Fig. 1. Changes in the mRNA levels of the different LAMP-2 splicing variants with age. Semi-quantitative real-time PCR was used to compare mRNA expression levels for LAMP-2A (A), LAMP-2B (B) and LAMP-2C (C) in total mRNA isolated from the livers of normally fed (Fed) or 48-hour starved (Starved) 4-, 12- and 22-month-old rats. mRNA expression levels for the three isoforms in fed rats exposed to mild oxidative stress (treated with two injections of 40 mg/kg body weight of paraquat every 24 hours) are shown as a positive control for LAMP-2A transcriptional upregulation. Values were corrected for actin amplification in each sample and are expressed as fold increase compared with values for the different isoforms in 4-month-old rats (given an arbitrary value of 1). Values are mean + s.e.m. from four different experiments. Significant differences were observed compared with values from 4-month-old rats (^*P<0.05, ^**P<0.01).