Experimental study of the effects of progesterone on fusion of the fetal mouse palate in vitro

Abstract

In the present study, the effects of progesterone on fusion of the secondary palate were examined in vitro.
Methods: The maxillary region of A/J mouse fetuses (13.5 days) was dissected and cultured in a chemically-defined serum-free medium for 72 hours. Progesterone was added to the culture medium in a concentration of 0.1, 1.0, or 10μg/ml.
Results: 1) Among 22 explants in the vehicle-control group, the palatal shelves completely fused in 10 (46%). The palatal shelves fused partially in 6 explants, contacted but did not fuse in 4, and failed to contact in 2.
2) In the group treated with 0.1μg/ml progesterone (n=21), complete fusion occurred in 13 explants (62%) and partial fusion in 7 (33%). The palatal shelves contacted but did not fuse in 1 explant, and failed to contact in no explant.
3) When treated with 1.0μg/ml progesterone (n=22), the palatal shelves fused completely in 21 explants (95%) and partially in 1 (5%). None of the cultured palates failed to fuse.
4) When the palatal explants were cultured with 10μg/ml progesterone (n=20), the palatal shelves fused completely in all explants. The complete fusion rate was significantly higher in the 1.0μg/ml and 10μg/ml groups than in the control group.
5) Head length, head width, and palate length were greater in all progesterone-treated groups than in the control group.