TGF-beta1 and high levels of glucose do not increase insulin cell proportions in the avian embryonic pancreas.

TGF-beta1 is thought to decrease the proportion of embryonic pancreatic beta-cells with respect to alpha-cells, whereas glucose is thought to enhance beta-cell proportions in rats. However, chick pancreatic cells may respond in a dissimilar way to glucose. Thus, the effect of TGF-beta1 on the proportion of beta-cells in embryonic chick dorsal pancreatic buds (DPBs) in vitro was tested with short-term exposure to high levels of glucose. Five-day-old chick DPBs were cultured on growth factor-reduced Matrigel, which contains reduced levels of growth factors including TGF-beta1, and a variety of culture media with and without high levels of glucose. TGF-beta1 reduced the proportion of beta-cells, as expected. A similar decrease in the proportion of beta-cells occurred in the presence of high levels of glucose.