Notes sur l'organisation économique et sociale de la pêche artisanale, du fumage et de la commercialisation du poisson dans la ville de Conakry

Les premières enquêtes effectuées par le C.R.H.B. semblent montrer que les activités halieutiques artisanales constituent à Conakry un milieu ouvert à des producteurs et des commerçants issus de secteurs économiques étrangers à la pêche et originaires de régions parfois éloignées du littoral maritime. Ces enquêtes suggèrent également qu'une étude des dynamiques des activités halieutiques dans la capitale guinéenne ne peut valablement être conduite qu'à l'intérieur d'une étude plus générale des dynamismes urbains dans leur ensemble. (Résumé d'auteur

Chronological approach of diet-induced alterations in muscle mitochondrial functions in rats

International audienceOBJECTIVE: Mitochondrial dysfunction might predispose individuals to develop insulin resistance. Our objective was to determine whether mitochondrial dysfunction or insulin resistance was the primary event during high-fat (HF) diet. RESEARCH METHODS AND PROCEDURES: Rats were fed an HF diet for 0, 3, 6, 9, 14, 20, or 40 days and compared with control. Soleus and tibialis muscle mitochondrial activity were assessed using permeabilized fiber technique. Insulin [area under the curve for insulin (AUC(I))] and glucose [area under the curve for glucose (AUC(G))] responses to intraperitoneal glucose tolerance test as well as fasting plasma non-esterified fatty acids (NEFAs), triglyceride, and glycerol concentrations were determined. RESULTS: AUC(I) and AUC(G) were altered from Day 6 (p < 0.01 vs. Day 0). In soleus, oxidative phosphorylation (OXPHOS) activity was transiently enhanced by 26% after 14 days of HF diet (p < 0.05 vs. Day 0) conjointly with 62% increase in NEFA concentration (p < 0.05 vs. Day 0). This was associated with normalized AUC(G) at Day 14 and with a decline of plasma NEFA concentration together with stabilization of intra-abdominal adiposity at Day 20. Prolongation of HF diet again caused an increase in plasma NEFA concentration, intra-abdominal adiposity, AUC(I), and AUC(G). At Day 40, significant decrease in OXPHOS activity was observed in soleus. DISCUSSION: Mitochondria first adapt to overfeeding in oxidative muscle limiting excess fat deposition. This potentially contributes to maintain glucose homeostasis. Persistent overfeeding causes insulin resistance and results in a slow decline in oxidative muscle OXPHOS activity. This shows that the involvement of mitochondria in the predisposition to insulin resistance is mainly due to an inability to face prolonged excess fat delivery