulted to be a specific indicator of bacterial infection or severity of infection, and to be a good control of the success of a therapeutic procedure. The clinical studies on the relevance of procalcitonin as a sepsis predictor in veterinary patients are few, likely due to the total absence of validated assays. For this reason, this study aimed to investigate commercial ELISA kits for the detection of canine and equine procalcitonin. Validation was performed evaluating linearity, limits of detection (LOD), recovery, and intra-assay and inter-assay variability; furthermore, clinical samples were analyzed. The results of the present study demonstrate that the human PCT ELISA kit is suitable to detect equine procalcitonin with a LOD of 56 ng/mL, and the canine recombinant PCT ELISA kit can be used to measure canine procalcitonin in plasma samples, showing an intra-assay and inter-assay coefficient of variation less than 20% and a LOD of 11 pg/mL.

Abstract

In human medicine, procalcitonin (PCT), the precursor of calcitonin, is used for the rapid identification of the origin and severity of sepsis. In veterinary medicine, PCT has been studied in horses, cattle, and dogs, but the use of PCT in diagnostic and/or prognostic settings is not possible because of the lack of validated assays to obtain reference ranges. The aim of the present study was the investigation of commercially available ELISA kits for the detection of canine and equine PCT in plasma samples. Validation of the ELISA kits was performed by using species-specific recombinant proteins spiked both in plasma and buffer samples; linearity, limit of detection (LOD), recovery, and intra-assay and inter-assay variability were calculated. Moreover, clinical samples obtained from sick and healthy animals were also analyzed with the tested kits. Canine PCT was measured with a recombinant canine and a canine PCT ELISA kit. Equine PCT was measured with an equine and a human ELISA PCT kit. Our data demonstrate that the canine recombinant PCT ELISA kit can be used to measure canine PCT in plasma samples, showing an intra-assay and inter-assay coefficient of variation less than 20% and a LOD of 11 pg/mL, whereas the present results do not support the use of the canine PCT ELISA kit. The human PCT ELISA kit is suitable to detect equine PCT with a LOD of 56 ng/mL, whereas the equine PCT ELISA kit did not detect recombinant equine PCT.

Ghrelin alterations during experimental and human sepsis

BACKGROUND

Ghrelin is a hormone mainly produced by cells of the gastric mucosa, which has been shown to possess anti-inflammatory and immunomodulatory properties. The objective of the study was to investigate ghrelin levels during sepsis, as well as in an experimental sepsis model.

METHODS

All consecutive admissions to the ICU of a tertiary hospital in Athens, Greece were screened for eligibility during the study. Thirty four non-septic patients upon ICU admission who subsequently developed sepsis were enrolled. Clinical data and scores were recorded, and blood samples were obtained at baseline (upon ICU admission), and at sepsis development. Total and active ghrelin, leptin, and cytokines were measured. Moreover, lipopolysaccharide (LPS) was administered to mice in order to induce endotoxemia and at specified time points, blood and tissue samples were collected.

RESULTS

In patients, serum total and active ghrelin concentrations were significantly elevated in sepsis compared to baseline (553.8 ± 213.4 vs 193.5 ± 123.2, p < 0.001; 254.3 ± 70.6 vs 56.49 ± 16.3, p < 0.001). Active ghrelin levels at the sepsis stage were inversely correlated with SOFA score and length of stay in the ICU (p = 0.023 and p = 0.027 respectively). In the mouse endotoxemia model ghrelin levels were elevated following LPS treatment, and the same trend was observed for leptin, TNFα and IL-6. Ghrelin administration managed to reduce IL-6 levels in mouse serum and in BALF. Pulmonary expression of ghrelin and its receptor GHSR1a was found decreased in LPS-treated mice.

CONCLUSIONS

In a well-defined cohort of ICU patients, we have demonstrated that active and total ghrelin increase in sepsis. The same is true for the experimental sepsis model used in the study. The inverse correlation of active ghrelin levels with SOFA score and length of ICU stay among septic patients is indicative of a potential protective role of active ghrelin during the septic process.

Ghrelin forms in the modulation of energy balance and metabolism

Ghrelin is a gastric hormone circulating in acylated (AG) and unacylated (UnAG) forms. This narrative review aims at presenting current emerging knowledge on the impact of ghrelin forms on energy balance and metabolism. AG represents ~ 10% of total plasma ghrelin, has an appetite-stimulating effect and is the only form for which a receptor has been identified. Moreover, other metabolic AG-induced effects have been reported, including the modulation of glucose homeostasis with stimulation of liver gluconeogenesis, the increase of fat mass and the improvement of skeletal muscle mitochondrial function. On the other hand, UnAG has no orexigenic effects, however recent reports have shown that it is directly involved in the modulation of skeletal muscle energy metabolism by improving a cluster of interlinked functions including mitochondrial redox activities, tissue inflammation and insulin signalling and action. These findings are in agreement with human studies which show that UnAG circulating levels are positively associated with insulin sensitivity both in metabolic syndrome patients and in a large cohort from the general population. Moreover, ghrelin acylation is regulated by a nutrient sensor mechanism, specifically set on fatty acids availability. These recent findings consistently point towards a novel independent role of UnAG as a regulator of muscle metabolic pathways maintaining energy status and tissue anabolism. While a specific receptor for UnAG still needs to be identified, recent evidence strongly supports the hypothesis that the modulation of ghrelin-related molecular pathways, including those involved in its acylation, may be a potential novel target in the treatment of metabolic derangements in disease states characterized by metabolic and nutritional complications.Level of evidence Level V, narrative review.

Special aspects of systemic inflammation course in animals

AIM

In this study, we identified characteristics of systemic inflammation associated with surgical sepsis in animals. We evaluated the role of purine metabolism, functionally associated lipoperoxidation processes of membrane structures, and the antioxidant system in the development of surgical sepsis in dogs.

MATERIALS AND METHODS

Dogs with a provisional exclusion of sepsis were included in the study. The control group (Group 1) included clinically healthy dogs (n=5), and medium-breed dogs with systemic inflammation response syndrome (n=30) were categorized in the experimental group (Group 2). Along with hemogram and biochemical analysis, we determined the amount of malondialdehyde, glutathione, superoxide dismutase, catalase, glutathione reductase, and glucose-6-phosphate dehydrogenase on the 1st and 14th day of the study. Treatment included a thorough reorganization of the septic focus, followed by antibacterial therapy. Sick animals were injected with a drug (dexamethasone) that suppresses the synthesis and inhibits the action of inflammatory mediators. Decompensation of the functions of organs and systems was carried out using symptomatic therapy.

RESULTS

We found that enhanced lipid peroxidation of unsaturated fatty acids of membrane structures stimulates the generalization of inflammatory process, as evidenced by the significant deviation from the physiologically normal values of lipid peroxidation, C-reactive protein, blood cell count, etc. The course of systemic inflammation associated with surgical sepsis in animals can be attributed to several consistently developing processes that function as a result of increased purine mononucleotide catabolism, peroxide compound formation, and their excessive breakdown in reactions associated with the consumption of glutathione due to the insufficient recovery of glutathione disulfide.

CONCLUSION

The amount of uric acid, glycosaminoglycans, hyaluronic acid in blood plasma, and the content of malondialdehyde, glutathione, and glutathione reductase in erythrocytes should be considered when assessing the severity of the systemic inflammatory process. The increased glutathione requirement in dogs with surgical sepsis requires intervention with pharmacological agents, and further research is needed in this aspect.

Adipokines in critical illness: A review of the evidence and knowledge gaps

Adipose tissue products or adipokines play a major role in chronic endocrine and metabolic disorders; however, little is known about critical conditions. In this article, the experimental and clinical evidence of alterations of adipokines, adiponectin, leptin, resistin, visfatin, asymmetric dimethylarginine (ADMA), and ghrelin in critical illness, their potential metabolic, diagnostic, and prognostic value, and the gaps in the field have been reviewed. The results showed considerable changes in the concentration of the adipokines; while the impact of adipokines on metabolic disorders such as insulin resistance and inflammation has not been well documented in critically ill patients. There is no consensus about the circulatory and functional changes of leptin and adiponectin. However, it seems that lower concentrations of adiponectin at admission with gradual consequent increase might be a useful pattern in determining better outcomes of critical illness. Some evidence has suggested the adverse effects of elevated resistin concentration, potential prognostic importance of visfatin, and therapeutic value of ghrelin. High ADMA levels and low arginine:ADMA ratio were also proposed as predictors of ICU mortality and morbidities. However, there is no consensus on these findings. Although primary data indicated the role of adipokines in critical illness, further studies are required to clarify whether the reason of these changes is pathophysiological or compensatory. The relationship of pathophysiological background, disease severity, baseline nutritional status and nutrition support during hospitalization, and variations in body fat percentage and distribution with adipokines, as well as the potential prognostic or therapeutic role of these peptides should be further investigated in critically ill patients.

Plasma procalcitonin concentrations are increased in dogs with sepsis

Sepsis, the life-threatening organ dysfunction caused by a dysregulated host response to infection, is difficult to identify and to prognosticate for. In people with sepsis, procalcitonin (PCT) measurement aids diagnosis, enables therapeutic monitoring and improves prognostic accuracy. This study used a commercial canine PCT assay to measure plasma PCT concentrations in dogs with gastric dilatation volvulus (GDV) syndrome and in dogs with sepsis. It was hypothesised that dogs with GDV syndrome and with sepsis have greater plasma PCT concentrations than healthy dogs and that dogs with sepsis have greater PCT concentrations than dogs with GDV syndrome. Before analysing canine plasma samples, the ability of the assay to identify canine PCT, in addition to assay imprecision and the lower limit of detection were established. The assay had low imprecision with coefficients of variation ≤4.5 per cent. The lower limit of detection was 3.4 pg/ml. Plasma PCT concentrations were measured in 20 dogs with sepsis, in 32 dogs with GDV syndrome and in 52 healthy dogs. Median (IQR) PCT concentration in dogs with sepsis 78.7 pg/ml (39.1-164.7) was significantly greater than in healthy dogs 49.8 pg/ml (36.2-63.7) (P=0.019), but there were no significant differences between PCT concentrations in dogs with GDV syndrome and controls (P=0.072) or between dogs with sepsis and GDV syndrome (P=1.000). Dogs with sepsis have significantly increased plasma PCT concentrations compared with healthy dogs, although considerable overlap between these populations was identified. Future investigations should confirm this finding in other populations and evaluate the diagnostic and prognostic value of PCT in dogs with sepsis.

Plasma procalcitonin concentration in healthy calves and those with septic systemic inflammatory response syndrome

The diagnosis of sepsis in calves is challenging. Blood culture and clinical signs combined with a complete blood count have been used for the diagnosis of sepsis. Recent literature in humans and animal species has been focused on sepsis-specific biomarkers, such as procalcitonin (PCT), that may more accurately and efficiently diagnose sepsis. The aim of this study was to evaluate plasma PCT concentrations in healthy and septic calves. Twenty healthy control calves and 58 sick calves with septic systemic inflammatory response syndrome (SIRS) based on SIRS score and clinical findings were included. Calves with septic SIRS were further divided in septic SIRS survivors (SSS) and non-survivors (SSNS). Plasma PCT concentrations were measured with a commercial ELISA assay for cattle. A receiver operating characteristic curve was used to determine cut-off values and corresponding sensitivity and specificity for the diagnosis of sepsis. Differences in plasma PCT concentration between groups (control vs. SSS vs. SSNS) were evaluated. Plasma PCT concentrations in healthy calves and those with septic SIRS were 33.3pg/mL (0-44.3pg/mL) and 166.5pg/mL (85.9-233.0pg/mL), respectively (P<0.001). The optimal cut-off value to predict septic SIRS was 67.39pg/mL (81.0% sensitivity, 95.0% specificity). Plasma PCT concentrations were 127.4pg/mL (72.2-216.0pg/mL) and 234.3pg/mL (204.5-309.4pg/mL) in the SSS and SSNS subgroups, respectively. Statistically significant differences were found among groups (control vs. SSS and SSNS, P<0.0001; SSS vs. SSNS, P>0.05). These results confirmed an increase in plasma PCT concentrations in calves with septic SIRS, as previously reported in humans and other species.

Procalcitonin is not a marker of sterile inflammation in dogs after ovariohysterectomy

CRP and WBC are the most widely used markers of inflammation in veterinary clinical diagnosis. Also, PCT is a specific APP marker of bacterial diseases in humans. This study evaluated the levels of PCT, CRP and WBC during postoperative monitoring of bitches undergoing ovariohysterectomy. Thirteen adult clinically healthy female crossbreed dogs aged between 7-24 months were used in the study. Ovariohysterectomy was performed via medial laparotomy using routine procedures. Blood samples were collected from the cephalic vein at 1, 4 and 7 days after surgery (post-op period). Mean serum concentration of PCT, CRP and WBC levels were increased after the surgery. CRP concentrations and WBC counts were increased significantly (p<0.001) on the first day after the operation and decreased to basal values. However, the PCT rise was not significant. CRP and WBC levels increased rapidly and decreased to normal values in dogs with ovariohysterectomy. CRP and WBC may be of help to determine the possible postoperative complications. Besides, aseptic surgical trauma did not affect PCT levels in dogs. Future studies are needed on canine PCT response focusing on specific bacterial infections.

Ghrelin and its Association with Nutritional and Inflammatory Status of Patients on Maintenance Hemodialysis in a South Indian Tertiary Care Hospital

BACKGROUND

Malnutrition and inflammation are associated with morbidity and mortality in patients on maintenance hemodialysis (MHD). Ghrelin, an orexigenic peptide hormone, is speculated to be associated with nutritional and inflammatory status in MHD.

AIM

To assess the serum total ghrelin levels and its possible relationship with inflammation and nutritional status in patients on MHD.

SUBJECTS AND METHODS

The study was conducted on 90 patients on MHD for 6 months and above (56 males, 34 females, mean age 52.6 [11.7] years; mean dialysis vintage 20.9 [12.1] months) and 70 healthy volunteers as control (5 males, 25 females, mean age 50.6 [9.7] years). Demographics were obtained for the study population, and dialysis-related data were collected for cases. Anthropometry, biochemical parameters, serum total ghrelin and inflammatory markers tumor necrosis factor-alpha (TNF-α), and high-sensitivityC-reactive protein (hsCRP) were assessed for cases and control. Self-reported appetite (five questions of appetite and diet assessment tool) and nutritional status (subjective global assessment-dialysis malnutrition score) were assessed for cases.

RESULTS

Ghrelin (242.5 [62.3] pg/mL vs. 80.2 [19.6] pg/mL; P < 0.001), TNF-α (39.8 [15.2] pg/mL vs. 6.5 [1.2] pg/mL; P < 0.001), hsCRP (10.2 [2.8] mg/L vs. 2.7 [0.54] mg/L; P < 0.001) were significantly elevated in cases versus control, anthropometry, and biochemical parameters were significantly decreased in hemodialysis patient. Of 90 cases, (13/90 [14.4%]) were well-nourished, (28/90 [31%]) mild to moderately malnourished, and (49/90 [54.4%]) were moderate to severely malnourished. Appetite was very good for14.4%, good and fair for 47.8%, poor and very poor for 37.8% patients. There was a significant difference in appetite with respect to nutritional status (P < 0.001). Ghrelin had positive correlation with inflammatory markers and negative correlation with nutritional status (P < 0.001).

CONCLUSION

The study identified the association of ghrelin with appetite, nutritional, and inflammatory status of the patients on MHD.

Plasma Procalcitonin Concentration in Healthy Horses and Horses Affected by Systemic Inflammatory Response Syndrome

BACKGROUND

The diseases most frequent associated with SIRS in adult horses are those involving the gastrointestinal tract. An early diagnosis should be the goal in the management of horses with SIRS.

OBJECTIVE

The objective of this study was to evaluate the plasma procalcitonin (PCT) concentration in healthy and SIRS horses to assess differences between the two groups.

ANIMALS

Seventy-eight horses (30 healthy and 48 SIRS).

METHODS

Prospective in vivo multicentric study. Horses were classified as SIRS if at least 2 of the following criteria were met: abnormal leukocyte count or distribution, hyperthermia or hypothermia, tachycardia, tachypnea. Healthy horses showed no clinical or laboratory signs of SIRS. Plasma PCT concentrations were measured with a commercial ELISA assay for equine species. Results were expressed as mean±standard deviation. T-test for unpaired data was performed between healthy and SIRS group. SIRS group was divided in 4 subgroups and t-test was performed between healthy versus each subgroup.

RESULTS

PCT concentrations in healthy and SIRS horses were 18.28 ± 20.32 and 197.0 ± 117.0 pg/mL, respectively. T-test showed statistical differences between healthy versus SIRS group and between healthy versus all subgroups.

CONCLUSIONS AND CLINICAL IMPORTANCE

Results showed an increase in PCT concentration in SIRS horses as previously reported in humans and dogs. PCT could be used as a single assay in equine practice for detection of SIRS.

Mechanisms of fever production and lysis: lessons from experimental LPS fever

Fever is a cardinal symptom of infectious or inflammatory insults, but it can also arise from noninfectious causes. The fever-inducing agent that has been used most frequently in experimental studies designed to characterize the physiological, immunological and neuroendocrine processes and to identify the neuronal circuits that underlie the manifestation of the febrile response is lipopolysaccharide (LPS). Our knowledge of the mechanisms of fever production and lysis is largely based on this model. Fever is usually initiated in the periphery of the challenged host by the immediate activation of the innate immune system by LPS, specifically of the complement (C) cascade and Toll-like receptors. The first results in the immediate generation of the C component C5a and the subsequent rapid production of prostaglandin E2 (PGE2). The second, occurring after some delay, induces the further production of PGE2 by induction of its synthesizing enzymes and transcription and translation of proinflammatory cytokines. The Kupffer cells (Kc) of the liver seem to be essential for these initial processes. The subsequent transfer of the pyrogenic message from the periphery to the brain is achieved by neuronal and humoral mechanisms. These pathways subserve the genesis of early (neuronal signals) and late (humoral signals) phases of the characteristically biphasic febrile response to LPS. During the course of fever, counterinflammatory factors, "endogenous antipyretics," are elaborated peripherally and centrally to limit fever in strength and duration. The multiple interacting pro- and antipyretic signals and their mechanistic effects that underlie endotoxic fever are the subjects of this review.

The effects of periodontal therapy on serum and salivary leptin levels in chronic periodontitis patients with normal body mass index

SUMMARY

Leptin concentrations are altered in favour of pro health after periodontal therapy.

BACKGROUND

Leptin, a non-glycosylated peptide hormone, not only maintains fat stores, but is also an integral part of host defense repertoire. Leptin levels have been found to be altered in an array of inflammatory diseases including chronic periodontitis (CP), but the role of non-surgical periodontal therapy (NSPT) in altering the leptin concentrations in saliva and serum of CP patients is yet to be ascertained. The aim of the present study is to quantify leptin levels in CP patients having normal body mass index (BMI) pre-therapy as compared to periodontally healthy controls and to address whether successful NSPT alters leptin concentration in serum and saliva.

MATERIALS AND METHODS

Twenty-two saliva (modified draining method) and serum samples (by venipuncture) were collected from CP patients with normal BMI (n = 22), before and at 4 and 12 weeks after completion of NSPT, and periodontally healthy, age- and gender-matched controls (n = 22). Leptin levels were estimated using enzyme linked immunosorbent assay kits.

RESULTS

At baseline, CP patients had significantly different periodontal clinical parameters and the leptin concentrations in saliva of CP patients were found to be significantly lower than periodontally healthy volunteers (4710.10 ± 1133.21 vs 8721.10 ± 1019.58 pg/ml) (p < 0.05), whereas in serum the leptin concentrations were significantly higher than healthy controls (10749 ± 2062.24 vs 8085.00 ± 2859.68 pg/ml). Significant improvement in periodontal parameters, serum and salivary leptin levels were observed in CP patients at 4 and 12 weeks post-therapy (p < 0.01).

CONCLUSION

Altered concentrations of leptin in serum and saliva are observed in CP patients which can be restored in favor of health after periodontal therapy.

The effect of ghrelin upon the early immune response in lean and obese mice during sepsis

Introduction

It is well established that obesity-related hormones can have modulatory effects associated with the immune response. Ghrelin, a hormone mainly derived from endocrine cells of the gastric mucosa, regulates appetite, energy expenditure and body weight counteracting leptin, a hormone mainly derived from adipocytes. Additionally, receptors of both have been detected on immune cells and demonstrated an immune regulatory function during sepsis.

Methods

In the present study, the effect of peripheral ghrelin administration on early immune response and survival was investigated with lean mice and mice with diet-induced obesity using cecal ligation and puncture to induce sepsis.

Results

In the obese group, we found that ghrelin treatment improved survival, ameliorated hypothermia, and increased hyperleptinemia as compared to the lean controls. We also observed that ghrelin treatment divergently regulated serum IL-1ß and TNF-α concentrations in both lean and obese septic mice. Ghrelin treatment initially decreased but later resulted in increased bacteriaemia in lean mice while having no impact upon obese mice. Similarly, ghrelin treatment increased early neutrophil oxidative burst while causing a decrease 48 hours after sepsis inducement.

Conclusion

In conclusion, as the immune response to sepsis temporally changes, ghrelin treatment differentially mediates this response. Specifically, we observed that ghrelin conferred protective effects during the early phase of sepsis, but during the later phase deteriorated immune response and outcome. These adverse effects were more pronounced upon lean mice as compared to obese mice.

Elevated circulating ghrelin, but not peptide YY(3-36) levels, in term neonates with infection

Early diagnosis and treatment of neonatal infection is important to prevent morbidity and mortality. The gastrointestinal tract-derived hormones ghrelin and peptide YY (PYY), which participate in the regulation of food intake and energy balance, may also play roles in the inflammatory response. Their involvement in neonatal infection is not known.

Plasma ghrelin and PYY(3-36) levels were serially measured (by ELISA) on Days 0, 1, 2, 3 and 7 following admission in 36-term neonates with febrile infection (22 of them were septic) and once in 20 healthy term neonates of similar postnatal age and gender distribution, as controls. Associations of ghrelin and PYY(3-36) levels with clinical and laboratory parameters, including anthropometrics, fever, leukocyte and platelet counts, serum glucose, C-reactive protein (CRP) and serum amyloid A levels, were assessed.

Plasma ghrelin levels were significantly higher in infected neonates than in controls at each study day (p=0.009), whereas PYY(3-36) levels did not differ significantly between patients and controls at any day. In infected neonates, ghrelin levels on admission correlated negatively with serum glucose levels (p=0.003), whereas fever change during the course of infection was significantly associated with change of ghrelin levels (p=0.01). Receiver operating characteristic analysis of ghrelin levels resulted in significant areas under the curve (AUC) for detecting infected neonates on admission (AUC=0.728, p=0.005).

Circulating ghrelin, but not PYY(3-36), levels are increased in neonates with infection, possibly reflecting and/or participating in the inflammatory process.

Establishment of a low dose canine endotoxemia model to test anti-inflammatory drugs: effects of prednisolone

Infusion of low doses of lipopolysaccharide (LPS) in human volunteers provides a standardised model to study novel anti-inflammatory drugs. However, low dose endotoxemia is not well characterised in animals larger than rodents and trials with immunomodulating substances are scarce. We conducted a dose-finding study to establish a canine endotoxemia model combining optimal cytokine response with minimal burden for the animals. We thereafter evaluated the pharmacodynamics and pharmacokinetics (PK) of prednisolone. For dose-finding, dogs randomly received a single bolus of 0.03, 0.1 or 1.0 microg/kg BW LPS i.v. The second part was a randomised, placebo controlled trial with 4 parallel groups. Either 0.25, 0.5 or 5mg/kgBW prednisolone or placebo were given for 3 days. On day 3, all animals received 0.1microg/kg BW LPS i.v. Blood was sampled to measure interleukin 6 (IL-6) and tumor necrosis factor-alpha, C-reactive protein, prednisolone and cortisol concentrations. In accordance with human endotoxemia, LPS substantially and dose-dependently increased IL-6 and TNF-alpha several 1000-fold. Prednisolone significantly attenuated the LPS-induced IL-6 and TNF-alpha responses by a maximum of 96 percent (p less than 0.03 for all treatment groups) and significantly reduced peak cortisol concentrations in a dose-dependent way (p less than 0.004 for all treatment groups). PK showed a non-linear kinetic. In conclusion, this dog model could provide a reliable setting to test experimental drugs for canine or human use.

Somatotropic axis resistance and ghrelin in critically ill foals

REASONS FOR PERFORMING STUDY

Resistance to the somatotropic axis and increases in ghrelin concentrations have been documented in critically ill human patients, but limited information exists in healthy or sick foals.

OBJECTIVES

To investigate components of the somatotropic axis (ghrelin, growth hormone and insulin-like growth factor-1 [IGF-1]) with regard to energy metabolism (glucose and triglycerides), severity of disease and survival in critically ill equine neonates. It was hypothesised that ghrelin and growth hormone would increase and IGF-1 would decrease in proportion to severity of disease, supporting somatotropic axis resistance, which would be associated with severity of disease and mortality in sick foals.

STUDY DESIGN

Prospective multicentre cross-sectional study.

METHODS

Blood samples were collected at admission from 44 septic, 62 sick nonseptic (SNS) and 19 healthy foals, all aged <7 days. Foals with positive blood cultures or sepsis scores ≥12 were considered septic, foals with sepsis scores of 5-11 were classified as SNS. Data were analysed by nonparametric methods and multivariate logistic regression.

RESULTS

Septic foals had higher ghrelin, growth hormone and triglyceride and lower IGF-1 and glucose concentrations than healthy foals (P<0.01). Sick nonseptic foals had higher growth hormone and triglycerides and lower IGF-1 concentrations than healthy foals (P<0.05). Growth hormone:IGF-1 ratio was higher in septic and SNS foals than healthy foals (P<0.05). Hormone concentrations were not different between septic nonsurvivors (n = 14) and survivors (n = 30), but the growth hormone:IGF-1 ratio was lower in nonsurvivors (P = 0.043).

CONCLUSIONS

Somatotropic axis resistance, characterised by a high growth hormone:IGF-1 ratio, was frequent in sick foals, associated with the energy status (hypoglycaemia, hypertriglyceridaemia) and with mortality in septic foals.

POTENTIAL RELEVANCE

A functional somatotropic axis appears to be important for foal survival during sepsis. Somatotropic resistance is likely to contribute to severity of disease, a catabolic state and likelihood of recovery.

Ghrelin, appetite and critical illness

PURPOSE OF REVIEW

Recovery and rehabilitation after critical illness is a vital part of intensive care management. The role of feeding and nutritional intervention is the subject of many recent studies. The gastric hormone ghrelin has effects on appetite and food intake and on immunomodulatory functions. Here we review the interactions between critical illness, appetite regulation, nutrition and ghrelin.

RECENT FINDINGS

Critical illness results in significant loss of lean body mass; strategies to prevent this have so far proven unsuccessful. Ghrelin has been shown to reduce catabolic protein loss in animal models of critical illness and improve body composition in chronic cachectic illnesses in humans.

SUMMARY

Enhancing recovery from critical illness will improve both short-term and long-term outcomes. Ghrelin may offer an important means of improving appetite, muscle mass and rehabilitation in the period after critical illness, although studies are needed to see whether this potential is realized.

Plasma ghrelin levels in patients with familial Mediterranean fever

BACKGROUND

Familial Mediterranean fever (FMF) is an auto-inflammatory disorder characterized by febrile attacks. Increased acute-phase reactants are characteristic during febrile attacks. Ghrelin is a natural G-protein that decreases secretion of pro-inflammatory cytokines and acts as anti-inflammatory agent. The aim of this study was to investigate whether there is any change in ghrelin levels and whether increases in ghrelin levels can be used as a marker in these patients.

SUBJECTS AND METHODS

Thirty-seven male patients and 30 healthy men as a control group were included in the study. Blood samples were obtained for ghrelin measurements both before the attacks (pre-attack period; ghrelin 1 group) and during the attacks (ghrelin 2 group). Samples were kept at -80°C until the analysis was conducted and plasma ghrelin levels were measured using an immune-sorbent assay method.

RESULTS

Mean ghrelin levels measured during the attacks were significantly higher (11.01 ± 4.78 pg/ml) as compared to pre-attack levels (5.78 ± 2.17 pg/ml; p < 0.001). Similarly, mean ghrelin levels measured in FMF patients during an attack were significantly different from that of the control group (6.57 ± 4.13 pg/ml; p < 0.001).

CONCLUSIONS

In this study, high ghrelin levels were measured during attacks in FMF patients. This finding is in line with previous results regarding the fact that inflammatory response arising during an FMF attack is an acute inflammatory event. Our findings suggest that ghrelin levels measured during FMF attacks could be used as a biochemical indicator for the FMF attack in FMF patients and that it could be used for support of the diagnosis of the disease.

Ghrelin - a pleiotropic hormone secreted from endocrine x/a-like cells of the stomach

The gastric X/A-like endocrine cell receives growing attention due to its peptide products with ghrelin being the best characterized. This peptide hormone was identified a decade ago as a stimulator of food intake and to date remains the only known peripherally produced and centrally acting orexigenic hormone. In addition, subsequent studies identified numerous other functions of this peptide including the stimulation of gastrointestinal motility, the maintenance of energy homeostasis and an impact on reproduction. Moreover, ghrelin is also involved in the response to stress and assumed to play a role in coping functions and exert a modulatory action on immune pathways. Our knowledge on the regulation of ghrelin has markedly advanced during the past years by the identification of the ghrelin acylating enzyme, ghrelin-O-acyltransferase, and by the description of changes in expression, activation, and release under different metabolic as well as physically and psychically challenging conditions. However, our insight on regulatory processes of ghrelin at the cellular and subcellular levels is still very limited and warrants further investigation.

Relationships among interleukin-6, tumor necrosis factor-α, adipokines, vitamin D, and chronic periodontitis

BACKGROUND

The aim of this study is to explore relationships among serum adipokines, vitamin D, and clinical and microbial parameters of chronic periodontitis before and after treatment.

METHODS

Weight, height, and smoking status were recorded for 56 patients with chronic periodontitis. Plaque, gingivitis, bleeding on probing, suppuration, probing depth, and clinical attachment level were measured at all teeth present. Subgingival biofilm samples from each tooth were analyzed for levels of 40 bacterial species using checkerboard DNA-DNA hybridization. Serum levels of interleukin-6 (IL-6), tumor necrosis factor-α, adiponectin, leptin, resistin, and vitamin D were measured at baseline. Sample collection was then performed in a subset of the population 6 months after therapy (n = 17). Serum samples were analyzed using enzyme-linked immunosorbent assay and immunoassays. Differences in clinical, microbial, and serum factors among groups were sought using the Mann-Whitney U test. Correlations among factors were evaluated using regression analysis. Effects of therapy were sought using the Wilcoxon signed rank test.

RESULTS

There were positive correlations between adiponectin/vitamin D and between IL-6/leptin, negative correlations between IL-6/vitamin D and leptin/vitamin D, but no associations between serum analytes and clinical or microbial parameters. Sex and body mass index were associated with levels of adipokines. Periodontal therapy improved clinical and microbiologic parameters but did not influence the levels of serum analytes.

CONCLUSION

Adipokines and IL-6 levels were affected by sex and body mass index. Serum analytes were not influenced by periodontal therapy.

Pathophysiologic and immunologic changes in a canine endotoxemia over a period of 24 hours

In this study, the pathophysiologic and immunologic parameters from a 24-hr of canine endotoxemia model by lipopolysaccharide (LPS) infusion were evaluated. For that, twelve healthy beagles received a continuous 24-hr IV infusion of low dose LPS (10 µg/kg/h, from Escherichia coli serotype O111:B4) dissolved in saline. Complete blood counts and serum biochemical analysis as well as histopathologic examination were performed to assess pathophysiologic changes such as neutrophil migration and organ injury. To evaluate immunologic parameters, the concentrations of plasma tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-10 were determined, and neutrophil activation was also evaluated based on cell surface expression of CD11b using flow cytometry analysis. As results, systemic signs of endotoxemia including fever, vomiting, and hemorrhagic diarrhea were observed within short time after LPS infusion. Severe leukopenia and increased fluorescent intensity of CD11b on neutrophils were observed at 3 hr while percent positive of CD11b was the maximum at 12 hr during the experiment. Plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and creatinine phosphokinase (CPK) concentrations increased markedly, and organ damage was confirmed on histopathologic examination. Plasma TNF-α peaked at 3 hr and decreased rapidly, while the concentrations of IL-6 and IL-10 increased gradually until 6 hr and decreased thereafter. Using this canine endotoxemia model, we were able to determine the kinetics of pathophysiologic and immunologic parameters over a period of 24 hr. This study will enhance our understanding of their mechanisms underlying canine sepsis.

Exogenous ghrelin attenuates endotoxin fever in rats

Ghrelin is a gut-derived peptide that plays a role in energy homeostasis. Recent studies have implicated ghrelin in systemic inflammation, showing increased plasma ghrelin levels after endotoxin (lipopolysaccharide, LPS) administration. The aims of this study were (1) to test the hypothesis that ghrelin administration affects LPS-induced fever; and (2) to assess the putative effects of ghrelin on plasma corticosterone secretion and preoptic region prostaglandin (PG) E(2) levels in euthermic and febrile rats. Rats were implanted with a temperature datalogger capsule in the peritoneal cavity to record body core temperature. One week later, they were challenged with LPS (50 μg/kg, intraperitoneal, i.p.) alone or combined with ghrelin (0.1mg/kg, i.p.). In another group of rats, plasma corticosterone and preoptic region PGE(2) levels were measured 2h after injections. In euthermic animals, systemic administration of ghrelin failed to elicit any thermoregulatory effect, and caused no significant changes in basal plasma corticosterone and preoptic region PGE(2) levels. LPS caused a typical febrile response, accompanied by increased plasma corticosterone and preoptic PGE(2) levels. When LPS administration was combined with ghrelin fever was attenuated, corticosterone secretion further increased, and the elevated preoptic PGE(2) levels were relatively reduced, but a correlation between these two variables (corticosterone and PGE(2)) failed to exist. The present data add ghrelin to the neurochemical milieu controlling the immune/thermoregulatory system acting as an antipyretic molecule. Moreover, our findings also support the notion that ghrelin attenuates fever by means of a direct effect of the peptide reducing PGE(2) production in the preoptic region.

Stress-related alterations of acyl and desacyl ghrelin circulating levels: mechanisms and functional implications

Ghrelin is the only known peripherally produced and centrally acting peptide hormone that stimulates food intake and digestive functions. Ghrelin circulates as acylated and desacylated forms and recently the acylating enzyme, ghrelin-O-acyltransferase (GOAT) and the de-acylating enzyme, thioesterase 1/lysophospholipase 1 have been identified adding new layers of complexity to the regulation of ghrelin. Stress is known to alter gastrointestinal motility and food intake and was recently shown to modify circulating ghrelin and GOAT levels with differential responses related to the type of stressors including a reduction induced by physical stressors (abdominal surgery and immunological/endotoxin injection, exercise) and elevation by metabolic (cold exposure, acute fasting and caloric restriction) and psychological stressors. However, the pathways underlying the alterations of ghrelin under these various stress conditions are still largely to be defined and may relate to stress-associated autonomic changes. There is evidence that alterations of circulating ghrelin may contribute to the neuroendocrine and behavioral responses along with sustaining the energetic requirement needed upon repeated exposure to stressors. A better understanding of these mechanisms will allow targeting components of ghrelin signaling that may improve food intake and gastric motility alterations induced by stress.

Procalcitonin gene expression after LPS stimulation in the porcine animal model

Procalcitonin (PCT), recognised as a marker of sepsis, was investigated in a porcine model of endotoxic shock. The results showed that continuous IV infusion (1-4 h) of LPS (40 μg/kg) in pigs was able to induce a generalised increase of PCT expression in lung, heart, kidney and liver. The increase in PCT was significant only in kidney and was accompanied by an increase in IL-6 gene expression. In vitro results demonstrated that peripheral blood mononuclear cells (PBMCs), as well as endothelial cells, were potentially capable of contributing to in vivo extrathyroidal PCT production. These findings support previous data from pigs concerning the occurrence of widespread activation of PCT extrathyroidal gene expression during endotoxic shock in pigs. Nevertheless, the levels of PCT detected were very low, suggesting the need for additional studies to validate the pig as a reliable animal model for investigating the role of PCT in sepsis.

Relationship between total ghrelin and inflammation in hemodialysis patients

In hemodialysis (HD) patients studies have shown that plasma ghrelin is increased and it has been speculated that ghrelin levels might be related to systemic inflammation. The present study attempted to correlate the serum levels of total ghrelin with serum TNF-α and IL-6, and with nutritional status and body composition in HD patients. Forty-seven HD patients from a single dialysis unit (18 women, mean age 55.3±12.2 yr; BMI 24.4±4.2kg/m(2); % body fat 29.4±7.4%) were studied and compared to 21 healthy subjects (12 women, 50.7±15.7 yr and BMI 25.6±4.0kg/m(2); % body fat 30.0±5.7%). Biochemical data, serum total ghrelin, TNF-α and IL-6 levels were measured. The body composition was evaluated by dual energy X-ray absortiometry (DEXA) and energy and protein intake were evaluated. Patients showed elevated plasma ghrelin levels when compared to healthy subjects (1.14±1.0ng/mL vs 0.58±0.4; p<0.001). There was a positive correlation between ghrelin levels and TNF-α (r=0.25; p<0.04), IL-6 (r=0.42; p<0.02), and a negative correlation between TNF-α and protein intake (r=-0.28; p<0.03), and energy intake (r=-0.34; p<0.01). No correlation was observed with any aspect of body composition. Plasma ghrelin levels are elevated in HD patients and associated with the state of systemic inflammation. We suggest that the inflammatory state may affect ghrelin bioactivity and metabolism in hemodialysis patients.

Evaluation of CALC-I gene (CALCA) expression in tissues of dogs with signs of the systemic inflammatory response syndrome

OBJECTIVE

To perform a qualitative evaluation of procalcitonin gene (CALCA) expression in a tissue-specific manner in dogs with signs of the systemic inflammatory response syndrome (SIRS).

DESIGN

Observational study.

SETTING

University Veterinary Teaching Hospital.

ANIMALS

Nine clinical cases and 5 research dogs.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Fresh tissue samples (thyroid, lung, liver, spleen) from 9 dogs that died with a diagnosis of parvoviral infection or SIRS were collected and immediately stored at -80 °C. Diagnosis of parvoviral infection was based on clinical signs, positive fecal antigen test, and confirmed by polymerase chain reaction (PCR). Clinical diagnosis of SIRS was based on the clinical criteria reported in veterinary literature. Necropsy was performed on all subjects in the study. Furthermore, thyroid, lung, liver, spleen were collected from 5 normal research dogs immediately postmortem for testing. The 9 dogs with a clinical diagnosis of SIRS died from either parvovirus (n=5), bacterial sepsis (n=3), or neoplasia (n=1). CALCA was amplified by PCR in the following samples: thyroid (9/9), spleen (6/9), lung (4/9), liver (3/9). Only thyroid expressed CALCA in the 5 normal dogs.

CONCLUSIONS

In SIRS, extrathyroidal transcription of CALCA was documented. Quantitative analysis (real-time polymerase chain reaction) in a wider population of SIRS and normal dogs will provide essential information about the extent and source of extrathyroidal expression of canine CALCA induced by septic and nonseptic systemic inflammation.

Regulation and prognostic relevance of serum ghrelin concentrations in critical illness and sepsis

Introduction

Ghrelin has been recently identified as a mediator of various beneficial effects in animal models of sepsis. At present, no data are available concerning specific properties of ghrelin in critically ill patients from large cohorts. In order to identify possible pathogenic functions of ghrelin in critically ill patients and human sepsis from a clinical point of view, we aimed at analyzing ghrelin serum concentrations in a large cohort of well characterized patients with critical illness.

Methods

A total of 170 critically ill patients (122 with sepsis, 48 without sepsis) were studied prospectively on admission to the Medical intensive care unit (ICU) and compared to 60 healthy controls. Careful assessment of clinical data, various laboratory parameters, metabolic and endocrine functions as well as investigational inflammatory cytokine profiles have been performed, and patients were followed for approximately three years.

Results

Ghrelin serum concentrations are elevated in critically ill patients as compared to healthy controls, but do not differ between sepsis and non-sepsis patients. The underlying etiologies of critical diseases are not associated with ghrelin serum levels. Neither pre-existing diabetes mellitus nor body mass index is correlated to serum ghrelin concentrations. Ghrelin is not correlated to markers of inflammation or hepatic function in critically ill patients. In the subgroup of non-sepsis patients, ghrelin correlates inversely with renal function and markers of carbohydrate metabolism. High ghrelin levels are an indicator for a favourable prognosis concerning mortality at the ICU in sepsis patients. Furthermore, ghrelin is significantly associated with the necessity of ventilation in critically ill patients.

Conclusions

Ghrelin serum concentrations are elevated in all circumstances of critical disease, including sepsis and non-sepsis patients. High ghrelin levels are a positive predictor of ICU-survival in sepsis patients, matching previous results from animal models. Future experimental and clinical studies are needed to evaluate ghrelin as a novel prognostic tool in ICU patients and its potential therapeutic use in sepsis.

Sepsis biomarkers: a review

INTRODUCTION

Biomarkers can be useful for identifying or ruling out sepsis, identifying patients who may benefit from specific therapies or assessing the response to therapy.

METHODS

We used an electronic search of the PubMed database using the key words "sepsis" and "biomarker" to identify clinical and experimental studies which evaluated a biomarker in sepsis.

RESULTS

The search retrieved 3370 references covering 178 different biomarkers.

CONCLUSIONS

Many biomarkers have been evaluated for use in sepsis. Most of the biomarkers had been tested clinically, primarily as prognostic markers in sepsis; relatively few have been used for diagnosis. None has sufficient specificity or sensitivity to be routinely employed in clinical practice. PCT and CRP have been most widely used, but even these have limited ability to distinguish sepsis from other inflammatory conditions or to predict outcome.

Choline or CDP-choline alters serum lipid responses to endotoxin in dogs and rats: involvement of the peripheral nicotinic acetylcholine receptors

We showed previously that choline administration protects dogs from endotoxin-induced multiple organ injury and platelet dysfunctions. Because sepsis/endotoxemia is associated with alterations in lipid metabolism, we have investigated whether choline or cytidine-5'-diphosphate choline, a choline donor, alters serum lipid responses to endotoxin in dogs and rats. In response to endotoxin, serum concentrations of triglycerides, choline-containing phospholipids, total cholesterol, and high-density lipoprotein cholesterol increased in a dose- and time-related manner. Administration of choline (20 mg/kg i.v. in dogs or 90 mg/kg i.p. in rats) or cytidine-5'-diphosphate choline (70 mg/kg i.v. in dogs) 5 min before and 4 and 8 h after endotoxin blocked or attenuated the increases in serum triglycerides, total cholesterol, and nonesterified fatty acids. Endotoxin-induced elevations in serum phospholipid levels did not change in rats and were enhanced in dogs by choline. In rats, serum lipid response to endotoxin was accompanied by severalfold elevations in serum levels of hepatorenal injury markers; their elevations were also blocked by choline. Pretreatment with hexamethonium blocked choline's effects on serum lipids and hepatorenal injury markers. Pretreatment with atropine blocked endotoxin-induced elevations in serum lipid and hepatorenal injury markers, but failed to alter choline's actions on these parameters. Choline treatment improved survival rate of rats in lethal endotoxin shock. In conclusion, these data show that choline treatment alters serum lipid responses to endotoxin and prevents hepatorenal injury during endotoxemia through a nicotinic acetylcholine receptor-mediated mechanism. Hence, choline and choline-containing compounds may have a therapeutic potential in the treatment of endotoxemia/sepsis.