Hydrogenation of pyridine compared to other heteroaromatic rings
When we reduce pyridine using the $\ce{H2/Pt/HCl}$ reagent-catalyst combination, we require a significantly lower temperature and pressure compared to other similar reductions (but without $\ce{HCl}$), because $\ce{H+}$ (and other Lewis acids for that matter) will go and add to the nitrogen atom, forming pyridinium salts.

This makes the compound more reactive towards reduction (as a partial positive charge will develop in the ring).