Nitrogen isotopes in the interstellar medium: A chemical journey across the Galaxy

One of the most important tools to investigate chemical history our Galaxy and own Solar System is measure isotopic fractionation elements. This process that distributes less abundant stable isotopes an element in different molecules. The ratios are governed by two main processes: 1. evolution whole due stellar nucleosynthesis; 2. local effects. In this Proceeding we report some results highlighting both processes towards massive star-forming regions.