RESUMO
Marine tunicates produce defensive amino-acid-derived metabolites, including 2-(3,5-diiodo-4-methoxyphenyl)ethan-1-amine (DIMTA), but their mechanisms of action are rarely known. Using an assay-guided approach, we found that out of the many different sensory cells in the mouse dorsal root ganglion (DRG), DIMTA selectively affected low-threshold cold thermosensors. Whole-cell electrophysiology experiments using DRG cells, channels expressed in Xenopus oocytes, and human cell lines revealed that DIMTA blocks several potassium channels, reducing the magnitude of the afterhyperpolarization and increasing the baseline intracellular calcium concentration [Ca2+]i of low-threshold cold thermosensors. When injected into mice, DIMTA increased the threshold of cold sensation by >3 °C. DIMTA may thus serve as a lead in the further design of compounds that inhibit problems in the cold-sensory system, such as cold allodynia and other neuropathic pain conditions.
Assuntos
Aminas/metabolismo , Canais de Cálcio/metabolismo , Células Receptoras Sensoriais/metabolismo , Aminas/administração & dosagem , Animais , Cálcio/metabolismo , Gânglios Espinais/metabolismo , Masculino , Camundongos , Técnicas de Patch-Clamp , Transdução de Sinais , Sensação Térmica/fisiologia , Urocordados , VertebradosRESUMO
The purpose of this article is to examine hospital social responsibility practices using a content analysis method. It selected a sample of 522 hospitals in U.S. and collected data from hospitals' official websites. Significant emphasis is found to be placed on CSR practices associated with marketplace activities that are mostly stakeholder-driven. Non-profit hospitals had stronger awareness on the actions of being a socially responsible organization. The results also confirm significant relationship between active CSR programs and hospital. The findings shed light on hospital social responsibility and provides a unifying conceptual basis that explains how hospitals in U.S execute CSR programs.