RESUMO
BACKGROUND: Excessive insulin is the leading cause of metabolic syndromes besides hyperinsulinemia. Insulin-lowering therapeutic peptides have been poorly studied and warrant urgent attention. OBJECTIVE: The main purpose of this study, was to introduce a novel peptide COX52-69 that was initially isolated from the porcine small intestine and possessed the ability to inhibit insulin secretion under high-glucose conditions by modulating large conductance Ca2+-activated K+ channels (BK channels) activity. METHODS AND RESULTS: Enzyme-linked immunosorbent assay results indicate that COX52-69 supressed insulin release induced by high glucose levels in pancreatic islets and animal models. Furthermore, electrophysiological data demonstrated that COX52-69 can increase BK channel currents and hyperpolarize cell membranes. Thus, cell excitability decreased, corresponding to a reduction in insulin secretion. CONCLUSION: Our study provides a novel approach to modulate high glucose-stimulated insulin secretion in patients with hyperinsulinemia.
RESUMO
The nano-scale spherical Na3V2(PO4)2F3 with a NASICON structure phase was prepared with a spray drying technique, and the bagasse in Guangxi, China was selected as the carbon source to prepare Na3V2(PO4)2F3/C. The optimal preparation conditions of the composite determined using thermogravimetry, X-ray diffraction, scanning electron microscopy and electrochemical testing were: a calcination temperature of 650 °C and a 20% carbon source. The Na3V2(PO4)2F3/C has obvious redox peaks, determined by cyclic voltammetry (CV), at 3.90 V and 3.75 V, 4.32 V and 4.15 V. These two pairs of redox peaks correspond to the escape/intercalation of the two pairs of Li+/Na+. Notably, compared with pure Na3V2(PO4)2F3, the specific discharge capacity of Na3V2(PO4)2F3/C-20%, which were used as a cathode material for lithium-sodium hybrid ion batteries, increased from 55 mA h g-1 to 125 mA h g-1, which was an improvement of twofold.
