FIG. 7.

β-Cell turnover in control group, showing the relative contributions of β-cell replication, formation of β-cells from other sources than replication (neogenesis), and β-cell apoptosis. In controls there was a minimal change in β-cell mass during the study, but the mathematic model revealed active β-cell turnover with the major contribution being from neogenesis rather than β-cell replication. In the absence of measurable apoptosis in monkeys given STZ, β-cell turnover could not be reliably computed, but given the absence of any change in β-cell mass, β-cell turnover can reasonably be assumed to not be adaptively increased to a clinically meaningful extent.