RESUMO
BACKGROUND: Chronically elevated interleukin-6 (IL-6) is implicated in obesity-associated pathologies, where a proportion of this cytokine is derived from adipose tissue. Proinflammatory prostaglandins, which regulate this cytokine elsewhere, are also produced by this tissue. OBJECTIVE: To investigate whether constitutively active cyclooxygenase (COX)/prostaglandin (PG) pathway in white adipose tissue (WAT) is responsible for basal IL-6 production. DESIGN: The effect of acetylsalicylic acid (ASA), an inhibitor of COX, on IL-6 was assessed in human subjects and mice. COX, downstream PG synthase (PGS) activity and PG receptor signalling were determined in subcutaneous (SC), gonadal (GN) WAT and adipocytes. METHODS AND RESULTS: In obese humans, low-dose ASA (150 mg day(-1) for 10 days) inhibited systemic IL-6 and reduced IL-6 release from SC WAT ex vivo (0.2 mM). Similarly, in mice, ASA (0.2 and 2.0 mg kg(-1)) suppressed SC WAT 6-keto-PGF(1alpha) (a stable metabolite of prostacyclin) and IL-6 release. Although both COX isoforms are comparably expressed, prostacyclin synthase expression is higher in GN WAT, with levels of activity correlating directly with IL-6. Both ASA (5 mM) and NS-398 (COX-2 selective inhibitor Assuntos
Tecido Adiposo Branco/metabolismo
, Aspirina/administração & dosagem
, Inibidores de Ciclo-Oxigenase/administração & dosagem
, Interleucina-6/metabolismo
, Obesidade/metabolismo
, Adipócitos/metabolismo
, Idoso
, Animais
, Aspirina/farmacologia
, Estudos de Casos e Controles
, Inibidores de Ciclo-Oxigenase/farmacologia
, Feminino
, Gônadas/metabolismo
, Humanos
, Masculino
, Camundongos
, Camundongos Obesos
, Pessoa de Meia-Idade
, Prostaglandina-Endoperóxido Sintases/metabolismo
, Receptores de Prostaglandina/metabolismo
, Gordura Subcutânea/metabolismo
, Fator de Necrose Tumoral alfa/sangue
RESUMO
BACKGROUND: To correlate obesity and colorectal cancer for Greek living conditions. PATIENTS AND METHODS: We studied 97 patients, who over the last 5 years were diagnosed histopathologically with colorectal cancer. 75.3% of the patients were either overweight or centrally obese; secondly, 21.6% patients had diabetes, percentages higher than those in the population (statistically significant). Hyperinsulinaemia and resistance to insulin have been implicated in colorectal carcinogenesis. CONCLUSIONS: As our sample was small, no statistically significant evidence correlating diet and/or physical activity to colorectal cancer has emerged.