The Effect of Human Amniotic Fluid on DNA Synthesis of Rat Pancreatic Islets in Tissue Culture

Summary

In this study we investigated the effect of human amniotic fluid (HAF) on the incorporation of ³H-thymidine into cultured rat islets. The addition of 1% HAF (1% HAF, 99% TCM) did not alter the incorporation of labeled thymidine, in comparison to TCM 199 alone (100%). The culture in the presence of 50% HAF (1:1 diluted with TCM, v/v) resulted in a significantly increased DNA synthesis. To exclude any effect of ionic composition or substrate dilution by the HAF, the TCM 199 was also either diluted (1:1) with saline or Hank's balanced salt solution (HBSS). Islets cultured under these conditions did not show any stimulated thymidine incorporation into islet DNA. From these results we conclude that HAF contains an activity which stimulates islet replication.

In order to concentrate this stimulatory activity, HAF was tested after it had been lyophilized or evaporated. Independent of the method used, in no case a stimulatory effect of concentrated HAF was found. In contrast, the concentrated form of HAF inhibited the incorporation of labeled thymidine into islet DNA.

Key Words

Human amniotic fluid - DNA synthesis - Rat pancreatic islets - Islet culture