Metallicity gradients of ten SN IIn host galaxies observed with the NOT+ALFOSC. Symbols and lines as in the bottom panel of Fig. 2. Black open squares with arrows correspond to upper limits. The gradients of the hosts of SNe 2006jd and 2005ip are not shown, as we could not measure the flux from bright H ii regions. Instead, we used literature data. For the host of SN 1995N, whose gradient is not shown, we only have one measurement and we did not assume any gradient, as it is an irregular and interacting galaxy.