Effects of calmodulin antagonists on calcium transport by chorioallantoic membranes of developing chicken embryos.

Sections of chorioallantoic membranes (CAM) from developing chicken embryos were incubated in the presence of calmidazolium (CMZ) or trifluoperazine (TFP). Both the forward (ectodermal to endodermal) and backward flux rates of calcium were higher in the presence of drug. However, the effect was greater in the forward direction and the agents produced a statistically significant increase in ectodermal to endodermal calcium transport. The initial rate of uptake of calcium into CAM sections was increased by TFP, and the efflux of calcium from preloaded sections was increased in the presence of TFP and CMZ.