Tumour necrosis factor-alpha and adenosine in endotoxin shockleading related cardiovascular symptoms

The immunomodulatory role of bile acids

Enzymatic oxidation of cholesterol generates numerous distinct bile acids which function both as detergents that facilitate the digestion and absorption of dietary lipids and as hormones that activate five distinct receptors. Activation of these receptors alters gene expression in multiple tissues, leading to changes not only in bile acid metabolism but also in glucose homeostasis, lipid and lipoprotein metabolism, energy expenditure, intestinal motility, bacterial growth, inflammation, and in the liver-gut axis. This review focuses on the present knowledge regarding the physiologic and pathologic role of bile acids and their immunomodulatory role, with particular attention to bacterial lipopolysaccharides (endotoxins) and bile acid and immunological disorders. The specific role that bile acids play in the regulation of innate immunity, various systemic inflammations, inflammatory bowel diseases, allergy, psoriasis, cholestasis, obesity, metabolic syndrome, alcoholic liver disease, and colon cancer will be reviewed.

Beneficial effects of theophylline infusions in surgical patients with intra-abdominal hypertension

BACKGROUND

Intra-abdominal hypertension (IAH) can cause high mortality. Recently, we found that IAH was associated with increased serum levels of adenosine and interleukin 10. Our present "hypothesis-generated study" was based on the above mentioned results.

MATERIALS AND METHODS

In this uncontrolled clinical trial, a total of 78 patients with IAH were enrolled representing a 13-20 mmHg range of intra-abdominal pressure (IAP). Patients requiring surgical abdominal decompression were excluded. Patients were treated with the following protocols: standard supportive therapy (ST, n = 38) or ST plus infusion with the adenosine receptor antagonist theophylline (T, n = 40). Over the 5-day measurement period, IAP was monitored continuously and serum adenosine concentration and other clinical and laboratory measurements were monitored daily. Mortality was followed for the first 30 days following the diagnosis of IAH.

RESULTS

Mortality of ST patients was 55%, which is compatible to other studies. Serum adenosine concentration was found to be directly proportional to IAP. Of the 40 patients receiving T treatment, survival was 100%. An increased survival related to theophylline infusion correlated with improving serum concentrations of IL-10, urea, and creatinine, as well as 24-h urine output, fluid balance, mean arterial pressure, and O(2)Sat.

CONCLUSIONS

Adenosine receptor antagonism with T following IAH diagnosis resulted in markedly reduced mortality in patients with moderated IAH (<20 mmHg). Theophylline-associated mortality reduction may be related to improved renal perfusion and improved MAP, presumably caused by adenosine receptor blockade. Because this study was not a randomized controlled study, these compelling observations require further multicentric clinical confirmation.

Adenosine inhibits the release of interleukin-1beta in activated human peripheral mononuclear cells

The effects of adenosine and subtype-specific activators of adenosine receptors (A1, A2A, A2B and A3) were studied on the release of interleukin-1beta (IL-1beta) from peripheral mononuclear cells, monocytes and lymphocytes. In the cells activated by the protein kinase C specific phorbol ester (phorbol 12-myristate 13-acetate) and Ca(2+) ionophore (A23187) both adenosine and the subtype-specific receptor agonists, CPA (A1), CGS 21680 (A2A) and IB-MECA (A3) induced a concentration-dependent inhibition of IL-1beta release. The rank order of potency in the inhibition of IL-1beta release was CPA=CGS 21680>IB-MECA>adenosine>NECA (in the presence of A1, A2A and A3 receptor inhibitors). The inhibitory actions of CPA, CGS 21680 or IB-MECA were significantly reduced in the presence of DPCPX, ZM 243185 or MRS 1191 as subtype-specific antagonists on A1, A2A and A3 adenosine receptors, respectively. It can be concluded that adenosine inhibits the release of IL-1beta from the activated human peripheral mononuclear cells. In this process A1, A2A and A3 receptors are involved.