The effect of retinoic acid on the proportion of insulin cells in the developing chick pancreas.
We assessed the potential role of all-trans-retinoic acid on the developing chick pancreas, specifically with regard to the proportions of insulin cells. The endodermal component of the dorsal pancreatic bud of 5-d-old chick embryos was cultured on Matrigel. Retinoic acid (10(-6) or 10(-5) M) was added to a standard serum-free medium, Ham's F12 containing insulin, transferrin and selenium (F12.ITS). Control grafts were cultured in F12.ITS alone or in F12.ITS with DMSO (the diluent for retinoic acid). After 7 d the explants were retrieved, freeze-dried, vapor-fixed, and embedded in resin. Endocrine cell types were identified by immunocytochemistry. The numbers of insulin cells were expressed as a proportion of the sum of insulin plus glucagon cells. Retinoic acid had a dose-related effect; the proportion of insulin cells in explants treated with the lower dose of retinoic acid (10(-6) M) was more than twice the proportion of insulin cells in explants treated with the higher dose (10(-5) M) of retinoic acid and more than three times that of the control grafts.
Penny
C
C
Department of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
Kramer
B
B
D000818:Animals; D002478:Cells, Cultured; D002642:Chick Embryo; D016895:Culture Media, Serum-Free; D005934:Glucagon / Q000378:metabolism; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000166:cytology* / Q000196:embryology / Q000378:metabolism; D010179:Pancreas / Q000166:cytology / Q000187:drug effects* / Q000196:embryology; D014212:Tretinoin / Q000494:pharmacology*
D016895:Culture Media, Serum-Free; D007328:Insulin; D014212:Tretinoin; D005934:Glucagon