Primary production and nutrient fluxes of the nothern coast of Peru: a summary

Analise the distribution and magnitude of primary measured during the 1977 ICANE cruise of the northern coast of Peru

Sobriété volontaire : en quête de nouveaux modes de vie

Textes d'Aurélien Boutaud, Jean-Claude Galey, Sylvia Generoso, Susana Jourdan, Jacques Mirenowicz, René Nouailhat, Sylvain Piron, Cécile Renouard, Yvan Rytz et Marie-Christine Zélem.

Glucose transporters in the regulation of intestinal, renal, and liver glucose fluxes.

Five functional mammalian facilitated hexose carriers (GLUTs) have been characterized by molecular cloning. By functional expression in heterologous systems, their specificity and affinity for different hexoses have been defined. There are three high-affinity transporters (GLUT-1, GLUT-3 and GLUT-4) and one low-affinity transporter (GLUT-2), and GLUT-5 is primarily a fructose carrier. Because their Michaelis constants (Km) are below the normal blood glucose concentration, the high-affinity transporters function at rates close to maximal velocity. Thus their level of cell surface expression greatly influences the rate of glucose uptake into the cells. In contrast, the rate of glucose uptake by GLUT-2 (Km = 17 mM) increases in parallel with the rise in blood glucose over the physiological concentration range. High-affinity transporters are found in almost every tissue, but their expression is higher in cells with high glycolytic activity. Glut-2, however, is found in tissues carrying large glucose fluxes, such as intestine, kidney, and liver. As an adaptive response to variations in metabolic conditions, the expression of these transporters is regulated by glucose and different hormones. Thus, because of their specific characteristics and regulated expression, the facilitated glucose transporters control fundamental aspects of glucose homeostasis. I review data pertaining to the structure and regulated expression of the glucose carriers present in intestine, kidney, and liver and discuss their role in the control of glucose flux into or out of these different tissues.

Journal des dames et des modes

1819/02/15 (N9,A23).

Journal des dames et des modes

1822/07/25 (N41,A26).

Journal des dames et des modes

1819/02/10 (N8,A23).

Journal des dames et des modes

1819/07/20 (N40,A23).

Journal des dames et des modes

1821/08/20 (N46,A25).

Journal des dames et des modes

1820/05/15 (N27,A24).

Journal des dames et des modes

1822/02/15 (N9,A26).

Journal des dames et des modes

1820/10/20 (N58,A24).

Journal des dames et des modes

1822/07/20 (N40,A26).

Journal des dames et des modes

1819/05/10 (N26,A23).

Journal des dames et des modes

1819/11/15 (N63,A23).

Journal des dames et des modes

1819/02/05 (N7,A23).