Regulatory effects and mechanisms of branched chain amino acids and metabolic intermediates on insulin resistance / 生理学报

Branched chain amino acids, as essential amino acids, can be used to synthesize nitrogen-containing compounds and also act as signal molecules to regulate substance metabolism. Studies have shown that the elevated level of branched chain amino acids is closely related to insulin resistance and type 2 diabetes. It can affect insulin signal transduction by activating mammalian target of rapamycin (mTOR) signal pathway, and regulate insulin resistance by damaging lipid metabolism and affecting mitochondrial function. In addition, abnormal catabolism of branched amino acids can lead to the accumulation of metabolic intermediates, such as branched chain α-keto acids, 3-hydroxyisobutyrate and β-aminoisobutyric acid. Branched chain α-keto acids and 3-hydroxyisobutyrate can induce insulin resistance by affecting insulin signaling pathway and damaging lipid metabolism. β-aminoisobutyric acid can improve insulin resistance by reducing lipid accumulation and inflammatory reaction and enhancing fatty acid oxidation. This paper systematically reviewed the regulatory effects and mechanisms of branched chain amino acids and their metabolic intermediates on insulin resistance, which will provide a new direction for the prevention and treatment of insulin resistance and type 2 diabetes.

Utilidad de la brecha aniónica en la práctia clínica / Usefulness of anion gap in the clinical practice

En este articulo se revisa lo mas relevante acerca de la brecha aniónica. En el suero equivale a las concentraciones de Na-(Cl+HCO3), siendo el valor de referencia 12 ñ 4mmol/ L; sin embargo, recientemente, como resultado de modificaciones en la técnica para medir el cloro sérico, el valor normal para la brecha aniónica disminuyó a 10 ñ 4 mmol/L. Se resalta la importancia diagnóstica de una brecha aniónica aumentada en el paciente con acidosis metabólica, asi como el uso de la brecha aniónica en la detección de estados ácido-base mixtos. Aunque la brecha aniónica no es una variable específica, su medición resulta útil en la evaluación de desequilibrio ácido-base. La brecha aniónica es fácil de calcular y continúa siendo una herramienta diagnóstica útil, siempre que se identifiquen sus limitaciones.

Products of non-reductive CO2 assimilation in the halophilic archaebacterium Haloferax mediterranei.

The products of CO2 fixation by heterotrophically grown Haloferax mediterranei were analysed. The main 14C-labelled alpha-ketoacid detected following incubation with NaH14CO3 and pyruvate or propionate was pyruvate. In presence of these organic acids and NH4+, 14CO2 was incorporated into glutamic and aspartic acids and alanine.