Human amniotic fluid obtained from diabetic women. A potent stimulator of islet cell replication

Recently, human amniotic fluid (HAF) from healthy women was found to stimulate growth and function of pancreatic B-cells. Here, the effect of HAF and serum from healthy probands (HS) was compared with that from probands with gestational (GD), noninsulin-dependent (NIDDM), or insulin-dependent diabetes (IDDM) on islet function and replication. Rat islets were cultured in the presence of either HAF or HS for 7 d. Insulin content and basal insulin release were not different after exposure of the islets to HAF or HS from healthy or diabetic women. In contrast to HS, HAF provoked the islets to deliver significantly more insulin during culture. Additionally, the same islets exhibited a more intense response to a glucose challenge. The degree of HAF-induced insulin release was not influenced by the type of diabetes. HAF and HS from GD and NIDDM women did not influence the islet DNA synthesis in comparison to HAF and HS from healthy pregnant women. However, HAF but not HS from IDDM pregnant women, elicited a significant increase in islet replication. Most effective in stimulating islet cell replication were HAFs from IDDM pregnant women belonging to the White D-type. It was shown that the relatively high concentration of insulin in the HAFs was not directly responsible for the observed increase of the islet DNA synthesis. HAF from women with long-term diabetes is supposed to contain factor(s) that might directly or indirectly enhance islet replication.