Insulin binding to cultured human fibroblasts increases with normal and precocious aging.

Specific and nonspecific [125I]insulin binding and concentration of unlabeled hormone producing 50 percent competition with 1.0 nanomolar [125I]insulin for specific binding sites correlated positively with age of fibroblast donors. Cells from four children with precocious aging--three with progeria and one with Rothmund syndrome-resembled those from the chronologically old.