β-Cell turnover: time profiles. Time profiles of rate of change in β-cell mass dM/dt (dotted line), rate of β-cell replication RR (○, data; solid thin line, smoothed profile), OSB (solid thick line), and rate of β-cell apoptosis RA (⧫, data; dashed line, smoothed profile) in WT (left) and HIP rats (right) aged 0.07–10 mo.