the data indicate : 1 ) insulin-secreting islet cell tumors have decreased storage capacity for insulin , 2 ) elevated concentration of proinsulin in tumors may be due to decreased capacity to store insulin and in some to decreased conversion of proinsulin to insulin as well , 3 ) tolbutamide stimulates the exaggerated release of a relatively constant fraction of insulin stored in adenomas .
C0033362
proinsulin
C0021641
insulin