Star formation and the interstellar medium in low surface brightness   galaxies. I. Oxygen abundances and abundance gradients in low surface   brightness disk galaxies
  We present measurements of the oxygen abundances in 64 HII regions in 12 LSB galaxies. We find that oxygen abundances are low. No regions with solar abundance have been found, and most have oxygen abundances $\sim 0.5$ to 0.1 solar. The oxygen abundance appears to be constant as a function of radius, supporting the picture of quiescently and sporadically evolving LSB galaxies. 
W.J.G. de Blok and J.M. van der Hulst (Kapteyn Astronomical Institute,   Groningen, The Netherlands)