Reverse transcription polymerase chain reaction (RT-PCR) for iNOS and MMPs. Representative semiquantitative RT-PCR result for iNOS and matrix metalloproteinases (MMPs) (A). Real-time RT-PCR demonstrated that adiponectin significantly increased the transcripts of iNOS and all three MMPs in the osteoarthritis (OA) chondrocytes (n = 4, triplicate, P < 0.05) at 30 μg/ml (B). The histogram with error bars represents the mean and the standard error of the mean. †P < 0.05 by Mann-Whitney test.