Taurine Supplementation Increases K(atp) Channel Protein Content, Improving Ca2+ Handling And Insulin Secretion In Islets From Malnourished Mice Fed On A High-fat Diet.

Pancreatic β-cells are highly sensitive to suboptimal or excess nutrients, as occurs in protein-malnutrition and obesity. Taurine (Tau) improves insulin secretion in response to nutrients and depolarizing agents. Here, we assessed the expression and function of Cav and KATP channels in islets from malnourished mice fed on a high-fat diet (HFD) and supplemented with Tau. Weaned mice received a normal (C) or a low-protein diet (R) for 6 weeks. Half of each group were fed a HFD for 8 weeks without (CH, RH) or with 5% Tau since weaning (CHT, RHT). Isolated islets from R mice showed lower insulin release with glucose and depolarizing stimuli. In CH islets, insulin secretion was increased and this was associated with enhanced KATP inhibition and Cav activity. RH islets secreted less insulin at high K(+) concentration and showed enhanced KATP activity. Tau supplementation normalized K(+)-induced secretion and enhanced glucose-induced Ca(2+) influx in RHT islets. R islets presented lower Ca(2+) influx in response to tolbutamide, and higher protein content and activity of the Kir6.2 subunit of the KATP. Tau increased the protein content of the α1.2 subunit of the Cav channels and the SNARE proteins SNAP-25 and Synt-1 in CHT islets, whereas in RHT, Kir6.2 and Synt-1 proteins were increased. In conclusion, impaired islet function in R islets is related to higher content and activity of the KATP channels. Tau treatment enhanced RHT islet secretory capacity by improving the protein expression and inhibition of the KATP channels and enhancing Synt-1 islet content.

A formação humana na perspectiva histórico-ontológica

The theme of human formation is at the centre of the philosophy of education, whose aim is precisely the process of human promotion brought about by education. Starting from the critical vigilance proper to philosophy, the text sketches a phenomenology of the present time, verifying that the ideas prevailing in education at present are centred on the critique of reason and on the notions of truth and objectivity. This neo-pragmatism, which in the attempt to oppose metaphysics becomes deeply metaphysical, reducing everything to language, is contested by the authors with Marx's thoughts as a historicising philosophy that concerns not abstract subjects, but real individuals, historical subjects that are constituted as a synthesis of social relations. To that end, the authors resort to the historical ontological reflection on human formation contained in Marx's Economic and Philosophical Manuscripts of 1844. The article concludes by defending the proposition that access to the classics is a necessary condition for human formation.